The sand blasting room produced by Dongguan Meijun sand blasting equipment is also called sand blasting room and sand blasting room. It is mainly suitable for the cleaning and rust removal of some large workpieces, and the effect of increasing the adhesion between the workpiece and the coating. Before large workpieces are painted, Sand blasting is generally used for surface treatment in order to obtain a rough and flat surface to improve the adhesion and decorativeness of the coating. Sand blasting systems are available in closed and open styles. For large workpieces, an open blasting system is generally used to blast the product in the blasting room, and the abrasives ejected are automatically recovered by the recovery device. According to different abrasive recovery methods, the sand blasting system can be divided into two types: mechanical and pneumatic. The abrasive blasting system of the mechanical blasting system is completed by the horizontal conveying device and the lifting device. The abrasive blasting system of the pneumatic blasting system is transported by air flow.
I. Pneumatic return sand blasting room
1 Working principle Pneumatic recycling sand blasting room is mainly composed of room body, sand blasting equipment, abrasive recovery device, ventilation and dust removal device, abrasive separation device and electricity
Control device. In order to simplify the equipment, the two parts of abrasive recovery and ventilation and dust removal can be combined. The fan sucks all the abrasive, dust, and airflow through the honeycomb floor to the abrasive centralized filter. The dust-containing gas is filtered by the filter, the dust is attached to the outer wall of the filter, and the clean gas is discharged through the filter to the outside of the plant, and part of it is circulated to the blasting room. The abrasive and heavy dust continue to pass through the abrasive tank to the sorter. The sorter has an inner and outer cone structure with an adjustable channel between the inner and outer cones. By adjusting the core body, the cut surface of the air flow channel can be changed, and the separation ratio can be adjusted. The separation process is: When the abrasive and dust pass through the channel, due to the effect of gravity, the dust and gas come out through the gap between the cones, and the abrasive and coarse particles fall to the vibrating screen below the cone. The vibrating screen further separates the abrasive and coarse particles. The separated pure abrasive enters the designated hopper through the sieve holes to the blasting tank for recycling. The dust and gas passing through the separator are filtered through a filter, the clean gas is discharged outside the plant, and the dust falls into the waste hopper.
2 Sand blasting system structure 2.1 Basic structure of sand blasting system According to process requirements, the sand blasting system chooses artificial blasting method, and special sand blasting tanks are used for products of different materials. The pressure and flow of the blasting tank can be adjusted at any time according to requirements. Each blasting tank is equipped with 1-4 spray guns, and the blasting system can work with 4 spray guns at the same time.
2.2 Structure of the room body The sand-blasted room body is welded by steel plates. Its skeleton is a door frame structure. The door frames are connected by cross connecting rods. The door frames are installed on the ground with anchor bolts through installation blocks. Pressed thin steel plates on both sides of the door frame, the thickness of which is 0.5 ~ 0.8 mm, and the surface is painted. In order to improve the service life of the room body, a 6mm-thick wear-resistant rubber plate is pasted inside the room body. The technical parameters of the rubber sheet are: hardness 38IRHD, tensile strength 26.6 MPa, elongation 81%, tear strength 83%, Xinyuantong environmental protection equipment, Xinyuantong environmental protection equipment | | | sandblasting room, wear index (Wet) 108, temperature range 4-70 ° C.
The lighting adopts a dust-proof lighting system, and the indoor illumination at a distance of 1.5 meters from the ground is not less than 650 lx. All the doors leading to the blasting room are equipped with electrical interlocks to ensure that the blasting system will stop working when any door is opened. Door peripheral warning light, when the light is on, sand blasting is in progress.
2.3 Honeycomb floor
The floor of the blasting room uses a special honeycomb floor, and the size of each honeycomb floor is 500mm × 500 mm. Each two rows of honeycomb floors along the length of the sand blasting room constitute a honeycomb floor module. After the abrasive falls into the honeycomb floor, the fan sucks it into the collection pipe through the material hole, and then sucks it out of the collection pipe.
2.4 Abrasive centralized filtering system Abrasive centralized and dust removal share a system, including centralized fan, centralized filter, etc. In order to ensure the visibility in the blasting room, the ventilation frequency is not less than 50 times per hour, and the ventilation air volume is 65 130 m3 / h. A 45 kW fan is used, in which the fan air volume is 21 010 m / h.
2.5 Abrasive recovery and sorting system
The abrasive recovery and sorting system includes an abrasive tank, a sorter, a filter, and a connection pipe. The abrasive is sorted and recovered from the abrasive tank through the connecting pipe to the sorter. In order to improve the service life of the sorter, abrasion-resistant rubber is pasted on the outside of the inner cone and on the surface of the outer cone. Due to the different materials of the products, the abrasives used for blasting are also different. In order to avoid the influence of iron abrasives on the aluminum alloy car body, a set of magnetic separation devices are added under the sorter to separate iron and non-ferrous abrasives to ensure the quality of sandblasted aluminum alloy car bodies. The magnetic separation device is a magnetic drum, and a permanent magnet is arranged under the magnetic drum. The magnetic drum rotates, and the iron abrasive is absorbed on the magnetic drum by the magnetic force on the side of the magnet; when the magnetic drum is turned to the side away from the magnet, the magnetic force disappears and the iron abrasive falls into a corresponding container. The drum rotates continuously to separate iron and non-ferrous abrasives in the abrasive.
2.6 Sand blasting equipment The entire sand blasting system is equipped with a double bin continuous working type blasting tank. Each blasting tank is equipped with two 10 mm diameter spray guns and two abrasive valves. An operation switch is installed on the handle of the spray gun, and automatic control can be realized, and the nozzle can be shot or shot. This can be used to remove airborne dust from the work surface after air cleaning.
3 Summary Because the pneumatic blasting system has no mechanical conveying parts, there is no mechanical failure and simple maintenance. The honeycomb floor is directly installed on the ground, and the foundation requirements are simple. The air flow is sent up and down, the dust reduction time is short, the indoor air circulation is good, and the same system is used with abrasive recovery, and the equipment is simple.