1. Oilfield:transporting a variety of oil, sewage, sump oil, polymer,crude oil (oil-gas mixture transportation).
2. Ship-building industry: used as marine cargo oil pump, sweeping-cabin pump, marine ballast pump, main engine lubricating oil pump, loading pump and so on.
3. Transportation and storage of petroleum products: used for oil storage, wharf, loading and unloading oil and transferring various oil products.
4. Petrochemical industry: a transportation and ejection pump for all kinds of acid, alkali, saline liquid and resin, pigment, printing ink, paint, glycerol, paraffin and so on
5. Thermal power plant: as heavy oil and thick oil transfer pump, heavy oil and fuel pump, fuel ejection pump.
6. Food industry: to ransport alcohol, honey, syrup, toothpaste, milk, cream, soy, plant oil, animal oil, wine and so on in distillery, food products factory, canning factory and so on to t.
7. Paint industry: the barrel loading pump and backward pump for coatings , paintings.
Advantages of twin screw pump:
1. High self-absorbing capacity
2. Low-noise, no pulsation, no emulsifying shearing for transporting media.
3. High efficiency
4. Different models apply to different purpose
5. Capable to Transport the mixture of gas and liquid
6. Capable to Transport volatile oil at high temperature; E.G. gasoline.
Performance of twin screw pump:
1. Flow rate: 3~2000m3 /h
2. Pressure: 0~4.0 Mpa
3. Temperature: -20C°~350 C°
4. Viscosity: 0~10000mm2/s ; it reachs 1×106mm2/s with special design.
Types
1. Installation type: horizontal type and vertical type
2. Structure type: casting type and welding type
3. Warming type: according to the demands of media, it can be warmed up.
4. Material: the materials of pump body contain cast-steel, cast-iron,cast stainless steel, Q235 steel, 304 stainless steel, 316L stainless steel, weld and so on. The materials of the screw cover cast-steel, cast stainless steel, ordinary steel, 304 stainless steel, 316L stainless steel, 17-4PH and so on. Meanwhile, customers can choose appropriate materials based on their different working situation.
The structure and work principles
1. The pump consists of pump body, driving and driven screws, axle sealing, synchromesh gear and safety valve, etc.
2. The screw is in symmentrical rectangular surface thread type . Driving the synchromesh gears make the driving and driven screws engage to move each other. The media is inhaled from both sides of pump and carried to the centre outlet of pump.
3. Safety valve is mounted on the side of pump body, the factory original activated pressure is setted 1.1 times of work pressure. When practical work pressure changes a lot, it can be reseted according to actual working situation.
4. No Safety valve for pump with flow rate less than 15 m3 /h
Screw pump operation instructions and attention points
1. Mounting the pump and prime mover on the sufficient strength pedestalthat can prevent the component damaged by vibration and ensure the pump work regularly.
2. Requirements for the connection of the pump and power should not lower than government standard.
3. The general working type: facing input driving screw, the input is in the right , the outlet upside and the rotating direction is right rotation. Please advise requirements when place order if other type is necessary. The Vertical Pump is same structure, only main screw vertical when seting.
4. Necessary to add filter, and the filter's specification is 20 mesh. The filter flow area should be more than 4 times of the input area of pump.
5. . The size of pipe must be no difference with that of pump input and output mouth, otherwise, it will effect pump using performance.
6. Clear all pipe and filter before the first time using, to make sure pump work normally.
7. Before pump starting up, all valve on pipe must be open. After Normal working, it can be adjusted according to pratical need.
8. After pump starting up, notice the pump vacuum value, if no vacuum after 1 minute, the pump should be stopped and checked.
9. When using pump to sweep cabin, race rotation ran not to exceed 3 minutes, in case of the damage of seal.
10. The gear oil should use 180#middle load gear oil. Check oil level of gear box frequently to make sure pump working normally. When working normally, the temperature of oil in gear box do not exceed 70ºC. When pump work for long time, the temperature do not exceed 80ºC.
11. Check lubricating grease for gear frequently, and add oil regularly.
12. Closed screw seaking frame pump: leak in the downside of the right and left shaft sealing frame; If the sealing is damged and leakage happens, the other pipes can not be closed to avoid the bearing damaged.
13. The pump's flow rate is too large and its pressure is too high, according to different conditions, bearing and gear box is equipped with the water circulating to cool the temperature. The flow of circulating cooling water is about 2m3 /h.
14. When transporting high viscosity media, it should use the pump equipped with heating system.
Common troubles and its solving methods
1. The pump cannot aspirate oil or displacement was not suit for rating
a. May be input pipe leaking, the vacuum cannot be formed
Check the leaking part, and then tighten the bolt or replace the washer
b. The screw and the pump body could be abraded greatly after using for a long time
Replace screw and pump body
c. The vacuum degree of inlet is extra high, and the screw pump vibrates intensively
Check whether the filter or pipe blocked up
d. The axle seal damaged and the air enter the pump, which make the pump cavity antivaccum
Replace the damaged axle seal
e. After open the safety valve, please adjust valve or replace spring if the pressure can not reach requirments.
f. Safety valve interior has impurities to cause unsealing
Clean rubbish to reach the sealing requirement
2. If unusual noise, smoky and stop happen to the pump, the temperature of bearings and gears is higher than the standard
a. Driving screw and driven screw pump against the pump body caused by the damaged bearing
Replace the bearing
b. The bearing is lack of oil or damaged making the pump stop
Oiling or replace the bearing
c. The impurities gets into the pump cavity making the pump stop
Clean the pump cavityand repair it
d. The gearbox is lack of oil or the oil mixed by impurities or water
Oiling or replace the gearbox oil
e. The damaged gears caused by lack of oil
Replace the gears; after replace, put the screw gap in the middle place to avoid screw collision when working
Assemble and disassemble of screw pump
Disassemble of the pump input axle end
Disassemble
a.Disassemble the shaft coupling, take down the plain key
b. Remove the both end shaft-cup
c. Remove the bearing and retaining washer
d. Utilize the four screw holes on the shaft bracket, with suitable bolt, retract the shaft bracket forcefully
e. When remove the bearing of the shaft bracket, pay attention to adjusting washer under the bearing, and do not misplace it
f. Check whether the seal and the bearing are damaged, replace the damaged unit
g. Pull out the screw to check for damage and impurities, it is unnecessary to pull out the screw if there is no impurities in the pump cavity
1.2 Assemble
h. Assemble the shaft bracket, insert locating pin tightly before tighten the bolt
i. Put adjusting washer into the place of disassembled, if framework oil seal on the adjusting washer is damaged, replace it
j. Assemble the bearing, retaining washer and bearing nut(assemb;e bearing with exclusive sleeve tool)
k. Assemble several coupling of two bearing end shaft-cup
2. Disassemble of the pump gear box end
2.1 Disassemble
a. Disassemble the gear box
b. Remove gear compression nut and retaining washer, do not mistake the direction and place of gear
c. the rest steps are the same as the above c~f
2.2 Assemble
d. the same as the above 1.2 h~i
e. According to the direction and place of disassembled, assemble gear, retaining washer and gear compression nut
f. Assemble gear box and add gear oil
g. After finish assembling, running the screw to check whether it is flexible, if there is no problem, assemble the shaft coupling