What is the purpose of an alcohol evaporator in an air brake system?

The purpose of an alcohol evaporator in an air brake system is to reduce the risk of ice in the air brake valves. In cold weather conditions, moisture present in the compressed air can freeze, leading to ice accumulation in the air brake system. This ice can block the air supply and potentially impair the functionality of the air brakes, creating serious safety hazards.

The alcohol evaporator introduces a small amount of alcohol into the air system, which has a lower freezing point than water. By mixing with the moisture, the alcohol helps to prevent the formation of ice, ensuring that the air brake system operates efficiently even in frigid temperatures. This function is critical for maintaining safe braking performance in conditions where freezing might occur.

Overall, the inclusion of an alcohol evaporator is an essential aspect of air brake systems, particularly for vehicles operating in climates susceptible to low temperatures.