DEX
LIQUID RING VACUUM PUMPS OPERATION AND MAINTENANCE
MANUAL
INDEX
1. INTRODUCTION Page3
2. REVIEW OF THE SHIPPING DOCUMENTS,,3
政治八上思维导图
3. WARRANTY,,3
4. OPERATING PRINCIPLE,,4
5. TECHNICAL DESCRIPTION,,4
6. USE,,5
USE AS A VACUUM PUMP
USE AS A COMPRESSOR
7. OPERATING CONDITIONS,,6
OPERATING DATA
GAS AND VAPOURS
SERVICE LIQUID SUPPLY
8. TRANSPORT,,7
9. STORAGE,,8
SHORT TERM STORAGE
LONG TERM STORAGE
10. STANDARD NORMS FOR SAFETY,,8
GENERAL PRESCRIPTIONS
PRECAUTIONS DURING OPERATION
11. ADDITIONAL RISKS,,9
12. INSTALLATION,,9
13. CONNECTIONS,,10
PIPEWORK
ACCESSORIES
ELECTRICAL WIRING
14. SERVICE LIQUID SUPPLY ARRANGEMENTS,,10
15. START UP,,14
PREPARATION TO START UP
START UP
STOP
16. SHUT DOWN PERIOD,,15
17. MAINTENANCE,,15
18. OPERATING PROBLEMS AND TROUBLE SHOOTING,,16
19. REPAIR,,17
DISASSEMBLY OF THE CASING, PORT PLATE AND IMPELLER
REASSEMBLY OF THE IMPELLER, PORT PLATE AND CASING
20. SPARE PARTS,,21
21. PUMP SCRAP AND DISPOSAL,,21 ATTACHMENTS: SECTION WITH PART
1. INTRODUCTION
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The purpo of the prent manual is to ea the installation, the operation and the routine maintenance activities of the liquid ring vacuum pumps belonging to the DEX range.
Before proceeding with the installation and the start up of the pump, it is very important to undertake the reading of the prent manual, inform the operators and the plant personnel about the content of each ction in order to grant the correct operation of the equipment as well as the maximum safety of the personnel in charge for installation, start up and maintenance.
Plea note that the DEX liquid ring vacuum pumps could be potentially harmful to people and things for the following reasons:
-Rotating parts at high speed
!
-Deep vacuum
-Fluids and gas handled by the equipment could be hazardous and toxic Array -Prence of electric power
The non obrvance of the instructions reported in this manual or the improper u of the pump by u
nskilled and/or unauthorid personnel may result in vere damage to things or rious injury and even death of people!
The Technical and Service Departments are available for any technical assistance or clarification you may need. In ca of doubt, call up.
2. REVIEW OF THE SHIPPING DOCUMENTS
When receiving the goods, it is necessary to inspect and check them against the shipping documents. Make sure that no shipping damages are occurred to the equipment during transportation.
3. WARRANTY
The warranty does not cover for damages or failures caud by mishandling, incorrect installation and wrong
electrical wiring of any piece of equipment of the plant.
In any ca the warranty excludes the reimburment for any sort of damages originated by any cau.
Ing. Centra declines any responsibility for what concerns to injuries of people and damages to things due to
表格截图the improper u of its equipment.
For additional or replacement warranty claus in respect to the statements of prent manual, plea refer to the contractual conditions mentioned in the order acknowledgement.
Consumables are not subject to any warranty.
4.
OPERATING PRINCIPLE
Pumps belonging to the DEX range are designed and operating bad on the liquid ring principle.
The pump consists of a cylindrical housing within which an impeller with fixed blades turns off t in respect to the housing itlf.
The impeller rotation spins by centrifugal force the rvice liquid around the housing thus forming a ring of liquid concentrically to the housing. Becau of the off t between the housing and the impeller, during the impeller revolution, chambers between the blades are formed with a progressively increasing and decreasing volume resulting in producing respectively vacuum and compression. The prence of vacuum in the inlet port area draws in gas through the pump suction nozzle which is then compresd and discharged through the discharge port up to the dedicated pump nozzle.
During pump operation, it has to be supplied a continuos rvice liquid flow in order to remove the heat absorbed by the liquid itlf due to the isothermal compression.
FIG. 1
5. TECHNICAL DESCRIPTION
The DEX pump is single stage type, acting in parallel due to the symmetric design, with horizontal axis,provided with vary port valves. The rotating part is supported by two robust life grea lubricated ball bearings located in the casings at shaft ends.
The pump is lf standing on feet prent under each casing.
The pump shaft driving end has to be connected an electric motor in B3 construction through a flexible coupling.
The shaft aling is granted by two single mechanical als, standardized according to DIN 24960, fitted directly on the shaft and located in each casing (shaft ends).
The standardisation of specific items among different pump sizes reflects the modular design in order to rationali the construction of the whole range and reduce the amount of spare parts to be kept on stock.
SUCTION
DISCHARGE
SHAFT
INLET PORT
IMPELLER BLADES
LIQUID RING
DISCHARGE PORT
IMPELLER
6. USE
DEX pumps are mainly ud for the following applications:
Suction of gas and vapours from autoclaves and sterilizers Vacuum packaging, drying and impregnation Priming
Process under vacuum, suction of gas and vapours in the chemical, food and wine industry Dryers and evaporators ud in the textile, brick and soap industry Solvent recovery.
• USE AS VACUUM PUMP
The whole range of DEX liquid ring vacuum pumps can handle any gas suitable with the material of construction and with the rvice liquid as well as limited quantity of liquid carry over flowing into the
pump together with the process gas.公文排版
The deepest suction pressure which can be achieved by the pump is related to the vapour tension of the rvice liquid; any time the vapour tension comes clo to the suction pressure the pump may cavitate therefore it is advisable to keep the rvice liquid temperature as low as possible.
Process conditions clo to cavitation do require the installation of an anticavitation valve or relief valve to protect the pump (e ction 13).羊驼好养吗
In ca it is requested a deeper suction pressure compared to what the pump can provide, it is possible to combine the pump with a gas ejector (or other type of equipment) in order to achieve even 10 mbar abs. of vacuum.
The recommended operating limits are reported in TAB.1.
The extensive u of the pump under cavitation conditions may result in heavy damages to the pump itlf.
• USE AS COMPRESSOR
The DEX liquid ring pump range can be ud also as a compressor.
Normally when the gas suction pressure is atmospheric (1013 mbar abs.), the discharge pressure must not exceed the differential pressure stated in TAB.1 where are indicated the operating limits.
TAB. 1
PUMP MODEL
DEX 600-800
Max. pump speed
rpm
1750Max. inlet gas temperature
° C
100Max. rvice liquid temperature
° C
75Max. discharge pressure (vacuum pump)mbar 500
Max. differential pressure (compressor)
mbar
1100
7. OPERATING CONDITIONS
•OPERATING DATA
The nominal pump capacity and the absorbed power related to the suction pressure or differential pressure can be determined by reading the performance curve attached to the technical-commercial documentation
submitted with the offer or with the order acknowledgement; in any ca it will be provided copy of upon customer request.
•GAS AND VAPOURS
感冒引起头痛Gas and vapours handled by the pump as well as the rvice liquid must not contain solid particles which may damage the al surface of the mechanical al stationary and rotating ring; minor quantities of fine solids in suspension are admitted.
In ca the inlet temperature of the process gas is above 70°C, it may be necessary to increa the rvice liquid flow rate up to even 50% more compared to the design flow stated in TAB. 3.
If the inlet stream contains a consistent quantity of condensables, it is advisable to install a pre condenr ahead of the pump suction nozzle; the condensate resulting from the cooling can flow into the pump provided that the total amount shall not exceed the allowed max. quantity of liquid carry over stated in TAB 2.
•SERVICE LIQUID SUPPLY
As already mentioned above, the rvice liquid shall not contain any solid particles therefore it is rec
ommendable to install a strainer in the rvice liquid supply piping.
我的美丽家乡作文
The flow rates stated in TAB. 3 are mandatory; tho values are referred to suction conditions of dry gas only.
The pressure of the rvice liquid supply shall be adequate to overcome the pressure loss of the liquid through the piping and through the heat exchanger, if any, plus assure a positive pressure of 0,5 bar above the pump discharge pressure at pump rvice liquid inlet.
The lected rvice liquid must be compatible with the process gas and vapours, its density shall range from 800 to 1200 Kg/m3 and its viscosity shall be below 8 cST.
Pump improper u or not in accordance with what specified and recommended in the !
prent manual may result in malfunctioning of the equipment and in rious
conquences for people and things.
TAB. 2
Max. quantity of liquid carry over allowed
PUMP MODEL
through the suction nozzle (m3/h)
Continuos operation Discontinuous operation
DEX 6006,26,7
DEX 8007,88,4
TAB. 3
DESIGN SERVICE LIQUID FLOW RATE (m3/h)
VACUUM PUMP COMPRESSOR
PUMP MODEL RPM
Suction pressure (mbar)Differential pressure (mbar)
402006002006001000
高碑店豆腐丝
145021,91,81,81,71,6 DEX 60017502,22,2221,91,8
14502,52,252,12,22,12
DEX 80017502,52,252,12,22,12
