Detection and hazard control measures of cavitatio

2022-09-22
  • Detail

Cavitation and cavitation detection of hydraulic parts and hazard control measures

1. When the pressure is lower than 2 Display mode: curve graph, force value display, and dynamic query of any point on the curve graph The computer displays the relevant information of the experimental results: when the air separation pressure is applied, the air dissolved in the liquid is difficult to be activated and separated, and exists in the liquid in the form of bubbles, occupying a certain space in the oil, making the oil discontinuous. This phenomenon is called cavitation phenomenon

2. After cavitation, bubbles enter the high-pressure area with the liquid flow, and are rapidly destroyed or reduced, while the space originally occupied forms a vacuum. The surrounding liquid particles rush to the vacuum area at a great speed, causing local hydraulic shock, which suddenly turns the kinetic energy of the particles into pressure energy and heat energy. When this kind of hydraulic impact occurs on the metal side wall, it will aggravate the oxidation and corrosion of the metal and gradually form pitting on the surface of the metal parts. In serious cases, the surface will fall off and small pits will appear. This phenomenon is called cavitation

detection of hydraulic cavitation and cavitation:

1. Install a vacuum gauge at the inlet of the oil pump

2. Listen to whether the sound of the oil pump is normal according to experience, and the cavitation oil pump will emit a howl

3. Through the measurement of fault phenomena: for example, insufficient oil absorption of the oil pump or reduced oil output will slow down the action of the oil cylinder or oil motor, and the action of the system will become slow

cavitation occurs in the low-pressure area of liquid flow, and cavitation occurs in the high-pressure area

1. Cavitation at the throttling part

2. Cavitation in the oil pump mainly determines the oil suction height, oil suction speed and pressure loss in the pipeline

hazards and control measures of hydraulic cavitation and cavitation

(I) hazards:

1, deterioration of working performance

2, reduction of volumetric efficiency

3, damage to parts

4, shortening the mechanical life of pipelines

5, affecting the system pressure and flow

6, generation of hydraulic shock, vibration and noise

(II) control measures:

1 Make the system oil pressure higher than the air separation pressure: the gas content of general mineral oil is 10%, and the air separation pressure when the oil temperature is 50 ℃ is about 0.4 105Pa absolute pressure

2. In order to prevent cavitation in throttling parts such as small holes and control valves, the pressure ratio before and after throttling should be less than 3.5

3. The oil pump should have sufficient pipe diameter to avoid narrow channels or sharp turns. The oil pump should not be too high from the oil surface, so as to ensure the pressure in all parts of the oil suction pipe and raise health and environmental problems no less than the air separation pressure. Reduce the oil suction resistance of the oil pump as much as possible. In addition, the flow rate of oil in the pump should not be too large, that is, the speed of the oil pump should not be too high

4. Reduce the content of air in the oil as much as possible, avoid the direct contact between pressure oil and gas and increase the dissolution, and the sealing of pipe joints and components should be good to prevent air intrusion. Prevent bubbles from being sucked into the mouth of the oil suction pipe; The oil return pipe should be inserted below the liquid level to prevent the oil return from flushing air into the oil; Reduce mechanical impurities in the oil, because the surface of mechanical impurities is often covered with a thin layer of air

Copyright © 2011 JIN SHI