The main feature of the sandblasting room is that the operator is indoors during the blasting process. The protective clothing and helmet can prevent the operator from being impacted by abrasives, and the ventilation device provides fresh air to the operator through the helmet.
The blasting room is mainly used for large parts or using automatic blasting equipment to process very expensive parts. The nozzle manipulator installed in the sandblasting room can automatically sandblast the surface of the parts, and the hard-to-reach areas of automatic sandblasting can be completed by manual sandblasting. This not only maintains flexibility, but also reduces the requirements for the number of sandblasting operators.
The abrasive transportation method is another highlight of the equipment design. In addition to the well-known flat conveyor floor that requires a small installation depth, QGMA has extremely rich experience in screw conveyors and automatic scraper abrasive conveying technology.
The process of QGMA sandblasting room processing products is very simple. It is to build a room with rubber fixed inside. The shot material below can be recycled. There is a sandblasting machine outside. The internal operator uses the sandblasting machine to hit the sand at high speed on the workpiece. The surface, forming a certain degree of roughness, thereby improving coating adhesion and extending the service life of the workpiece! The sandblasting process is roughly divided into 5 steps to control: pre-control, abrasive control, tool control, condition control and quality control. Let me talk about the details of various controls.
Before sandblasting, check the surface of the workpiece carefully, remove welding slag, splashes and other attachments, and clean the surface grease and soluble dirt. Sandblasting can only be carried out under the premise of cleaning the surface of the workpiece.
When the sandblasting machine is in operation, the air pressure of the air compressor is 6.0×105～6.5×105Pa, and the air pressure range is 0.5×105～1.0×105Pa. Generally, the air pressure of the sand bucket is 4.5×105～5.5×105Pa, not less than 4.0×105Pa. Before sandblasting, check whether the pressure vessel manufacturer holds the production license issued by the relevant department, whether the protective tools worn by the sandblaster, the safety belt (rope) and the oxygen supply device are safe and reliable, and whether the nozzle is worn out. The nozzle should be replaced when the diameter is increased by 25%.
The compressed air used in the sandblasting room must be treated by a cooling device and an oil-water separator to ensure dryness and oil-free; the oil-water separator must be cleaned regularly. The distance between the nozzle and the surface of the base steel should be 100-300mm, and the non-sand-blasting parts should be shielded and protected before sand-blasting. The angle between the spray direction and the surface normal of the base steel is preferably 15°-30°.
After sandblasting and rust removal, before proceeding to the next process, in case of rain or other conditions that cause the surface of the base steel to be wet, after the environment has reached the construction conditions, use dry compressed air to dry the surface moisture before the construction, if necessary Sandblasting, do not reduce the abrasive requirements, so as not to reduce the roughness.
When the blasting room is working, the nozzle of the blasting machine should not stay somewhere for a long time. Sporadic operations should be avoided in the blasting operation, but the spray area should not be too large at one time. The time between the painting or thermal spraying process and the surface pretreatment process should be considered Interval requirements. Use manual or power tools to remove rust on the parts that cannot be sprayed by the spray gun.
The sand used for rust removal in the sandblasting room must be hard, angular, dry, free of dirt and other impurities; quartz sand is better, coarse river sand is also acceptable; at the same time, the sand transportation conditions, unit price, and recovery capacity should be considered Factors such as: sand size is 0.5~1.5mm, it must be dried before screening, stored in a shed, indoors, sieve size: coarse sieve 40~48 holes/cm2 (particle size 1.2 mm), fine sieve 372～476 holes/cm2 (particle size 0.3mm).
After the rust removal plan is determined, the abrasive can be river sand, quartz sand or a mixture of the two. In the consolidation of Gangnan Reservoir, after pre-spraying comparison, the rust removal effect of mixing quartz sand and river sand at a ratio of 1:1 is the best.
After the sandblasting room is completed, the sandblasting and rust removal parts should be thoroughly inspected first, and then the cleanliness and roughness of the surface of the base steel should be inspected. The focus should be on the parts that are not easy to spray, and the requirements for rust removal by hand or power tools can be appropriately reduced. When inspecting the cleanliness and roughness of the surface of the base steel, firstly, it is strictly forbidden to touch with hands; secondly, it should be carried out under good scattered sunlight or artificial lighting conditions with equivalent illuminance to avoid missed inspection.