Today, Yankang will share with you the precautions of the use of blow molding machines for hydraulic oil – water pollution.
Nowadays, with the development of industrial automation, hydraulic equipment is being used more and more widely with its unique advantages. However, hydraulic components and hydraulic systems have different properties from mechanical equipment. Once a hydraulic system fails, it will not only cause equipment damage, product quality degradation, production line shutdown, but also endanger personal safety, cause environmental pollution, and cause huge economic losses.
So how to ensure the normal operation of the hydraulic system, how to find faults in time has become a growing concern.
The practice has proved that oil contamination in hydraulic systems is the main cause of system failure. It seriously affects the reliability of the hydraulic system and component life.
Therefore, people are increasingly aware that the life of hydraulic systems and components is closely related to the cleanliness of oil.
In recent years, the pollution control technology of hydraulic systems has been greatly developed, and many aspects have formed special scientific research, production, and application system.
This paper analyzes the causes of water pollution of hydraulic oil and puts forward reasonable preventive measures and treatment methods in combination with daily maintenance work, which greatly improves the service life of hydraulic equipment and reduces maintenance costs.
In production operations, one of the main reasons for the deterioration of hydraulic oil performance is that water enters the hydraulic fluid.
Moisture is one of the main pollutants in oil can cause many problems.
The ingress of water, especially a large amount of free water, destroys the formation of the lubricating oil film in the hydraulic system, the lubricating property of the oil drops sharply, causing wear, sticking and metal fatigue on the moving surface, and some metal abrasive grains are generated, and these metals The presence of small particles, especially copper or iron particles, becomes a catalyst for the oxidative decomposition of water and oil, which accelerates the reaction.
- The reaction will generate acidic corrosive products, insoluble pollutants, and other harmful substances, causing parts to be corroded, valves stuck or forming sludge;
- Water will increase the viscosity of the oil or thin the oil film;
- In addition, the water in the hydraulic oil will react with the oil at a higher working temperature to oxidize and degrade the oil, reducing the service life of the oil;
- After the water enters the oil, the compressibility of the oil is increased, resulting in unstable work;
- Under low-temperature working conditions, the particles in the oil condense into ice particles, block the gaps or small holes of the control components, causing system failure; easy to breed bacteria in the system, reducing the service life of the oil, increasing the Oil change cost;
- The additive in the oil is dissolved in the water to cause loss, which reduces the performance of the hydraulic oil; reduces the lubricity of the oil, resulting in unstable operation of the equipment;
- Accelerate the surface fatigue of the metal, protect the metal parts from being insufficient, easily rust or corrode, and reduce the service life of the metal parts;
- Blocking the filter reduces the filtration effect and directly increases the filtration cost.
Ways of moisture in oil
(1) The fuel tank cap condenses into moisture in the air due to alternating hot and cold.
(2) The seal of the cooler or heat exchanger is damaged or the cooling tube is broken to allow water to leak into the oil.
(3) The humid air entering the system through the piston rod of the hydraulic cylinder is not tightly condensed into water droplets.
(4) The water brought in by the oil and the water absorbed by the oil in contact with the water in a humid environment.
Hazard after mixing water into the oil
(1) When a certain amount of water is mixed into the oil, the hydraulic oil is emulsified into a white turbid state. If the hydraulic oil itself has poor anti-emulsification ability, after a period of time, the water can not be separated from the oil, so that the oil is always in a white turbid state. This white turbid emulsified oil enters the inside of the hydraulic system, which not only rusts the components inside the hydraulic valve but also reduces the lubricating performance so that the wear of the parts is intensified and the efficiency of the system is lowered.
(2) After the iron-based metal in the hydraulic system is rusted, the rusted rust flows in the hydraulic system piping and hydraulic components and spreads and spreads, causing rust inside the entire system and generating more flaking rust and oxide.
(3) Water can also react with certain additives in the oil to produce pollutants such as sediment and gel, which accelerates the deterioration of the oil.
(4) The action of sulfur and chlorine in water and oil produces sulfuric acid and hydrochloric acid, which aggravates the abrasive wear of the components, accelerates the oxidative deterioration of the oil, and even produces a lot of sludge.
(5) These water pollutants and oxidation products become catalysts for further oxidation, which eventually lead to blockage or seizure of the hydraulic components, causing malfunction of the hydraulic valve system, blockage of the distribution pipe, reduction of the efficiency of the cooler, and blockage of the oil filter. Series failure.
(6) In addition, at low temperatures, water condenses into tiny ice particles, which also easily clog the gaps and dead ports of the control element.
This equilibrium occurs very quickly when the hydraulic fluid is in contact with moist air, typically 0.02% to 0.03% at typical operating temperatures.
When the climate is warm, the absolute humidity of the air is large and the water content in the oil is correspondingly increased.
When the climate cools, the dissolved water in the oil is supersaturated. When the water does not come out and enters the air, it generates tiny water droplets in the hydraulic oil.
When the temperature rises again, part of these tiny water droplets will become dissolved again, and the other part will coalesce together, or become sedimentary water, still in the state of free water, so the hydraulic oil will also absorb moisture from the air. Saturated.
This state is repeated many times, which causes the hydraulic oil to be flooded in a large amount.
So what to do?
Hydraulic fluids can be completely replaced in hydraulic systems where oil contamination is particularly severe or where dewatering is lacking. After the water-contaminated oil is cleaned, add new oil to the lowest oil level that the oil pump can circulate, and start the oil pump to cycle. Various actions of the hydraulic system are continuously performed to return the oil of the moisture that is trapped in the various valve members and moving parts to the fuel tank. Then drain the fuel tank and replace it with new working oil. This way the machine can be used normally.
As a professional blow molding machine manufacturer, Yankang Plastic Machinery adopts a servo-hydraulic system, which is safer and more efficient than the traditional hydraulic system, saves energy by more than 40%, and has low noise.
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