The statement about the operation of the reciprocating vacuum pump start up is wrong

Turn the rotor by hand, if you can't move, it is stuck, at this time, don't turn hard, you need to disassemble the machine to check it, to see if the valve plate or piston ring is stuck, there are many reasons why the pump can not operate normally, and it needs to be eliminated one by one Shanghai Feilu Vacuum Pump Factory Technical Department kindly provided.

1. The rubber soft connection can be used before and after the gate valve, and its function is to absorb shock, the second is the need for heat expansion and contraction, and the third is to facilitate the disassembly and assembly of the valve and the maintenance needs; The check valve only needs to be on the lifting pipe behind the pump, and its function is to protect the pump. It is generally installed after the gate valve.

3. The actual installation sequence should be: rubber soft connection, check valve, gate valve. The pressure gauge should ideally be installed on the outlet of the water pump, but it must be in front of the check valve.

4. The rubber soft connection is for vibration reduction. Of course, the connection between the pump and the piping system.

5. During normal operation, the gate valve is not very operable, and the check valve is frequently operated, so the maintenance probability is large, and the gate valve of the pump outlet pipe can be repaired without affecting the normal operation of the system by closing the pump outlet pipe during maintenance.

6. The pressure gauge is installed in front of the check valve, which can prevent the impact and damage of the pressure gauge by water hammer.

7. Some people propose that large-diameter pipes and check valves are installed behind the gate valve for opening and closing, which is unrealistic. Because when the pump is stopped, due to the presence of the check valve, the water pressure before and after the gate valve installed behind the check valve is the same, and there is no problem with the opening and closing of the gate valve. Of course, the large-diameter valve itself is a little more difficult to operate.

a.When determining the moisture of the fertilizer, the vacuum pump should be connected to the dry disinfection oven (correct answer) BIn order to speed up the filtration, a vacuum pump can be connected to the suction filter bottle (correct answer) in the case of slow sedimentation after filtration

c.Vacuum drying ensures that the water in the sample is removed at a lower temperature to avoid high-temperature decomposition of the sample (correct answer).

d.When the vacuum pump is running, pay attention to the temperature of the motor, and do not exceed the specified temperature (correct answer).

The high vacuum valve should be closed first, and then the low vacuum valve. Then stop the rotary vane vacuum pump.

It is then deflated (e.g. with an electromagnetic vacuum with a deflation valve, which can be automatically deflated to prevent oil from returning to the vacuum system.

Vacuum pump refers to a device or equipment that uses mechanical, physical, chemical or physicochemical methods to pump air from the pumped container to obtain vacuum. In layman's terms, a vacuum pump is a device that uses various methods to improve, generate and maintain vacuum in an enclosed space.

According to the working principle of vacuum pumps, vacuum pumps can basically be divided into two types, namely gas capture pumps and gas transfer pumps. It is widely used in metallurgy, chemical industry, food, electronic coating and other industries.

If there is a check valve at the outlet of the pump, the vacuum of the system will not be affected, and the valve needs to be opened to relieve the pressure.

2) Stopping: When using the 2SK series two-stage water ring vacuum pump alone, the parking is in the following order:

1. Close the gate valve on the inlet pipeline.

2. Close the gate valve on the water supply pipeline, and after the water is stopped, the pump should not be stopped immediately, so that the pump continues to rotate for 1-2 minutes to discharge part of the working liquid.

3. Turn off the motor.

4. If the parking time is more than one day, the screw plug at the bottom of the pump body must be opened and the water should be cleaned.

Parking of 2SK-P1 series water ring-atmosphere pump unit:

1. If the air pump is directly installed on the inlet flange of the two-stage water ring pump, the parking can be controlled according to the stopping sequence of the 2SK series two-stage pump.

2. If the air pump is connected with a two-stage water ring pump on the bypass pipeline and the solenoid valve is opened and closed, the air pump can be stopped first, and then the two-stage pump can be stopped.

For vacuum pumps, the following is correct for the jujube method ().

a.The compression ratio cannot be definitively determined.

b.The outlet pressure is equal to the atmospheric pressure.

c.The inlet pressure is equal to the atmospheric pressure.

d.The compression ratio is greater than 4

Correct answer: B