Wet or water type spray booths primarily utilize water to capture paint mist generated during the spraying process. When spray gun is triggering, the paint mist encounters the water curtain or water screen inside spray booth. The paint mist particles interact with the water, due to the viscosity and other water properties, paint mist is adsorbed into the water, thus achieving separation of the paint mist from the air. This process effectively prevents paint mist from spreading in the air, reduced the workshop pollution and protected operators’ health.
Working Principle of Water Curtain Spray Booth
The scattered overspray paint mist is attracted by the airflow to the water curtain for purification. After further purification by spraying, the purified gas is discharged outdoors through an air-water separation device.
The paint mist captured by the water curtain flows into a water tank, is pumped and filtered, and paint residue floats on the water surface.
Then add the paint coagulant into the water tank. The paint residue will immediately coagulate into loose clumps. Regularly remove the residue and treat it as hazardous waste to keep the water clean, thereby achieving the paint mist purification effect.
Classification of Wet Spray Booths
Wet spray booths mainly include water vortex spray booth, venturi spray booth, water curtain spray booth and pump-free water film spray booth.
Water vortex spray booth includes a laminar flow suppression method to prevent paint mist diffusion. They use hydraulic vortex tank to filter the paint mist, achieving a filtration efficiency of over 99%. This is a technically complete spray booth, and the water vortex spray booth is currently the most widely used spray booth mode.
Venturi spray booths use a special venturi structure to atomize water to treat waste paint mist. The filtration efficiency can reach over 99%, and it is not easily clogged. The indoor noise is relatively low. Venturi spray booths are often used in situations with particularly large paint volumes. It represents the highest level booth construction because the venturi box involves a lot of calculation according to actual installation.
Water curtain spray booth is also known as waterfall spray booth, form a water curtain on the inner wall of the spray booth’s front side. When spraying, paint mist collides with the water curtain and is absorbed by the water, flowing down to the lower water tank for storage. Paint mist that is not absorbed by the water is then absorbed by a water spray device.
Water curtain is a basic function for all type of wet spray booth design but doesn’t mean it can’t be working stand alone. For a simplified booth structure, a water curtain is enough to handle light weight operation.
Pump-free water film spray booth: Air containing paint mist is subjected to a high-speed airflow by a ventilator. The impact force generated by the airflow atomizes the water, achieving an effect of cleaning paint mist.
Structure of Wet Spray Booths
Water curtain spray booth is composed of a chamber body, water tank, stainless steel water curtain plate, water circulation system (including paint mist treatment process), and exhaust filtration system, etc., they effectively prevent waste paint discharge and environmental pollution while completing the normal workpiece spraying process.
The spray booth has a water curtain panel in front, an overflow trough above the water curtain panel, a multi-stage water curtain filter behind the water curtain panel. During spraying, the paint mist entering spray booth firstly encounters the water curtain then washed into the water tank. The remaining paint mist is completely intercepted in the water as it passes through the multi-stage water curtain filter.
Water in the water tank is pumped to the overflow trough at the top of the water curtain and multi-stage water curtain filter, overflowing onto the water curtain panel to form a water curtain.
Characteristics and Advantages of Wet Spray Booths
Characteristics
The water curtain spray booth has a stainless steel water curtain panel inside, ensuring airflow speed, improving coating coverage and residual paint capture rate; and making the water curtain layer uniform, continuous, reliable, uninterrupted, and splash-free.
The vortex device and the modular, detachable air-water separation baffles can fully wash and separate residual paint and water, achieving environmental purification, effectively solving the problem of cleaning and preserving paint residue on the panel, and facilitating maintenance.
Advantages
It can efficiently collect paint mist, reducing the emission of volatile organic compounds (VOCs). For environmental protection requirements, this is crucial for enterprises to meet environmental regulations. Without paint mist permeating the workshop, the air quality is greatly improved. Operators no longer need to be exposed to a paint-mist-filled environment for extended periods, reducing health risks such as respiratory illnesses. At the same time, it also reduces the pollution of equipment and products in the workshop caused by paint mist.
The relatively stable airflow and environment inside the water curtain spray booth facilitate more precise spraying operations. Because the paint mist can be processed in a timely manner, it will not interfere with the spray gun’s spraying effect, resulting in more uniform spraying and improved product appearance quality.
