The shot blasting tank is the core power source in shot blasting equipment. Its type and characteristics directly determine the processing capacity, efficiency and application scope of the equipment. The following is a detailed introduction to the types and features of shot blasting tanks for you.
The shot blasting tank, professionally known as "pressure shot blasting machine", "pressure tank" or "sandblasting tank", works on the principle of using compressed air to create pressure in a sealed tank, which pushes the abrasive (shot) out and then sprays it at high speed onto the surface of the workpiece through a spray gun.
Types of shot blasting tanks (mainly classified by operation methods)
Shot blasting tanks are mainly divided into two categories: direct pressure type and siphon type (ejection type). Among them, the direct pressure type is the mainstream in industrial applications and can be further classified into various operation types.
1. Direct pressure shot blasting tank
This is the most common and powerful type. Its characteristic is that the tank itself bears pressure, and the abrasive is "pressed" into the mixing chamber under the action of air pressure, and then mixes with the air and is sprayed out.
According to the feeding and exhaust methods, it can be classified as:
Manual shot blasting tank
Workflow: This is the most fundamental type. Before starting work, the machine must be completely shut down and the pressure released. Then, the operator should manually open the top cover, add the abrasive, close the top cover again, and resume the operation after re-pressurizing. This process needs to be repeated after each can of abrasive is used up.
Features
Advantages: Simple structure, low manufacturing cost, and convenient maintenance.
Disadvantages: Extremely low production efficiency, cumbersome operation, unable to work continuously, high labor intensity for workers, and dust is prone to escape.
Application: It is suitable for small-scale, intermittent maintenance operations or situations with extremely limited budgets.
Semi-automatic shot blasting tank (usually referring to mechanical feeding)
The working process: The tank usually has two compartments, upper and lower (the upper tank is the storage compartment and the lower tank is the working compartment), separated by a conical valve in the middle. When adding materials, a set of levers or pneumatic mechanisms is used to first close the conical valve to release the pressure in the upper tank. Then, new abrasives are added. After that, the pressure in the upper tank is increased to be the same as that in the lower tank. Finally, the conical valve is opened to allow the abrasives to fall into the lower tank by gravity. The entire process does not require a complete shutdown for pressure relief.
Features
Advantages: Compared with manual operation, it achieves semi-continuous operation and improves production efficiency.
Disadvantages: The feeding mechanism is relatively complex and still requires manual intervention for feeding, which is not truly continuous.
Application: Currently, its application is relatively rare and it is more commonly seen in some old-fashioned devices.
Fully automatic shot blasting tank (mainstream industrial choice)
Workflow: This is the standard configuration of modern shot blasting machines. It also adopts a dual-chamber design, but the entire process of feeding, pressurizing and venting is automatically controlled by a PLC program. The continuous and automatic replenishment of abrasive is achieved through the sequential opening and closing of a series of precise pneumatic valves (such as butterfly valves, ball valves and conical valves).
Advantages
Continuous operation: It can achieve 24-hour uninterrupted production with extremely high efficiency.
High degree of automation: No manual intervention for feeding is required, and it is integrated into the entire automated production line.
Stable processing effect: Due to the stable pressure inside the tank and the constant abrasive flow rate, the shot blasting intensity is very consistent.
Environmental protection and safety: Fully enclosed system, excellent dust control.
Disadvantages: Complex structure, high manufacturing cost and maintenance requirements.
Application: Widely used in the cleaning of large castings and forgings, steel structure treatment, steel plate pretreatment lines, continuous hook/belt type shot blasting machines, etc.
Ii. Siphonic (ejection or suction delivery) shot blasting system
Working principle: It has no pressure tank. The abrasive is stored in an open hopper. By taking advantage of the Venturi Effect in the design of the spray gun structure, the high-speed flowing compressed air creates a negative pressure (vacuum) in the mixing chamber of the spray gun, which "sucks" the abrasive from the hopper and then mixes with the air in the spray gun tube before being sprayed out.
Advantages
The equipment is simple and lightweight: There is no pressure vessel, and the cost is low.
Easy to operate: Abrasive can be added at any time.
Suitable for small-scale operations: Commonly seen in handheld spray gun operations.
Disadvantage
Low efficiency and power: The shot blasting impact force is much less than that of the pressure type, and the shot blasting intensity is low.
Unstable abrasive flow: It is easily affected by the length and height difference of the spray gun tube and the amount of abrasive.
The application range of abrasives is narrow: It is difficult to convey abrasives with high density and coarse particles.
Application: Mainly used for small-scale on-site maintenance, local cleaning, paint and rust removal and other light operations, it is commonly found in small workshops or repair shops. It is not suitable for industrial scenarios that require high productivity and high-intensity shot peening.
Summary comparison and selection guide
For a more intuitive understanding, the following table summarizes the core features of various shot blasting tanks:
Type, working principle, advantages, disadvantages, typical applications
Direct pressure type (manual) shutdown feeding, simple whole tank pressurization structure, low cost, extremely low efficiency, cannot be continuous, high labor intensity, extremely small, intermittent maintenance
Direct pressure type (semi-automatic) double-chamber, mechanical feeding can semi-continuously operate, complex mechanism, still requires manual feeding, old-fashioned equipment, application reduced
Direct pressure type (fully automatic) double-chamber, PLC-controlled valve automatic feeding, continuous production, high efficiency, stable effect, complex automation structure, high cost, high maintenance requirements, large-scale cleaning machine, production line, steel structure treatment
Siphonic (ejector) suction equipment that utilizes the Venturi effect is lightweight, low-cost, and easy to operate. However, its efficiency and power consumption are low, and the effect is unstable. It requires manual maintenance, paint removal, and rust removal for small areas
How to choose?
Pursuing production efficiency, processing strength and quality stability (for industrial applications) : Fully automatic direct pressure shot blasting tanks must be selected. It is the absolute main force of modern shot blasting and shot peening cleaning centers.
For small-scale, low-intensity on-site processing (maintenance-level applications) : A siphonic shot blasting system can be selected due to its portability and low cost.
Manual and semi-automatic types have been largely phased out in the new equipment market due to their obvious efficiency disadvantages.
It is hoped that the above detailed introduction can help you have a comprehensive understanding of the types and features of shot blasting tanks.