pneumatic outflow control

Transcription

1 Technical Information pneumatic outflow control Pneumatically driven control elements for precise flow limitation of wastewater and rainwater partly filled pneumatic outflow control IDM-based fully filled pneumatic outflow control partly filled pneumatic outflow control, dry installation LDM-based partly filled pneumatic outflow control, with pinch valve IDM-based Fully filled pneumatic outflow control, with pinch valve

2 Table of contents Table of contents... 2 Areas of application... 3 Hallmarks of success... 4 Technical structure... 5 Application examples... 8 Function Self-check Example assembly sequence Advantages Technical data Theoretical overall lengths Communication interfaces contact details Pneumatic outflow control April 2019 STEBATEC AG 2

3 Areas of application the pneumatic discharge control can be used in combination with two of Stebatec s flow measurement systems, one for fully filled and one for partly filled pipes. They are mainly implemented: At the outlet side of storm water tanks and mixed water spillways for limiting the inflow into the sewage treatment plant and for activating reservoir volume. At the outlet side of road run-off treatment plants to limit the flow rates. For inlet limitation of wastewater treatment plants flow direction Pneumatic outflow control April 2019 STEBATEC AG 3

4 Hallmarks of success Pneumatic outflow controls are important components in the dynamic control, operation and monitoring of sewer networks. The throttle value can be variably parameterised/adjusted in the entire outflow spectrum The control can be controlled remotely and is compatible with all commercially available process control systems. Enables the dynamic control of sewer networks. Measures the flow rate with a maximum deviation of 1% from the measured value, regulates with high precision within the shortest reset times and without running time limitation. Combined flow measurement and control system including a flow calming section with minimum space requirement Detects accumulation of deposits and discharges it in a targeted manner (rinsing shock function, bed load discharge, etc.) In the event of a power failure an emergency program continues throttling Allows partly filled operation and prevents deposits Is easy to maintain and can be dismantled/opened for cleaning without tools Works with a standardized, mature control program The units come in dry or wet installation pneumatic outflow control Pneumatic outflow control April 2019 STEBATEC AG 4

5 Technical structure Control valve combined with full flow measurement example of a suspension adaption cable with protective conduit valve flange bolts Valve open spring for pressureless opening lifting bags rope suspension point drain collar splash guard Valve closed IDM-controlled discharge control with pinch valve connection to building flow measurement service lid pinch valve connection to pipe coupling Pinch valve open/closed Pneumatic outflow control April 2019 STEBATEC AG 5

6 Wet-installed flow control with partly filled flow measurement flow measurement with electronics handle gas spring dry weather gutters Valve open pneumatic drive rope suspension point sensor cover valve Valve closed Pneumatic outflow control April 2019 STEBATEC AG 6

7 Dry-installed flow control with partly filled flow measurement service lid inlet Service lid outlet control valve Service lid open level measurement enclosure Connection to pipe coupling Service lid closed LDM-controlled pneumatic flow control with pinch valve level measurement service lid LDM pinch valve Pinch valve open/closed Pneumatic outflow control April 2019 STEBATEC AG 7

8 Application examples Wet-installed flow control with partly filled flow measurement The wet-installed, partly filled pneumatic outflow controller with normal constructon length. Shortened construction where the calming section on the inlet-side was built into the wall and in the room before it. Exemplary channel formation in the inlet of the flow controller where the channel shape is already transformed to rectangular a few meters before the throttle section. Pneumatic outflow control April 2019 STEBATEC AG 8

9 Dry-installed flow control with partly filled flow measurement Pneumatic outflow control April 2019 STEBATEC AG 9

10 Function The pneumatically driven valve ensures full filling of the IDM (if present), throttles the flow rate to an adjustable maximum value and ensures self-cleaning of the flow measurement by means of a flushing impulse. When the pneumatic drive is inflated, the valve is closed via a lever axis. In the depressurized state, the valve remains open without counterpressure. full fill control With dry weather and the flow falls below the throttle value, the system switches to automatic full fill control (if function is activated). Controlled by the signal of the integrated level measurement, the control valve opens only so far that the sensor is always fully filled. This way, the sensor (magnetic-inductive flow measurement for full filling) provides highest measuring accuracy. full fill level Both versions in combination with fully filled IDMs automatically keep themselves fully filled - the illustration above with a control valve and below correspondingly with a pinch valve. full fill level quantity regulation As soon as the parameterised maximum outflow/throttle quantity is reached, the system automatically switches into flow control. The control is controlled according to the signal of the flow measurement and limits the flow rate accordingly. Pneumatic outflow control April 2019 STEBATEC AG 10

11 Emergency operation in case of power failure and device malfunction The pneumatic outflow control has different ways to respond in case of emergency. These will be defined together with the corresponding sales engineer. Emergency choke In a powerless state, the valve normally would be open. This may not be suitable in some applications as the throttle value could not be maintained in such a situation. In the event of a power failure, the emergency throttle short circuits the pressure cushion on the controller with the pressure vessel on the compressor via a pressure reducer. The setting of the pressure reducer defines the cushion pressure in case of emergency. The setting are definded situatively - we are happy to support you. Flushing impact for deposit prevention The system is equipped with a self-cleaning function (flushing impulse) in order to counteract deposits, which can partly be caused by the basic backlog of the full fill regulation, or also to bring "dynamics" into the sewer network. The valve is closed at adjustable intervals and a surge flush is generated by the subsequent rapid opening of the valve. Partial fill mode The partial fill mode is permanently activated for versions with partly filled flow measurement. When the maximum flowquantity is reached, the system automatically switches into flow control. In the version with electromagnetic flow meter (IDM), the control valve automatically keeps the system fully filled. This leads to a basic congestion in the pipes upstream from the IDM. On the contrary, the partial fill mode allows the control valve to remain open during dry weather and only switch to full fill and volume control mode when the water level rises. Without a basic congestion, the risk of possible deposits in the canal system disappears. If the IDM is to be used again later, the partial fill mode can simply be suppressed by a click in the user interface of the controller. Pneumatic outflow control April 2019 STEBATEC AG 11

12 Self-check The pneumatic discharge control works according to three reference signals, these are flow rate (flow measurement), water level and pneumatic counterpressure in the pressure cushion. The ratios between these three references must always be within a defined limit; otherwise the system will change its state: If the water level is too high in relation to the flow rate and counterpressure in the cushion, deposits in the area of the control valve are assumed = valve opens briefly. If the back pressure in the cushion increases, but the flow and water level remain constant, the valve may be jammed by debris = valve opens briefly. Pneumatic outflow control April 2019 STEBATEC AG 12

13 Example assembly sequence The assembly sequence shown here using the example of a partly filled pneumatic outflow control also applies analogously to the fully filled pneumatic outflow control. Lowering of the pneumatic control through the entrance into the shaft using ropes. Place the device horizontally above the previously mounted suspension adapter and lower it until the upper edge of the wedge plate is flush with the suspension adapter. The support legs of the control unit have been adapted to the channel during initial installation so that, in the end, the unit is positioned horizontally. Pneumatic outflow control April 2019 STEBATEC AG 13

14 Advantages Reliability The uncomplicated system design and the use of suitable materials ensure safe and long-lasting operation. Control accuracy The control valve is arranged immediately after the flow measurement, so that it reacts quickly to flow changes and can also maintain the programmed control value within the smallest deviation. In comparison to a plate gate valve flow control, the rule of thumb of 1 to 10 can be applied: While a plate gate valve can approach 100 individual positions in stages, the pneumatic outflow control creates at least 1000 individual positions thanks to the infinitely variable pressure control - which is the basis for the high control accuracy. Ease of maintenance The devices are designed in such a way that the flow inside of them is laminar which allow for solids and bedloads to be discharged in a targeted manner. This results in an extension of the maintenance intervals. The suspension adaptation (for wet-installed systems) and the maintenance opening (for closed systems) facilitate maintenance considerably. The screwless design fits snugly, eliminating the need to align the unit after installation. cost reduction In many applications, pneumatic outflow control can be used without or, compared to other systems, with fewer structural adjustments, reducing overall costs. Pneumatic outflow control April 2019 STEBATEC AG 14

15 Technical data measuring range: 0, l/s (depending on the system nominal diameter) control range: from 0,2 l/s nominal diameters: 200 mm 1500 mm materials: Polypropylen; Metall V2A or on request gasket material: EPDM temperature: 0 45 C ph range: 6 9 degree of protection: IP 68 compressed air supply: Compressor with automatic dewatering power supply: max. 13A 230VAC Theoretical overall lengths Partly filled wet installed construction method NW Total length with valve open Total length with valve closed Overall length with shortened design and open valve width height Additional space is required for the slider in front. Other sizes, shortened versions and solutions for special hydraulic conditions on request. Pneumatic outflow control April 2019 STEBATEC AG 15

16 Partly filled dry installed construction method NW overall length Overall length with shortened construction method width height Additional space is required for the slider in front. Other sizes, shortened versions and solutions for special hydraulic conditions on request. Pinch valve with fully filled flow measurement NW overall length Overall length with shortened construction method width height Pneumatic outflow control April 2019 STEBATEC AG 16

17 Control with fully filled flow measurement NW Total length with valve open Total length with valve closed Overall length with shortened design and open valve width height Additional space is required for the slider in front. Other sizes, shortened versions and solutions for special hydraulic conditions on request. Pneumatic outflow control April 2019 STEBATEC AG 17

18 UFM-controlled pneumatic flow control with pinch valve NW overall length Overall length with shortened width height construction method With a constant cross-section and slope of the inlet pipe a shortened design with service cover can be used. Communication interfaces Standard with modem for use of all mobile networks up to 4G/LTE, Fixnet Internet connection and VPN technology signal outputs: signal inputs: communication: 4 20 ma: Instantaneous flow rate and set control value Digital (active/passive): quantity counter and 2x malfunction 4 20 ma: Target control value Digital (floating): OPEN (Remote); CLOSE (Remote); AUTOMATIC; MANUAL START CLEANING; RS485 (Modbus RTU/ASCII), RS232, Ethernet (Modbus TCP) Connection via Internet/VPN. VPN connection for remote maintenance with STEBATEC (Internet connection necessary) Wiring diagram on request Pneumatic outflow control April 2019 STEBATEC AG 18

19 NEW! The pneumatic flow control system includes a touch display with zoom and wipe functions, as well as a data logger and a local browser process control system which can be accessed within the local network or on request from the Internet. contact details STEBATEC AG Mattenstrasse 6a CH-2555 Brügg Tel. +41 (0) Fax +41 (0) info@stebatec.ch Pneumatic outflow control April 2019 STEBATEC AG 19