series-1 series-2 series-3 Large capacity liquid ring ... · Large capacity liquid ring vacuum pumps series-1 series-2 series-3 ... Compared with other vacuum pumps the Maxima-K water-sealed

DEKKER Vacuum Technologies, Inc./Maxima-K/June2007 1

InstallationOperation

andMaintenance

Manual

Large capacityliquid ring vacuum pumps

series-1series-2series-3

SERIAL NO.:___________________________ June 2007/1

INTRODUCTION


The Maxima-K (series 1, 2 and 3) liquid ring vacuum pump guarantees you improved reliability and reducedmaintenance costs. Compared with other vacuum pumps the Maxima-K water-sealed liquid ring vacuum pumpsystem offers the advantages of no metal-to-metal contact between the impeller and casing. Grease lubricatedbearings are mounted external to the pumping chamber, isolated by packed gland or mechanical shaft seals. Thismeans that the pump requires no internal lubrication.

DEKKER pumps and systems have been designed to provide safe and reliable service with low maintenance.Because a vacuum pump is a rotating piece of equipment, the operator must exercise good judgment and followproper safety procedures to avoid damage to the equipment or personal injury. Please review and follow allinstructions in this manual before attempting to install, start or operate equipment.

SafetyAll products offered by DEKKER have been designed and manufactured for safe operation. However, theresponsibility for safe operation rests with those who use and maintain these products. Your safety departmentshould establish a safety program based on OSHA, federal, state and local codes. It is important that dueconsideration be given to hazards which arise from the presence of electrical power, hot liquids, toxic gases androtating equipment. Proper installation and care of protective devices is essential to safe system operation. These

safety procedures are to be used in conjunction with the instructions contained in this manual.

STORAGEKeep the pump in a cool dry environment and close the seal fluid isolation valve. Plug all open ports to keep outdirt and foreign objects. Every 2 - 3 months add a small amount of rust inhibitor into the inlet of the liquid ringpump and rotate the impeller by rotating the shaft by hand.

If the pump has been idle for more than 2 years, replace the bearing grease before starting up. Use #3 lithiumgrease.

After a long idle period, empty the pump completely and remove any scale deposit by using the speciallyformulated DEKKER descaling compound Scale-Ex. When the descaling process is complete, add a smallamount of rust inhibitor and rotate the impeller by rotating the shaft by hand. If you cannot rotate the shaft becausethe impeller is locked up, contact the factory.

INSTALLATIONThe design of the piping system, foundation layout and plant location are the responsibility of the purchaser.DEKKER Vacuum Technologies, Inc. and its representatives may offer advice but cannot assume responsibilityfor operation and installation design.

Please consult an authorized dealer or a specialist skilled in the design of plant layout, system piping design andfoundation design. The installer should carefully read this manual before installing the equipment. DEKKER oryour local dealer can provide start up assistance in most instances at reasonable cost.

UnpackingUpon receipt of pump or system, immediately inspect for signs of damage. Carefully remove the packingor crating from around the pump or system. Be sure to keep equipment in the upright position. DEKKER productsare shipped F.O.B. factory, which means that any damage is the responsibility of the carrier and should bereported to them.

LiftingLift the equipment carefully and with weight evenly distributed. DEKKER is not responsible for equipment thathas been damaged through mishandling or dropping.

LocationInstall the unit in a well ventilated and dust free area. The pump or system should be a minimum distance of 3feet from surrounding walls to allow for checking fluid level, temperatures, pressures and general servicing.

MountingThe pump or system must be installed on a level surface in a horizontal position. The foundation must bedesigned to support the total unit weight, without any settlement or crushing, be rigid and substantial enough toabsorb any equipment vibration, maintain true alignment with any drive mechanism, and must permanentlysupport the baseplate at all points.


The vacuum pump system must be leveled and secured with foundation bolts. Foundation bolts must be ofadequate size to withstand the mechanical stresses exerted on it.

All systems should also be grouted into position. The foundation should be constructed to allow for ¾ to 1-½inch of grout. The baseplate is set on shims and the grout is poured between the foundation and the baseplate.To have the required body to support the baseplate, grout should be at least ¾ inch thick.

The number and location of shims will be determined by the design of the baseplate. Firm support should beprovided at points where weight will be concentrated at the anchor bolt locations. Use enough, and large enoughshims to provide rigid support. Baseplates are usually designed with openings to allow pouring grout. When thebaseplate has been shimmed and leveled and the anchor bolts have been snugly tightened, a dam is constructedaround the foundation to contain the grout. The dam level should be at least ½ inch above the top surface of theshims. Grout should be poured inside and around the outside of the baseplate and leveled. Allow the grout todry for a minimum of 48 hours before tightening the anchor bolts.

Please note that the pump/motor coupling and V-belt units will need to be realigned prior to start-up,except with monoblock units.

WORKING PRINCIPLE AND CONSTRUCTION

Working Principle

Liquid ring

Inlet port

Discharge port

Casing

Rotor

The rotor is mounted off-center in a cylindrical pump casing. As the impeller revolves in the direction of thearrow , the seal liquid forms a liquid ring by centrifugal force. As a result, a half moon shape is developedbetween the rings inner face and the rotor hub. When the impeller goes from point A to point B, the pocketbetween the two adjacent blades will increase with gas drawn in. When the rotor turns from point C to point A,the corresponding pocket will reduce from large to small with the previously-drawn gas compressed. Whenthe pressure is equal to or slightly larger than ambient pressure , the compressed gas will be expelledthrough the discharge port.

Seal LiquidThe seal liquid should be fresh, clean water of ambient temperature of neutral pH (soften if necessary). Theseal liquid not only forms a liquid ring, but also dissipates the heat developed by compression and seals theclearances between the impeller and the port plates.During operation, the pump has to be continually supplied with fresh water, as part of the seal liquid suppliedis discharged together with the compressed gas.Use the seal liquid as cool as possible. The seal liquid must not contain solid materials, e.g. sand, otherwisethe casing will be subject to heavy wear or the impeller will jam.

Ultimate Suction Pressure (Maxima-K 2 and 3 series only)


For the Maxima-K 2 and 3 series the minimum suction pressure depends on the temperature of the sealliquid used.The ultimate suction pressure is down 1”Hg Absolute with the seal liquid and gas at the temperature 60oF and70oF respectively. Without cavitation protection the suction pressure must not fall below 2.5”Hg Absolute(ultimate pressure) for continuous operation. If the seal liquid has a higher temperature (higher vaporpressure), minimum suction pressure is correspondingly higher.

WARNINGOperation of the pump below the minimum permissible suction pressure for a prolonged period oftime can result in the pump being damaged by the cavitation. For high vacuum operation usecavitation protection.

Construction DescriptionAll Maxima-K series pumps consist of the following ten principle components:(1) Casing(2) Rotor: of which the impeller and shaft are combined through shrinking process. The shaft is equipped with

shaft sleeves.(3) Port Plates: the front and rear port plates are bolted to the end housings.(4) Valve Plate Combination: consisting of a steel plate and a flexible Teflon valve, mounted on the discharge

port of each port plate, allows for the pump to operate at maximum efficiency over the full vacuum range..The flexible Teflon valve is a wearing part.

(5) Shaft Seal Assembly: Large-sized pumps usually use packing seals. Mechanical shaft seals are availableas an option. There are two shaft sealing methods for lubrication: internal water supply and external watersupply. The stuffing box is mounted in a direction depending on the shaft sealing method used. Details asper the following figures.

Internal water supply method for External water supply method forAll Maxima-K series All Maxima-K series

Internal water supply method is indicated External water supply method is indicatedwith number 4 cast above the axis with number 4 cast under the axis

Details of specifications of packing as per table belowThe pumps are supplied with external water supply as standard.

Maxima-K 1-seriesDV4501K-KDV6000K-K

DV8001K-KDV9001K-K

DV100001K-KDV13001K-KDV18001K-K

(Packing CrossSection)x circumference (19X19)X710 mm

(19X19)X820mm

(19X19)X890mm

(19X19)X980mm

Maxima-K2-series, 3-series

DV2303K-KDV3503K-KDV4002K-K

DV4003K-KDV5002K-K

DV6503K-KDV7002K-K

DV9003K-KDV11002K-K

DV13003K-KDV15002K-K

(Packing CrossSection)x circumference (13X13)X530 mm

(16X16)X633mm

(19X19)X710mm

(19X19)X820mm

(19X19)X890mm

(19X19)X980mm


Note: external water supply is employed with clean water of ambient temperature supplied to shaftsealing water feed pipe when toxic gases are handled and no seal liquid is allowed to leak from theshaft seal.(6) End Shield(7) Bearings: ball bearings are used for axial shaft loading while the cylindrical roller bearings bear the radial

loads.(8) Water feed pipes: through which working water is supplied to the pump.(9) Shaft Sealing Water Feed Pipes: through which cooling and sealing water is supplied to the stuffing box

when external water supply is employed.(10)Automatic Drain Valve: used to control the water level in the pump at start-up.

For cut-away view of the Maxima-K 1-series, see page 13 at the end of this manual.For cut-away view of the Maxima-K 2- and 3-series, see page 14 at the end of this manual.

INSTALLATION OF PUMP, MOTOR AND DRIVE

Note: the pumps are subject to strict tests and inspections at the factory before being shipped.

Installation of pump, motor and drives must be carried out by experienced technicians.

The drive variations for all 3 Maxima-K series are either direct, via belt drives or gear reducer.The mounting methods are:

Direct DriveCheck drive coupling alignment. Angular alignment should be within .035”- .175”. Parallel alignment should bewithin .010” - .025”. Consult the factory for specific system size alignment. Mono-block units do not requireany field adjustment (motors are C-face mounted).

Note: Misalignment may occur during the lifting and handling processes. Re-align the unit ifnecessary.

V-Belt Drive

For units utilizing V-belt drives, make sure the sheaves are properly installed and aligned before attempting totension the drive. The V-belts should be placed over the sheaves and in the grooves without forcing them overthe sides of the grooves. The tensioning steps 1, 2, 3 and 4 can be used for all types of V-belts, all crosssections and number of belts and all types of construction.

Avoid excessive heat (140oF and higher); belt life will be shortened. Never switch or mix belts from onegroove to another on the sheaves. Do not use belt dressing. Sheaves should remain free of oil and grease.When replacing belts install an identical set.

For more specific V-belt tensioning guidelines consult factory.

1. With all belts in their grooves, adjust centers to take up the slack until they are fairly taut. Use standard V-belt tensioning guidelines.


2. Start the drive and continue to adjust until the belts have only a slight bow on the slack side while operatingwith load conditions.

3. After several days of operation, the belts will seat themselves in the sheave grooves. Further tensioningmay be necessary to the point that the drive shows a slight bow in the slack side. Insufficient tension isoften evidenced by slipping (squealing) at start-up.

4. If the unit is idle for an extended period of time, the tension on the belts should be removed.

Note: To guarantee safety operation, set on belt guards.

Gear Reducer Drive

If a gear reducer drive is supplied follow manufacturer’s instructions.

ARRANGEMENT AND INSTALLATION OF PIPING

Before installing piping, especially the suction pipe, clear out welding slag, rust and other foreign matter.When dealing with new pipes, mount a mesh filter screen (20/30 mesh) between pipe and pump flange.The screen should have a certain amount of extension beyond the circumference of pipe to prevent it frombeing sucked into the pump. Clean the screen whenever it is clogged by foreign matter, which will restrictthe gas flow. In general stop the pump to clean the filter once a week until the system inside is cleanenough. After a period of time, it may be removed after making sure that there is no foreign matterremaining inside.

Note: Use straight piping as much as possible at site. Use piping not smaller in diameter than thepump connections to prevent higher suction and discharge resistance.

Mount the pressure gauge on the water feed pipe and vacuum gauge on the suction pipe respectively.

Based on the different handling duties, the piping are to be arranged with reference to Figures 5,6,7 on thenext page.


1. Pump 6 Compound Gauge 11 Vacuum Gauge 16 Level Indicator

2. discharge Pipe7 Feed Valve forWorking Water

12 Suction Pipe 17 Check Valve

3. Flush and Drain GateValve

8 Shaft Sealing WaterFeed Pipe

13 Gas and WaterSeparator

18 Suction Valve

4. Automatic Drain Valve9 Shaft Sealing Water

Valve14 Cylindrical Separator 19 Stuffing Box Drip

5. Working Water FeedPipe

10 Pressure Gauge 15 Heat Exchanger20 Flush and Drain

Connection

Pump Set Arrangement


Description of Figure 5Shows a no recovery, or once-through seal liquid system. This arrangement is preferred when large quantities of seal liquidare available and no financial advantages are foreseen for re-utilization of the same.

Description of Figure 6Shows a full-recovery liquid ring vacuum pump systems offering total re-circulation of the seal liquid. In this arrangementthe seal liquid is re-circulated in a closed loop system through a heat exchanger, which removes the heat of compression.This arrangement is used when corrosive or toxic gases are conveyed.

Description of Figure 7Shows a liquid ring vacuum pump systems configuration with partial recovery or partial re-circulation of the seal liquid.This arrangement allows for up to 50% savings of seal liquid. Variations in application and pump models will affect theamount of seal liquid savings.

Description of Figure 8Shows a pump installation with floor discharge. The discharge trench should have sufficient flow crosssection, for the seal liquid to discharge by gravity. Mount a check valve on the suction line to prevent backflow of gas and liquids.Note: If no circulation of seal liquid is required drain in accordance with the environmentalregulations.

START AND STOP

Preparations before starting(1) When the pump has been out of operation for a prolonged period of time ( more than two years) , renew

the grease for the bearings of the pump before starting. The grease recommended to use is 3# lithiumgrease. Clean the bearings thoroughly with solvent before regreasing.

(2) Flush the pump through the water feed pipes. Turn the rotor by hand to drain the dirty water out throughthe discharge line. Before re-starting, two days or more of normal operation, flush the whole piping systemwith water to flush out scale and rust.

(4) Check the electrical connections for safety and correctness.(5) Check the pump for rotation direction, see arrow on pump.(6) Check the coupling or V-belt alignment.

Start-upSee Figure 5(1) Open the water feed valve 7 to supply water to the pump (if the pump employs shaft sealing water supply,

open the shaft sealing water valve 9 at the same time). When there is water coming out of the automaticdrain valve 4, shut down water feed valve 7.

(2) Open the suction valve 18.(3) Start the motor with no water coming from the automatic drain valve 4. When the pump starts running, open

the water feed valve 7 to a point where compound gauge 6 shows pressure. At higher vacuum the gaugeshould show between 0 – 5” Hg.

(4) In case of external shaft sealing water supply, adjust the shaft sealing water valve 9 to a point where thewater sealing supply pressure gauge 10 shows a reading between 3 – 5 psig.

Shut-down(1) Check if all the corresponding equipment of the pump set has been put into stop mode before stopping the

unit.(2) Shut down the water feed valve 7 and shaft seal water supply valve 9 (if applicable) and at the same timeshut down the motor.(3) Open the drain valve 3 to drain water from pump if pump is to be stopped for an extended period of time.


OPERATION, SUPERVISION AND MAINTENANCE

During the operation, check the following :(1) The voltage and the shaft power (current).(2) The temperature rise of the bearings of the pump. The temperature rise should not exceed 100oF, i.e. the

real working temperature should not be more than 180oF.(3) Water flow rate of the pump and shaft sealing external water supply if any.(4) If fitted with V-belt drive check belt tension. New belts are easy to stretch and deform. Stop the unit to check

and adjust 20 minutes after first start-up.(5) Renew the grease of the bearings every 2500 hour-operation period. The amount of the grease accounts

for 2/3 of the free space of the bearing(6) If fitted with packed gland stuffing box tighten the packing slightly. Adjust it through the packing gland and

the bolts. There are normally some water drops leaking from the shaft seal. When the packing has beenused too long to be adjusted further, renew it. When renewing, remove the old one, clean the traces ofstuffing box. When mounting the packing, stagger the packing with its cuts at 90°.

(7) Use soft water if possible when water is required as sealing water. If not possible, take away the limedeposits from the working liquid at appropriate intervals. If the impeller jams after a prolonged standstillperiod because of lime deposits, flush with DEKKER descaling compound Scale-Ex and then flush withclean water. In case of heavy deposits, clean by disassembling the pump

.

ASSEMBLY AND DISASSEMBLY

Disassembly of Maxima-K pumpsFor construction, refer to cut-away views on pages 13 and 14 at back of manual.

Separate the pipes and take out the coupling. If belt drive, remove the pulleys.1. Dismantling the Front Bearing

a) dismantle the inner bearing cap 11 and then loosen the lock nuts, stop washer and oil catch ring.b) Referring to the Figure 9, screw the four M12 screws uniformly to the M12 threaded holes in the frontbearing housing until the front bearing housing and the inner bearing cap are ejected.

Front bearing all series back bearing, 1-series back bearing 2 – and 3-series

2. Dismantling of Back BearingReferring to Figure 10a) Unscrew the screw 1 one by one. Take out carefully each compensating washers set 2 on the screws

with a small thin steel plate. Place different washers on floor with reference to the corresponding screwsand then remove the outer bearing cap 3.


Note: The pumps are supplied with axial clearance set correctly between the impeller and portplates.The compensation washers act as adjusting the axial clearance between the impeller and both thefront and rear port plates. When dismantling, care should be taken to distinguish among thewasher sets. Store them separately. Make sure that they shall be re-mounted in their originalplaces respectively. Otherwise, the front and back axial clearances may be distributed unevenly,affecting the pump performances or causing the impeller to jam.b) Remove the lock nut 4 and the stop washer 5.c) Unscrew the screws 6 tightened evenly and take out the springs 7 distributed uniformly in the inner

bearing cap.d) Put on the stripping ring (see figure 11) , and then re-screw the screws 6 uniformly.

Stripping ring 1-series Stripping ring 2- and 3-series

The Rear Bearing disassembly, such as dismantling bearing housing, inner bearing cap and etc. , isperformed in the same manner of that of the Front Bearing. The ball bearing inner race can not bear theforce without using the stripping ring when disassembly of the bearing. In this case, the bearing will bedamaged. The unit is supplied together with the stripping ring. Customers’ requirements for it areaccepted.

3. Get the pump to stand up vertically across the two blacks with its drive end upward ( see Figure 12).Dismantle it into pieces part by part . when the present condition limits, the pump may be disassembledwith the whole unit placed horizontally. As a matter of fact, there are some ways to perform the disassembly.We are ready to provide the corresponding diagrams when the customers request.

4. Because of the bearings of Maxima-K pumps have large magnitude of interference, they may difficult toremove in the manner stated in Figure 10 and 11. It is recommended that both the front and rear bearingare to be dismantled to the extent as shown in the figure 13 and 14 and then the bearing inner face willact as bearing point to enable the bearings to be pressed out. Refer to the reference books for themethods of disassembly of bearings.When the back bearing is drawn out with its outer ring bearing force, it will be damaged.

2 - 3series

d D S

30 125 165 10

35 148 191 10

40 168 223 10

1series

d D S

40 168 223 10


5. It is an important task to examine and clean all the components after the disassembly. According to theconcrete conditions. Carry out the repair, replacement on them or decide whether they are capable ofcontinuing to work or not.Bearings- Check for smooth running. According to the fault and corrosive state, renew them if necessary.The Front and Rear Port Plates- they are subject to finish turning process when there are some deepscratch on the faces, which will affect the pump performances.Shaft Bushing- Renew it based on the wear state.Impeller- Its face is subject to finish turning process when it has been so worn out to affect the pumpperformances. As the difference between the impeller and the pump body in length is the axial clearance,the two should reduced the same in length through finish turning process.

Assembly of Maxima-K pumpsThe assembly of the pump is performed in the reverse manner of the disassembly. In addition to that, attentionshould be drawn to the facts that:

1. When the pumps was assembled on a uneven floor, the four pump feet would not remain horizontal like aplane surface and the clearance between the impeller and the port plates would be reduced with theimpeller jamming after completing the assembly. The correct method is: the pump body is placed on itsbed plate or on a even floor with its end shields mounted on it and then loosen the screws, tighten themafter making sure that the four pump feet are in good touch with the plane surface.

2. Tighten the screws after replacing the compensating washers to their original places, which act asdominating the distribution of the axial clearance.

3. Adjust the axial clearance again where the rotor is renewed or the finish turning is performed on theimpeller and the port plates.

Adjustment of Axial Clearancea) Loosen the screws one by one ( See Figure 2).b) Put a shaft clip on AS end of the shaft.c) Put a dial meter on the AS end of the shaft.d) Prize the rotor toward AS with a steel stick to make it be in touch

with the front port plate.e) Set the meter at zero, prize the rotor toward BS to enable it to be in

touch with the front port plate.f) The reading shown in the meter is the total axial clearance value ó

of the pump.g) Replace the compensating washers in their original places. The

washers, made of steel, take three sizes of 0.1mm, 0.2mm and0.5mm in thickness. All the washers sets are the same in thickness.

h) Secure the screws tightly. At the moment, the meter reads ó/2.It is likely that he clearance on AS is slightly larger than that on BS.The minimum clearance on BS should be in conformity with therequirements specified. Otherwise, paper washers will be added toboth ends of the pump body.


Troubleshooting

Symbols Causes Points to check and actions1. Difficult in starting,

Motor circuit –breaker tripsor over-heat

1. Water level too high insidewhen starting;

2. Packing gland too tight;3. Belt too tight;4. Wear developing in pump;5. Discharge pressure too high;6. Failure to adjust the current

protection of the electriccabinet.

1. Start with the water level specified;2. Loosen the gland adequately;3. Loosen the belt adequately;4. Turn the rotor with force and flush with water;5. Check if the pipes and valves are too small in

diameters;6. Adjust the thermal relay to the rated current

setting.

2

Jamming during trial ornormal operation

1.Welding slag or other foreignmatters have been drawn infrom new pipes with cominggas.

2.Heavy lime deposit

1. Loosen both the front and back shrouds, turnthe rotor and flush it with water until it rotatefreely and then secure them. In case of failure,open it for checking.

2. Dismantle for cleaning or acid washing.

3 Pump capacity low.Vacuum degree low.

1. Speed low due the beltslippage;

2. Insufficient water feed or watertoo hot;

3. Leakage occurring in thesystem;

4. Excessive clearance in thepump due to excessivecorrosive allowance orcorrosive substance in themedium;

5. Leaks from packing seal;6. Heavy lime deposits in pump;7. Corrosion in pump;8. Axial clearance not in

conformity with therequirements after repair;

9. Damage to the flexible valveplate.

1. Tighten the belt;2. Adjust the water flow. Check the feed pipes

for clogging;3. Check the joints for sealing;4. Clean the medium preventing solids from

entering. Replace the worn parts;5. Tighten the packing gland;6. Remove the lime deposits;7. Replace the parts if necessary;8. Calibrate the axial clearance.9. Replace the valve plate.

4a

Unexpected noiseAll series

1. The belt too loose;2. Gas blowing and ejecting;3. Suction and discharge pipes’

walls too thin;

1. Tighten the belt;2. Move the discharge opening to outdoor;3. Use the pipes with thicker walls;


4b

Unexpected Noise2- and 3-series

4. Cavitation occurring when thepump running under vacuum

4. Use cooler working water or replenish gas inthe suction side; use gas ejector.

5 Excessive vibration 1. The bed plate connected withfoundation badly, the anchorbolts loose;

2. Misalignment

1. Pour mortar around and under the base plate.tighten the bolts;

2. Make re-alignment and lock.

6 Bearings overheat 1. Belt too tight ;2. Misalignment of pump with

motor;3. Inadequate lubricating, the

grease too dry or too much;4. Bearings inadequately

mounted;5. Wear, rust and damage

developing.

1. Loosen the belt adequately;2. Make re-alignment;3. Improve the lubricating conditions;4. Re-mount the bearings.5. Replace the bearings.



Documents

series-1 series-2 series-3 Large capacity liquid ring ... · Large capacity liquid ring vacuum pumps series-1 series-2 series-3 ... Compared with other vacuum pumps the Maxima-K water-sealed