The choice of screw pump type screw pump must first determine whether to buy their own need for liquid medium conveying what is inside, which contains the chemical composition in order to determine the suitable rubber sleeve meet the conditions included in the furniture industry, transport paint, screw pump customers only provide transportation paint, paint to find out whether it contains toluene, such as rubber sleeve can the use of fluorine rubber material containing toluene to meet the conditions, if the choice of ordinary nitrile rubber sleeve is broken easily, users do not understand the situation will mistakenly think there is a problem and the viscosity of the medium quality manufacturers, and the proportion of large or medium, such as viscosity solid content to reduce the speed of screw pump based on ordinary speed, low speed and wear can be reduced, so the selection of screw pump type and important. Below Huaian diaphragm metering pump manufacturer's small editor to tell you what to pay attention to when choosing the type of screw pump.

1. Determine the pressure of the screw pump:

The maximum output pressure of the screw pump is determined according to the number of bushing series, that is, the guide number of the bushing.

1 stage screw pump: the maximum working pressure is 0.6 MPa;

2 stage screw pump: the maximum working pressure is 1.2 MPa;

4 stage screw pump: the maximum working pressure is 2.4 MPa;

As the medium of the screw pump is different, for the medium with serious wear, please refer to table 1 to select the bushing series.

Two. Determine the rotational speed of the screw pump.

Screw pump because of its structural features, most used in the transportation of high viscosity liquid and liquid containing particles, so it is key to the choice of rotation, the screw pump parts, compact structure, small volume, simple maintenance, the screw pump rotor and the stator is vulnerable, screw pump has the advantages of simple structure, convenient assembly and disassembly. Is a new type of pump to mesh volume by circumventing the work principle. The main working parts are eccentric screw (rotor) and fixed bushing (stator). The use of non-toxic and tasteless edible rubber, working temperature up to 120 degrees Celsius, if the use of high temperature 120 degrees Celsius - 350 degrees centigrade can be customizable. Due to the special geometric opening of the two parts, a separate sealed chamber is formed respectively. The flow of the medium is carried out uniformly in the axial direction. The internal flow rate is low and the volume remains the same. Screw pump pressure is stable, so it will not produce eddy current and agitation. The output pressure of each level pump is 0.6MPa - 1.2MPa, head 60m - 120m (clean water), and the self - suction height is generally above 3M.

How to maintain high efficiency of screw pump

How to maintain the high efficiency of screw pump, screw pump or pump wells production capacity greater than the inlet gas separation is not good, a part of the pump displacement by interference and loss, if the interference and control principle of screw pump pump gas to eliminate the running time, the pump displacement is matched with the inflow at the bottom, you can to improve the efficiency and reduce the cost.

The high yield rate of pumping oil by screw pump is as follows:

1. The liquid level of the sound wave should be measured to determine the relative depth of the liquid level and the suction port of the pump. If the surface of the screw pump is higher than the suction port of the pump, it is impossible for the well to be exploited with the maximum output. If the gas interference affects the yield, the liquid level is higher than the pump intake; if the pump is too large to lead to low output, the liquid surface should be at or near the suction port of the pump.

2. Determine the percentage of pump full coefficient, and use the integrated data acquisition system to obtain motor power and indicator data at the same time. One of the main uses is to diagnose how the pump operates and to analyze the downhole problem. Application of the production level measurement with dynamometer can understand well whether the maximum yield production, the liquid column height is higher than the pump suction depth, screw pump is not completely full and free gas is along the casing annulus upward migration.

3. Diagnosis of low energy efficiency well. The diagnostic method is to determine the total efficiency of the pumping system, while the total efficiency is determined only by measuring the power of the input prime mover, measuring the bottom hole production pressure and accurate production test data. The total efficiency of the general pumping system should be about 50%, if it is lower than this, its performance should be improved. The technologies to increase total efficiency include maintaining high volumetric efficiency (matching of pump specifications and wellbore injection, eliminating gas interference, screw pump evacuation controller or timer control pumping) and replacing excessive motor.

4. Separation of underground gas. Ineffective pump operation is often caused by air interference, and can be diagnosed by sonic liquid level measurement and indicator diagram. It is better to put the pump intake at the bottom of the fluid entry layer, and if the gas separator is placed above, the gas separator should be used. If the seat short section is arranged at least 10ft below the bottom of the fluid entry layer, the effective gas separation can occur in the annular air, and the casing will act as the outer cylinder of the separator. But the conditions of the well do not allow the pump to be placed under the fluid entry layer, and the downhole gas separator is considered. A conventional gas separator is composed of a fluid entering part (such as a perforated short section), an outer cylinder (such as a tubing with a plug at the bottom) and a sealing tube at the bottom of the pump.

5, control pump displacement, can be controlled by adjusting 4 parameters: stroke length, pump number, daily operation time. Because of the high cost of the equipment, the screw pump usually does not change the size of the pump. The simplest way is to change the configuration of the ground equipment, such as moving rod to change the stroke length of the ground and pump, and then replace the motor belt pulley to control the number of pumps. The matching problem between pump volume and well productivity can be achieved by changing daily running time. The following devices can be used to control operation time: air pumping controller, interval timer and percentage timer. If the pump is not fully filled, the pump is stopped. The timer controls the running time of the pump, which is cheaper and easy to operate. The duration of the stop pump should be shorter than the oil layer pressure of no more than 10% of the production pressure at the bottom of the well.