HYDRAULICS. H89.8D - Hydraulic Bench

Transcription

1 HYDRAULICS H89.8D - Hydraulic Bench 1. General The H89.8D and ancillary equipment have been developed to provide a comprehensive range of experiments in fluid mechanics. The bench is of robust construction and all wetted surfaces are of corrosion resistant material for long and trouble free use. The unit is self-contained and requires only the electrical supply. The unit is supplied with manuals which describe all parts of the trainer, the installation and utilization procedures, as well as many exercises with the relative results. Basic hydraulic bench (Code ) The bench consists of a trolley-mounted steel frame bearing on top a drainage tray with a suitable flat working surface. A reservoir with calibrated orifices enables continuous measurement of water flowrate. Water is delivered to the bench by a motor-driven pump or by mains. It is possible to determine the mechanical characteristic of the pump by varying the flowrate. DIDACTA Italia S.r.l. - Strada del Cascinotto, 139/ Torino - Italy Tel Fax info@didacta.it

2 2. Composition The bench includes: Trolley-mounted frame Electric centrifugal pump: - power: 0.37 kw - speed: 0 to 2900 rpm by inverter - flowrate: 1.6 to 4.8 m 3 /h - head: 13.3 to 9 m H 2 O Feeding tank: 60 l capacity Graduated reservoir with calibrated outflow Vacuum/pressure gauge: -1 to 3 bar Electric control board fitted with: - Circuit breaker and differential switch - Potentiometer for electric pump speed regulation - Digital rpm meter On request, the following other versions of the hydraulic bench can be supplied: Code Hydraulic Bench with Fixed Speed Pump Same as Code , but with fixed speed pump and following composition: Trolley-mounted frame Electric pump: - power: 0.37 kw - speed: 2900 rpm - flowrate: 1.6 to 4.8 m3/h - head: 13.3 to 9 m H2O Feeding tank: 60 l capacity Graduated reservoir with calibrated outflow Vacuum/pressure gauge: - 1 to 3 bar Motor protection switch Code Hydraulic Bench with Transparent Variable Speed Pump Same as Code , but with transparent pump cover for visualization of cavitation phenomena. Code Hydraulic Bench with Transparent Fixed Speed Pump Same as Code , but with transparent pump cover for visualization of cavitation phenomena. Code Hydraulic Bench with Feeding from Mains Same as Code , but with hydraulic feeding from mains and following composition: Trolley-mounted frame Feeding tank: 60 l capacity Graduated reservoir with calibrated outflow Pressure gauge. 3. Experimental units HYDRODYNAMICS KIT (Code ) Completely made of transparent plexiglas, this kit has been designed for a quick assembly of three different apparatuses: Orifice tank This apparatus consists of a cylindrical tank allowing to determine the flow characteristics through two different orifices and to trace the trajectory of a horizontal jet under different conditions of flow speed and head. Impact of jets This apparatus consists of a cylindrical tank in which a water jet coming out from a nozzle hits a baffle. The reaction force is measured by an arm balancing device. Three different types of baffle are supplied: cup, flat and 45. Hydraulic ram This apparatus has been designed to demonstrate a typical system to pump water. A large quantity of water falling from low head is used to raise a small quantity of water to a higher head. Page 2

3 KIT TO STUDY THE BERNOULLI S THEOREM AND IMPLICATIONS (Code ) Completely made of transparent plexiglas, this kit has been designed for a quick assembly of three different apparatuses: Bernoulli s apparatus This apparatus allows to study and demonstrate Bernoulli s theorem. The equipment comprises two graduated vessels connected by a convergent-divergent tube. Piezo tubes allow to show the typical head distribution. Moreover, it is possible to visualize the Osborne-Reynolds experiment. Flow through Venturi This apparatus is a convergent-divergent tube allowing to study a Venturi tube and to observe the degree of pressure recovery at the end of the divergent section. Friction loss in pipes This apparatus allows to study the head loss in pipes of different diameter and with sudden change of section. SET OF BENDS, VALVES AND CONNECTIONS (Code ) The set allows to determine losses in various profile pipe bends, valves with different characteristics and connections. Losses are visualized on the piezo tubes supplied with the kit Code HYDROSTATIC KIT (Code ) Completely made of transparent plexiglas and corrosion resistant material, this kit allows to carry out the following experiences: Stability of a floating body This apparatus allows to study the stability of a floating body. A rectangular pontoon is fitted with a bar on which a sliding weight can be used to indicate the angle of heel on a graduated scale. The centre of gravity can be varied in order to check the effect on the stability conditions. Metacentric height Centre of pressure The determination of the metacentric height is obtained by graphical analysis of the pontoon tilting angles for various positions of the centre of gravity. The determination of the centre of pressure is easily performed with a toroidal sector. APPARATUS FOR PRESSURE GAUGE CALIBRATION (Code ) This apparatus can be used to calibrate the pressure gauge supplied with the basic hydraulic bench or other pressure gauges of similar characteristics. It consists of a stainless steel plunger with a weight carrier and a set of weights. WEIR TANK (Code ) The apparatus consists of a transparent plexiglas tank with still compartment, designed for mounting weirs. As standard, we supply a rectangular weir and a triangular weir as well as a depth gauge (0-210 mm scale, 1 mm resolution) for the measurement of the water surface.

4 VORTEX APPARATUS (Code ) General The apparatus can be easily connected to the Basic Hydraulic Bench H89.8D or self-sufficient with hydraulic feeding from mains and allows to study both free and forced vortices. It is possible to create a forced vortex putting a fixed amount of water into a cylindrical vessel, rotating by means of a variable speed DC motor. In order to create a free vortex we place a second transparent vessel inside the main tank thus creating an annulus. Flowing the water inside the annulus, the water passes through the large number of holes and forms a number of spirals which form a surface falling towards the center. An air core is produced in the center. The fitted instruments allow to measure the surface profile and the speed and head of the water in the different points. The apparatus is supplied with user s manual and exercise book. Composition and Description The apparatus consists of the following components: External transparent rotating tank, diameter 400 mm, height 200 mm Internal transparent perforated tank, diameter 300 mm, height 200 mm Low voltage, variable speed DC motor Electrical Supply and Control Unit No.2 axes with linear scales graduated in mm to measure the water surface profile Pitot probe with integral transparent tube to measure the head variation. Topic Experiments Determination of the surface profile of a free vortex Determination of the surface profile of a forced vortex Determination of the head variation in a free vortex Determination of the head variation in a forced vortex Comparison between experimental and Theoretical values SERIES AND PARALLEL CENTRIFUGAL PUMPS TEST SET (CODE ) The apparatus consists of a fixed speed pump, 0.37 kw power 2900 rpm speed, which can be connected to the bench feeding pump both in series and in parallel by means of a hydraulic circuit fitted with valves. Two flowmeters, placed at the delivery of both pumps, allow for the direct reading of the flow rate of each pump; besides, additional mano vacuum meter and manometer allow, by means of fast connections, for the measurement of the delivery and suction pressure of the pump itself. The series and parallel connection of two centrifugal pumps can be studied. PELTON TURBINE (Code ) The apparatus consists of a Pelton turbine of reduced dimensions made of AISI 304 stainless steel, mounted on bearings and fitted with nozzle. The Pelton turbine develops a power of about 10 W and the front part is transparent so as to allow for the visualisation of the flow. The water inlet pressure is measured by means of a Bourdon gauge placed at the inlet of the nozzle (range bar). The speed of the turbine is measured by means of a portable digital tachometer, while the torque is measured by means of two spring dynamometers with scale 0-10N (0.1 N division). Page 4

5 FRANCIS TURBINE (Code ) The apparatus consists of a Francis turbine of reduced dimensions made of AISI 304 stainless steel, mounted on bearings. The Francis turbine develops a power of about 3 W and the front part is transparent so as to allow for the visualisation of the flow. The water inlet pressure is measured by means of a Bourdon gauge placed at the inlet (range 0-1bar). The speed of the turbine is measured by means of a portable digital tachometer, while the torque is measured by means of two spring dynamometers with scale 0-10N (0.1 N division). BASIC HYDRAULICS SOFTWARE (Code ) The basic hydraulics software for H89.8D makes it possible to flank the theoretical notes with a wide range of exercises for the study of basic hydraulics. The software runs in the MS-Windows environment and makes it possible to perform practical exercises on the basic bench and its optional kits with the aid of a Personal Computer. The experimental data obtained from each exercise are entered manually by the user and are processed by the software, which creates charts that can be displayed on screen, saved and printed. Minimum PC configuration required PC minimum Pentium with HD >10Gb, CD drive, graphic card SVGA minimum, mouse, 32MB RAM, USB port Windows XP or later versions. Graphic printer. The following equipment can also be supplied from the Basic Hydraulic Bench H89.8D. For technical characteristics, please see the separate catalogue. H53D FLOW MEASUREMENTS Made of transparent material, the unit allows to study different types of devices for flowrate measurements (Venturi meter, calibrated orifice, rotameter) and their comparison. It allows to study head losses due to sudden section widening and restriction. It is available in two versions: Code Hydraulic feeding from Bernoulli Kit Code Self-sufficient with hydraulic feeding from mains. H65D OSBORNE-REYNOLDS APPARATUS (Code ) The apparatus allows to visualize laminar and turbulent flow, introducing the students to the importance of Reynolds number in fluid mechanics. It can be supplied both from H89.8D and from mains.

6 H130D MASS OSCILLATIONS AND WATER HAMMER STUDY UNIT The unit allows to study the mass oscillations and the water hammer. It is available in two versions: Code Hydraulic feeding from H89.8D. Code Hydraulic feeding from mains. H139D - CAVITATION DEMONSTRATION UNIT (Code ) This unit is designed to demonstrate to students the phenomenon of Cavitation and its association with the Vapour Pressure of a liquid. Water can be supplied from mains. 4. Exercises Determination of the characteristic curve of a centrifugal pump, that can be performed with the basic bench. Study of flow through holes can be performed with the hydrodynamic kit. Study of the impact of jets can be performed with the hydrodynamic kit. Study of the phenomenon of the water hammer can be performed with the hydrodynamic kit. Study and demonstration of Bernoulli s theorem can be performed with the Bernoulli kit. Study of flow through a Venturi tube can be performed with the Bernoulli kit. Study of pressure drops in a tube can be performed with the Bernoulli kit. Study of localized pressure drops can be performed with the set of bends, valves, connections. Study of the stability of a floating body can be performed with the hydrostatic kit. Determination of the meta-centric height and the pressure centre can be performed with the hydrostatic kit. Calibration of a pressure gauge can be performed with the ad hoc calibration equipment. Study of flow through weirs can be performed with the weir tank. Study of vortices can be performed with the apparatus for the study of vortices. Study of the measurement of flow can be performed with the flow measurement unit H53D code Study of the water hammer can be performed with the water hammer study unit H130D code Study of the phenomenon of cavitation can be performed with the cavitation demonstration unit H139D code Required services Vortex Apparatus - Code Water supply 8 l/min or from Didacta Hydraulic Bench H89.8D Electrical Power Supply single phase 220/240 V AC, 50/60 Hz 6. Weight and dimensions H89.8D - Hydraulic Bench single phase 220/240 V AC, 50/60 Hz; 0,5 kw Vortex Apparatus - Code H89.8D - Hydraulic Bench Dimensions mm 750 x 750 x 500 h 1000 x 730 x 1100 h Weight kg Cod. R00575/E 0313 Ed. 01 Rev. 05 In any time and without notice, Didacta Italia can carry out any appropriate modification on the product details, always maintaining their main features, according to the designing and teaching necessity. Page 6