Regulating return valve and current of centrifugal pump

The performance of the centrifugal pump is a curve, not completely linear. The shaft power consumed by the centrifugal pump is only related to the flow of the pump, and the flow of the centrifugal pump is related to the outlet pressure. When the centrifugal pump has a return, the equivalent of the outlet pressure becomes smaller, the flow rate of the centrifugal pump is larger than the rated state, so the current of the centrifugal pump is increased. When you close the return valve of the centrifugal pump, the output flow of the centrifugal pump is actually reduced, and the shaft power required by the centrifugal pump is also reduced, so the motor current is reduced in response. Centrifugal pump as long as directly through the adjustment of the outlet valve can be achieved flow regulation. The function of installing the return pipe is only related to the process. Of course, some centrifugal pumps open the return valve when compressing the actual flow to reduce the damage caused by the pressure in the centrifugal pump to the machine seal.

2024-05-16

Anti-freezing and Thawing Measures for Water Pump in Northern Winter

Recently, some motor enterprises semi-annual report and performance forecast show good. In the first half of 2018, the company achieved operating income of 201.4216 million billion yuan, an increase of 48.06 over the same period last year, and net profit of 26.4757 million billion yuan, an increase of 49.01 over the same period last year, completing the 63.02 of the annual plan target. Ocean Electric disclosed the third quarter results show

2024-05-16

Screw pump leakage causes and precautions

There are several reasons for the sudden leakage of the screw pump during normal operation. One is the leakage of the mechanical seal, the other is the misalignment of the installation, the shaft sleeve is worn, the pump body and the bushing of the pump are integrated (collectively referred to as the pump body), and the shaft seal is a mechanical seal. Screw pump has a variety of structural forms, generally a small flow rate of 0.2~6.5 m3/h, the pump body and bushing are integrated (collectively referred to as the pump body), and the shaft seal is a mechanical seal

2024-05-16

Solution to Oil Leakage of Loader Gear Pump

Loader "gear pump oil leakage", refers to the hydraulic oil will skeleton oil seal breakdown and overflow. Gear pump oil leakage is widespread, which seriously affects the normal work of the loader and causes environmental pollution. This paper will analyze the causes of oil leakage of gear pump oil seal in detail and put forward the method to solve the problem

2024-05-16

Starting method and matters needing attention of gear oil pump

The no-load start of the gear oil pump is to check whether there is collision and friction between the rotating parts and the fixed parts, whether the bearing temperature is normal, whether the swing and vibration are qualified, whether the various instruments are normal, whether the oil pipelines, joints, valves, etc. are leaking, and determine the motor Starting characteristics and other related parameters.

2024-05-16

Gear pump maintenance should pay special attention to the following matters

1 Maintenance Considerations 1.1 strictly implement the process operation procedures and related systems. Before 1.2 and starting the equipment, it is necessary to check whether the device is complete and reliable. During the operation of 1.3 equipment, it is not allowed to wipe the operating parts. 2 Maintenance Precautions Before 2.1 equipment maintenance, clean the equipment and pipelines, close the inlet and outlet valves or add blocking blind plates, and isolate them from the system. Handle the overhauling formalities after being qualified. Cut off the power supply of the 2.2 equipment before maintenance, and hang the "No Move" sign at the power supply after reexamination before maintenance. 2.3 maintenance tools, dismantled, cleaned and replaced parts shall be placed in the specified place, neatly placed and civilized construction shall be carried out. 3 Commissioning Precautions 3.1 gear pump commissioning work should be responsible for, and under the unified command. 3.2 start and stop shall be operated by special personnel, and the operator shall hold the "operation certificate" of this post ". Obvious test run signs shall be set up 3.3, and irrelevant personnel shall be prohibited from entering the test run site. Before the 3.4 test run, check whether the rotation direction of the drive motor is correct. After the rotation direction is correct, connect the coupling and install the protective cover before the test run. 3.5 in strict accordance with the pump start-up procedures. 3.6 During the test run, pay attention to whether the gear pump is running normally. If abnormal vibration and sound are found, and the current exceeds the rated value, stop the machine immediately for inspection and treatment, and then test run after elimination.

2024-05-16

Measures to Improve the Operating Life of High Temperature Gear Pump

Maintain the normal operation of high temperature gear pump The high temperature gear pump should be regularly overhauled and maintained after a period of time to ensure the better operation of the high temperature gear pump. High temperature gear pump operation and maintenance methods are: 1, start should be injected into the pump delivery liquid. 2. Check the tightness of all pipeline flanges and joints before starting. 3, start should be injected into the pump delivery liquid. Disc coupling, no friction and collision sound. 4. Before starting, the valves in the suction and discharge pipelines should be fully opened, and the shut-off valve should be strictly started. 5. After verifying the rotation direction of the motor, start the motor. Measures to improve the operating life of high temperature gear pump: I. Because the pump body operates at high temperature, the pipe shall be provided with hinged support during cold installation to prevent pipe displacement after heating up. II. The coupling is hot-oriented after the pump body heats up to avoid additional torque during operation. III. Interlock stop alarm shall be set at the pump outlet pressure measuring point, otherwise, once the discharge pipeline is blocked, the pump body will be easily damaged. IV. When the pump is started, when no pressure is formed at the outlet, it cannot be blindly increased to prevent premature damage to the shaft or bearing. V. When cleaning the pipetting, do not use the pump to transport the cleaning liquid. The inner parts should be removed and installed after the pipetting is completed to avoid foreign matter mixed into the pump. VI. The temperature of the heat medium jacket of the pump body can be slightly lower than the heat medium temperature of the front and rear jacket tubes. Because the melt viscosity and shear rate into a decreasing function, gear extrusion, bearing shear will make the melt temperature after the pump rose 3~5 ℃, reduce the heat medium temperature can prevent melt degradation. The data show that by reducing the temperature of the bearing area, the bearing capacity can be greatly increased, there is no need to replace the large-capacity pump, and the output capacity of the gear pump can be increased by 50% only by increasing the speed. VII. Speed increase should be carried out slowly, do not make the front and rear pressure rise sharply, so as not to damage the bearing or make the melt block the lubrication channel. VIII. The melt filter behind the pump outlet should be replaced regularly, and do not run at high pressure or even upper pressure limit for a long time. IX. Regular replacement of bearings can save maintenance costs. When it is found that the amount of wear on the inner surface of the shaft or bearing is close to the thickness of the hardened layer, the shaft can be polished and used again, and only the bearing can be replaced, which can extend the life of the pump shaft by 8 to 10 years. XI. In case of power failure or interruption of heat medium circulation for more than 3Omin, the pump should be disassembled and cleaned and reassembled to avoid melt solidification. Pyrolysis, etc., resulting in poor lubrication of bearings and damage to the pump.

2024-05-16