Anti-wear properties

Anti-wear propertiesfuels determine the reliability and, in particular, life of the friction pairs of fuel equipment. These couples work in modes of rolling friction, sliding and combined friction during different workload, temperature, relative speed of displacement in terms of liquid and boundary lubrication. Friction among the various units of the fuel system more intensively wears a pair of plunger-bevel washer. It serves as the control property when assessing pair anti-wear fuels in operating conditions. Wear areas plungers depends on wear resistance of materials, duration and conditions of work.

Was, that auxiliary pumps, working with less feed (with a smaller angle washers), wear out faster. This is due to the, that small angle prevails sliding friction washers. With increasing angle of inclination increases the proportion of rolling friction, Accordingly, changes in contribution protivoiznosnyj effect working Wednesday (fuel).

The main factor, contributing to the level of antiwear properties of Jet fuels, is the content of reactive and surfactants. Plays a decisive role and level of viscosity fuels. Studies have shown, wear rate decreases with increasing viscosity.

Aromatic hydrocarbons show best anti-wear properties compared to alkanes. In General, dependence and wear indicatork. t.. the level of viscosity of fuel without additives is defined by the equation

lgIk. t..= 2 - 0,125v20.

With the increased content of sulfur compounds and especially mercaptans anti-wear properties of fuels is getting worse.

Oxygen-containing compounds, present in fuels and as additives, improve anti-wear properties. Oxygen removal, dissolved in the fuel, allows you to reduce the wear of friction pairs. The concentration of oxygen in the fuel can be reduced not only by blowing inert gas, but as a result of the oxidation of molecules of fuel consumption.

Evaluation of anti-wear properties at different temperatures showed, as the temperature increases the wear of the first increases due to viscosity reduction, then slows down and, reaching some maximum, wear begins to decrease (rice. 18.1).

Rice. 18.1. Wear parts the temperature dependence

Include measures, that allow you to solve the problem of antiwear properties of Jet fuels:

1) introduction of anti-wear additives in fuel gidroočiŝennye;

2) a more wear-resistant materials;

3) site design change of friction pump controller;

4) Introduction to fuel corrosion inhibitor, warning wear and jamming of friction pairs.

In foreign practice for these purposes use additive Hitec E515 (santolen with). The specified additive at high temperatures adversely affects the fuel's propensity to form sediments. Search for anti-wear additives, no other added glazing which decreases the operational properties of fuels and fairly cheap.