The working principle of the fuel filter
In order to ensure uninterrupted work of diesel from the fuel tank out of the impurities must be removed carefully. If bad fuel filtration, fuel pump and injectors is in the precision coupling will quickly wear or stuck. Precision coupling of wear and tear, will cause oil tank uniformity, increased fuel consumption and power down.
Diesel engines are generally installed in the two filters. The first is the coarse filter, before it is installed in the pump, engine filter out the larger impurities. The second is fine filters can filter out small impurities, before it is installed in the fuel pump.
Generally use the comb filter strainer. Usually fine filter paper and felt-type filter type and gap-type high-pressure filter.
First, the paper filter type filter
It is mainly from the filter, filter housings and seat of three parts. Fuel from the pump into the engine fuel filter, through the paper filter to remove impurities in the fuel, oil filtering barrel into the chamber, and then set the oil through the filter seat chamber, leading to the fuel pump. Back seat with the engine oil filter connector, built-in relief valve, when the engine fuel filter inside the fuel pressure exceeds 0.08MPa, the excess fuel from the oil return connection back to the fuel tank. Low-pressure fuel line connecting the arrow direction of the seat should not be connected correctly. Filter gasket mounted on the bottom of the spring seat, the spring washer will seal the underside of the nut close to the seal. Filter holder and connecting rod between the shell and by and with the rubber ring seal, filter seat top with bleed screw, you can use the open air screw loose inside the air filter clean fuel.
Second, the felt-type filter
Felt mainly by the filter-type filter, the filter and filter cover and so on.
Filter installed in the filter body, which consists of metal mesh, silk sheet sets and blankets filter composed of thick filter by the seven, eight thin, each other alternately mounted on the filter. Filter plate welded in the top, bottom welded base, screw a nut on the base, under the tray will be felt through the filter sheet pressed in the top platen.
Covered with a spin filter into and out of pipeline joints and bleed cocks, deflated with the cock on the mouth.
Between the filter body and engine filter cover to connect with center rod, one end screwed into the filter body at the bottom of the plug on the other end of the rotation with the nut, will connect the two. Filter is installed in the spring on the plug pressed in the filter cover.
Fuel filter from the intake pipe 7 into the cavity between the shell and then engine filter through felt and silk sleeve into the cavity and the metal mesh along the pipeline flow from here to the tubing, tubing installation is intended to draw clean air and no fuel, and engine air filter were gathered in the upper part. Put cyclone chamber from the oil plug to let out the air fuel filtration. Diesel engine exhaust air must be set before starting.
Third, the high-voltage gap-type filter
Before entering the fuel nozzle, diesel engine is also equipped with many high-voltage gap-type filters, filters for the last time. This filter cartridge by a grinding steel rod, with a small gap (about 0.02-0.04mm) into the sleeve, in the filter rod mill, 8 – 40 tank, half of the oil into the , the other half of the oil, the two intertwined, since the end of the fuel to enter through the gap, from the other side out, make some small impurities remain in the tank to achieve the purpose of filtering. And to extend the use of injector time, but the fuel quality is better, this filter can work 400-500 hours after cleaning.