The hazards of oil pollution in the hydraulic system of coal mine equipment include hydraulic pumps, hydraulic motors, oil cylinders, valve groups, filtration devices, pipelines, and hydraulic protection devices. Due to excessive oil pollution, the common impacts are as follows:

Common impacts of hydraulic motors include wear and leakage of valve plates, gears, needle stator, rotor, and damage to sealing rings;

Common effects of hydraulic cylinders: damage to plungers, plunger rods, guide sleeves, and sealing rings;

Damage to hydraulic accessories: The pressure regulating control mechanism and valve group are stuck and unable to operate or operate flexibly, the safety valve core is padded by pollutants, and the filter is abnormally clogged.

Strengthening on-site maintenance management is an effective measure to prevent external pollutants from entering the system and to filter out pollutants in the system.

1. Regularly check the cleanliness of the oil. Check the cleanliness of the system oil, oil tank, and oil filter, and conduct regular spot checks on the hydraulic system of key equipment;

2. Regular cleaning. Another effective method to control oil pollution is to regularly clean the filter screen, filter element, oil tank, oil pipe, and internal dirt of components. When disassembling and assembling components and oil pipes, attention should also be paid to cleanliness. All oil ports should be sealed with plugs or plastic sheeting to prevent dirt from entering the system;

3. Regularly filter the oil and control its lifespan. The service life or replacement cycle of oil depends on many factors, including the environmental conditions and maintenance of equipment, the filtration accuracy of hydraulic system oil, and the allowable pollution level. Due to prolonged use of oil, oil, water, dust, metal abrasive particles, etc. can turn the oil into a mixture containing various pollutants. If not replaced in a timely manner, it will affect the normal operation of the system and lead to accidents. Whether to change the oil depends on the degree of contamination of the oil. Currently, there are three methods to determine the oil change period:

Visual oil change method: It relies on the experience of maintenance personnel to determine whether to change the oil based on the observed changes in the conventional state of the oil (such as the oil turning black, odorous, turning milky white, etc.); This method is too subjective and requires judgment based on the experience of maintenance personnel, with significant uncertainty.

Regular oil change method: According to the environmental and working conditions of the equipment location, as well as the oil change cycle of the oil used, replace it upon expiration. This method does not consider the quality of the oil and replaces it on time, which can result in poor lubrication if the oil is not replaced in a timely manner due to poor quality; Or if the oil quality is still good and needs to be replaced, it will result in a waste of manpower and material resources.

Sampling and testing method (particle counting method): Regularly sample and test the oil, compare the actual cleanliness level of the oil with the specified oil degradation standards, and determine whether the oil should be replaced or not. This method is the most scientific, and a suitable liquid particle counter is selected. The instrument measures the unit volume of liquid to determine the particle pollution level and particle size distribution. The LPC series particle counter developed and produced by Honghe can be used for detecting particle content in oil products or other transparent liquids. It adopts high-precision laser sensors with a wide detection range and stable performance. It can be used for bottle sampling analysis of the measured medium or connected to the tested system for continuous detection. The detection results can be output according to various commonly used standards such as NAS1638, ISO4406, GJB420A, GJB420A, etc., and support custom detection channels, allowing users to freely set particle size.