Principle and characteristics of Roots pump of vacuum sewage suction truck

Principle and characteristics of roots pump of vacuum sewage suction truck

The sewage suction trucks are all vacuumed. The tank body is pumped to a vacuum by a vacuum pump, and the pressure difference between the atmospheric pressure and the negative pressure in the tank is used to press the dirt into the tank. The advantage is that the vacuum system and the suction pipeline are relatively independent, the dirt does not need to be in contact with the pump, and only air is pressed in, which can ensure the working environment of the pump and the vacuum system. Then the vacuum pump is very important. The vacuum pumps currently in mainstream use include wiper/rotary vane vacuum pumps, water ring vacuum pumps, and in recent years, Roots pumps and sludge pumps have also been used in sewage suction trucks. The following mainly introduces the principle and characteristics of Roots pump.

Working principle: The working principle of Roots pump is similar to that of Roots blower. Due to the continuous rotation of the rotor, the pumped gas is sucked from the air inlet into the space v0 between the rotor and the pump casing, and then discharged through the air outlet. Since the v0 space is fully enclosed after inhalation, there is no compression and expansion of the gas in the pump cavity. However, when the top of the rotor turns over the edge of the exhaust port, and the v0 space is connected to the exhaust side, due to the higher gas pressure on the exhaust side, a part of the gas rushes back into the space v0, causing the gas pressure to suddenly increase. When the rotor continues to rotate, the gas is discharged out of the pump.

Roots pump has the following characteristics:

Larger pumping speed in a wide pressure range;

Start fast and work immediately;

Not sensitive to dust and water vapor contained in the pumped gas;

The rotor does not need to be lubricated, and there is no oil in the pump cavity;

The vibration is small, the rotor dynamic balance condition is better, and there is no exhaust valve;

The driving power is small, and the mechanical friction loss is small;

Compact structure, small footprint;

Operation and maintenance costs are low.

Therefore, Roots pumps are widely used in the metallurgy, petrochemical, paper, food, and electronic industries.