In our daily work to choose a system is stable and high efficiency of hydraulic machinery, hydraulic baling press, it is very important for us. Because the words are referred to as the "to do a good job, will be a good first". So to ensure our efficient hydraulic machinery operation, there are several hydraulic harmful phenomenon, for our staff is very important to us.
A: we want to understand the phenomenon that the hydraulic impact of hydraulic shock this harmful phenomenon is caused by mutations that cause the hydraulic oil hydraulic components work instantaneous has risen sharply, produce the high hydraulic pressure peak, a shock wave passing, this phenomenon is called hydraulic impact or call it "water hammer"
In daily work to ensure that the mechanical properties of the good we have a better way to reduce the hydraulic impact is good method to provide good service to our customers.
1. To extend the time of the closing of the valve, reducing the speed of the reversing valve core.
2. Appropriate increase pipe diameter in order to reduce the flow velocity (pressure line is commonly 3-5 m/s).
3. Set limit pressure relief valve.
4. Set the hydraulic buffer device, reduce the speed of the large inertia in the moving parts of the runtime changes.
5. The use of accumulator and rubber hose to absorb hydraulic impact energy.
2: cavitation
According to Bernoulli equation can know through the valve for the hydraulic medium mouth contraction cross section, the pressure to reduce, the pressure drops and bubbles generated in the hydraulic oil.
For example, when pressure is reduced to the medium of saturated steam pressure, will produce cavitation phenomenon, thus forming a large number of steam bubble.
When pressure reduce to medium air separation will have a lot of air is sucked out from the liquid to form a large number of air bubbles.
3. The cavitation phenomenon:
Bubbles with high flow was brought to the downstream, the bubble volume shrinking dramatically or breaking, bubbles of air or steam or condensed liquid back into the liquid. At the instant of the bubble breaking, the bubbles breaking out of the local high temperature and high pressure, resulting in a hydraulic impact and with noise and vibration. The hydraulic oil oxidation. Bubbles breaking such as occurred in hydraulic components of the solid surface is generated when the bubble breaking the jet erosion, high temperature, chemical corrosion effect of joint action. Eventually lead to hydraulic components surface spalling and bad corrosion phenomena.
May occur in the hydraulic system of air-pocket and the parts of the corrosion phenomena are mainly:
Pump oil suction mouth, overflow valve valve mouth, with large inertia load of actuators, etc.
So how do we reduce and prevent cavitation and erosion phenomenon?
1. The right design line, limit pump oil suction mouth from the fuel tank of liquid level height (shortened as much as possible and improve the suction characteristic).
2. Improve the pipeline sealing to prevent air infiltration.
3. Select cavitation resistant material, improve the quality of components of surface (overflow valve, throttle valve, etc.)