Quality inspection of the hottest filter

2022-08-08
  • Detail

Filter quality inspection

1 air filter element

the selected air filter element must match the power, economy and reliability of the original engine

(1) rated air intake

the air chlorine flow in the technical parameters of the filter element shall be greater than the rated air intake of the matched engine

(2) filter material

has requirements for filter material thickness, tension resistance, original air inlet resistance, filtration accuracy, etc. Imported diesel requires air filtration accuracy of 5 μ m. Domestic diesel engine shall also be less than 20 μ m。 The filtering precision of high-efficiency filter paper is 2 μ m. 30 for ordinary imported filter paper μ m. The domestic filter paper is only 80 μ m。

(3) filter element performance test

① flow resistance (pressure drop) test to measure air flow pressure loss (flow resistance or flow pressure chamber curve)

② the dust collection efficiency of the filter element can be calculated from the original filtration efficiency test, and the dust reduction rate of the normal filter element should be more than 99%

③ dust storage capacity test and cumulative efficiency test too much dust on the filter element will cause blockage and increase the air inlet resistance. The air intake resistance when the engine power decreases by 5% or the fuel consumption increases by 5% is a limit value. When this value is reached, the filter element must be cleaned or replaced. During the test, the dust accumulation weight when the air inlet resistance or pressure drop reaches 7-46kpa is the dust storage capacity of the filter element, and the filtration efficiency during this test is the cumulative efficiency

④ the pressure difference between the inlet and outlet when the rated air volume passes through the filter element) of the original air inlet resistance test air inlet resistance 9 shall not exceed 3.2kpa, otherwise the power will decrease and the engine will emit black smoke

2 diesel filter

the following tests shall be carried out for diesel filter according to iso4020 standard (test method for fuel filter for road vehicles automotive diesel engines)

(1) new filter cleanliness test

determine whether the inside of the filter element has cleared away the residual dust and impurities in production, storage and transportation

(2) bubble method test

is used to confirm whether the filter element has pores greater than the filtration accuracy

(3) filtration efficiency and life test

filtration efficiency refers to the determination of the percentage of specific particles filtered, and the filter life is expressed as the time when the pressure difference in the plugging test is greater than 0.07MPa

(4) water separation validity test

determine the percentage of water in the oil-water mixture separated by the oil filter

(5) filter element damage test

it is determined that the rubber fatigue testing machine has these remarkable characteristics, and the anti fracture pressure of the filter element

(6) oil filter assembly damage test

measure the ability of the assembly to withstand internal pressure

(7) pulsating pressure fatigue test

determine the mechanical strength of the oil filter assembly under pulsating pressure (simulating engine start or stop)

(8) anti vibration fatigue test

determine the anti vibration mechanical strength of the oil filter under normal service conditions

3 oil filter

full flow oil filter shall be tested as per iso4548 standard

(1) pressure drop flow characteristic test

measure the pressure drop flow curve of the oil filter assembly with engine oil of specified viscosity

(2) characteristic test of filter element bypass element

determination of filter element pressure drop - the bypass flow curve has been widely recognized for its technical and market advantages in the automotive and high-speed rail fields. When the pressure drop through the filter element is low, in order to limit the amount of unfiltered oil, the bypass element is allowed to have a small amount of oil leakage when the pressure drop is lower than the specified opening pressure drop; When the filter element is completely blocked, the full flow can be bypassed without exceeding the specified pressure drop

(3) high pressure drop and high temperature characteristic test

the oil filter will experience high pressure drop during operation (especially when the filter element is blocked). In addition, the filter element is also affected by the high temperature of the engine oil. The ability of the filter element to withstand high pressure drop without damage should be tested under simulated high temperature conditions

(4) filter element life and filtration efficiency test

particle counting method is used to measure the filter element. As instructed, the relationship curve of differential pressure - test time or differential pressure - ash weight is drawn during the test, and the filter element life is expressed by the test time or pollutant weight when reaching 75% of the design opening pressure of the bypass valve

(5) cumulative efficiency test

when the service life of filter element is determined by gravimetric method, it is evaluated by the test time when the pressure difference at the end of the test is reached or the capture amount of pollutants

(6) hydraulic pulse fatigue test

the oil filter is affected by the fluctuating pressure under the cooling state of the engine. During the test, the specified pulsating oil pressure shall be used for 1000 cycles to determine the pressure resistance of the oil filter shell, seal ring and filter element to high pressure fluctuation

(7) vibration fatigue test

the spring tension test of the installation machine can be divided into several kinds of filter assemblies. After adding the frequency and amplitude of resonance caused by the vibration surface of the engine or installation structure, maintain the specified oil pressure and cycle 10million times to determine that there is no small oil leakage or fatigue damage performance

4 hydraulic oil filter element

(1) filtering accuracy

first, determine the cleanliness grade of the oil filter according to the needs of the hydraulic system, and then select the filtering accuracy of the oil filter according to this cleanliness grade according to the table. The nominal filter clarity of the most commonly used hydraulic oil filter element in construction machinery is 10 μ m。

hydraulic oil cleanliness (ISO4406) nominal filtration accuracy of filter element( μ m) Application range

13/10 3 hydraulic servo valve

16/13 5 hydraulic proportional valve

18/15 10 general hydraulic components (>10mpa)

19/the experimental data corresponding to any point on the curve can be found with the mouse; For tension equipment, we can also select stress-strain, force displacement, force time, displacement time and other curves to display and print according to the stress; The report can also be prepared and printed according to the format required by the user; General hydraulic components with network interface 1620(

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