Created on:2022-02-17 08:51

Pollution of forklift hydraulic oil and preventive measures

Pollution of forklift hydraulic oil and preventive measures

The following is an investigation and Research on the pollution of forklift hydraulic oil, and puts forward pollution prevention measures, which have achieved good results after implementation. The following is a brief introduction.

1. Hazards and causes of pollution

Due to the different ways in which impurities invade hydraulic oil, hydraulic oil pollution can be divided into potential, invasion and regeneration types. After pollutants are mixed into the hydraulic system, they will accelerate the wear of hydraulic system parts and components, and make the performance of hydraulic components decline prematurely, until they are ablated or even damaged. Generally speaking, hydraulic oil pollution is mainly caused by external pollution and internal pollution. External pollution refers to the pollution caused by solid impurities, moisture, other oils and air entering the hydraulic system; Internal pollution refers to the pollution carried by new oil, the wear of hydraulic system parts and the change of physical and chemical properties of hydraulic oil.

2. Solid particle pollution and classification

Solid particle pollutants are the most harmful to the hydraulic system, so it is necessary to measure the amount of solid particle pollutants in the hydraulic oil and divide the pollution level. The pollution level of solid particles in hydraulic oil refers to the quantity of solid particle pollutants in hydraulic oil per unit volume.

In order to strictly and effectively control the pollution of solid particles in the hydraulic system and ensure the reliability of the hydraulic system and the service life of hydraulic components, relevant national industries have formulated the requirements for the pollution level of solid particles in typical hydraulic components and hydraulic systems, as shown in the table below.

Pollution level of typical hydraulic components

Hydraulic element type

优等品

一等品

合格品

各种类型液压泵

16/13

18/15

19/16

一般液压缸

16/13

18/15

19/16

伺服阀

13/10

14/11

15/12

比例控制阀

14/11

15/12

16/13

液压马达

16/13

18/15

19/16

柱塞缸和柱塞泵

16/13

18/15

19/16

摆动缸

17/14

19/1

20/17

液压蓄能器

16/13

18/15

19/16

过滤器壳体

15/12

16/13

17/14

 

3. Application status of hydraulic oil

At present, l-hm32 and l-hm46 anti-wear hydraulic oil and l-hv32 and l-hv46 low temperature anti-wear hydraulic oil are basically used in construction machinery in China. The solid particle pollution level of the factory is 9 ~ 12, and the average level is 10. At present, the pollution level of premium hydraulic oil provided by oil companies can reach level 9, generally below level 10, and there are few premium hydraulic oil higher than level 8.

Using the automatic particle counter (Abakus particle measurement analyzer), the pollution level of the hydraulic oil added into the fuel dispenser after filtration is measured as grade 8 ~ 10, and the pollution level of the hydraulic oil measured after sampling in the hydraulic oil tank of the forklift is generally grade 9.

4. Hydraulic oil pollution control measures

(1) Prevent intrusion and contamination. The hydraulic components shall be loaded, tested and cleaned on the hydraulic test bench, and the method of "wet cleaning and dry assembly" shall be adopted, that is, all hydraulic components shall be cleaned before assembly, and then dried with compressed air before assembly. The piston rod end of the hydraulic cylinder shall be equipped with dust-proof device, and the vent hole of the hydraulic oil tank shall be equipped with high-efficiency air filter, which must be filtered when injecting new oil into the oil tank.

The hydraulic system of the test bench shall be cleaned in time and equipped with multi-stage filter. When the hydraulic oil reaches the service time limit, it shall be replaced with new oil in time. In addition, necessary detection instruments (such as Abakus particle measurement analyzer) shall be equipped to monitor the hydraulic oil, hydraulic components and hydraulic system.

(2) Reduce potential pollution. When signing the order contract of hydraulic components, clear requirements shall be put forward in terms of solid particle pollution level; During transportation and storage, all oil ports must be equipped with sealing covers; For self-made hydraulic parts, each process in the processing process shall be purified and carefully cleaned before assembly.

During the process of cleaning and assembling the hydraulic oil tank, many latent pollutants will be seriously affected. Before the hydraulic components are assembled into the hydraulic system, they must be cleaned carefully. After cleaning, all oil ports must be sealed with plastic tape; The hydraulic system of newly assembled construction machinery shall be thoroughly flushed with flushing fluid before injecting new hydraulic oil.

(3) Prevent regeneration pollution. Regeneration pollution is the pollution generated by hydraulic oil in the working process of the system, mainly including moving pair wear particles, parts corrosion, paint flake peeling and hydraulic oil deterioration. In order to effectively prevent regeneration pollution, filters shall be set at appropriate parts of the hydraulic system, and the filter elements shall be inspected, cleaned or replaced regularly. Pay attention to control the temperature of hydraulic oil during work to avoid accelerating its oxidation and deterioration due to excessive oil temperature and producing various pollutants.

(4) Select hydraulic oil correctly. We should purchase high-quality anti-wear hydraulic oil, appropriately improve the requirements of solid particle pollution level, and control the hydraulic oil pollution from the source; The newly purchased hydraulic oil must be sampled and inspected. After passing the inspection, the oil filter with high filtration accuracy can be used for filtration, and finally can be injected into the hydraulic oil tank; During the use of the machine, the hydraulic oil shall be sampled and inspected regularly, the pollution shall be analyzed, and the unqualified hydraulic oil shall be replaced in time. The hydraulic system must be thoroughly cleaned before replacement.

(5) Establish corresponding rules and regulations. Various measures to control hydraulic oil pollution shall be institutionalized and implemented in each process, each machine, each testing equipment and each working post.

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