The noise of the gear pump is mainly the aerodynamic noise produced by the gas or liquid during transportation, the structural noise caused by the vibration of the motor housing, the noise caused by the vibration of the machine base, and the noise of the motor. The peak of this kind of noise level is mainly concentrated in the low octave band, about 100-450Hz. The sound source belongs to steady-state noise when the gear pump room is running normally. Pipe noise refers to the noise produced when the medium flows in the pipeline. In addition, the signs of cavitation and water hammer of gear pump can also produce instantaneous noise. The noise generated by the water supply pipeline is affected by the flow rate and pressure.
The noise produced by the whole facility of the gear pump room is mainly mechanical noise. At present, the acoustic principle of noise control methods are more commonly used to control the transmission of noise, such as sound insulation, sound absorption, noise elimination and so on.
Sound insulation is the use of sound insulation structure to separate the sound source from the receiving point; sound absorption is the use of sound absorption structure or sound absorption material to reduce noise; noise suppression is to exercise the principles of impedance, resistance, porous diffusion and so on to reduce the noise value.
Noise control measures should be based on the principle of acoustics and fully exercise the environment and conditions of the site as far as possible. Such as:
1. according to the environment of the pump room, close the sound source to the imprecise pump room for sound insulation treatment, adopt sound absorption / sound insulation treatment for the noise room produced by the pump room, and do sound insulation treatment for doors and windows, etc.
2. Control the noise generated by machinery, equipment and equipment parts. The pump foundation of the new pump house should be heavy to prevent noise caused by vibration. In addition, rubber vibration isolation pads should be set up to isolate vibration, so as to reduce the noise of vibration; each water pump unit should set up a separate foundation to prevent resonance. In the pump suction, pressure pipe as far as possible the use of "soft" connection.
Regular maintenance, such as root leakage, equipment parts loose, equipment parts wear tension, mechanical vibration and so on should be timely maintenance, so as to reduce noise. Because the working principle and structure of different manufacturers and types of gear pumps are different, the site investigation and analysis of noise sources are very tight to the design of sound insulation and noise reduction scheme of pump room and the selection of materials.
The specific steps to start the gear pump are as follows:
1. When you turn the gear pump coupling by hand, it should feel light and uniform.
2. Check whether the rotation direction of the pump is correct, which should be consistent with the direction indicated by the sign on the pump body. if there is no special requirement, the general gear pumping station looks at the end of the motor and is left in and right out.
3. Check whether there is an unloading circuit in the hydraulic system to prevent full load start or stop.
4. Check whether the safety valve in the system is in the set allowable pressure range.
5. Fill the oil outlet with medium to avoid damage to the internal parts caused by dry grinding when the pump is started.
6, no-load operation of not less than 2 seconds, check whether the running sound of the pump is normal and whether the direction of the liquid flow is correct.
7. Adjust the pressure of the relief valve to rotate below 1.0MPA for about 10 seconds, and check whether the action of the system, external leakage, noise, temperature rise and so on are normal.
8. Adjust the pressure of the relief valve to the safety protection pressure operating range of the hydraulic system.
9. Start the motor to see whether the rotation and sound of the pump are normal.
