Roots vacuum pump structure

Roots vacuum pump is a kind of vacuum pump without internal compression, usually the compression ratio is very low, so high and medium vacuum pumps need front-stage pumps, because of the special working environment and industry needs, the requirements for equipment is very high, divided into different types of products. How to arrange the two rotors of Roots vacuum pump in the pump body determines the overall structure of the pump.

Choosing the right equipment is very important. If it does not match the working environment, it will not only fail to give full play to its advantages, but even wear out the equipment. Therefore, it is necessary to understand the classification and structure of Roots vacuum pump before purchasing it.

Roots vacuum pump structure:

1. Vertical type: the axis of the two rotors is installed horizontally, but the plane of the axis of the two rotors is perpendicular to the horizontal plane. This kind of structure, the inlet and outlet of the pump is arranged horizontally, so it is convenient to assemble and connect the pipeline.

2. Horizontal type: the axes of the two rotors are installed horizontally, and the plane formed by the axes of the two rotors is horizontally oriented. The inlet of the pump with this structure is above the pump and the outlet is below the pump (and vice versa). The exhaust ports below are usually horizontally connected, so the intake and exhaust directions are perpendicular to each other. The exhaust port is connected with a three-way pipe which opens in two directions. One end is connected with the exhaust pipe, and the other end is used when the by-pass valve is dead or connected with the by-pass valve. The structure is characterized by low center of gravity and good stability at high speed. Large and medium-sized pumps at home and abroad mostly use this structure.

3, vertical shaft type: two rotors of some roots pumps abroad are installed perpendicular to the horizontal plane. The assembly gap of the structure is easy to control, and the assembly of the rotor is convenient and the occupied area is small.

4. With relief valve: In order to prevent accidents caused by overload, the equipment is equipped with a relatively reliable safety protector, that is, there is a relief valve installed on the bypass pipeline. The relief valve is closed when the exhaust port is under specified pressure. When the exhaust outlet pressure exceeds the prescribed pressure, the valve of the relief valve is automatically jacked to produce overflow, and when the exhaust outlet pressure becomes normal, the relief valve closes again by itself. It can automatically adjust, is also the pump’s allowable differential pressure device, so the greatest advantage of the relief valve is that the equipment together with the front pump, in a variety of pressure range can be continuously operated. This design can shorten the pumping shutdown time of the vacuum vessel in coarse vacuum by 30-50%. For larger pumps, the relief valve is installed in the bypass pipeline beside the pump body, while for smaller pumps, the relief valve is installed in the pump shell.

5. With steam condenser: In the case of the need to pump steam, the pumping unit must be designed to make the steam condenser, the condenser can be installed before or after the pump, not on the pump body. Under certain circumstances, the condensation heating up can reduce the heat of roots pump. Assuming a double condenser is used, the dirt can be removed with appropriate solvents during maintenance, and the steam can flow smoothly through the duct.

It can be seen from the layout of Roots vacuum pump structure that when the overall structure is decided, the structure and shape of the pump body itself will be determined accordingly. Therefore, we should pay attention to the important parts in the process of selecting products, so as to ensure the quality of products.