Correct application of rotary vane vacuum pump

Before application, carefully read the product specification, and check the shipping quality after unpacking. Put away the spare parts and technical documents, and remove the protective parts of the exhaust port. According to the request, install the device, connect the wiring and try the steering. The water cooling pump is connected with water.

In order to avoid fuel injection due to oil return and reverse rotation, first open the pump port and turn the oil in the pump into the oil tank by hand according to the rules. Check the oil level at the same time. It should be above the center of the oil scale, but do not fill the oil scale. If it is too much, drain it.

Auxiliary method for judging steering. Put the sheath upside down on the pump port. If it is sucked after starting the pump, it is positive, blown off and reverse. Normal sound is positive, abnormal sound is reverse.

If the pump port is equipped with an inflation solenoid valve, it shall be installed horizontally and act at the same time with the pump.

When the relative humidity is high or the extracted gas contains condensable steam such as water vapor, the gas ballast valve shall be used.

Vacuum pump oil shall be recommended according to the instruction. Note that ester vacuum pump oil can not be mixed with mineral oil vacuum pump oil and other oils. It must be strictly cleaned before changing into ester vacuum pump oil.

Check the limit pressure of the pump, subject to the compact mercury vacuum gauge. The full pressure gauge should pay attention to the matching calibration and standby comparison between the gauge and the regulator. It is suggested to install a ball valve between the regulation and the tested pump. Closing the valve in case of accident can prolong the application time of regulation.

Maintenance of rotary vane vacuum pump

l. First, understand the type, characteristics and current situation of the pump. Understand the application request and confirm the repair purpose. Be prepared to test the wrist before stopping the repair.

2. Identify and diagnose problems. Accurate judgment can save trouble. The diagnosis needs textual research.

3. Eliminate problems, first simple and then complex, first easy and then difficult. Do not disassemble those that do not need to be disassembled. To reduce new damage caused by short special tools and improper operation, and reduce position change and running in operation time. Generally speaking, the spliced rotor is not removable, otherwise the geometric tolerance will not be guaranteed, and the rotor will be scrapped.

4. For toxic, harmful and corrosive pumps, please ask the user to clean them first and inform the necessary protective measures to ensure the health of maintenance personnel.

5. Fault classification

It is suggested that faults be divided into operation faults and performance faults.

Operation problems can include pump failure, too high pump temperature, oil leakage, water leakage, excessive maximum power, etc.

Performance problems may include the failure to meet the requirements of limit pressure, limit full pressure, extraction efficiency, noise, fuel injection, gas ballast performance, etc.

6. Examples of fault discrimination and diagnosis

6.1 the pump does not run. If the condition is unknown, do not start the pump first to avoid aggravating the problem. Can and cannot be turned by hand.

6.1.1 the pump can be turned without rotation. The reason can be the fault of the coupling; Belt slipping; Incorrect motor wiring; Motor damage; No power, etc.

6.1.2 if it cannot be turned or it is very heavy, the reason can be that the starting pump temperature is too low and the pump oil viscosity is too high; The reason for design and manufacture is that there is too much oil return after stopping the pump. Too much oil is returned when the pump is stopped due to too high oil level (too much oil is added, or water vapor condenses in the pump, or the water condensed in the exhaust pipe returns to the pump); There are foreign matters in the pump (welding slag and oxide in the air inlet pipe; debris of pump parts such as rotary leaf spring; rotary leaf is deformed and stuck; bite occurs (copper sleeve, rotor, middle wall, pump cover, stator and bearing).

6.2 the pump temperature is too high. It means that the maximum oil temperature measured near the left of the low-level exhaust valve exceeds the rule value of the application specification. The increase of the pump temperature will greatly reduce the viscosity of the pump oil, increase the saturated vapor pressure of the pump oil, increase the limit pressure of the pump and reduce the extraction efficiency; make the rubber parts easy to age; thermal shrinkage will reduce the operating clearance, especially the thickness direction and copper of some non-metallic rotating blades The inner hole clearance of the sleeve affects the reliability of the pump operation. The reason for the high pump temperature can be that the ambient temperature of the pump is too high, the inlet temperature is too high, the inlet cooling installation fails, the pump operates continuously for a long time, and the inlet pressure is too high; the cooling water of the water cooling pump is lack, the circulating water design effect is poor; the temperature control water regulating valve fails, etc.

6.3 oil leakage. It can occur on the sealing surface of shaft seal, oil tank and pump parts, oil drain plug, oil standard, oil hole bulkhead, the connection between stator parts and through holes of support, and air ballast valve (such as 2x-8) And other parts. It can be caused by aging seals, improper devices, damage and failure, uneven appearance, impurities, roughness and loose castings. If the oil returns after stopping the pump, the oil will enter the gas ballast valve, and oil leakage may occur if the gas ballast valve is not closed. When making self-made rubber pads, oil resistant rubber must be used according to the original design shape. If the sealing surface is too large, oil leakage will occur if it is not pressed tightly.

6.4 water leakage can occur at the water pipe joint, water jacket blind cover plane, drain hole plug, drain valve, etc. water jacket drilling through, casting defects and frost crack may also lead to water leakage.

6.5 high power exceeds the standard. It can be caused by long-term continuous operation, too high inlet pressure, too high exhaust pressure, seizure of sundries, too high pump temperature, too small matching clearance of rotating blades, too high voltage, too much pump fluid returning into the pump, etc., which will damage the motor. Try to prevent long-term continuous operation near the maximum power rate. If there is accumulation on the surface, it should be removed and cleaned regularly.

6.6 the limit pressure is not up to standard.

It can be caused by external leakage, internal leakage, oil hole infarction, poor pump oil quality or pollution transformation, condensable substances such as water vapor, distortion of instruments and meters, abnormal pump operation, etc.

When there are many external leaks, white steam can be seen at the exhaust port. There are many bubbles at the oil standard, and the exhaust pressure can be felt by hand at the exhaust port. There are many bubbles on the oil surface at the low-level exhaust valve. The power will increase. At this time, first check whether the gas ballast valve has been closed. Since each new pump leaves the factory and measures the limit pressure at the pump port, if there is external leakage, deal with the pump port, pipeline and valve Check the containers one by one. External leakage can also be caused by the failure of the outer shaft seal, no oil in the oil cup and air leakage at the oil hole bulkhead. Internal leakage can be caused by the moving clearance in the pump, the plane of the exhaust valve seat, the sealing surface of the exhaust valve, the plane of the inner shaft seal, the pump cover, the intake pipe and the sealing parts of the air ballast valve. Wear, corrosion and occlusion will increase the running clearance. When the oil hole is blocked, turn over the oil hole to listen to the noise of the pump It will be lighter. Under the condition that the oil tank is well sealed, if your hand feels sucked on the exhaust port, the exhaust valve may fail.