Bestech introduce working principle of shot blasting machine

一.Shot blasting machine function

　　　　 1. Remove the rust layer, welding slag and oxide scale on the surface of the workpiece to obtain a uniform metallic luster.

　2. The surface produces a certain degree of unevenness, increases the surface density, increases the friction coefficient of the components and the adhesion of the coating, so as to improve the coating quality and anti-corrosion effect of the steel.

二.　 Shot blasting machine working principle 

1 　 shot blasting machine working principle

　　　 Shot blasting machine is the main part of shot blasting machine accessories. The shot blasting machine is composed of impeller, split blasting wheel, orientation sleeve, spindle and other spare parts.

The steel shot flows into the blasting wheel from the funnel by its own weight, and the blasting wheel that rotates at the same speed as the main shaft rotates with the steel shot. Under the action of centrifugal force, the iron pellets are pressed to the inner side of the orientation sleeve. When the iron pellets reach the opening of the orientation sleeve, they will be thrown out from the opening. At a speed of 60~80m/s, it is thrown towards the workpiece to be cleaned in a fan shape, so that the surface of the workpiece to be cleaned can be cleaned. Adjusting the position of the opening of the directional sleeve can change the direction of the steel shot, so that the thrown iron shot is projected to the workpiece to be cleaned as much as possible. The incorrect position of the directional sleeve not only reduces the efficiency of shot blasting, but also increases the abrasion of the arc-shaped guard plate. The size of the outlet of the directional sleeve will affect the spread angle of the steel shot (the angle between the sectors). The larger the outlet, the larger the spread angle and the worse the cleaning effect. Therefore, after the opening of the directional sleeve is worn, it needs to be adjusted in time. When the amount of wear exceeds 15 mm, it needs to be replaced.

　　　　The main parameters that affect the cleaning efficiency of the shot blasting machine are the ejection speed and shot blasting volume of the steel shot. The higher the ejection speed, the greater the impact force; the increase in the amount of shot blasting per unit time, the greater the concentration of iron shots on the unit area of the tool to be cleaned. The effect of increasing the ejection speed and distance. After the steel shot is thrown from the shot blasting machine, the speed will gradually decrease due to the resistance of the air during the movement. Under normal circumstances, the kinetic energy loss of the iron shot increases by about 10% for every additional meter of the projectile distance. Generally, the distance between the surface of the workpiece to be cleaned and the centerline of the shot blasting device is preferably 0.7~1.5m. Too close, the steel shot mark is too deep and the projecting area is too small, and too far to reduce the cleaning effect.
2　The working principle of the separator.
The pill-sand mixture flowing in from the bucket elevator is screwed from the bottom to the upper part of the sorting area, and the bottom helix makes it uniformly transported along the separator over the entire length of the sorting area, forming a pill-sand flow curtain like a waterfall. At the same time, the dust removal fan draws air through the tuyere of the separator, and uses gravity winnowing to effectively separate the projectiles, molding sand, metal oxide fragments, broken projectiles, and dust in the flow screen, and then flow into the silo after secondary filtration by the bottom screen. , Store and enter the next step of recycling.

During the descending process, the pellet-sand mixture is pushed by the horizontal airflow to the particles, thus forming a skewed curved trajectory. 　Due to the difference in the specific gravity and particle size of the particles, the degree of deflection is not the same, so that the pellets and slag can be separated. The dust is sucked into the dust collector for purification treatment, the broken pellets, sand, oxide scale, etc. enter the waste storage hopper, and the qualified shot blasting and some small debris are screened again and enter the storage hopper for recycling.
The better separation effect of the separator is achieved by adjusting the position of the weight on the gate, the position of the adjustment plate on the primary and secondary skimmer and the butterfly valve on the pipeline. Reasonable adjustment can obtain a good separation effect and make the separation The efficiency can be as high as 99% or more.
　　　　 is equipped with a pulse wheel on the shaft of the cloth spiral, which can detect and follow the working status of the cloth spiral. Once there is a malfunction such as blockage, it will immediately feedback the signal to the PLC, start an emergency signal or stop gradually to ensure the safe operation of the equipment.

The choice of 　 steel shot is directly related to the cleaning effect of the workpiece and the surface quality of the workpiece. The grain size and material of the steel shot should be selected according to the difference of the workpiece to be cleaned.

3　 working principle of hoist


The hoist is composed of a cycloidal pinwheel reducer, upper and lower rollers, conveyor belts, hoppers, closed covers and tensioning devices.

The inlet of the bucket elevator is connected with the screw conveyor, and the outlet is connected with the separator.

　　　　The hoist cover adopts bending forming welding structure. There is an inspection door on the hoist cover, which can repair and replace the hoisting hopper. Open the door cover on the lower cover to repair the lower transmission and eliminate the blockage of the projectiles at the bottom. This machine uses a flat belt to rotate. When working, the hopper fixed on the conveyor belt scrapes up the pellets at the bottom of the elevator, and then is driven by the elevator motor to send the pellets to the top of the elevator, and then drop the pellets by centrifugal gravity. Enter the pill sand separator.

In order to ensure that the conveyor belt does not slip during work, the roller is made into a squirrel cage type, which not only improves the friction between the lifting belt and the pulley, avoids the slipping phenomenon of the old-fashioned smooth pulley, but also reduces the pre-tightening force of the lifting belt. Extend the service life of the lifting tape. At the same time, the hoist is equipped with a set of tensioning device. When the belt is slack, the belt can be tightened by adjusting the adjustment bolts on both sides of the upper part of the hoist.


4　The working principle of dust collector

When the dust-containing gas enters a large settling chamber, because the cross-sectional area of the settling chamber is much larger than that of the dust suction pipe, the dust-containing gas flow rate of the shot blasting machine is greatly reduced, and the flow rate can be reduced by 10-20 times. During the period of time when the dust-containing gas passes through the settling chamber, the larger dust particles have enough time to settle down under the action of gravity in the settling chamber, and the purified dust-containing gas is discharged from the other end of the settling chamber. Since the settling chamber is a dust collection device that uses gravity to make dust settle naturally, it is also called a gravity settling chamber, or settling chamber for short.
　　The settling chamber of the dust collector of the shot blasting machine has the advantages of simple structure, low cost, low energy consumption, low pressure loss, simple maintenance and management, and the ability to directly process high-concentration dust-containing gas. But its large size and low dust collection efficiency are its fatal shortcomings. In the past, the sedimentation chamber was mostly used in industry to capture dust particles >40um, or used as a pre-collection of multi-stage dust collection system.