Sediments In Throttle Valves

- Mar 21, 2019-

The source of throttle valve body sediments is more complex, but can be summed up in the following categories:

1. Mechanical impurities in the oil or oxidized colloid, bitumen, carbon slag and other dirt accumulation in the throttle gap. 2. Because of the aging of oil or the production of charged polarized molecules after extrusion, and the existence of potential difference on the metal surface of the throttling gap, the polarized molecule is adsorbed to the surface of the gap, forming a firm boundary adsorption layer, the thickness of the adsorption layer is generally 5~8 micron, thus affecting the size of the throttling gap. When the above accumulation, adsorption growth to a certain thickness, will be washed away by the liquid flow, and then re-attached to the valve mouth.

As a result of this cycle, the flow of the pulse.

3. When the valve mouth pressure difference is large, due to the valve mouth temperature is high, the degree of liquid extrusion is enhanced, the metal surface is also more susceptible to friction and the formation of potential difference, so the pressure difference is easy to produce blockage phenomenon. 4.PCV Exhaust Gas Source: a mixture of gases formed after a combustible mixture in the combustion chamber enters the crankcase through a piston gap and is mixed with oil vapour. To avoid dilution and contamination of the oil, the mixture is pumped into the inlet by the crankcase forced ventilation system (PCV) to participate in two combustion.

This part of the exhaust gas into the inlet, due to the temperature reduction will condense the formation of liquid phase, wherein the "unstable components" will be oxidized at high temperature condensation, in the throttle valve surface to form a oil scale and adhesion. 5. Turbocharged compressor in-depth lubricating oil: For turbocharged engines, there is a general exhaust gas drive mode, that is, the use of the exhaust channel generated by the high-pressure exhaust gas drive turbine, and through the coaxial drive in the inlet gas blades, the formation of inlet airflow pressurization.

However, the coaxial bearing in the long-term and harsh operating conditions, easy to produce lubricating oil penetration and evaporation, and then add the inflatable efficiency multiplied, more likely to form heavy oil pollution to aggravate the adhesion of throttle valve body sediment.

6. Fuel vapor discharged from the carbon tank: in the fuel steam adsorbed by the engine carbon tank, it is easy to form a throttle valve sediment as long as it is cyclopentadiene, which can oxidize and condense at continuous high temperature to form a colloidal oil scale.