Drawings of a water curtain for the camera. Painting booths with a water curtain. Heating and lighting of the spray booth

How does a water curtain sprayer work?

Any task spray booth ensure air purification in the spraying area from paint mist and solvent vapors.

Water spray booths have several levels of air purification from paint.

Level 1- frontal water curtain - this is the visible part of the spray booth with a water curtain. A stream of water flows down it in a continuous and continuous stream. It must be uniform and completely cover the entire front area (surface) of the curtain.

Level 2 -internal air purification - perhaps the main filtration and purification of air from paint waste is carried out here. Depending on the design of the spray booth and the manufacturer, there are various systems internal air purification.

Level 3 - dry filtration - carries out final cleaning of the air from remaining paint particles and protects the fan blades from paint sticking. Depending on the manufacturer, dry filtration is carried out in Italian painting booths with a water curtain, in Russian painting booths - in others, such as China, there is no filtration at all.

Below are diagrams of the structure of Italian and Russian paint booths:

1) Scheme of a water spray booth ZINCOVELO ZA Italy
2) Video of the painting booth in Italy

3) Scheme of a water spray booth made in Russia

4) Video of the Russia paint booth in operation (built into a clean room, overpressure chamber)

2

The operating principle of a spray booth with a water curtain is as follows.

When spraying the material, a paint mist is formed. The fan, which is installed on the roof of the spray booth, creates a vacuum and draws contaminated air through the opening in the paint booth at the bottom of the front curtain.

Also, particles of paint and dust are deposited on the front front surface, which are captured and carried away in a continuous stream into the bathtub of the paint booth and settle in the water.

Contaminated air, which entered the internal cavity of the painting water chamber with the air flow, is subject to additional cleaning. In Italian painting booths there are several water cascades, in Russian painting booths there is filtration by an irrigation system. The air is purified from spray waste.

Final cleaning - dry filtration installed in front of the fans (or)

Water spray booths can be of various modifications: with a floor, with side walls, without a floor and without walls. The choice of model depends on the painting technology and the product, as well as the requirements for the quality of the coating.

Painting booths perform the function of air extraction and purification.

When creating a painting area, it is very important to ensure the correct microclimate in the spraying area (the desired temperature regime), as well as the incoming air must be cleaned of dust and dirt, this allows you to achieve excellent conditions for obtaining high quality coverings.

Let's figure out what types of cameras there are for painting furniture parts. Depending on how many and what sizes the parts will be painted, what paint and varnish materials you will use, the required one is selected spray booth.

2.

• water spray booth without side walls and floor (front curtain only)
• water spray booth with active water floor
• water spray booth without floor with side walls
• water spray booth with active water floor and side walls
• water spray booth with active water floor and active water walls
• small painting booths, otherwise small-sized or laboratory ones for painting small products in piece production, instrument making, 1 and 2 meters long.

Spray booth with dry filters

Due to its design, when painting in a dry spray booth, excess paint mist and contaminated air are removed from the paint application area, while cleaning it. All this works when correct selection fan

What happens when using a spray booth with dry filters?

When operating a dry spray booth, the following processes occur:

• removing paint particles and dust from the spray area
• removal of paint aerosol, while preventing its spread into adjacent rooms
• conditions are provided for receiving paint coating high quality
• the air that is removed from the painting area is cleaned of mechanical paint particles that remain in the filters and released into the atmosphere.

How is air filtered in a dry spray booth?

The air flow, which is contaminated with paint and varnish products, with the help of a fan moves by inertia into the opening of the chamber where it is installed one or two filters.

Spray booth with water curtain

A spray booth with a water curtain ensures maximum cleanliness and dust removal in the painting area. All this allows you to create ideal conditions for obtaining a high-quality glossy paint finish.

The frontal water curtain captures paint mist, and the air flow created by the fan additionally draws in contaminated air.

What happens when a spray booth operates with a water curtain?

When operating a water spray booth, the following processes occur:

• removing paint particles and dust from the spray area
• removal of paint aerosol and eliminating the possibility of its spread to surrounding areas
• security ideal conditions to create high quality coatings
• the removed air is cleaned of mechanical particles of paint and part of aerosol vapors and released into the atmosphere.

How to care for a spray booth with a water curtain?

The first thing to do when operating a chamber with a water curtain is replacing the water. They change it depending on the degree of contamination in the cabin.

How quickly the chamber gets dirty depends both on the intensity of painting, that is, how much paintwork is applied per shift, and on the paint guns used. In spray guns with a low material transfer coefficient, a lot of paint is spent on fogging, which means more paint settles in the cabin. If the water is dirty, it will be less able to capture paint mist and dust.

How do you clean water from paint in a spray booth with a water curtain?

In small factories, water is simply poured into the sewer, which is basically impossible, and the accumulated paint at the bottom is scooped out with shovels and other available means.

“Advanced” companies use coagulants and a collection of paint waste to remove paint. The addition of a coagulant allows the paint to turn into flocs, which precipitate or float to the surface as flakes. Flakes are removed manually or using a waste collector.

How is air purified in a spray booth with a water curtain?

Water spray booths have three levels of air purification from paint:

1. At the first level, air purification is carried out using a frontal water curtain. A stream of water flows down this part of the chamber in a continuous and continuous stream.
2. At the second level, internal air purification occurs; here the main filtration and purification of the air from paint waste takes place. Depending on the design of the spray booth and the manufacturer, there are various internal air purification systems.
3. At the third level, dry filtration is carried out - the air is cleaned of remaining paint particles and protects the fan blades from paint sticking.

Water chamber design diagrams

Different manufacturers of spray booths have different filtration systems; for example, here are several diagrams of water spray booths.

Example of a paint booth from furniture production

Here are photos of a paint booth that were taken during a tour at a real operating enterprise.

How does a water curtain sprayer work?

The task of any paint booth is to ensure that the air in the spray zone is cleared of paint mist and solvent vapors.

Water spray booths have several levels of air purification from paint.

Level 1- frontal water curtain - this is the visible part of the spray booth with a water curtain. A stream of water flows down it in a continuous and continuous stream. It must be uniform and completely cover the entire front area (surface) of the curtain.

Level 2 -internal air purification - perhaps the main filtration and purification of air from paint waste is carried out here. Depending on the design of the spray booth and the manufacturer, there are various internal air purification systems.

Level 3 - dry filtration - carries out final cleaning of the air from remaining paint particles and protects the fan blades from paint sticking. Depending on the manufacturer, dry filtration is carried out in Italian painting booths with a water curtain, in Russian painting booths - in others, such as China, there is no filtration at all.

Below are diagrams of the structure of Italian and Russian paint booths:

1) Scheme of a water spray booth ZINCOVELO ZA Italy
2) Video of the painting booth in Italy

3) Scheme of a water spray booth made in Russia

4) Video of the Russia paint booth in operation (built into a clean room, overpressure chamber)

2

The operating principle of a spray booth with a water curtain is as follows.

When spraying the material, a paint mist is formed. The fan, which is installed on the roof of the spray booth, creates a vacuum and draws contaminated air through the opening in the paint booth at the bottom of the front curtain.

Also, particles of paint and dust are deposited on the front front surface, which are captured and carried away in a continuous stream into the bathtub of the paint booth and settle in the water.

Contaminated air, which entered the internal cavity of the painting water chamber with the air flow, is subject to additional cleaning. In Italian painting booths there are several water cascades, in Russian painting booths there is filtration by an irrigation system. The air is purified from spray waste.

Final cleaning - dry filtration installed in front of the fans (or)

Water spray booths can be of various modifications: with a floor, with side walls, without a floor and without walls. The choice of model depends on the painting technology and the product, as well as the requirements for the quality of the coating.

Painting booths perform the function of air extraction and purification.

When creating a painting area, it is very important to ensure the correct microclimate in the spraying area (the desired temperature regime), and also the incoming air must be cleaned of dust and dirt, this allows you to achieve excellent conditions for obtaining high-quality coating.

A paint booth is a room equipped for painting cars. One of the key factors affecting the usability of a spray booth is the ventilation system.
The size of the hood directly depends on the size of the paint job

During the process of painting a car, fumes that are toxic to the human body are released from the paint and the solvent added to it; a paint mist is formed, which impairs visibility and settles on the vehicle body. The supply and exhaust system replaces exhaust air with fresh air, providing optimal conditions for painting the car.

From this article you will learn what a paint booth hood is, what filters it comes with, and how to calculate the ventilation yourself. We will also provide instructions, following which you can arrange the hood in the paint box yourself.

Types of ventilation systems and their comparison

Painting a car is work involving the use of toxic substances, the application technology of which requires compliance temperature regime and maintaining air purity at a given level. The hood not only affects the safety of the painter, but also the quality of the painting process and polymerization of the applied coating.

A garage hood for painting must meet the following requirements:

• Air supply temperature when painting is 20-30 degrees, air temperature when drying the coating is 50-85 degrees;
• The speed of the air flow is 1.3-1.5 m/sec (if the speed is excessive, the paint sprayed by the spray gun is carried away by the air flow, which interferes with the work);
• The rate of air renewal in the box is 5-150 volumes/hour (for precise definition the required multiplicity is calculated for the ventilation of the production premises);
• The air pressure in the box is 20-30 kPa higher than the natural atmospheric pressure of the environment;
• The flow injected into the chamber is clean, free of dust and mechanical impurities (an air filter is used for cleaning);
• The air flow moves from top to bottom, or with minimal vertical deviation.

Based on the type of ventilation, paint booths are classified into two groups:

1. Single-engine;
2. Twin-engine.

Single-motor ventilation plenum performing forced discharge fresh air into the box, while exhaust air is pumped out naturally due to the pressure difference inside and outside the chamber. The supply openings are located in the upper part of the room, the air flow entering the box deposits the paint mist downwards, then the fumes enter the exhaust nozzle and are discharged outside.

In twin-engine boxes, ventilation ensures forced supply and intake of air from the chamber, which provides effective circulation and a high air exchange rate.

It is rational to choose a specific type of ventilation based on the size of the box and the volume of work carried out in it. If the chamber is used throughout the whole working day, and dozens of cars pass through it, it makes sense to install dual-motor ventilation. In small-sized boxes, it is advisable to use single-motor systems - productivity will be sufficient, in addition, you will save on the initial cost of equipment and subsequent maintenance.

Supply and exhaust ventilation

A type of dual-motor systems is a supply and exhaust hood, operating in 3 operating modes:

1. Circulation inside the chamber - air is pumped out of the box, passes through a layer of filters and is pumped back into the room. Used when cleaning the chamber before starting painting work;
2. Supply from outside - the supply compressor takes air from outside the box, filters it and passes it through the heat generator, where the air is given the required temperature. The flow is supplied to the chamber, after which the exhaust compressor pumps the exhaust air out. Used in the car painting process to eliminate paint mist;
3. Recirculation with heating - the air taken from the chamber is filtered, passed through a heat generator with heating to a given temperature and supplied back to the box. Used to maintain temperature conditions when drying the body surface after painting.

Supply and exhaust ventilation requires precise positioning of the input and output air ducts, since if the ducts are incorrectly positioned in the box, “blind zones” are formed in which air circulation does not occur. They contain suspended particles of paint - paint mist, which subsequently settle on the surface of the body, which negatively affects the quality of the final coating.

Calculation supply and exhaust ventilation consists in determining the volume of air supply that provides the air exchange rate necessary to reduce the concentration of toxic paint fumes (MPC) in the room to the standard level.

The amount of paint evaporation depends on the type of solvent added:

Calculation of supply ventilation based on the air exchange rate is carried out using the formula K = d*S*H, in which:

• d is the required air exchange rate of the room;
• S - box area (m2);
• H - box height (m).

In force regulatory documents standards for the air exchange rate in paint booths are not given, however, experts recommend calculating the supply ventilation of the room based on a rate of 5 (for partial painting) and 150 (for complete repainting of the body).

An example of calculating air exchange in a paint booth with an area of ​​4 * 7 m and a height of 4 m using the multiplicity formula (taking into account the maximum value of 100) is as follows:

• K = 150*28*4 = 16800 m 3 /hour;

Manufacturers of paint booths take into account an air supply reserve of 25-30%. Factory chambers of similar sizes have an air exchange of 20-25 thousand m 3 /hour (800 m 3 /hour for each m 2 of box area).

Calculation of air exchange, ensuring a reduction of the maximum permissible concentration to the norm, is carried out using the formula: , in which :

• W is the amount of harmful fumes from paint per 1 hour of operation (mg/h);
• Kv - maximum permissible concentration of evaporation in the air inside the box (mg/m3);
• Kp - maximum permissible concentration of evaporation in the supply flow (when air is taken from outside the chamber = 0).

Harmful fumes per 1 hour of operation are determined by the formula: W = 1*Kv*V, Where:

• 1 - constant;
• Kv - standard maximum permissible concentration of the material (mg/m3 per hour);
• V is the volume of the box.

Ventilation is carried out according to the formula: U = d*V, where d is the air exchange rate, V is the volume of the box. The amount of air pumped out and forced into the chamber is always the same.

After determining the air exchange, an aerodynamic calculation of the ventilation system is performed, during which the required cross-section of the air ducts and the air flow rate are calculated, taking into account the resistance of the filter materials.

Filters for spray booths

The absence of dust and mechanical particles in the air supplied to the box is a factor that determines the suitability of the camera for use, since contaminants that fall on the car body during the painting process negate all the efforts of the painter.

Depending on the filtering method, boxes are classified into two groups:

1. Dry spray booths equipped with roll or panel coarse and fine filters;
2. Painting booth with a water curtain - when supplied, the air flow passes through a water cascade or a tank with an irrigation system. Water filtration in them replaces the primary coarse filter.

Filters for spray booths are classified according to their functional purpose into:

• Coarse cleaning - mounted on the external air duct of the supply ventilation, cleans the flow from large mechanical particles;
• Fine cleaning - installed on the ceiling of the box or on the internal supply air duct, cleans the air from dust;
• Floor filter for a painting booth - installed on an exhaust fan, cleans the pumped air from toxic paint fumes.

Filters for painting booths - consumables that become contaminated during operation, resulting in a reduction in their throughput and cleaning quality. When servicing the box, consumables are replaced, the frequency depends on the filter material:

• Cardboard camera filters are changed every 2 weeks;
• Fiberglass - once every 40 days;
• Ceiling standard EU5 - every 1000 hours;
• Floor-standing - every 150 hours.

Do-it-yourself supply and exhaust ventilation

The hood in the paint booth is installed with your own hands upon completion of installation of the box box. The first stage of installation is the creation of a raised subfloor and the placement of an air intake duct in it, through which air is discharged outside the chamber.

The raised floor is constructed by pouring concrete into the formwork, which has grooves for laying air ducts, or is formed on an existing floor. With this approach, a grid floor 20-40 cm high is welded from reinforcing bars, an air intake is placed inside the grid and connected to an exhaust compressor.

The supply air duct box is placed on the ceiling of the chamber; a compressor is connected to it, coupled with a heat generator or electric heating elements, due to which the flow entering the chamber is heated to the required temperature.

To prevent “blind spots” along the side contours of the chamber, 8 air ducts (2 for each wall) are routed from the supply duct along the perimeter of the box walls, providing horizontal air supply.

Hood safety

Painting booth - room, with high level fire danger. For its equipment, it is permissible to use only explosion-proof ventilation units.

WATCH VIDEO INSTRUCTIONS

Safe operation of the box is achieved due to the following factors:

• The heat exchanger that heats the supply air is equipped with a protective thermostat;
• The thermal insulation of the chamber is made of fire-resistant materials - mineral or basalt wool;
• Boxing is completed autonomous system fire extinguishing;
• Ventilation heating elements are grounded according to
• The air ducts are equipped with explosion-proof air supply shut-off valves and check valves;
• In places where fire-hazardous paint fumes accumulate (particles settle in the lower part of the box), additional air intakes are installed if necessary.

Spray booth with water curtain mod. W3000 is designed for:

• significant improvement in the quality of paint and varnish coatings;
• significant reduction in maintenance time for painting areas;
• increasing the productivity of painting areas;
• ensuring acceptable sanitary and hygienic working conditions for painters and support staff;
• immediate removal of solvent vapors from working area, in order to prevent the formation of explosive concentrations;
• significantly reducing emissions of paint and varnish sludge into the environment;
• reducing the fire hazard of the paint job.

Applications

The W3000 water curtain spray booth is successfully used for painting metal, glass, wood, plastic and products made from them.

The range of painted products is very wide:

• painting wheel rims
• painting of large metal structures
• painting of garden and agricultural equipment
• painting drills
• painting pipes and poles
• painting piles
• painting welded air ducts
• painting formwork
• painting elements of building structures
• painting cement-fiber boards and other building and finishing materials
• painting (varnishing) electronic boards and components
• painting aircraft parts
• painting elements of boats and boats
• car bumper painting
• restoration of furniture and antiques
• furniture painting
• painting MDF facades
• painting tables
• painting chairs
• window painting
• painting doors
• painting molded products (door moldings, skirting boards)
• painting parquet and floor boards
• painting of other furniture and joinery products

Operating principle

Some of the paint and varnish material sprayed by the painter does not fall on the product. At the same time, fine dust from the quick-drying components of the varnish is formed in the air - dust, which, thanks to the painting booth, is removed from the working area by an air flow parallel to the floor.

A significant part of the varnish dust is deposited on the water curtain (up to 85%).

Additional filtration systems (optional) - a labyrinth of barrier panels that repeatedly change the direction of air flow, as well as quick-release cassettes with an inexpensive replaceable element - a fiberglass filter - allow achieving a degree of purification from solid particles of up to 99%.

A “side effect” of using water in the filtration system is the absorption of solvents when the chamber begins to operate. After the water is saturated with solvent molecules, the absorption of “odors” stops, and the illusion of their filtration disappears.

Basic equipment

Prefabricated casing and settling tank made of galvanized steel with a large number longitudinal, transverse and vertical stiffeners.

Provides durability and reduced vibration during operation.

Double cascade of water curtains.

The front curtains of both cascades (those through which water flows) have a quick-release design. Thanks to this, not only is full access to the interior of the chamber for maintenance possible, but it also makes it technically possible to narrow the gap between the lower edge of the curtain and the water in the bathtub located below. For the upper cascade, this is the bath of the lower cascade, and for the lower cascade, this is the settling bath.

This design has a number of advantages, the main ones being:

• due to the absence of long sections of free fall of water, the formation of splashes in both the upper and lower parts of the working area is eliminated;
• water rushing off the lower edge of the water curtain creates a dense flow that additionally cleans the air of suspended particles, which eliminates the need to install water sprinklers;
• the speed of air flow after entering the painting booth is reduced by 4-5 times, which allows suspensions to settle into the settling bath, increasing the degree of purification of the emitted air.

1. Attached bath to accommodate the pump>

   The location of the bath is universal (to the left or to the right of the camera). In this way, the service side can be selected during installation.

   The location of the service area outside the chamber allows for visual control of operation and avoids external contamination of the pump, which leads to its overheating and premature failure.

   Valves located outside make it easy to regulate the water flow in the water curtains, as well as to quickly drain water from the chamber using a standard pump during its scheduled maintenance.

   A stainless steel pump that pumps lumps of coating sludge with a diameter of up to 35 mm, as well as a built-in overheating protection system.

2. A system of circulation water lines, including a water circulation valve, an automatic water drain valve, all necessary hoses, passage units, flanges, clamps and other installation materials
3. Mounting kit including bolts, nuts, washers, sealant, etc. according to camera configuration
4. Packaging for transportation by road
5. Passport and instruction manual
6. CD with diagram and photo illustrations of the assembly

Additional options

Explosion-proof exhaust fan.

Explosion-proof design, with an explosion-proof motor (optional - with a general industrial motor or not explosion-proof).

1a- Fan with a wafer-type supporting body. Thanks to the installation of additional amplifiers through a rubber gasket directly on the roof of the chamber and the placement of additional amplifiers in the fan installation area, vibration resulting from clogging of the fan blades during intensive operation of the spray booth is minimized.

The fan motor together with the impeller is completely removed from the housing. To do this, you do not need to caulk the air ducts, disconnect the electric motor from the electrical network, etc. This fan design minimizes maintenance time.

1b- Fan with supporting frame. The fan can be installed in any convenient place, incl. outdoors, and is connected to the chamber by an air duct (the air duct is excluded from the supply).

The design provides the ability to remove the motor together with the impeller from the fan housing without caulking the air ducts. This ensures ease of maintenance and minimizes technological downtime of the painting chamber.

Additional air filtration devices

The combined use of devices allows achieving a degree of solid particle removal of up to 99%.

2a- A labyrinth of barrier panels that repeatedly change the direction of air flow. At the same time they are additional diagonal stiffeners. Recommended for installation when placing the fan on the roof of the chamber.

2b- Quick-release filter cassettes with an inexpensive replaceable element - a fiberglass filter.

Electrical control panel

3a- Shield in a plastic case with automatic switches– for placement outside the hazardous area

3b- Shield in a metal case with on/off/emergency shutdown buttons – for placement outside the hazardous area.

Explosion-proof fluorescent two-lamp lamp, 2x36W. The lamp is supplied with 2 lamps.

Increasing the depth of the working area by 500 mm

Set of two side panels and a roof panel.

Water floor

The water floor bath is integral with the settling bath of the paint booth and has a height of 300 mm from the workshop floor level. Thus, no gangways are required, making it easier for the operator to move around. The large volume of water filling the bath makes it possible to increase the interval for cleaning paint and varnish materials from accumulated sludge, reducing process downtime. Galvanized gratings covering the water floor can withstand a footprint load of at least 200 kg and 450 kg/m2.

1. The supply fan and set of filters for the “economy project” include:

   • Supply fan of general industrial design. To create excess pressure in the paint sprayer, the capacity of the supply fan is selected to be 10-20% greater than the exhaust fan, taking into account the fact that additionally the resistance of both the pocket filter and the filter of the air distribution device must be overcome.
   • A pocket filter in its own housing, designed for connection with the supply fan. The filter design is quick-release. The filter is designed for repeated use. Its regeneration is carried out manually, mechanical cleaning and blowing.
   • A roll of fine filter (20x2 meters) for the buyer to independently sew an air distribution hose.