Rules for operation of Roots vane vacuum pump unit
Rules for operation of general wet Roots vane vacuum pump units
General Roots vacuum unit operation in accordance with the relevant rules of dry Roots vacuum pump, but also need to pay attention to the following related matters;
1) Pump should be run empty before use to check whether the rotating parts are flexible, whether there is blocking phenomenon, whether the rotation direction is correct, whether there are abnormal noise and vibration in the pump. Before starting, pull the pulley by hand, check whether there is any obstacle, and inject proper amount of clean water, and inject the prescribed grease into the gear box. Connect to the power supply, click a few times first, observe whether the situation is normal, and then measure the current after starting. If it is found that there is no indication on the vacuum gauge or the reading is very small, it is necessary to check whether the valves on the gas-water separator are sealed, whether the valves on the suction pipeline and the closure doors on the suction tank are sealed, and whether the flanges, joints and pump shells on the pipeline are leaking, and to eliminate them after finding out the causes.
2) Before starting the pump, the valve on the suction pipe should be opened and other valves should be closed.
3) The shutdown operation should follow the following procedures.
Press stop press and turn off the power supply;
(2) Vacuum sealed cooling water and re-tighten the water plug (temporary parking can not be emptied);
(3) Temporary shutdown, although not water, should be put into the air to destroy the vacuum condition in the pump, so that the next start-up is easy.
4) Notes for operation and use.
(1) Pumping should be started before the vacuum equipment is pumped;
(2) Pump shutdown should be after braking the vacuum pumped equipment;
(3) Water injection and exhaust should be done before starting the pump.
(4) Controlling the vacuum degree of the pump can adjust the valve on the inlet pipeline and adjust the closure door of the outlet of each suction tank when changing the vacuum degree of each suction tank.
_When the vacuum is too high, appropriate amount of air can be put into the water injection valve on the inlet pipe.
_When choosing a pump, attention should be paid to the balance between the external load and the pump's capacity. If the pumping speed of the vacuum equipment is greater than that of the pump, the pump's capacity is insufficient, and the vacuum degree is greatly reduced, which can not meet the proper use requirements. At this time, several pumps can be considered in parallel.
When the load of the external equipment is not much larger than the capacity of the pump, the speed of the pump can be increased, the speed of the pump can be increased, the pumping speed should be increased, and the power should also be increased, but the increase of the speed should not exceed 25% of the rated speed.
_After using for a period of time, the side plate of the stabilizer box and the lower drain bolt should be removed, the rotor rotated, the dirt washed out with water, and then assembled for reuse.
Basic Principle of Roots Vacuum Pump with Direct Exhaust Atmosphere
Roots pump uses internal cooling method, heat is directly taken away by circulating cooling air from the heat source, that is, the exhausted gas, when it is compressed or discharged, it is cooled by cooling air, so this kind of pump can be used where the standard pump can not work.
The pump chamber can be cooled by itself, because the impeller and the working chamber have a special working part. When this special part is working, a part of the working chamber is closed, blocking the inlet and outlet. Through the special ventilation port, the cooling gas flows out from the pressure side, or enters the working chamber again, and then from the outlet side by the pressurized cooling. But when the gas is filled, the gas is circulated.
Roots pump with internal cooling in gas cycle is controlled by a special impeller head without additional control elements. Therefore, the structure of this kind of Roots pump with internal cooling is simple and clean as that of ordinary Roots pump. It connects the cooler with the exhaust port, and the cooler is installed outside the pump housing for easy maintenance and replacement.
If the cooler is designed correctly and the pipe size for conveying cooling gas is large enough, the cooling effect is very good, so that Roots pump can work under various pressure differential conditions.
Pump heating depends not only on speed and circulating cooling dose, but also on pressure difference, which is proportional to speed. In addition, the clearance between the blade and the pump housing should be kept at a minimum. This is conducive to the improvement of volumetric efficiency in order to obtain a higher vacuum.
Gas cycle cooling Roots pumps are most suitable for those processes that discharge and compress gases or vapors. These exhausted or compressed gases should not be in contact with oil or harmful liquids before entering the pumps, such as nitrogen cycle in cryostat. If the pressure difference between intake and exhaust is very large and the required limit vacuum is very high, three Roots pumps can be considered in series. In addition, there are also water cooling or multi-stage pumps.
