1. Check whether all parts of the vacuum pump are complete;

 

2. Check the oil level at different oil level mirrors and confirm that the oil level is about 3mm above the midline of the oil level mirrors;

 

3. Check and confirm the state of each valve of the vacuum unit;

 

(1) Process inlet valve is closed

 

(2) the inlet filter blowdown valve is closed

 

(3) The outlet pipeline is smooth and the outlet drain valve is open

 

(4) Cooling water inlet pipeline and outlet pipeline valve open

 

(5) Nitrogen line valve is opened, purging gas pressure is 0.5bar, nitrogen sealing gas pressure is 3bar, purging valve is closed

 

(two) screw vacuum pump boot operation steps

 

1. Contact with the central control on site, confirm that it can be started, and start the vacuum pump through the start button of the field operation column;

 

2. Close the drain valve of the outlet pipe;

 

3. Check or adjust the flow rate of nitrogen sealing gas and confirm that the flow rate is 2.5-3L /min;

 

4. Open the purge valve, confirm that the flow of the flowmeter is adjusted to the maximum, and close the purge valve after 5-10 minutes of purging;

 

5. Open the process inlet valve and cut into the system;

 

6. During the operation of the vacuum pump, pay attention to the body temperature. The temperature can be controlled by adjusting the water volume through the temperature regulating valve (the water volume is the maximum when the temperature regulating valve is located at the 0 scale, and the water volume is the minimum when the 5 scale is located).

 

(three) screw vacuum pump shutdown operation steps

 

1. Close the process inlet valve and cut out the system;

 

2, open the purge valve, purge 20-40 minutes, close the purge valve;

 

3. Stop the machine through the stop button of the field operation column;

 

4. Close the nitrogen valve;

 

5, close the cooling water valve; If not used for a long time in winter, it is necessary to drain the cooling water in the body and pipeline to prevent freezing;

 

6, open the outlet pipe drain valve and the inlet filter drain valve, check whether there is condensation.

 

Each process is very important, please the majority of operators can operate in strict accordance with the instructions, in order to achieve the best use of the state!

 

Screw vacuum pump purge function

 

First, screw vacuum pump cleaning and purging

 

Cleaning and purging is especially important for removing corrosive, toxic or viscous materials such as resins.

 

Generally, the inlet valve of the vacuum pump is closed before the pump is stopped, and the inlet is filled with nitrogen or water vapor after 20 ~ 30 minutes of operation. The screw in the cavity is purged, and the process gas residual in the cavity is cleaned or the sticky material adhered to the surface is cleaned.

 

Two, screw vacuum pump cooling purge

 

Cooling purge is used for the cooling of screw rotor and vacuum pump inner cavity.

 

When the vacuum pump works, the process gas inhaled by the inlet is compressed along with the rotation of the screw rotor and sent to the exhaust port. During the compression process, the temperature of the gas rises, which requires cooling purge to protect the vacuum pump from being stuck due to overheating.

 

Air is usually used as the cooling purge medium, but in special cases nitrogen or cooled process gases may be used as the purge medium. A strainer is installed near the exhaust port to draw in air for cooling purge.

 

Three, screw vacuum pump seal purge

 

Sealed purge is pressurized with nitrogen inside the front cover to prevent process gas or liquid from entering the tank containing the gears and bearings. There are 2 nitrogen inlet, located at the top of the front end cover. Nitrogen purge pressure ≤0.5bar.