GRAVIMAT SHC501 Gravimetric Dust Concentration Measuring System

Transcription

1 Title OPERATING INSTRUCTIONS GRAVIMAT SHC501 Gravimetric Dust Concentration Measuring System Description Installation Operation

2 Document Information Described Product Product name: GRAVIMAT SHC501 Document ID Title: Operating Instructions GRAVIMAT SHC501 Part No.: Version: 1.1 Release: Manufacturer SICK AG Erwin-Sick-Str Waldkirch Germany Phone: Fax: info.pa@sick.de Place of Manufacture SICK Engineering GmbH Bergener Ring Ottendorf-Okrilla Germany Trademarks IBM is a trademark of the International Business Machine Corporation. MS-DOS is a trademark of the Microsoft Corporation. Windows is a trademark of the Microsoft Corporation. Other product names used in this document may also be trademarks and are only used for identification purposes. Original Documents The English edition of this document is an original document of SICK AG. SICK AG assumes no liability for the correctness of an unauthorized translation. Please contact the manufacturer or your local representative in case of doubt. Legal information Subject to change without notice. SICK AG. All rights reserved. 2 GRAVIMAT SHC501 Operating Instructions V1.0 SICK AG

3 Contents Contents Introduction Safety instructions Important safety notes Use in accordance with instructions, conditions of use Use Instructions for system safeguard Authorized users Safety precautions, protective measures Danger from items of electrical equipment Preventative measures for safe operation Detecting malfunctions Avoiding consequential damage in the event of equipment malfunction Environmental information and instructions for disposal Device Description Range of application Measuring principle Technical measuring regulations (conformity) System components Overview GS 5 Filter head probe Probe head Probe shaft Multichannel hose Probe mount Dust collectors LC dust collectors HC dust collectors Soot collector SHC-AE501 Evaluation unit Electronic unit Condensate separator Extraction pump GRAVIMAT SHC 501 basic functions Accessories and optional extras Preparing for measurement Choosing a measuring site On-site preparation

4 Contents 3.3 Preparation of dust collectors General Fitting with filter material LC dust collectors HC collectors Determining the empty mass of the prepared dust collectors Transportation Installing the measuring system Installing the GS 5 filter head probe Inserting the dust collectors Installing and connecting the evaluation unit Adaptation to the available supply voltage Function test before measuring starts Measuring General Description of menu Menu "parameters" "Automatic" menu "Special functions" menu Extraction measurement Manual operation Evaluating measurements Determining the gross weight of the dust collector Drying Weighing Calculating the dust concentration Maintenance Maintenance of the GS 5 filter head probe Regular maintenance Leak check Maintenance of the evaluation unit Calibration of the evaluation unit Zero point setting Aperture constants Setting time and date for protocol Troubleshooting No measurement possible Troubleshooting table

5 Contents 8 Technical Data Overview of technical data GRAVIMAT SHC 500 standard design Accessories, optional extras Consumable parts Spare parts Scale diagrams Filter head probe AE-SHC501 Evaluation unit Appendix Overview of formulae Physical composition

6 6 Contents

7 Introduction Notes on these instructions These Operating Instructions contain basic information on safety, system features, planning, installation, commissioning and regular servicing of the device components. Short descriptions on the measuring procedures as well as the function of the complete system and its important parts are provided. They act as a support for the level of knowledge that is requir-ed for accurate installation and servicing of the measuring device. The comparison of characteristic features in the system varieties available should be facilitated during the planning phase, when deciding on the opti-mum configuration to suit the given conditions. The content of the Operating Instructions does not constitute a part of any legal relationship. All obligations of SICK AG arise from the purchase contract concerned, which also contains the complete and solely applicable warranty provisions. These Operating Instructions contain only the information required for a standard application and associated installation and relate to the technical data explained in the Appendix. For special applications, the SICK subsidiary will provide you with the necessary support. It is advisable to seek recommendation from SICK specialists in every case of application. SICK AG Waldkirch Germany 7

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9 1 Safety instructions 1.1 Important safety notes The following symbols in these Operating Instructions are used to denote important safety information for the user. It is essential that these safety instructions, in particular the warnings, are noted and obeyed accordingly. Danger indicates possible dangers to people, especially from items of electrical equipment. Danger indicates possible hazards to people if system components are handled incorrectly. Warning indicates risk to system components or possible impairment of functions. Note contains important additional information for the user on the system or system components and gives further advice. 101

10 1 Safety instructions 1.2 Use in accordance with instructions, conditions of use Use It is assumed that installation planning, mounting, installation, commissioning, servicing and maintenance work will be carried out by adequately trained staff, and that this work will be checked by responsible qualified people. Operation of the measuring system should only be in the manner intended by the manufacturer. The responsible qualified staff must specifically ensure that: All system components are used only for their intended purpose, The application corresponds to the technical data and the details on possible use, installation, connection, environmental and operating conditions (to be obtained from the order documents, the device summary data, type plates and documents supplied), The general mounting and safety instructions are observed, Work is carried out in accordance with the site and installation specific factors, also taking into account hazards and rules due to operational factors, Tools, lifting and conveying equipment are correctly used, System components with no protective system as supplied are fitted with protective devices by the operator There is sufficient safety equipment and personal protective clothing and that this is properly utilized by staff Instructions for system safeguard The GRAVIMAT SHC 501 is a sophisticated electronic measuring system which requires careful handling in all operations, transportation and storage: The gas path and extraction pump must be dried after each measurement is completed! Never store the unit unprotected in the open! Transport and store only in original packaging Store in a dry place Never leave cable ends or plugs unprotected. Always insulate cable ends. When not in use, cable plugs must always be protected against moisture and dirt with protective covers or suitable packaging material. Corroded connectors lead to faults during operation! 102

11 1 Safety instructions 1.3 Authorized users It is essential that those responsible for safety ensure that: Installation design, assembly, installation, commissioning, servicing and maintenance work are carried out only by trained and qualified employees or qualified people and that this is checked by responsible qualified staff. Qualified employees are people conforming to DIN VDE 0105, IEC364 or directly comparable standards. Qualified people have been authorized to undertake this work by those responsible for personal and equipment safety on the basis of their education and training, experience or instruction, and their knowledge of the relevant standards, instructions, accident prevention regulations and site conditions. The important factor is that such people should be able to recognize and avoid potential hazards promptly. Knowledge of First Aid and of local rescue equipment is required and assumed. These people have accurate knowledge of operational hazards, for example, risks due to toxic or pressurized gases, liquid gas compounds or other media. For work on power stations, unqualified persons must not be employed (governed by DIN VDE 0105 or IEC 364). Work on or at close proximity to hazardous system components by unqualified people is forbidden. 1.4 Safety precautions, protective measures Danger from items of electrical equipment The GRAVIMAT SHC 501 is designed for use in industrial power stations. During installation, commissioning, operation and maintenance, it is possible for; Open components or parts that are not insulated to be live at dangerously high voltages, Physical or material damage to be caused by unauthorized removal of the necessary coverings, incorrect operation or insufficient servicing of system components Preventative measures for safe operation The operator must ensure that any malfunctions, shut down of the Gravimat SHC 501 or faulty measurements do not lead to operating conditions that are dangerous or that can cause unacceptable damage. In order to prevent device malfunction, it is necessary that the prescribed servicing and inspection is carried out regularly by qualified and experienced staff. 103

12 1 Safety instructions Detecting malfunctions Variations from standard operations are indications of functional restrictions and must be taken seriously. These include, among other things: Response of the monitoring devices, Excessive drifting of the measuring results, Increased power consumption, Higher temperatures in system parts, Unusually excessive vibrations, Unusual operating noises, Unusual odours or smoke Avoiding consequential damage in the event of equipment malfunction In order to avoid personal injury or physical damage caused directly or indirectly through malfunction or breakdown of the GRAVIMAT SHC 501, the operator must ensure that: The responsible servicing personnel are trained to recognise and react correctly to faults in the device and any associated operational malfunctions, Any necessary or accidental switching off of the GRAVIMAT SHC 501 does not lead to indirect consequential damage. 1.5 Environmental information and instructions for disposal The GRAVIMAT SHC 501 modules are easily disassembled and they contain no toxic or environmentally hazardous materials, with the exception of a few elements of the printed circuit boards. The principle components are steel, stainless steel, synthetics, aluminium and wood, consequently posing no difficulties for future disposal. A few electronic components contain slight traces of toxic materials. Electronic scrap such as printed-circuit boards must therefore be disposed of as problem waste. 104

13 2 Device Description 2.1 Range of application The GRAVIMAT SHC 501 is a mobile measuring system for gravimetric determination of the dust content in ducted gas flows. Dust-laden gas is extracted isokinetically (at the same speed of flow) by means of the GS 5 filter head probe (internal filter probe). The dust is retained by a dust collector with a plane filter and is subsequently weighed. Fig GRAVIMAT SHC 501 Gravimetric measurements for determining dust concentrations are required for: Checking dust emissions and keeping within the limit values according to BImSchG (German emissions legislation) Functional checks of dedusting systems Acceptance testing for warranty certification of dust separators Assessing emission behaviour (e.g. for procedural changes, increase of capacity) Checking process parameters The calibration of continually operating dust measuring equipment. 201

14 2 Device Description 2.2 Measuring principle Based on fundamental gravimatrical processes, the dust content is determined by: time-limited extraction of partial gas quantity measurement of the extracted partial gas quantity separation and subsequent weighing of the dust contained therein. Isokinetic extraction Dust collection In order to avoid measuring faults the partial volume flow must be isokinetically extracted i.e. at the same velocity as the main volume flow. This prevents apparent demixing and provides an exact and representative dust quantity at the measuring site. The velocity of the main volume flow is measured for isokinetic extraction. The extracted partial volume flow is regulated in such a way that the speed of entry into the dust collector's extraction orifice corresponds to that of the main volume flow. All dust particles in the partial volume flow are retained by the filter in the dust collector. After extraction the filter is weighed together with the extracted dust. The basic requirements for ensuring accurate measurements, as well as for very small measuring ranges of dust concentration, are: constructive configuration of the extraction and dust retainment system correct preparation and after-care for the measuring filter the resolution of the precision balance used. For measuring the smallest dust contents with the GRAVIMAT SHC 501, an optimized retaining system (LC dust collector, see section 2.4.4) is used, which is weighed along with the extraction tube, filter and collected dust. Uncontrollable dust losses or measuring errors caused by unrecorded dust contamination in the extraction tube can thus be completely prevented. Due to the chosen method, as well as the low weight of the LC dust collector, even the smallest of dust concentrations are accurately and reliably detected with the GRAVIMAT SHC 501. Single point measurement Network measurement With a single point measurement the dust concentration in a dustladen gas stream is determined in g (dust) / m³ (gas) at the respective measuring site. Network measurements are required in order to obtain the representative mean value concentrations of the main volume flow across duct cross-sections. For this purpose the duct cross-section is separated into several axes with various measuring points along these axis. The mean value is determined by dust sampling across all these network points (see VDI 2066 Sheet 1). 202

15 2 Device Description A basic requirement for accurate sampling with several dust collectors are identical extraction times and extraction orifices at all network points. In the same it is possible to divide a network measurement in individual measurements, completely independent of one another. Information on dividing up the duct cross-section and arranging the measuring points are contained in VDI 2066 Sheet Technical measuring regulations (conformity) The most important regulations for measuring stationary particulate emissions are contained in the following guidelines: VDI 2066 Sheet 1 VDI 2066 Sheet 2 VDI 2066 Sheet 3 VDI 2066 Sheet 5 VDI 2066 Sheet 7 ISO 9096 CENprEN 264 VDI 2066 Sheet 8 (Basics) (4/12 m 3 /h - filter head unit) (40 m 3 /h - filter head unit) (grain size determination by impactor) (1 m 3 /h- plane filter head unit) (corresponds to international standard) (designed to European standard) (soot spot measurement) For the calibration of automatic emission measuring equipment (e.g. dust measuring devices), additional regulations can be found in VDI 3950, Sheet 1. Information on measurement planning, the selection of representative measuring points in a measuring network, installation location and evaluation methods are contained in VDI 2066, Sheet

16 2 Device Description 2.4 System components see section Overview The GRAVIMAT SHC 501 (see Fig. 2401) consists of the following components in the basic version: GS 5 Filter head probe Special case with dust collector set l LC dust collectors for low dust contents l HC dust collectors for high dust contents SHC-AE501 Evaluation unit Optional mounting parts (installation supports, probe mount). Installation support GS 5 Filter head probe Multichannel hose SHC-AE501 Evaluation unit Probe mount Dust collector Optional (for evaluation) Optional Fig GRAVIMAT SHC 501 system overview The GS 5 filter head probe with integral dust collector is inserted into the duct. The dust collector collects the extracted particles. The probe head contains measuring orifices on the side of the dust collector for measuring the gas velocity v, partial volume flow Q and the sensor for measuring the gas temperature T in the duct. The filter head probe is connected to the evaluation unit via a multichannel hose with a safety lock connector. 204

17 2 Device Description The evaluation unit controls the isokinetic extraction and registers the measured values. The necessary functional units (see section 2.4.4) are housed in a robust flightcase. Device functions are controlled using operation and evaluation software contained in the evaluation unit. Either a PC (laptop) or a serial printer for logging the measured results can be connected to the RS 232-interface on the evaluation unit GS 5 Filter head probe The filter head probe consists of the following components: Probe head with integrated extractor for the dust collector, with pressure sensors for determining the gas velocity in the duct and the partial volume flow, and with a Pt 100 temperature sensor for accurate measurement of the exhaust gas temperature at the extraction orifice. Stainless steel probe shaft Multichannel hose with extraction lline, pressure sensing lines for conducting pressure signals to the pressure sensors in the evaluation unit and integrated temperature sensing line. Fig Filter head probe with extension The main construction of the GS 5 filter head probe is shown in Fig

18 2 Device Description P 2 P 1 P 3 P 4 P Dust collector 2 Ring plug screw 3 Support plate 4 Filter housing 5 Measuring orifice 6 Extraction line 7 Pressure sensing line 8 Probe shaft 9 Multichannel hose 10 Temperature sensor 11 Temp. sensing line 12 Purge air duct Fig GS 5 Filter head probe See section for description of dust collector See section for assembly See Fig Probe head The assembled dust collector (1) is inserted into the filter housing (4). A ring plug screw (2) presses the collector at its outer edge evenly onto a sealing washer via a filter diaphragm and a seam. The filter diaphragm lies against a support plate (3), which prevents the pressurized filter diaphragm from being destroyed. The support plate with sealing washer can be used with gas temperatures up to 250 C. For higher gas temperatures (up to 400 C or 600 C with the HT version) a support plate should be used without a sealing washer (see Chapter 8). When using the support plate without a sealing washer, an additional error up to a maximum of 3% should be expected in the measurement of the partial volume flow. A measuring orifice (5) with pressure sensing orifices p 4 and p 5 is located behind the support plate, for measuring the pressure drop across this orifice as a basis for determining partial volume flow. Apart from the task of dust collecting, the probe head also has the function of a dynamic pressure sensor. Pressure sensing orifices (p 1, p 2, and p 3 ) are arranged on the cylindrical outer surface of the filter housing for determining the gas flow velocity in the duct, as well as the angle of flow in the probe. During installation of the dust collector, the extraction port is aligned parallel to the total pressure port (p 1 ). (Notch on the outer edge of filter housing). 206

19 2 Device Description A Pt 100 temperature sensor (10) is provided for measuring the gas temperature. The probe head with extraction line (6) and the five pressure sensing lines (7) is fixed to the probe sleeve (8). Lines (6 and 7) and the temperature sensing line (11) run to the probe sleeve through a multichannel hose (9). The filter head probe and its sensors supply all measuring signals required for checking and monitoring isokinetic extraction and for extracted partial volume acquisition Probe shaft The stainless steel probe sleeve (8) is 1 m in length as standard. Probe extensions can be screwed on if longer penetration depths are required. For ease of handling a grip is mounted at the end of the probe sleeve. A support spring prevents the multichannel hose from kinking. A marking on the grip piece indicates the position of the extraction port in the duct (align correctly when assembling the probe!) Multichannel hose The multichannel hose conducts the partial volume flow and the pressure and temperature sensing signals from the filter head probe to the automatic control unit. Connection to the automatic control unit takes place by means of a safety lock, which guarantees the correct alignment of the respective pressure sensing signals to the corresponding pressure sensors in the automatic control unit. The standard length of the multi-channel hose is 5m. An optional hose extension can also be connected. When higher gas temperatures are involved (see section 8.1), two free channels in the multichannel hose are supplied with cooling air. The cooling air penetrates the probe shaft. See Chapter 8 See section 3.5 See Chapter 8 for data on cooling air Fig Multichannel hose with safety lock and plug for temperature sensor 207

20 2 Device Description Probe mount A probe mount and corresponding installation tube with the appropriate dummy plug should be provided for the filter head probe in the flue gas duct. The cast-aluminium mount provides safe, smooth conduction and fixing for the filter head probe. The protective sleeve on the mount prevents damage to the collector during installation and handling of the probe. The bayonet-type screw fitting on the probe mount allows quick connection to the appropriate installation tube. Suitable adapter fittings can be manufactured for existing on-site installation tubes Installation tube (R89x4) 2 Probe mount with protective sleeve 3 Filter head probe with LC dust collector Fig Mount for filter head probe before measurement Duct Direction of flow Fig Filter head probe in measuring position 208

21 2 Device Description 2.4.4Dust collectors LC dust collectors The LC dust collector (low concentration) is used to determine very low to medium dust concentrations (see section 8.1). The collector consists of a curved extraction tube and a domed filter plate. The flat edge of the filter plate holds the filter diaphragm with its aluminium foil seam (see section 3.3.2). As a condition for isokinetic extraction, the extraction tubes have graded diameter openings D S for adapting the system extraction performance to the duct flow. X D S Extraction tube Filter diaphragm Alu. seam D S = 4.2 / 5.2 / 6.4 / 8.0 / 10.0 / 11.5 mm 0,3 0,2 D s 0,5 Fig LC dust collector The standard equipment is 24 LC dust collectors, together with the seaming device, aluminium foil and plane filter material. These are housed in a special transportation case (see Fig. 2408). Each collector is identified by the Ds extraction diameter and a consecutive registration number for the respective diameter. Fig Special case with LC dust collector set 209

22 2 Device Description HC dust collectors The HC (high concentration) dust collector enables the determination of medium and high dust concentrations. It consists of a funnel with considerably greater volume capacity than the LC collector, and replacable extraction tubes with graded diameter openings. As with the LC collectors, these extraction tubes enable partial flow extraction to match the main flow velocity in the duct. Dummy plug Filter plane diaphragm Quartz padding (for high dust contents) Support plate Important: A cavity can be made in the quartz padding with the dummy plug, so that the dust in the filter material is better distributed and so that the pick-up capacity is increased. Extraction channel Cavity made by means of dummy plug Funnel Ds Fig D S = 4.2 / 5.2 / 6.4 / 8.0 / 10.0 / 11.5 mm HC dust collector Filter head probe Like the LC collector, the HC collector is fitted with a filter plane diaphragm of D=50mm. The filter plane diaphragm is secured to the collector by means of an aluminium seam ring. Unlike the LC collector, the HC collector with padding has a considerably higher capacity for extracting dust (approx. 10 times; max. 20 g, irrespective of dust type), without allowing the filter resistance of the plane filter to increase too much. Dust concentrations are measurable up to 50 g/m³ (irrespective of dust type), according to the selected sample time and the extracted partial flow volume. 210 The HC dust collector can also be used for determining lower dust concentrations (with or without padding). Owing to the higher empty weight (approx. 70 g without extraction tube, approx. 92 g with extraction tube), the attainable accuracy is highly dependant upon handling when weighed. The factors to consider here are: accuracy of the available precision balance when weighing the complete collector possible dust loss caused by weighing the filter diaphragm (and padding) separately and from dust residues stuck in the extraction tube and funnel.

23 2 Device Description The standard set is supplied complete with 4 funnels, 1 set of extraction tubes, 1 dummy plug, as well as ring plug screw, seam device, and aluminium foil. These are housed in a special transport case. Fig Special case with HC dust collector set Soot collector Through the use of a soot collector in the filter head probe, the GRAVIMAT SHC 500 can be set into operation for soot spot measurement (in keeping with VDI 2066, Sheet 8). The soot collector consists of the funnel (as for HC collector), and a special inlet nozzle, which is screwed onto the funnel instead of the extraction tube. The inlet nozzle provides a smooth and steady flow to the filter diaphragm. The cone angle of the funnel is designed according to VDI 2066, Sheet 8. Inlet nozzle Funnel Filter head probe Filter plane diaphragm Support plate Fig Soot collector 211

24 2 Device Description The soot spot measurement can be carried out with this collector in the following way: Enter a sampling diameter of 10 mm in the "Parameters" menu. Determine the partial gas volume to be extracted Warning The value under operating conditions should be determined, i.e. the figure in VDI 2066 Sh. 8 corresponding to the respective operating parameters should be used. Extract the determined partial gas volume under the "manual operation" menu (see section 4.4) The soot particles contained therein are deposited in the plane filter. The amount of soot can then be determined by optical evaluation of the plane filter SHC-AE501 Evaluation unit The evaluation unit contains all the necessary components for data acquisiton, isokinetic extraction and operation of the GRAVIMAT SHC 500. All components are housed in a robust "Flightcase". The lid of the Flightcase provides space for accessories. The individual components of the automatic control unit are: electronic unit condensate separator control valve, shut-off valve vacuum pump with silencer The flightcase is open during measurements. The following functions can be selected by using the keys on the front panel: Parameters Set the parameters for the measurement (extraction diameter, collector number, standard density of humid exhaust gas, gas humidity, fixed temperature) Automatic Automatic, isokinetic extraction with configurable display of the extraction values (extracted partial gas volume, velocity and temperature of the exhaust gas in the duct, partial volume flow, probe pressure p 40, flow angle of the probe) Special functions For function checks, comparison, language setting, manual operation, coding. Special service functions are available by entering a code word. 212

25 2 Device Description Fig SHC-AE501 Evaluation unit Electronic unit The electronic unit consists of the modules: Front panel with l keyboard for menu selections l illuminated LC-display l RS 232 interface Microprocessor board with 2 pressure sensors Sensor panel with 4 pressure sensors Power supply module for microprocessor board and valves with connections for the vacuum pump and 2 fuses Complete control of the internal functions including valve control, key enquiries, triggering of LEDs as well as measurement and processing of all analogue signals from the pressure sensors and temperature sensor, is done via the microprocessor board. 213

26 2 Device Description All internal device comparison data and work settings are saved to EEPROM. An external PC (laptop) or a printer can be connected to the RS 232 interface on the front panel for measured value protocols and servicing information. The power supply ensues via the mains connection. Adaption to the local mains supply (230 V AC or 115 V AC) is possible by replacing the extraction pump (see section 3.5.4). Note In order to set the GRAVIMAT into operation the extraction pump (with 7 pin plug) must be wired in Gas cooler Exhaust gases from industrial plants have higher vapour contents as a rule. Heated residues along the partial gas ways lead to condensate precipitations, which cause serious corrosion through the extraction of gas components such as SO 2, SO 3, HCl etc.. The condensate is retained in the gas cooler to protect the pump and valve Extraction pump The pump is a rotary disk valve pump with an asynchronous motor with auxiliary separator. The pump housing is made of stainless steel, and the rotor and blades are graphite. The pump housing is extremely resistant to the effects of corrosive gases. Warning At the end of the measurement the extraction pump must be cleaned of condensate deposits with ambient air and dried, otherwise the pump life will be considerably reduced (Condensate deposits lead to corrosion). Connection is via a 7 pin plug connector, guaranteeing coordination with the available mains supply. The permitted supply voltage is indicated on the connection box of the extraction pump (see section 3.5.4). Warning The extraction pump must be laid out for the respective mains voltage! It is essential that the power supply required must either be stated when ordering or in the technical questionnaire! 214

27 2 Device Description GRAVIMAT SHC 501 basic functions The filter head probe and the evaluation unit unit are interconnected by the multichannel hose. The filter head probe is connected to the multichannel hose by means of a safety lock, guaranteeing constant alignment of the pressure sensing lines to the respective sensors. 1 Pt 100 temperature sensor in 4 lead switches 2 Measurement gain 3 Gas cooler 4 Shut-off valve 5 Motor actuator 6 Extraction pump 7 Differential pressure sensor p 45 8 Pressure sensor p 40 Measuring diaphragm p 45 p Filter head probe 14 9 Diff. pressure sensor p Diff. pressure sensor p Diff. pressure sensor p Barometric pressure sensor 13 Pressure sensing port p 1 14 Pressure sensing port p 2 15 Pressure sensing port p M 3 5 Filter p 12 p 13 p 10 p baro Evaluation Unit 11 Fig SHC-AE501 Evaluation unit mode of operation The partial volume flow is channeled via the gas cooler (3) and the opened shut-off valve (4) on the extraction pump (6). The shut-off valve blocks the partial gas conduit before and after the extraction process in order to prevent disruptive backflows to the dust collector. Via the control valve (5) the partial volume flow is controlled by an artificial air supply so that extraction is isokinetic. The extracted partial volume flow is determined via diaphragm measurement. The differential pressure sensor p 45 (7) (measuring range 0 to 25 mbar) measures the pressure drop of the diaphragm. Additionally, the pressure p 40 is measured in front of the diaphragm by the pressure sensor (8) (measuring range +100 to -500 mbar) relative to the ambient pressure. 215

28 2 Device Description p 10 = p 1 - p 0 = p 1 - p Baro See Chapter 9 for calculation formulae p 12 = p 1 - p 2 p 13 = p 1 - p 3 The pressure p 10 is measured by the differential pressure sensor p 10 (11) (measuring range 70 to +70 mbar) relative to the ambient pressure. The ambient air pressure is detected in a range from 770 to 1250 mbar with the barometeric sensor (12). The effective pressures (differential pressure) p 12 and p 13 are determined via the pressure measuring points p 1 (13), p 2 (14) and p 3 (15). With normal (symmetrical) flow, both effective pressures are the same. They vary with oblique flow. The ratio of these effective pressures delivers the corresponding flow angle α in the range of -22,5 to +22,5 C, with a normalised characteristic dynamic pressure transmitter. From the sum of both effective pressures, the dynamic pressure of the mean volume flow is determined by means of a second calibrated characteristic curve (depending upon α). The gas velocity in the duct and the angle of flow is determined from p 10, p 12 and p 13. The Pt 100 temperature sensor (1) in the probe is connected to the evaluation unit via a 4 conductor circuit by means of a pin and socket connector. The connection cable between the Pt 100 and the pin and socket connector is provided in one channel of the multichannel hose Accessories and optional extras See Chapter 8 for accessories Flightcase SHC5-TU The flightcase SHC5-TU can be used for transporting accessories, as well as housing the laptop, printer, probe mount, tools, spare parts, mains extension and protective gloves. The flightcase is not part of the standard scope of supply. Precision balance A precision balance is required for weighing the dust collectors. A balance with a range of 0 to 30 g with a dispersion of 0.1 mg is recommended for weighing LC dust collectors. A balance with a measuring range 100 g is required for weighing HC dust collectors. An precision balance is not supplied as standard. 216

29 3 Preparing for measurement 3.1 Choosing a measuring site Selecting a suitable installation site for gravimetric dust measurement requires accurate knowledge of the plant. Smooth, uninterrupted flow patterns in the exhaust gas duct are a prerequisite for representative measuring values, and in particular for official measuring requirements. These are most likely expected with long inlet and outlet sections. In accordance with VDI 2066, Sheet 1: The lengths of the inlet or outlet sections should amount to at least three times the "hydraulic diameter" (total length therefore at least 6 times the hydraulic diameter). With round and square duct crosssections the hydraulic diameter and duct diameter are the same. Although these requirements can not always be met, the best possible site should be selected in existing plants. Further criteria for selecting as well as for determining nework point measurements are set out in VDI 2066, Sheet 1. In order to avoid planning errors the measuring location should be decided by experts (e.g. professional opinion of a suitable measuring point, according to BImSchG (German emissions legislation)). Inlet and oulet sections Hydraulic diameter D 4A A = Cross-sectional = U surface U = Circumference Professional opinion of the measuring site 3.2 On-site preparation The following conditions are required for carrying out gravimetric measurements with the GRAVIMAT SHC 501; measuring orifices in the exhaust gas duct with mounted installation supports (normally welded in), with an internal diameter > 62 mm, a sufficiently large and safe working platform with power supply and lighting should be provided if the measuring orifices are higher than 1.6 m above ground level. For the number and alignment of measuring orifices see VDI 2066, Sheet 1. The probe mount is secured to the installation support by means of a bayonet-type connection. Should another installation support already be installed, the option of altering the probe mount by means of an adapter flange must be checked (see Fig for connection dimensions) Cone nut Threaded bolt M ±0,5 150 Fig Adapter flange 301

30 3 Preparing for measurement 3.3Preparation of dust collectors General The respective dust collectors are to be selected, depending on the measuring task (determination of low or high dust contents or soot spot measurement). The collectors are to be prepared before each measurement. The following procedures are necessary: cleaning the dust collectors fitting of the collectors with the filter material drying the assembled dust collectors determining the empty mass of the collectors storage in desiccator Warning The preparation of the dust collectors requires the most meticulous care particularly for the detection of the smallest dust concentrations. The steps described below should only be regarded as foundation work. A comprehensive description of the handling of dust samples can be found in the draft for the European norm CENprEN264. Note for LC collectors: If the extraction diameter Ds of the LC collector to be used is not known before the measurement, then several collectors of different extraction diameters should be prepared (HC collectors are provided with the required extraction tube on site). Cleaning Clean the empty dust collectors (funnel and extraction tube or inlet nozzle for soot spot measurement with HC collectors) of dust and grease (i.e. in ultrasonic bath) Fitting with filter material LC dust collectors Commercially available plane filter material with a diameter of 50 mm can be used as a filter diaphragm. The selection of filter material depends on the expected maximum temperature load and the pore size required. Capillary pore filter diaphragms are preferable for measurements of extremely low dust concentrations (less than 1 mg/ m 3 ), or for higher accuracy requirements. Alongside other advantages, these micro filters absorb only a very low amount of moisture (check maximum permitted temperature!). 302 The filter diaphragm is secured to the dust collector by means of a seam made of aluminium foil. The seam has to be shaped from a foil ring (Fig. 3301). The foil ring (1) is first concentrically clamped into the seaming device (2). Then the protuding edge is bent by sliding over the top part (3).

31 3 Preparing for measurement Then the bent seam (4) is laid in the recess of the component (5) together with the filter diaphragm (6) and the collector (7), as shown in Fig The collector is then closed by bending the edge over using a rounded wooden or plastic spatula (8) Fig Making the seam Fig Securing the filter diaphragm The thus prepared dust collectors are next dried in a warming cabinet, conditioned in a desiccator and then weighed (see section 3.3.3). 303

32 3 Preparing for measurement HC collectors The preparation of HC collectors for dust concentrations > 50 g/m³ is carried out in accordance with VDI 2066 regulations, Sheet 3. Here the measuring filter consists of an HC collector padded with quartz wadding and a filter plane tipped funnel. Quartz wadding is recommended as filter material, with an average fibre diameter of approx. 10 µm. Assemble the filter material according to the following procedure: Core With the dummy plug in place, fill the funnel with approx. 3 g of quartz wadding. The filling should contain linked balls of wadding. Pack and compress the quartz wadding as much as possible so that there are no continuous channels. Sealing The plugged funnel is sealed as per section with a plane filter diaphragm (diameter 50 mm) and an aluminium seam. The dummy plug is removed. The measuring filter is then complete. Dummy plug Funnel Aluminium seam Filter plane diaphragm Quartz wadding Fig Preparing HC dust collector 304

33 3 Preparing for measurement Determining the empty mass of the prepared dust collectors Drying Dry the prepared dust collectors in a drying oven for at least an hour. The drying temperature should be at least 20 K above the gas temperature at the measuring site. Then equilibrate the dust collectors for a period of at least 4 hours either in a desiccator or at the very least in an air-conditioned room. The equilibration and weighing of the collectors should take place on the same site. Note for HC collectors: If the necessary extraction diameter for the measuring process is known, the corresponding extraction tube can be screwed onto the measuring filter before drying and weighing it. Weighing The dust collectors are weighed individually immediately after being removed from the desiccator. In order to prevent inaccurate measurements, the measured value for each collector should be determined after the same period of time on the balance (e.g. always 10s after placing on the balance). Then the collectors are placed in the special carrying case. Warning The balance must be set up in a vibration-free area (if necessary use a padded underlay). Note The zero point of the balance should be checked after each weighing, particularly when determining small dust contents. In such cases it is further advisable to create a "norm" with a mass similar to that of the dust collectors, in order to detect possible balance deviations. This "balance norm" should be weighed after about every 4 measurements. 305

34 3 Preparing for measurement 3.4 Transporting The measuring equipment is transported in the following units: Carrying case with probe and maximum 2 extensions of 1.5 m Special carrying case with the prepared LC or HC dust collectors, seaming device, aluminium foil rings and plane filter material Evaluation unit in the flightcase Flightcase (optional) with probe mount, tools and other accessories. Note When transporting and storing the GS 5 filter head probe always insert the cap (see Fig. 3501) in the filter housing. Fig 3401 Transport packaging for the GRAVIMAT SHC501 standard version 306

35 3 Preparing for measurement 3.5 Installation of the measuring device Installing the GS 5 filter head probe The filter head probe should be taken out of the carry case at the measuring site. The probe bracket is pushed over the multichannel hose up to the probe head. Then the grip handle should also be pushed over the hose and screwed to the probe shaft. Place the temperature sensor on the connector in the notch when doing this! When using two probe extensions (section ), a hose extension (length approx. 5 m with cable for temperature sensor) should be used for safer handling (accessory, see Chap. 8). The grip handle should be aligned in such a way that the marking on the filter head corresponds to the position of the pressure measuring site p 1. The direction of the whole pressure bore p 1 can be seen by inserting the face spanner in two 2 mm bores on the back of the filter head Inserting the dust collectors The dust collectors prepared for the extraction process, or the cap (7) for the velocity/temperature measurement, should be inserted in the following way (see Fig. 3501): Loosen the screw plug (2) with the face spanner (1) and take it out; take out the cap (7). Mount the dust collector (3) on the support plate (4) in the filter head housing in such a way that the extraction orifice (5) points in the same direction as the marking (6) on the probe head. Screw in the screw plug (2) again so that the concentric pressure surface presses against the sealing washer on the support plate. (tighten gently with the face spanner) For velocity/temperature measurements as well as transporting and storage insert the cap(7) in place of the dust collector. The insertion of the dust collector is shown for the LC collector. The HC collector should be inserted in the same way, and the screw plug on the collector should be used Fig Insertion of the dust collectors 307

36 3 Preparing for measurement Installing and connecting the evaluation unit When erecting the evaluation unit the following points should be considered: The installation site should be sheltered from rain. Note constantly sloping gas paths, so that the build-up of water pockets is avoided. Warning The possible flow of condensation back into the probe after turning off the extraction pump must be absolutely avoided! GS 5 Filter head probe RS 232 Interface The connection of the filter head probe to the evaluation unit is carried out in the following way: Screw the safety lock nut (see Fig. 2404) on the connector of the multichannel hose up to the limit Put the safety lock of the multichannel hose on the connector of the evaluation unit in such a way that the sealing surfaces lie flat against one another. Screw the safety lock nut hand-tight in a clockwise direction; the nut must be easily moveable Put the plug for the temperature sensor in the socket and screw up. Note Check the thread and joint on the connector for damage or dirt, if necessary clean the thread with a wire brush, thread damage can be carefully removed with a triangular file. Warning A tool to tighten the nut should not be necessary if the threads are in an orderly condition! The RS 232 interface can be connected via a connection cable to a laptop's serial interface or to a printer for data logging. RS 232 Interface Connection for temperature sensor Connection for multichannel hose Connection for power cable 308 Fig Connections to the evaluation unit

37 3 Preparing for measurement Adaptation to the available supply voltage The evaluation unit is set in the factory for the supply voltage (115/ 230 V AC) specified at the time of ordering or in the technical questionaire. The adaptation is carried out by installing the relevant extraction pump (corresponds to coded connectors in the pump plug). Danger The evaluation unit may only be operated if the local supply voltage corresponds to the mains voltage setting! When exchanging the extraction pump, it is essential that the operating voltage of the extraction pump and the local power supply are compatible! Note The operating voltage of the extraction pump is noted on top of the pump motor's terminal box and on the pump plug. Pump plug Indication of operating voltage Connection box for pump motor Extraction pump Fig Extraction pump 309

38 3 Preparing for measurement 3.6 Function test before measuring starts To check the correct functioning of the GRAVIMAT SHC501 the following test steps can be carried out before the measuring operation is begun. In the "Special functions / Manual operation" menu check the displays without the filter head probe connected: Velocity = 0 m/sec p_probe (p 40 ) = 0 mbar Angle = 0 deg. If the displayed values deviate from these, a zero-point calibration should be carried out ("Special functions / Calibration / Zeropoint"; see section 6.3.1) Note Air currents (wind, draught etc.) must not be present at the location where the evaluation unit is mounted. Once the filter head probe is connected and the cap has been inserted, start an extraction procedure in the "Special functions / Manual operation" menu, select "volume" display and start the extraction (select "new measurement"). Regulate the isonetic value to MAX using the O key and check the subsequent values. When the device is functioning correctly the following values must be displayed during the the extraction: extr. volume = 0 m³/h p 40 = approx mbar VDuct = 0 m/sec Angle = 0 deg. Note The filter head probe must not be exposed to air currents If other values are displayed, the air-tightness of all lines should checked (see section 6.1.2), or a malfunction check carried out as shown in Chap

39 4 Measuring 4.1 General After completing all the required preparatory work according to Chapter 3, the filter head probe should be inserted into the probe mount which is mounted onto the installation flange and locked (see Figs and 2406). The GRAVIMAT SHC 501 is operated via the buttons on the front panel of the evaluation unit. These are: Mains switch Cursor key field for menu selection and parameter setting Start key for starting an extraction process Stop key for ending an extraction process and for cancelling an entry (Escape-function) Start key Cursor key Stop key Mains switch Fig Evaluation unit keys The LC-Display lights up after switching on the mains switch, displaying the main menu with: Parameter Automatic Special functions. The LEDs on the keys indicate whether the functions are available or not. If the respective LED does not light up then the corresponding key has no function. The following settings are available with the cursor key: Key l Confirms selected menu point and enters into the submenu l Confirms selected parameter and enters into edit mode l Confirms input/selection and exits edit mode 401

40 4 Measuring Keys O and U l Selects a menu point in the main menu l Jumps back from a submenu into the main menu (O key) l Chooses the next highest (O key) or next lowest (U key) digit in edit mode l Sets the partial volume flow in the "manual operation" menu by: selecting the display "volume flow" and switching on the extraction pump, followed by modifying the actual value. Keys L and R l Selects parameters, functions and measuring values in a submenu l Changes the cursor position between higher or lower digit values in edit mode 4.2 Description of menu See Appendix section 9.2 for determining standard density and gas humidity Menu "parameters" The "parameters" menu includes the following setting options: Diameter (extraction diameter of the dust collector) Collector diameter (inserted dust collector number for registration of probe) Normal density (humidity) Humid factor (gas humidity) Pt100 temperature (input of fixed temperature in lieu of the measured value from temperature sensor) Protocol. With this, the necessary basic values for isokinetic extraction can be set. The setting can then be checked under the menu point "protocol". 402

41 4 Measuring The extraction diameter can be determined with the help of the following table: Extr.-ø Gas velocity in the duct in m/s in mm ,2 0,25 0,50 0,75 1,00 1,25 1,50 1,75 1,99 2,24 5,2 0,38 0,76 1,15 1,53 1,91 2,29 2,67 3,06 3,44 6,4 0,58 1,16 1,74 2,32 2,89 3,47 4,05 4,63 5,21 8,0 0,90 1,80 2,71 3,62 4,52 5,43 6,33 7,24 8,14 10,0 1,41 2,83 4,24 5,65 7,07 8,48 9,90 11,31 12,72 11,5 1,87 3,74 5,61 7,48 9,35 11,22 13,09 14,96 16,83 Values in m 3 /h Operating range of the extraction pump (0,6-2,4 m 3 /h) Table 4201 Collector selection depending on the gas velocity in the duct Parameter x y Diameter Collector no. Normal density H2O humidity Temperature Protocol PT mm Entry of a max. Entry using the Entry using the Diameter R 4 digit number LR keys for LR keys for * 5.2 mm using the LR position selection position selection Collector no. R keys for position and OU keys for and OU keys for * 6.4 mm selection and the figure selection figure selection Norm. density R OU for figure * 8.0 mm selection H 2 O humidity R * 10.0 mm R 11.5 mm * continual automatic display of the set parameters Fig Operating process in the "Parameters" menu By entering the gas temperature measured in the duct, isokinetic extraction can still be carried out even when the temperature measuring equipment is faulty (malfunction of the temperature sensor or similar). The steps necessary for this are illustrated in Fig Note x - y 403

42 4 Measuring x y H 2 O humidity PT100 Constant temperature Protocol temperature xx grdc PT100 constant Entry of max. 4 digit R number via the LR keys for position selection and the OU keys for figure selection ( C) Fig Partial process for "Input constant temperature" Note: The operating processes shown in the figures 4202 to 4206 are only shown in one direction in each example. They can also be carried out in the reverse order "Automatic" menu All steps necessary for isokinetic extraction are carried out under the "Automatic" menu. The start and end of an extraction process is carried out by pressing the corresponding key (see section 4.3). During the extraction process, the extraction time, and when selected also the current measured values, are shown on the LC display. extraction volume (partial gas volume in m³) velocity (Gas velocity in the duct in m/s) temperature (exhaust gas temperature in C) volume flow (partial volume flow in m³/h) p_probe (p 40 ) (probe pressure in mbar) angle (angle of the current in ) After the "Angle" parameter comes the menu point Dry pump. In the subsequent menu point Measuring protocol after the end of the extraction process, the mean value of the measured and calculated values will be shown continuously on the LC display. After being displayed, the values on the RS 232 interface are available for printing. Printer requirements: serial interface, set to 9600, N, 8,

43 4 Measuring "Special functions" menu With this menu the functions shown in the following overview can be selected as standard. Special fct. Calibrate Lang. 2 Service Manual 3 Codeword About instrument Zero point German Serial number R R Date English ID number R Time Program version 1 Device state * After selection with the Print protocol * continual display of the device parameters, return by pressing the Stop key Device reset Fig 4203 Overview of special functions After entering the level 2 password (only for service purposes) the following settings are also possible: Calibration After setting the time, the aperture constants can be entered or corrected. Service After the menu point "Language"comes the menu point "Service" with the current values for: Pressure sensors (p 10, p 12, p 13, p 40, p 45, air pressure), Device temperature, Pt100 temperature sensor (current, voltage), Current inputs 1 and 2 Volume flow Temperature Control variable After the menu point "Password" comes the menu point "Control variable", which enables the setting of time constants (medium, slow, fast), minimum throughput, isokinetic factor. Note 1 Note 2 Note 3 Note Settings and displays under the menu point "Manual operation" are described in section

44 4 Measuring 4.3 Extraction measurement After selecting and entering the necessary basic paramteres as per section 4.2.1, the extraction of a partial volume flow can begin. The extraction process is carried out as shown in the following diagram: Automatic a Start Continue measuring b New measurement b O Stop no Dry pump R yes Measuring protocol O R b Start Stop Fig Operating process in the "Automatic" menu Note a Display of measured values After selection of the "Automatic" menu the following measured values can be displayed in the manner shown: Extr. volume Velocity Temperature Volume flow p40 Angle Dry pump Meas.protocol * Extraction time Angle * * Extr. volume Air pressure * * Volume op. cond. damp p10 * Volume op. cond. dry * p40 Velocity * * Volume flow * * * Continual automatic display of the measured values Temperature 406 Fig Measured value display in the "Automatic" menu

45 4 Measuring After the start of a measurement (continue measuring or new measurement) or after enquiring about the measuring protocol in the Dry pump submenu, the following values can be displayed in the order shown by using the R or L keys: extr. volume velocity temperature volume flow p40 angle Label b Through the subdivision into "Continue measuring"/"new measurement" the possibility exists for interrupting an extraction process (e.g. to change a dust collector or move the filter head probe to another measuring point) and then continue with the extraction ("Continue measuring") or begin a new extraction process ("New measurement"). Note Menu point "Continue measuring" The partial gas volume extracted in a previous measurement is used as a basis when continuing the extraction process. During the extraction process the menu point "Volume flow" can be used to control whether the extraction is taking place isokinetically. The instantaneous "actual" extracted partial gas volume is compared with the nominal value for the pump control "nominal". If they are the same, the extraction is isokinetic. If no agreement can be reached then it should be checked whether an unsuitable sampling diameter was used or whether perhaps a malfunction could have been present Warning The nominal value must be within the operational range of the extraction pump (see section Table 4201). If necessary, another sampling diameter should be entered in the "Parameters" menu and the corresponding collector inserted in the filter head probe. Note A small variation from the nominal value depends on the plant or system, as the plant parameters are measured in real time and the GRAVIMAT adapts itself continuously to the measured values. 407

46 4 Measuring 4.4 Manual operation The procedure for an extraction process under the "Manual operation" menu is carried out in the same manner as under the "Automatic" menu (see Fig. 4307). Manual operation a Start Continue measuring b New measurement b O Stop Dry pump no R yes Measuring protocol R b Start Stop Fig Operating procedure in the "Manual operation" menu After pressing the Start key a previous measurement can be continued as under the "Automatic" menu ("Continue measuring") or a new measurement can be started. Warning If the "New measurement" menu point is chosen, all average values from the previous measurement are irretrievably erased! The measured values can be displayed in the same way as with an extraction measurement: After calling up the "Manual operation" menu (Note a ) After the start of a measurement or after enquiring about the measuring protocol in the Dry pump submenu (Note b ). 408

47 5 Evaluating measurements 5.1 Determining the gross weight of the dust collector Drying The dust laden dust collector must be completely dried before each weighing process so as to eliminate faulty measurements caused by the influence of moisture. The drying process takes place in the same manner as described in section 3.3.3: Weighing The dust collectors should be weighed immediately after being removed from the desiccator. Provide a precision balance with the measuring range required for the type of dust collector used (HC or LC). (LC dust collector - min. 20 g, HC dust collector - min. 50 g). The dust-laden collectors should be weighed using the method described in section Note for HC collectors: In case the only weighing machine available has a range of less than 100 g, the filter element (filter diaphragm and quartz wadding) can be weighed without the funnel and extraction tube. This is done by carefully removing the aluminium seam from the funnel as well as loosening the filter diaphragm and quartz wadding from the funnel. For this procedure it is essential that the net weight of the filter element is determined before measurement. Warning Adherent dust residues on the funnel and extraction tube should not be weighed when removing the filter element, due to the risk of inaccurate measurements. Note If the GRAVIMAT SHC 501 is only operated via the front panel on the evaluation unit, the dust concentration must be calculated separately from the empty mass and gross weight of the dust collector. For this the evaluation formulae are used (Appendix of this operating manual). 501

48 5 Evaluating measurements 5.2Calulating the dust concentration See VDI 2066, Sheet 1 for definitions Dust load (dust content): mass flow of dust per volume flow of gas The dust concentration c is the ratio of the dust mass m contained in a determined volume v. Dust concentration under operating conditions: c i.b. = m V m net - m tara c i.b. = (5.1) V c i.b m tara m net V = dust concentration under operating conditions = empty weight of dust collector = gross weight of dust collector = extracted partial gas volume Dust concentration under normal conditions See Chapter 9, Appendix for calibration formula m c i.n.f. = net - m tara (5.2) c i.n.f. V i.n.f. V i.n.f. = dust concentration under norm. conditions wet = extracted partial gas volume under norm. conditions wet m c i.n.tr. = net - m tara (5.3) V i.n.tr. c i.n.tr. V i.n.tr. = dust concentration under norm. conditions dry = extracted partial gas flow under norm. conditions dry Note: Standard values calculated with the GRAVIMAT contain no calibration of the oxygen content. This must be done separately (see Chapter 9, Appendix). Dust mass flow l M = A duct l v ax l c (5.4) For calculation of v ax, see Appendix l M A duct v ax = main mass flow in duct = cross-sectional surface of duct = mean value of axial velocity components Use the respective dust concentration for calculating dust mass flow under operating and normal conditions. 502

49 5 Evaluating measurements Note The values required for determining the dust concentration and dust mass flow: volume flow op. cond. in exhaust gas duct (for wet gas) gas temperature in exhuast gas duct extracted partial voulme are calculated by the GRAVIMAT SHC 501 from the "crude measuring values" of the 6 pressure sensors and the temperature sensor. Internal comparison of the pressure sensors, blend constants and gain is performed with the help of digital correction values, which are then saved to EEPROM. See Appendix for formulae The values measured or calculated by the GRAVIMAT can be selected using the front panel keys and displayed on the LC-Display. The mean values of the last respective measurement are saved. Warning When starting a new extraction measurement or determining velocity/ temperature patterns, the saved values from the previous measurement are overwritten. When analysing the dust concentration from several measuring processes, the data of each measurement must be logged. The measured values are registered by: connecting a laptop to the RS 232 interface and saving the data in a file with the help of a terminal program. printing out the values of each measurement process on a printer entering the values into the formula provided (see Appendix). 503

50 504 5 Evaluating measurements

51 6 Maintenance 6.1 Maintenance of the GS 5 filter head probe Regular maintenance In the following table the necessary maintenance work is subdivided into basic and intensive cleaning procedures. This maintenance work should be carried out at regular intervals and, where possible, also after each measurement of long duration. Task Removing of condensate residue Removal of deposits Inspection of rubber components Pt 100 temperature sensor Remarks Basic cleaning Blow-drying the partial gas and pressure sensing lines from the end of the multichannel hose using (compressed) air. Overpressure > 500 mbar must be strictly avoided. Intensive cleaning Removing and cleaning the support plate and the measuring orifice. Warning! Do not damage the sharp edges of the orifice bores. Cleaning is performed by purging or by blow-cleaning using water - air - alcohol - air. This sequence of application must be observed. Dust deposits, corrosion and similar contamination must be removed regularly from the probe, the filter head and the temperature sensor. To do so remove the support plate and orifice if necessary. Basic cleaning Clean with cloth, brush and bristle using water and then alcohol. Intensive cleaning The same method as required for basic cleaning, but preceded by cleaning with a caustic agent (caustic solution: 25% HNO 3, 2% HF, rest H 2 O). Warning! Observe work safety instructions for handling acids! After temperature loads >200 C the sealing washer in the filter head should be checked and replaced as required. The multichannel hose, particularly at the ends, must be inspected for cracks and brittle sections. If necessary, the damaged end should be cut off or the hose replaced (for advice on replacement, see Chapter 9). The temperature sensor should be checked for insulation resistance and replaced if necessary (including the temperature sensing line). Note: Blow-drying can be done using the extraction pump ("drying" menu). This is done by connecting a suitable hose to the pump outlet. 601

52 6 Maintenance Task Filter head probe safety lock Remarks Check seam for contamination or tears. Warning! The seam must not be damaged! Cleaning is performed by washing and blow-drying with water - air - alcohol- air. This sequence must be observed. Test screw thread for impurities or damages. Clean screw thread with bristle. Any damages can be carefully corrected using a triangular file Leak check To check the tightness of the sampling lines and pressure measuring lines the filter head probe should be connected to the evaluation unit. Pressure measuring lines for p, p und p (Determination of the gas velocity in the exhaust gas duct) At the pressure measuring bores p 1, p 2 und p 3 on the probe head the following test pressures are produced, by means of an injection with a shortened needle and either a pierced soft rubber screen or a rubber suction foot: Meas. variable Value Display in "Automatic" menu under p 1 ca. 10 mbar p_duct (p 10 ) p 2 and p 3 10 mbar v_duct or angle The pressure displays must remain constant for this. Pressure measuring lines for p und p (Determination of 4 5 the partial volume flow) Set the "Manual operation/volume flow" menu, turn on the pump and close the control valve with the O key. The extraction orifice should be sealed tightly on the inserted LC or HC dust collector (e.g. with the Pressure sensing line p finger cone). 5 Tightness criteria: p 45 = 0 p 40 between -200 and -500 mbar 602 If errors or implausible values appear during the leak check, the internal piping can be checked with the help of Fig Loose hose connections should be replaced (see Spare parts, section 8.4). To exchange the hose connections in the electronic unit, the front panel should be removed.

53 6 Maintenance Cooling air connector D a 13 D i 7 Free channel in multichannel hose Cooling air separator D a 13 Free channel in multichannel hose Multichannel hose connector D i 7 Shut-off valve D a 16 D i 10 M Control valve Filter PG 16 D a 13 D i 7 Condensate separator Silencer Extraction pump D a 13 D i 7 Fig Internal piping of the evaluation unit Pressure sensing line p 1 Pressure sensing line p 2 Pressure sensing line p 3 Purge air channel Purge air channel Pressure sensing line p 4 Pressure sensing line p 5 Positioning pin Extraction line Fig Probe safety lock connector on the evaluation unit 603

54 6 Maintenance 6.2 Maintenance of the evaluation unit Maintenance of the evaluation unit is basically limited to cleaning work. Gas cooler The gas cooler must be emptied after each measurement. In order to do this the condensate separator has to be unscrewed and removed from the evaluation unit (see Fig. 6201). Lid for gas cooler Gas cooler Fig Removed gas cooler Warning The relevant legal stipulations should be observed and adhered to when disposing of the collected condensate (the condensate should be handled as hazardous waste)! 604