LRH Manual - US Vacuum Pumps
Contents
1. 19 13 Sectional Drawings amp Parts List 1 kkkkkkkkkkkkkkkkkkkkkkkkkkkk US Vacuum Pumps LLC CONGRATULATIONS on your purchase of a new Liquid ring Vacuum Pump from US VACUUM Please examine the pump for shipping damage and if any damage is found report it immediately to the carrier If the pump is to be installed at a later date make sure it is stored in a Clean dry location and rotated regularly Make sure covers are kept on all openings If pump is stored outdoors be sure to protect it from weather and corrosion LRS vacuum pumps are built to exacting standards and if properly installed and maintained will provide many years of reliable service We urge you to take time to read and follow every step of these instructions when installing amp maintaining your pump WARNING Serious injury can result from operating or repairing this machine without first reading the service manual and taking adequate safety precautions IMPORTANT Record the pump model and serial number in the OPERATING DATA form below You will save time and expense by including this reference information on any replacement parts orders OPERATING DATA It is to the user s advantage to have the requested data filled in below and available in the event a problem should develop in the vacuum pump This information is also helpful when ordering spare parts Model No Sealing Fluid Serial No2. on the seal housing Slide the shaft and the bearing housing with gasket through the discharge casing ref 107 secure it in place with four allen screws ref 914 1 Be sure to locate the seal housing draining hole pointing to the bottom Position the pump vertically resting on the bearing housing Fit on the shaft the key ref 940 1 of the impeller ref 230 Introduce the impeller on the shaft making sure that the orientation of the impeller blades are pointing in the direction of rotation Make sure the shaft key way is not worn to insure a tight fit of the key into the keyway Place a gasket ref 400 on the pump discharge casing Fit the intermediate plate ref140 with particular attention not to damage the radial seal ring ref 421 and placing the reference marking pointing to the casing connection then place a gasket ref 400 on the sealing face of the intermediate plate Fit on the shaft the other keys ref 910 1 of the first stage impeller ref 230 Introduce the impeller on the shaft to set the blades as the second stage impeller ref 230 1 Place the suction casing ref 106 on the pump Introduce the three tie bolts ref 905 leaving the nuts finger tight Place the pump on a flat and horizontal table align all the pump components and tighten the tie bolts to 29 foot pounds 4kgm using a torque wrench Ascertain that the shaft shoulder is 35 5 mm 0 5mm deep relative to the external face of the suction casing ref 10
3. the pump capacity increases and at higher temperatures the pump capacity decreases The temperature efficiency ratio is not linear and the most profound effect in terms of percentage of change is at low pump pressures Most pumps are recommended to utilize a water flow orifice which regulates the amount of water flow if at least 15 PSI water pressure is supplied PROCEDURE FOR MINIMUM SEAL WATER REQUIREMENTS The requirements for seal water as shown in out specifications are the maximum GPM for any application To determine the minimum quantity of seal water required for a specific application proceed as follows Lower the pump suction pressure to between 50 150 mm Hg abs To steady the pressure with in this range bleed air into the suction of the pump and adjust this air until the pressure level remains constant within the range of 50 150 mm Hg With the pressure level steady slowly decrease the flow of seal water into the pump until the pressure begins to fluctuate and then gradually increase the flow until the pressure again becomes steady and this is the setting to allow the minimum seal water flow CAVITATION Cavitation is recognized as a metallic noise in the pump when the pressure is low and the air flow is slight When this occurs slowly bleed air into the pump through the cavitation valve until the noise disappears Bleeding air into the pump suction will also eliminate this noise but a rise in pressure will occur STARTING
4. Operating Vacuum Startup Date Inlet Gas Composition Motor Hp Hp Accessories supplied NOTES GENERAL UNPACKING Inspect the box and pump carefully for any signs of damage incurred in transit and report with in 7 days of receipt Since all our pumps are shipped F O B our factory such damage is the responsibility of the carrier and reported to them The inlet amp exhaust of the pumps are covered with plastic caps to prevent dirt and other foreign substances from entering the pump Leave the caps in place until you are ready to pipe the pump to your equipment The pumps are tested and preserved with a water soluble preservative prior to shipment As the pump cannot be completely drained some of the preservative remains in the pump when shipped This solution should be flushed from the pump if it is to be used on a closed system where other than water is used LOCATION Install the pump in a horizontal position on a level surface so that the pump is evenly supported on it s steel baseplate Leave 12 18 of access around the pump to allow proper access for maintenance If the unit is provided as an AIR COOLED system allow for proper air circulation around the radiator When selecting a location for the pump one consideration should be that the pump liquid must not be allowed to freeze POWER REQUIREMENTS A schematic diagram for the electric motor terminal box is located either inside the junctio
5. body ring s plate s and impeller if necessary 12 Remove DE bearing cover and shaft locking nut 13 Remove DE bearing and mechanical seal housing 14 Remove DE shoulder ring from shaft 15 Remove mechanical seal 16 Slide shaft and impeller from DE casing 17 Remove keyed impeller from shaft Use a flat file to detect and remove burrs from the impeller s ends before reassembly 20 DISASSEMBLY AND REASSEMBLY CONT REASSEMBLY 1 10 Place the shaft ref 210 vertically into the vice with the drive end pointing down Moisten the rotating part of the mechanical seal ref 433 1 with soapy water water NO OIL and fit onto the shaft Lubricate the O ring of stationary seal part ref 433 1 and press the latter into the seal housing ref 357 Clean the two faces of the mechanical seal with soft tissue Insert the seal housing on to the shaft and hold it pushing the mechanical seal down Introduce onto the shaft the spacer ref 505 having a thickness of 2mm Place the wafer spring ref 935 in the bearing housing Heat the bearing and fit it on the shaft pushing down until it comes to rest against the spacer Lock the bearing on the shaft with the snap ring ref 932 Place on the bearing housing the bearing cover ref 365 1 With the help of a gear puller press the bearing cover and the wafer spring so that the snap ring ref 932 3 comes to rest in it s groove then remove the gear puller Place the gasket ref 400 2
6. carryover from the process can reach the pump If this possibility exists a knock out liquid separator should be installed contact U S Vacuum for recommendations If an exhaust manifold is used install a drip leg near the pump exhaust port and drain to prevent exhaust conden sate from entering the pump exhaust box INTRODUCTION Models covered by this manual This manual contains installation and maintenance procedures for LRH 45 to LRH 850 The nameplate on the pump provides a letter coding for pump material of construction Nameplate Data Example LRH 850 FB The first letters LRH designate Liquid Ring High vacuum pump The number designation represents nominal pumping capacity in CFM at 60Hz operation example 850 cfm The letters after the pumping capacity represents the pump material of construction The first letter represents the casing amp endplate construction with the second letter representing the impeller construction Cast B Bronze S Stainless steel 316 Suitable Applications U S Vacuum Liquid Ring Vacuum Pumps LRH are reliable non pulsating pumps LRH are two stage Configuration suitable for operation down to 30 Torr absolute approx 29 inches Hg vacuum reference 30 inch barometer when sealed with 60 Deg F water Specifications Model LRH Speed Drive Standard Motor 3 60 230 460V Sealant Liquid required 60 deg F NO recovery Sealant Liquid required 60 deg F Parti
7. only be disassembled to the extent necessary Begin disassembly from Non drive end and begin reassembly with the drive end Gaskets between cylinder Casings can be held in place during assembly with grease In an emergency casing gaskets can be made from kraft paper which can be obtained locally The smaller pumps can be disassembled and reassembled on a bench by standing the pump on the drive shaft end with the shaft extending down through a hole in the bench top The larger pumps should be disassembled and reassembled in the horizontal position It is necessary to support the cylinder casing sections with blocks in order to hold sections in place while the tie rods are removed or inserted and all sections drawn together when assembling Before tightening the tie rods the pump should be placed on a flat surface with each leg sup porting a substantial amount of the pump s weight DISASSEMBLY The following steps are to be taken to disassemble the pump 1 Drain as much liquid from the pump as possible 2 Mark necessary parts to insure correct reassembly and alignment in that all surfaces are joined and aligned as before 3 Remove bypass 4 Remove bearing cover 5 Remove bearing nut 6 Remove bearing amp mechanical seal housing 7 Remove mechanical seal 8 Remove delivery casing Note when NDE casing is unsealed water will rush out of the pump 9 Unscrew tie bolts amp remove 10 Slide NDE casing from shaft 11 Remove middle
8. seal c c w Plug Manifold Mechanical seal c w j Plug Shaft Mech seal locking ring Plug Impeller Shoulder ring Tie bolt Impeller Spacer sleeve Nut Ball bearing Seal bush A3 only Nut Bearing Seal housing Grease nipple Bearing cover Fitting Bearing cover Screw Recommended spare parts WARRANTY VACUUM PRODUCTS Subject to terms and conditions hereinafter set forth and set forth in General Terms of Sale US Vacuum Pumps LLC the seller warrants products of its manufacturer when shipped and its work including installation amp start up when performed will be of good quality and will be free from defects in material and workmanship This warranty applies only to sellers equipment under use and service in accordance with seller s written instructions recommendations and ratings for installation operating maintenance and service of prod ucts for a period if 12 months Because of varying conditions of installation and operation all guarantees of performance are subject to plus or minus 5 variation THIS WARRANTY EXTENDS ONLY TO BUYER AND OR ORIGINAL END USER AND IN NO EVENT SHALL THE SELLER BE LIABLE FOR PROPERTY DAMAGE SUSTAINED BY A PER SON DESIGNATED BY THE LAW OF ANY JURISDICTION AS A THIRD PARTY BENEFICIARY OF THIS WARRANTY OR ANY OTHER WARRANTY HELD TO SURVIVE SELLER S DIS CLAIMER All accessories furnished by seller but manufactured by others motor will bear only that manufacturer s standard warranty All
9. suction pressures Excessive pressure build up could cause damage or injury Accidental starting or operation of the pump while maintenance is in progress may cause injury or damage e Lift only with the frame mounted eyebolts WARNING THE BELTGUARD OR COUPLING GUARD MUST BE PROPERLY SECURED IN PLACE AT ALL TIMES WHILE THE PUMP IS RUNNING CAUTION DO NOT OPERATE THE PUMP DRY MAKE SURE COOLING LIQUID IS AVAILABLE TO THE PUMP amp SEALS DO NOT ALLOW SEALANT LIQUID TO FREEZE IN THE PUMP DISCHARGE PIPING SHOULD NOT EXCEED 24 INCHES ABOVE THE DISCHARGE FLANGE SUCTION MANIFOLD MUST BE FREE OF WELDING SLAG DO NOT START THE PUMP WITH SEALANT LEVEL ABOVE SHAFT CENTERLINE TABLE OF CONTENTS 1 Safety Page 2 PARETI 6 7 4 SPECHICAHONGr 8 5 System COMPORENIS sers ie xe dune Ua nemo ie abe Pure Page 9 6 Principle of Operations egeo o eese Page 10 7 Seal Water Page 11 8 Properties of Page 12 9 Type of Sealant Page 13 1 14 11 Disassembly amp Page 17 12 Trouble shooting
10. 130 Shaft Bearing 145 140 Mechanical Seal 15 Manifold 16 Impeller Shaft 17 Drive Key 18 Ist Stage Key 19 2nd Stage Key Ch On B wn Pumping Capacity Absolute Pressure Torr 160 110 80 60 40 30 25 Vacuum Hg Hg 23 6 25 6 26 8 27 5 28 3 28 7 28 9 Pump Model LRH 45 LRH 75 LRH 100 LRH 140 LRH 200 LRH 250 LRH 300 LRH 400 LRH 500 LRH 850 18 MAINTENANCE GENERAL Elementary rules of cleanliness periodic inspections and a preventative maintenance policy of the pump will produce optimum performance and prolong the life of the pump SHAFT BEARINGS The two shaft bearings should be lubricated every 3000 hours of operation Grease should be added through the Zirks while the shaft is turning The temperature of the bearings should not exceed 140 Deg F too much grease will cause the bearings to overheat Some pumps are supplied without external grease fittings these pumps have permanently packed bearings MECHANICAL SEALS The pump come with mechanical seal s as a standard component with Viton elastomers No seal adjustment is required STORAGE If the pump is to be idle for an extended period of time the interior must be preserved by circulating a water soluble rust inhibitor through the pump with ports sealed Rotate the pump by hand periodically 19 DISASSEMBLY AND REASSEMBLY It is seldom that pumps require complete disassembly and they should
11. 6 Lubricate the seal rotating part soapy water water NOT OIL and fit it on the shaft Lubricate the O ring on the stationary seal and press this part in the seal housing ref 357 Place gasket ref 400 on the seal housing and fit this on to the suction casing ref 106 with draining holes located at the bottom Lock the assembly with 4 screws ref 914 1 Introduce on the shaft the 2mm spacer ref 505 Fit the heated bearing ref 320 on the shaft until it rests against the spacer Place the snap ring ref 932 on the shaft Install the bearing cover ref 365 securing it with the snap ring ref 932 3 Fit the coupling key ref 940 on the shaft drive end If required mount the manifold ref 147 on to the flanges of the suction casing ref 106 and discharge casing ref 107 with gaskets ref 400 8 between the flanges Secure with flange bolts ref 901 8 Rotate the pump shaft by hand to ascertain that it rotates free without internal metal contact Test the pump to a hydrostatic pressure of 60 psi to verify that there are no leaks 21 TROUBLESHOOTING CONDITION CAUSE REMEDY Seals leaking Seal incorrectly installed Re install seal Seal worn or damaged Replace seal Reduced capacity Rotational speed too low Check supply voltage Excessive noise Vacuum leak Locate and repair High sealant temperature Check coolant flow and temperature Check heat exchanger cleanliness Incorrect sealant flow rate Defecti
12. LRH SERIES TWO STAGE LIQUID RING VACUUM PUMPS Models LRH 45 75 100 140 200 250 300 400 500 850 INSTALLATION OPERATION MAINTENANCE MANUAL WARNING DO NOT OPERATE BEFORE READING MANUAL US VACUUM PUMPS LLC P O BOX 909 CANTON TX USA 75103 TEL 888 416 7366 FX 877 416 7599 EMAIL USVACUUM EARTHLINK NET WWW USVACUUMPUMPS COM FORWARD This manual contains installation operation maintenance and troubleshooting information for the Model LRH 45 LRH 75 LRH 100 LRH 140 LRH 200 LRH 250 LRH 300 LRH 400 LRH 500 LRH 850 Liquid Ring Vacuum Pumps Please read it in its entirety before operating the pump Our Liquid Ring Vacuum Pumps are designed to ensure safety when used properly It is the responsibility of the user to follow safety related warnings cautions notes and other requirements described in this manual Returned equipment will not be accepted by our company without prior authorization Prior to shipping please call for a returned goods authorization number RGA Our company reserves the right to cancel the warranty if the pump is disassembled without authorization if pump fluids are used that are not compatible with the design and materials used in the manufacturer of the pump and if unauthorized spare parts are used SAFETY INSTRUCTIONS FOR LIQUID RING VACUUM PUMPS Please read the following safety information on this page before operating your vacuum pump Do not operate the pump without the
13. THE PUMP If the pump has been idle for an extended period of time it is advisable to turn the pump over by hand prior to energizing the motor to determine that the impeller is free to turn Some conditions to consider are 1 has the pump been idle for an extended period of time and not properly preserved or 2 have repairs or alterations caused the piping to be disconnected thus the possibility of harmful objects entering the pump If the shaft can not be turned loosening the tie rods may free the impeller Tighten the tie rods when impeller is free Lightly tap the pump body with a soft faced hammer if scale build up is obstructing the impeller The water level must be no higher than the pump shaft when starting the pump in order to prevent overloading the pump and motor The cavitation valve is convenient for lowering the pump liquid to shaft level however this method may be too time consuming and if so a drain cock should be provided on the seal water piping CAUTION THE PUMP MUST NOT BE RUN DRY STOPPING THE PUMP e Isolate the pump from the system e Shut off the seal water supply e Stop the pump amp bleed off excess water 17 Suction Ist Stage Suction Disc Ist Stage Impeller Ist Stage Cylinder Ist Stage Discharge Disc 2nd Stage Suction Disc 2nd Stage Impeller 2nd Stage Cylinder 2nd Stage Discharge Disc 10 Discharge Cover 11 110 Bearing amp Mechanical Seal Housing 125 120 Bearing Covers 135
14. al recovery Sealant Liquid connections Inlet Outlet Length Width Height Weight 75 100 140 200 250 300 400 500 850 1750 1200 Direct 7 5 7 5 10 15 20 25 40 50 75 15 18 5 30 37 56 7 9 9 10 22 13 13 14 19 27 34 34 38 84 1 5 1 75 2 2 5 3 5 4 5 4 5 5 11 6 7 8 10 13 17 17 19 42 1 2 1 2 1 2 1 1 1 1 1 4 1 1 4 1 1 2 1 1 2 2 3 4 16 22 21 73 23 15 25 91 26 73 29 09 30 66 33 35 36 70 42 05 6 29 9 84 9 84 9 84 11 81 11 81 11 81 13 98 13 98 16 14 8 82 12 60 16 42 16 42 20 35 20 35 20 35 23 98 23 98 31 18 156 156 209 295 315 332 513 557 1091 System Components The following are some of the components available for installation either when the pump is ordered or later to be installed in the field Inlet elbow Used to adapt vertical pump inlet to horizontal for mounting inlet check valve etc A similar elbow may be used to connect the discharge separator tank Inlet vacuum gauge Used to measure pump inlet vacuum Standard 2 1 2 and optional 4 dial gauge has brass bourdon tube and reads 0 30 Hg The gauge is mounted on the pump suction Stainless steel vacuum gauges are available at additional cost Inlet check valve Used to automatically isolate the pump from the process chamber when the vacuum pump is shut down by blocking the backflow of air and sealant Valve m
15. ater and discharges it through a separator tank to drain without re circulation This arrangement is most common on small pumps in installations where water conservation is not a factor or where contamination of sealant may be a problem PARTIAL SEALANT RECOVERY Figure 3 page 11 This arrangement has the pump discharging water and gas into a gas liquid separator tank where the gas water mixture is separated releasing the gas to atmosphere and retaining the water Some water is disposed of through an overflow and the remainder is retained in the separator tank for re circulation A small continuous amount of sealant is added in quantity necessary to maintain the operating pressure This is the most commonly used arrangement where sealing liquid conservation is required FULL SEALANT RECOVERY Figure 4 page 11 This arrangement is similar to Partial Recovery the difference being that incoming make up sealant is controlled by a level switch on the recovery tank and a heat exchanger is added The heat exchanger may be refrigerated water shell amp tube or cooled air Radiator At pressures above 100 mm Hg a circulation pump is installed to insure the proper amount of sealant is re circulated Full recovery systems often operate under conditions where condensation will cause the liquid level to rise The opposite condition can exist whereby liquid evaporation will make it necessary to add make up liquid GENERAL When installing a No S
16. belt guard or coupling guard properly attached Disconnect the pump from the electrical supply at the main before removing the guard Replace the guard before reconnecting the power supply Operating the pump without the guard secured in place exposes people in the vicinity of the pump to risk from rotating drive parts Make sure the pump is completely reassembled the belt guard is replaced and all drain and fill valve and plugs are closed before reconnecting the power supply Do not operate the pump with oxygen enriched gas in the suction line where the proportion of oxygen exceeds 20 unless the pump is using water as a sealant or an inert fluid suitable for the application Pumping oxygen enriched gases with mineral oil or other non inert fluids can cause an explosion in the pump resulting in damage or injury Take precaution to avoid prolonged or excessive exposure to oil mist or process materials from the discharge of the pump or prolonged or excessive exposure to oil mist from oil sealed pumps Do not allow the pump to discharge into closed room or a room without adequate ventilation Always use a discharge oil mist eliminator for oil sealed systems Venting the outlet of the pump or oil mist eliminator to the open air is highly recommended Do not restrict the pump discharge line in any way or place any valves in the discharge line The vacuum pump is a compressor and will generate high pressures without the motor stalling when at low
17. claims for defective products parts or work under this warranty must be made in writing Immediately upon discovery and in any event within one 1 year from date of shipment of the applicable item by seller Unless done with prior written consent of seller any repairs altera tions or disassembly of sellers equipment shall void warranty Installation and transportation costs are not included and defective items must be held for seller s inspection and returned to sellers Ex works point upon request THERE ARE NO WARRANTIES EXPRESSED IMPLIED OR STATUTORY WHICH EXTENDS BEYOND THE DESCRIPTION ON THE FACE HEREOF INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS OF PURPOSE After buyers submission of a claim as provided above and its approval seller shall at it s option either repair or replace its product part or work at the original Ex works point of ship ment or refund an equitable portion of the purchase price The products and parts sold hereunder are not warranted for operation with erosive or corro sive materials or those which may lead to a build up of material within the product supplied nor those which are incompatible with the materials of construction The buyer shall have no claim whatsoever and no product or part shall be deemed to be defective by reason of failure to resist erosive or corrosive action nor for problems resulting from build up of material within the unit nor for problems due to in
18. compatibility with the materials of construction Any improper use operation beyond capacity substitution of parts not approved by seller or any alteration or repairs by others in such manner as in sellers judgment affects the product materially and adversely shall void this warranty No employee or representative of seller other than an officer of US Vacuum Pumps LLC is authorized to change this warranty in any way or grant any other warranty Any such change by an officer of the company must be in writing In no event shall buyer be entitled to incidental or consequential damages Any action for breach of this agreement must commence within 1 year after the cause of action has occurred 24 NOTES 25
19. ealant Recovery System a drain connection may be installed as shown in figure 4 page 6 to drain liquid down to shaft level prior to starting the pump Draining to shaft level may be necessary to avoid overloading the pump and motor when starting Normally it is not necessary to drain to pump level prior to starting if during the prior pump shutdown the incoming sealant flow is stopped simultaneously while stopping the pump An automatic solenoid valve normally closed is convenient for this use As the pump creates it s own vacuum it will draw in the required amount of seal water so that the seal water need will not be under pressure when pumping below 150 mm Hg If there is extensive piping fittings valves and other restrictive devices in the seal line the water would need to be adequately pressurized in order to overcome the pressure drop due to these fittings When operating a fixed amount of seal water is being drawn into the pump The pressure on the seal line will vary depending upon the inlet pressure On a Full Recovery System which does not use a circulation pump the seal water is drawn into the pump under pump suction entirely For sustained operation above 150 mm Hg abs a circulation pump may be required 16 OPERATION SEALING LIQUID The pump performance curves are determined by the temperature of the sealing liquid and influences the base pressure and pumping speed capacity cfm At lower sealing liquid temperatures
20. ies water fed to the pump is discharged down the drain or used for another purpose XS MX lt SYSTEM INLET wi PUMP OVERFLOW OVER SEAL WATER FLOW INLET Note schematics are not binding FIGURE 2 e E CHECK VALVE TEMPERATURE GAUGE m OPTIONAL gt CG COOLING WATER z COMPOUND GAUGE AIR OR GAS p lt GLOBE VALVE VG MIXTURE GAS SEAL FLUID VACUUM GAUGE FE SEAL FLUID pe SHUT OFF VALVE ba SOLENOID VALVE STRAINER NC RECIRCULATING PUMP s VACUUM PELSE VALVE Lever SWITCH MAN HEAT EXCHANGER 12 DISCHARGE VENT PARTIAL RECOVERY WATER SEALED LIQUIDRING VACUUM PUMP SYSTEM About 50 of the seal water is re circulated while fresh seal water is added for make up Consideration must be given to heat build up SYSTEM INLET PUMP OVERFLOW SEAL WATER OVER INLET FLOW Note schematics are not binding FIGURE 3 CHECK VALVE TEMPERATURE GAUGE OPTIONAL FLOW CONTROL COOLING WATER COMPOUND GAUGE AIR OR GAS GLOBE VALVE MIXTURE GAS SEAL FLUID VACUUM GAUGE SEAL FLUID SHUT OFF VALVE SOLENOID VALVE EA STRAINER RECIRCULATING PUMP DOE Lever SWITCH MAN HEAT EXCHANGER x e Z 4 13 DISCHARGE VENT FULL RECOVERY CLOSED LOOP LIQUIDRING VACUUM PUMP SYSTEM Close to 100 of seal water is recovered and re used Because of heat build up a heat exchanger needs to be used However if the separator tank
21. is large and the pump is small radiation can dissipate sufficient heat and the system could work without a heat exchanger SYSTEM SEAL WATER INLET MAKE UP COOLING WATER INLET OVERFLOW DRAIN COOLING WATER Note schematics are not binding DISCHARGE FIGURE 4 CHECK VALVE TEMPERATURE GAUGE OPTIONAL COOLING WATER FLOW CONTROL COMPOUND GAUGE AIR OR GAS GLOBE VALVE MIXTURE GAS SEAL FLUID VACUUM GAUGE SEAL FLUID SHUT OFF VALVE SOLENOID VALVE EA STRAINER RECIRCULATING PUMP ep Lever SWITCH MAN HEAT EXCHANGER x e Z 4 14 Properties of sealants Water is the most commonly used sealant in liquid ring vacuum pumps Other fluids may be used to obtain process compatibility In these applications special consideration should be given to the properties of the seal ant which may affect pump performance Some of the properties of sealant which should be considered are Specific gravity Specific heat Viscosity Vapor Pressure Additionally the solubility of process gas in the sealant can be of significance and should be evaluated espe cially if the partial or full recovery system is used When water is the sealant its chemical content should be evaluated since certain conditions will affect the service life of the pump Generally if water is suitable to drink it is suitable for pump use Hardness greater than 500 PPM will result in internal plating and fouling of pump parts Service with hardness of
22. less than 500 PPM depends on operating temperature and the nature of the salt de posit Naturally occurring well water with organic acid of pH 5 or higher is generally suitable however pH of 7 or higher is preferred Chemically treated water with sulfur content requires pH 7 or more Water which has a pH less than 5 should be treated or the pump should have special materials of construction Sealant temperature The rated capacity ACFM of LRH Liquid Ring vacuum pumps are based upon the use of incoming seal water of 60 Deg F Seal water temperature affects the pump capacity To calculate pumping capacity ACFM when using water at other than 60 Deg F the following formulas apply Sa S60 x P1 Pc P1 13 3 Where Actual capacity in ACFM at P1 S60 Pump capacity with 60 Deg sealant at P1 P1 Inlet pressure in Torr Pc Vapor pressure of sealant at actual sealant temperature Two stage liquidring vacuum pumps REFERENCE CHART For calculating pumping Capacity of two stage Liquid ring vacuum Pumps using various Seal water temperatures o 12 2 S a o o 100 150 200 250 300 400 500 700 760 Suction pressure in mmHgA Torr 15 OF SEALANT SYSTEMS NO SEALANT RECOVERY Figure 2 page 11 This arrangement takes water directly from the water main circulates the w
23. mpeller and casing The impeller is offset above center of the pump casing and as the impeller rotates pumping action begins in the space between the impeller amp pump casing by filling and emptying similar to a reciprocating compressor Gas inlet and discharge ports are positioned so as to draw gas into the cavity inside the liquid sealed ring during the expansion seg ment and discharges gas along with some liquid during the compression segment The discharged liquid can recovered and re circulated through the use of a gas liquid separator Water is normally used as the liquid seal but may be un suitable for some pump applications Other commonly used fluids are oil glycol and solvents INLET DISCHARGE v1 CASING SEAL LIQUID INLET DISCHARGE IMPELLER 11 SEALING WATER ARRANGEMENTS There are three 3 sealing liquid arrangements as shown in figure 2 3 4 based upon the amount of sealing water recovered and recirculated The water available at the pump site may contain minerals which when used as a Seal water will cause an undesirable scale to form inside the pump This should be a consideration In selecting the most satisfactory arrangement as any pump size and model can have any one of the three arrangements Figures 2 3 4 CAUTION The pump must not run dry Never start the pump with liquid level above the shaft line DISCHARGE VENT NO RECOVERY WATER SEALED LIQUIDRING VACUUM PUMP SYSTEM As the name impl
24. n box cover 3 phase or on the side of the motor itself 1 phase The motor must be connected according to applicable electrical codes through a fused switch in order to protect the motor against electrical or mechanical overload conditions The over load of the motor starter must be set at a level equal to the full load motor current listed on the nameplate After the motor starter and disconnect switch have been installed turn the pump by hand and determine that the impeller is free to turn and then momentarily start the motor to check direction of rotation The direction of the pump must rotate as indicated by the arrows on the drive and casing If the pump rotates in the wrong direction have an electrician reverse any two of the motor leads WARNING DISCONNECT PUMP FROM SOURCE OF ELECTRICAL POWER PRIOR TO MAKING REPAIRS OR ADJUSTMENTS TO ANY COMPONENT OF THE UNIT VACUUM CONNECTION Use a pipe size that is at least the size of the pump inlet connections Smaller lines result in reduced pump capacity Pumps operating in parallel on a common main line should have a manual or automatic shut off valve or positive acting check valve installed in the suction line of the pump Should the process gas contain dust of other foreign material a suitable inline particulate filter should be connected to the inlet port contact U S Vacuum for recommendations The vacuum piping should be designed to insure that no liquids such as condensate or liquid
25. ust be mounted in a horizontal position Inlet vacuum relief valve Used to control pump inlet vacuum If pump capacity exceeds the system require ments at present vacuum then the valve open and admit ambient air Valve selection is dependant upon desired vacuum setting and pump size Flexible connector Used to accommodate some motion and misalignment between pump and system Inlet shut off valve Used to positively isolate pump from process chamber Ball valves are supplies up to 2 NPT Butterfly valves are supplied for connections larger than 3 Sealant solenoid valve Used to establish sealant flow when motor is energized and return to closed position when motor is de energized Also prevents flooding the pump with sealant when pump is off Flow controller Used to establish sealant flow rates to the vacuum pump Sealant circulation pump Used to circulate recovered sealant Required for use when operation at high pres sure such as frequent cycling or when operating for prolonged periods above 400 Torr Strainer Used to filter solid particles from the sealant Heat exchanger Used to cool circulated sealant 10 PRINCIPLE OF OPERATION U S Vacuum Pumps LRH series Liquid ring Vacuum Pumps are durable Two Stage pumps having pumping speeds which range from 45 850 CFM with vacuum capabilities to approximately 29 Hg When the pump is operating a continuous flow of seal liquid is entering the pump and forms a seal between the i
26. ve bearing Too much sealant liquid Coupling misaligned Cavitation Adjust to correct flow rate Replace Decrease flow rate Align Open attenuation valve or reset vacuum relief valve to increase flow Defective bearing High sealant temperature Suction open to atmosphere Replace Check coolant flow and temperature Adjust isolation valve Excessive Vibration Coupling misaligned Align Pump not properly anchored Anchor See excessive noise Check inlet pressure amp gas flow Motor overloaded Excessive back pressure Too much sealant liquid Reduce height of pump discharge Decrease flow rate Misalignment Realign motor amp pump Defective bearing Replace bearing Abnormal bearing wear Misaligned pump assembl Realign motor amp pump Impeller binding Accumulation of rust or scale Foreign object in pump De scale or remove rust Dismantle pump amp remove object Mechanical seals squeal Insufficient cooling liquid Increase coolant flow to seal 22 106 107 110 Sectional Drawing with Mechanical Seal 9018 107 147 110 1 521 110 106 9037 905 433 2 9033 636 323 p s m 5 RU ANZ T zzy T xd 274 ies rl en SSS A Ws SSSS gt 4 SSIS SS SS Tr Suction casing Discharge casing Impeller casing Plug Impeller casing Radial seal ring Plug Intermediate element Mechanical
Download Pdf Manuals
Related Search