Dry air compressor for car painting quality improvement

Abstract

The humidity used in the painting process greatly determines the result of painting the car body. This study aims to develop a dry air compressor that can be used to overcome car paint defects. This system consists of a 2 HP compressor engine for sucking air from the atmosphere, two air collection tubes where the first tube contains air obtained from the atmosphere and the second tube contains dry air obtained from the first tube. The inside of the first tube is given a copper coil measuring 5 mm in diameter which is connected to a 120-watt cooler while the second tube is not given a copper coil. Each tube has a diameter of 50 cm and a height of 100 cm. The addition of copper coil aims to separate air from water by means of the condensation process which is the development of this study. Testing of compressor performance is done by turning on the compressor with the exhaust valve closed. After 60 minutes, the air pressure in each tube increased from 0 Psi to 89 Psi, the humidity decreased from 52 % to 38 %, and the temperature decreased from 31.6 °C to 18.2 °C. To see the effect of cooling on the air, the exhaust valves on both tubes were opened. In the first tube there is water coming out, as much as approximately 100 ml while in the second tube there is no water coming out. The water that comes out of the first tube is caused by the condensation process that separates the air from the water and due to the influence of gravity the water falls to the bottom of the tube. The dry air contained at the top of the first tube is flowed into the second tube and is ready to be used for painting the car body. The painting results show that there are no more small holes or paint defects on the paint surface