Operation of roots water ring vacuum unit

Roots vacuum pump (hereinafter referred to as roots pump) is a kind of mechanical vacuum pump which uses a pair of high-speed rotating double leaf rotors (i.e. "s" shape, straw shoe type) to pump out gas. Its structure and working principle are similar to roots blower. Because the gap between the pump rotor and the cavity is often small (0.1-0.15 mm), so as to ensure that there is a large pumping speed between 10-1-10-2 Torr, which just makes up for the defect that the pumping speed of the oil seal mechanical pump and the oil diffusion pump is very small in this pressure range, and plays a role of increasing pressure in the vacuum system, so it is also called the mechanical booster pump.

Under high pressure, the average free path of gas molecules in roots pump is smaller than the width of the gap (< 0.1-0.15mm). Relatively speaking, the gap has a considerable conduction capacity, which is easy to make a large amount of gas flow back to the pumped container through the gap, so that the pump can not work effectively. On the contrary, under low pressure, the average free path of gas molecules increases, and the conduction capacity of the gap decreases greatly Small, that is to say, the resistance of gas leakage through the tiny gap increases, so that the pump can work effectively and obtain a higher compression ratio, that is to say, a higher vacuum degree.

Therefore, the roots pump can not directly discharge the gas to the atmosphere, so it must be equipped with a pre vacuum pump, so that the exhaust end of the roots pump creates a certain pre vacuum, otherwise it can not obtain a higher vacuum degree. And the rotor will be stuck or even damaged due to overload and overheating.

According to the purpose of the air extraction system, the pre-stage pump required by roots pump can select the pump that can operate from atmospheric pressure, such as the air pump of oil seal machinery, water ring vacuum pump, and water ring vacuum pump with air ejector, etc. The size of the front stage pump, according to the conditions of use and the pumping characteristics of the front stage pump, is generally 1 / 10-1 / 2 of the roots pump pumping speed. When the pump operates continuously under high pressure, the front pump with large pumping speed shall be selected. When the pump operates under high vacuum, the front pump with small pumping speed shall be selected. For the oil seal mechanical vacuum pump, the pumping speed is only 1 / 4-1 / 10 of that of Roots vacuum pump, but when the water ring vacuum pump is selected, the air volume should be 1 / 2 ^ - 1 / 3 of that of roots pump; in addition, when the small roots pump is used between roots pump and the front pump, the pumping speed is 1 / 2.5-1 / 5 of that of the large roots pump.

In many cases, water ring vacuum pump is more advantageous than other vacuum pumps. This is not only because the water ring vacuum pump has the advantages of simple maintenance, convenient operation and few faults, but also because it can pump out a lot of condensable steam. When the ability of removing condensable steam is not enough, or the pumped gas will deteriorate the pump oil and affect the performance, and the vacuum system does not allow oil pollution, the use of water ring vacuum pump is more effective Profit.

Roots Vacuum Pump

Piston Vacuum Pump

industrial vacuum pumps,vacuum furnaces