(3)除单螺杆泵外,其他螺杆泵无往复运动，不受惯性力影响，故转速可以较高，一般转速为1500~ 3000r/ min。
Advantages of special pump for aerated concrete
(1) The flow rate is uniform. When the screw rotates, the seal chamber is pushed forward continuously, and the instantaneous discharge is the same. Therefore, the screw pump flow than reciprocating pump, gear pump to uniform.
(2) The stress condition is good. The driving screw of most screw pumps is not affected by radial force, and all driven screws are not affected by torsion moment. Therefore, the service life of screw pump is longer. Some pumps made of double suction structure, can also balance the axial force.
(3) In addition to single screw pump, other screw pumps have no reciprocating motion and are not affected by inertial force, so the speed can be higher, generally 1500 ~ 3000r / min.
(4) Smooth operation and low voice. The transported liquid is not agitated. Screw pump seal cavity space is large, there is a small amount of impurity particles do not hinder the work.
(5) It has good self-priming ability. Because of the good sealing performance of screw, it can discharge gas. It can be used for gas-liquid mixed phase transportation without tank pump when starting. Due to its good sealing performance, it can work under high pressure, and the pressure can reach 300 * 10Pa.
3、 Characteristics of aerated concrete pump
The comparison of the three types of screw pumps is shown in table 2-2.
4、 Application of special pump for aerated concrete in oil and gas mixed transportation
In the oil and gas field development project, the gas-liquid two-phase flow pump or oil-gas-water multiphase flow pump used for long-distance transportation of untreated crude oil or partially treated oil-gas-water multiphase mixed liquid is called multiphase pump or mixed transportation pump. The application of multiphase pump technology can shorten the production cycle of oilfield, improve the production of oilfield, save investment and prolong the life of old oilfield.
At present, many kinds of multiphase pumps have been developed abroad, which can be divided into onshore multiphase pumps and underwater multiphase pumps; According to different working principles, it can be divided into rotary power multiphase pump and positive displacement multiphase pump. The former includes spiral axial flow multiphase pump, centrifugal pump, counter rotating wet compressor, etc., while the latter includes single screw pump, twin-screw pump, diaphragm pump, linear piston pump, etc.