The removal of the residual oil of the mechanical anchor bolt is mainly to remove the residual oil on the surface of the mechanical anchor bolt after quenching the cooling oil and heat treatment oil attached to the fastener during the cold or cutting process.
① Alkaline water cleaning method
The simplest alkaline water cleaning is to directly or indirectly heat the cleaning water tank. The cleaning solution is 3%-10% n 2CO 3 or NaOH aqueous solution. The main disadvantage of the alkaline water cleaning method is that the cleaning effect is not very good, especially the blind holes and grooves of the mechanical anchor are prone to stains and residues. The wastewater generated by alkaline water cleaning must be neutralized, and the waste oil can be recycled and discharged only when the relevant environmental protection requirements are met.
② Cleaning method of metal cleaner
In order to overcome the shortcomings of the alkaline water cleaning method and improve the cleaning effect, special metal cleaning agents can currently be used. The detergent can be diluted into a 1%-3% solution in water at 40-70°C, and the mechanical anchor plug is immersed in the solution for 15-20min, then washed with hot water, and finally dehydrated with a dehydrator. Can be used in washing machines.
③ Cleaning method of organic solvent
The cleaning effect of trichloroethane, trichloroethylene and other organic solvents is very good. When the mechanical anchor is quenched and cleaned by immersion or spraying under atmospheric pressure, the volatilization and splashing of organic solvents will pollute the environment. In order to improve the cleaning effect, a sealed vacuum solvent vacuum cleaning device is used. The vacuum pump is used to exhaust air. The mechanical anchor is exposed to high-density solvent vapor without air, and the solvent and oil are recovered by vacuum evaporation. The solvent content in the recovered oil is reduced from 20% to below 4%, which is less than 50 ppm of trichloroethylene.
④ Combustion degreasing
Before the cold head or mechanical anchor enters the heat treatment process, the oil on the surface must be cleaned. Therefore, the fastener can be heated to 350°C~400°C in a degreasing furnace to vaporize or burn the oil, so as to achieve the purpose of removing oil or phosphorus on the surface of the mechanical anchor bolt.