Created on:2021-08-30 14:11

Fault diagnosis and maintenance of marine hydraulic equipment_ Determination of pollution source of fin stabilizer oil

Fault diagnosis and maintenance of marine hydraulic equipment_ Determination of pollution source of fin stabilizer oil

(1) Source and harm of oil pollution

The hydraulic control system of fin stabilizer is complex and requires high cleanliness of oil. The pollution of hydraulic oil will block the filter element, corrode metal, reduce the lubricity of oil, degrade the performance of pump and valve, and produce noise. Therefore, the pollution of oil must be controlled. There are many sources of hydraulic oil pollution, which can be roughly divided into three situations: pollution in manufacturing and production process, regeneration pollution and external pollution. However, the overall causes of system pollution mainly include two aspects: the pollution invaded from the outside, mainly various solid particles, water, air, etc; Internal pollutants are mainly the products of component wear, hydraulic oil deterioration and component corrosion during system operation.

(2) Measurement of oil contamination in fin stabilizer hydraulic control system

① Determination of oil pollution by solid particles and water hydraulic oil is generally light yellow to dark yellow or light blue to dark blue. After shaking, it is defoaming fast, slightly hanging the bottle, and has a good sense of smoothness. Compare the new oil with the oil sample taken in the system, and estimate the pollution degree of the oil by looking, smelling and touching, so as to determine whether it is necessary to replace the new oil and take treatment measures. The degree of oil pollution can be judged by filter paper filtration. The specific methods are as follows: take a small amount of oil sample and new oil, drop them on 240 mesh filter paper respectively, and compare the patterns formed by the two filter papers after a few minutes, so as to determine whether it is necessary to replace hydraulic oil or take treatment measures. The filtration determination method is shown in the table below.

 

Filtration assay

Filter paper pattern

判 别 处 理

油滴中心呈褐色,外圈不明显,扩展性很强,不溶污物少

纯净油

油滴中心颜色很淡,外圈有混圈,扩展性较强

污染较轻,能继续使用

油滴有分布均匀的暗色中心,外圈明显

污染较重,建议不再使用

油滴呈均匀暗色,外圈很清晰,颜色随污染加深

污染严重,重新换油

 

② Measurement of air pollution to oil during system operation, the reading of vacuum gauge can be observed. If the reading of vacuum gauge is too low, the pressure gauge jumps unsteadily, and there are a large number of bubbles at the oil return pipe, it indicates that air has entered the system to cause pollution; Or before the system works, clean and dry the parts that may enter the air, such as the pump, the joint of the oil suction pipe and the seals of the system, apply a layer of grease, smooth it to form a protective film, and then start the system. If the protective film is wrinkled, cracked or misplaced due to oil suction, it indicates that the seal is not tight and air will enter the system.

 

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