Sandblasting room is also called air blasting booth, abrasive blasting room. It is suitable for clean the oxide scale, rust and coating of medium structure parts, irregular parts and batch processing parts surface, which can increase the adhesion between the workpiece and coating.
The sandblasting room is powered by air compressed, which can make the abrasive and compressed air fully mixed. After speed up via the venturi nozzle, the abrasive and air mixture spray to the metal surface with the high speed to clean the oxide scale, rust and oil, so that achieve to the process requirements. In the rust removal progress it will have a large amount of dust and the sprayed abrasive will splash around. So the entire sandblasting progress need to be carried out in a closed space with negative pressure.
Features of sandblasting room
- The sandblasting room can be designed by customers requirements and workpiece characteristics. There is no need to dig the complex foundations, it can greatly save the construction cost;
- The sandblasting room have its own abrasive reclaim system, so it can not jam abrasive in the reclaim system. It not only have high recovery rate but also have high abrasive utilization rate;
- The mainly electric components are all use well-known brand at home and abroad, which have stable performance, long service life and simple maintenance and other advantages;
- The sandblasting room chamber have high definition visibility, the inlet opening adopt the naturally replenishes the air and save a part of the energy consumption;
- The sandblasting room adopt two-stage dust removal, the first stage is use the settling chamber to separate the big particles and dust, the second stage use the filter cartridge to filter the dust. So that the cleaning efficiency can up to 99.5%.
Working principle of sandblasting room
Before the sandblasting, we need to do some preparation works. Such as move the workpiece into the sandblasting room chamber, connect the electric and pneumatic control device, turn on the lights, wear the protective clothes and turn on the ventilation device on the helmet.
Then close the doors, hold the sandblasting gun, open the switch and clean the workpiece. The used abrasive will fall into the reclaim system, then through the screw or scraper transport the abrasive into the bucket elevator. Via the air-wash separator, the abrasive, broken abrasive, the rust slag and dust will be separated.
The qualified abrasive will directly into the storage silo to recycle to use, the broken abrasive and the rust slag will fall into the waste box. The dust will be sucked away by the dust collector and absorbed on the surface of the filter cartridge. The pulse valve of the dust collector will generate pulse signals to release the air compressed stored in the air bag regularly, and instantly form an expanding airflow to act on the inside of the filter cartridge. The dust adsorbed on the surface of the filter cartridge is shaken off and dropped into the lower dust collect box for regular cleaning.
Application industries of sandblasting room
Sandblasting rooms are widely used in casting, mould, steel, aerospace, aviation, shipbuilding, electromechanical, military industry, containers, railway locomotives and many automobile manufacturing industries.
Such as cleaning and strengthening of the surface of casting parts; cleaning and strengthening of fixtures and materials; surface cleaning of parts before electroplating, oxidation and painting; cleaning of contaminants on the surface of barrels, tubes, pans, tanks and utensils tools, molds, pipes, plates and cleaning of operating parts; surface cleaning of glass molds, rubber molds, metal castings and extrusions; trimming welds; removing oxide scale on the surface of the workpiece, and removing color difference during processing (castings, forgings); clean up large turbines, engine castings or complex small parts; clean up parts (such as cylinder blocks, pistons and spark plugs) during engine maintenance; remove the surface of the workpiece paint and dirt etc.
Construction of sandblasting room
Sandblasting room is mainly constructed of blasting room wall, door, lighting, material handling system, sandblasting machine and abrasive reclaim system.
Blasting room wall
The blast room walls are fabrication by sandwich panel with noise attenuation interlayer, which total thickness is 50mm. To prevent wear, the inside of the chamber adopts 5mm thick wear-resistant rubber guard board for protection. Each sandwich panel (2 meters) has a strong frame made from the square tube. This ensures they will not deformation during transportation and installation, the grinding and painted square tube will be far enough to be resistant the corrosion by the natural environment.
The dust removal tuyere set up on the principle of the “top feed, bottom suck, top emissions”, so that it can make the dust flow to the bottom as far as possible to increase the operator’s visibility.
Sandblasting room doors have a variety of choices.
- Double swings door
- Roller shutter door
- Sliding door
- Access door
Depending on your requirements, you can choose to have only one door or two doors. A door workpiece enters the sandblasting room through this door and exits through this door. Two units doors is flow-through design with doors on both ends of the sandblasting room where objects enter from one end, and exit through the door. An exclusive sealing system prevents the loss of abrasive materials and makes the closing of the doors possible without effort.
Design the number of lights according to the size of sandblasting room. Light fixtures use high efficiency LED lamps, which enables maximum utilization of the luminosity, to ensure the sufficient brightness in the room, and the indoor operator can clearly see the workpiece and the surface effect after blasting. The fastening system of the blasting room allows easy removal for maintenance.
Material Handling System
One of the most important considerations when designing the sandblasting room is how the object items blasted are going to be moved in and out of the blast room.
These are some very important questions that need to be asked about material handling…
Every facility is different, if you are designing a new facility, you have one chance to get it right.
If upgrading an existing facility, you need to look at what material handling options will work
in with what I already have….There are many options and ways to move product through your
blast and paint area. When it comes to material handling, there are several options that can speed up moving objects in and out of the enclosure.
Forklift transportation requires the floor of the blasting room to be level with the floor of the workshop to ensure that the forklift can enter the blasting room smoothly, so the blasting room needs to have a foundation pit.
Trolley (rails in the floor)
Trolley is also a great solution for heavier items. The objects to be blasted is placed on the trolley outside of the room and then get in to be blasted. The wheeled trolley stays in the room during blasting and can be mounted on tracks or rails when required.
Monorail systems can be installed inside the blast room or outside with a brush seal providing containment of abrasive within the room. Monorails allow objects to be hang below them and moved in and out of the room and can be motorized.
According to the number of operators in the sandblasting room and requirements, customer can choose the size and number of sandblasting pot. QGMA sandblasting tank adopts manual remote control spray gun, and the operator controls the nozzle sand blasting or air injection. This can be used to remove floating ash from the working surface after blasting.
Boron carbide nozzle with high efficiency, good wear resistance, long life, strong injection force, to ensure uniform, high quality cleaning work.
The working process is as follows: power on, when the lower level gauge of the blasting machine touches the abrasive, the air intake of the tank is closed, and the blasting machine and air jet control system get the signal to start the operation. Once the lower level gauge cannot touch the shot material, the feeding mechanism starts to work. When the upper level gauge of the shot blasting touches the abrasive, the feeding mechanism stops working and the tank body is inflated and closed.
Abrasive reclaim system
Abrasive reclaim system including floor reclaim system, bucket elevator and air wash separator.
Abrasive from floor reclaim system into bucket elevator, then into the air wash cleaner system, and then the abrasive that can used into hopper then into abrasive dosing unit, can not used abrasive get out the reclaim system.
Floor recycling system
There are two types of floor recycling systems, pneumatic recycling and mechanical recycling. Pneumatic recovery, also known as honeycomb recovery, is completely absorbed from the ground to the separation by the fan. Mechanical recovery is a form of recovery of abrasive scattered on the ground into elevator by mechanical movement, now the most used is mechanical recycling.
According to requirements, there are 6 kinds of floor recycling systems to choose.
Sweep-In/ Shovel Chute Reclaim System
Sweep-in / shovel chute reclaim system is the basic and the most economical floor reclaim system.
The shovel chute is directly connected to the bucket elevator. After the work, the workers push the abrasive into the shovel, and then directly into the elevator, to achieve the purpose of recycling. More suitable for small size sandblasting room.
Single screw partial reclaim system
Single screw partial reclaim system means is only one unit screw conveyor on the floor. According to the requirements, the position of the screw can be changed at will. This is the most affordable solution for small and medium-sized sandblasting rooms. The screw can be replaced with a scraper.
Located at the bottom of the cleaning room, when working, the screw conveyor rotates to transport the abrasive to the discharge port, and then flows into the bottom of the bucket elevator from the discharge port. The spiral blade is welded to the drive shaft, and the entire spiral shaft is processed as a whole after welding, thus ensuring the coaxiality of the spiral shaft. The inner and outer circles of the spiral blade are processed by a special process and then stretched. The pitch and outer circle dimensions are very accurate, which improves the life of the spiral.
The sealing of the bearing adopts labyrinth discs, bearing pads, etc., so as to better protect the bearing from damage due to the entry of shot sand, maximize the service life of the bearing, and reduce the maintenance cost of the equipment.
H shaped partial reclaim system
H shaped partial reclaim system is composed of one unit crosswise screw conveyor and two units scraper recovery system. Of course, the screw can be replaced with a scraper. What is scraper?
The scraper conveyor is composed of air cylinders, connecting rods, scrapers, rollers, etc. Simple structure, simple installation and maintenance, safe and reliable, long life, low maintenance cost. When the plate conveyor is working, the cylinder pushes the scraper assembly, and the scraper pushes the abrasive forward by one cylinder stroke under the action of the stopper. When the scraper returns to its original position, the scraper automatically tilts up and will not bring back abrasives. Improve transportation efficiency and reduce energy consumption.
The drive system uses a cylinder, which is stable and reliable, and has a low failure rate; the scraper adopts step-by-step propulsion, the material moves uniformly and reliably, and has low noise and long service life; the required foundation depth is very small, only 0.3-0.5 meters deep, which is greatly Reduce the cost of foundation production. It has incomparable superiority in resistance to harsh environments such as humidity.
U shaped partial reclaim system
U shaped reclaim system is very similar with H shaped reclaim system, the different is the position of the screw conveyor.
H reclaim system the screw conveyor in the middle and U reclaim system the screw conveyor on either side.
Full floor reclaim system
The full floor reclaim system utilizes one unit screw and multiple scraper recovery system assemblies to create a fully automatic, high volume abrasive reclaim system where 100% of the abrasive blast media is returned to the bucket elevator during the blasting operation. This abrasive blast reclaim system is well suited for pass-thru and/or high production requirements.
The floor of the sandblasting room adopts a metal grille, which is conducive to the collection and discharge of steel grit on the one hand, and is conducive to the safety of workers walking on the other hand. In order to prevent large impurities and foreign bodies from entering the sandblasting tank through the conveyor during working hours, blocking the spray gun. This equipment is equipped with a filter in the lower part of the grille (floor recovery) to prevent impurities and foreign objects from entering. The cleaning of impurities and foreign objects is very convenient. You can completely clean up the grille laid on the floor inside the house, so as to ensure that the recycling pipe network can work smoothly for a long time. ;
The floor grille is welded with 40*4mm flat steel bars. The specific format and quantity are determined by the size of the house and the track spacing of the work trolley. Generally, the floor grid inside the sandblasting room has a bearing capacity of less than 200kg per square meter. If a larger floor grid bearing requirement is required, the customer needs to put forward special design requirements.
The bucket elevator is composed of a reducer, upper and lower pulleys, conveyor belts, buckets, closed shells and tensioning devices.
The bottom inlet of the bucket elevator is connected with the floor reclaim system, and the top outlet is connected with the air wash separator.
When working, the bucket fixed on the conveyor belt scrapes the steel shot at the bottom of the elevator, and then is driven by the elevator motor to send the steel shot to the top of the elevator, and finally fall down by centrifugal gravity, and the steel shot is input air wash separator.
Air wash separator
During the descending process of the mixture of steel shot and residue, it is pushed by the horizontal airflow to the particles, thereby 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 steel shot and the The residue is separated, the dust is sucked into the dust collector for purification treatment, broken pellets, oxide skin, etc. enter the waste storage hopper, and qualified steel shots and some small debris are screened again into the storage hopper for recycling.
Dust removal system
As the dust extraction fan extracts the gas and dust in the blasting room, the airflow outside the blasting room enters the blasting room through the coarse filter on the top of the blasting room, and then enters the blasting room through the uniform flow plate on the top of the blasting room. In the sandblasting studio, a top-down airflow is formed in the cross-section of the sandblasting room, and the dust and dirt in the sandblasting room will enter the dust extraction port with the airflow, and finally enter the dust removal system through the dust removal pipe, and then pass through the dust removal system. The filtered, clean air is
discharged into the atmosphere, and the dust and dirt are stored in the dust cylinder for regular cleaning.
In the sandblasting room, the dust removal system adopts a circular dust removal method with upper air intake and side suction air. The clean air enters the sandblasting room from the top of the room body, and the dust removal fan sucks the polluted air in the room into the dust collector through each dust suction port for collection and processing.
Since the dust recovery suction inlets of the environmentally friendly pneumatic recovery sandblasting room are all arranged under the room body and on the sidewalls, the airflow drives the dust to always move from top to bottom, and the dust is always suppressed in the lower part of the sandblasting room.
The dust concentration in the space above 0.5 meters in the sandblasting room is very low, which provides high visibility and a good working environment.
How to design sandblasting room?
As an investment product, how to design a suitable sandblasting room is a question worthy of attention. A suitable sandblasting room can not only help you save costs, but also create profits for you and help your business to a higher level.
Choosing a sandblasting room is a relatively open question, but in general, these criterions should always be followed:
1 The size of sandblasting room
You need an encloser place to put the sandblasting room. The size of the space depends on the size of object item that need to sandblasting. And when designing the size of the room, in addition to the size of the workpiece, you also need to consider the area required by the workers for sandblasting activities, the best blasting distance between the spray gun and the workpiece, etc. Generally, adding a distance of 1m around the workpiece is sufficient.
2 Material Handling system
The conveying method of the workpiece is also the focus of attention when designing the blasting room. How to put the items you need to blast into the blasting room, and handle them safely and conveniently, and then move the items out for storage, or proceed to the next process?
Most users will choose a trolley with rails for material handling and movement. This is the most economical and safe method. During sandblasting, the trolley is parked in the sandblasting room and the workpiece can be easily sandblasting.
If you are handling very large and heavy pieces of equipment like a pump station or engine block, with low volume, using a forklift could be the right solution for you.
Another method is to install an overhead conveyor on the roof of the blasting room, which allows the items to hang below them and moved in and out the blasting room.
Some users will choose the crane they already own, and design a movable roof controlled by cylinder, can let the crane into the blasting area with workpieces when the movable roof is opened.
3 Floor recovery system
Floor Recovery System is an efficient and inexpensive solution for recovering used abrasive with minimal effort from operator. System is suitable for large or small rooms, and offers flexibility in recovery floor layouts. Abrasive residues must be swept or shoveled into floor hopper to be recovered by system.
This recovery system can handle major light-to-heavy abrasives available on the market today, including heavy media such as aluminum oxide, steel shot, and steel grit. With media recovery capacity of over 2,000 lb. per hour and various floor hopper layouts, this system is designed for maximizing operator productivity while simplifying room cleaning after blasting operations.
4 Sandblasting Room Ventilation
During the sandblasting process, a large amount of dust will be generated, which will make the inside of room dusty. And the chemical nature of the dust will endanger health. Designing a suitable dust collector is needed.
There are three different airflow options to achieve this:
The working principle of the dust removal system in the room is: because the dust extraction fan extracts the gas and dust in the sandblasting room, the airflow outside the sandblasting room enters the sandblasting room through the coarse filter on the top of the sandblasting room, and then passes through the top of the sandblasting room. The uniform flow plate enters the sandblasting studio in the sandblasting room, forming a top-down airflow on the cross section of the sandblasting room, and the dust and dirt in the sandblasting room enter the dust extraction port with the airflow, and finally pass through the dust removal The pipeline enters the dust removal system, and the clean air is filtered by the dust removal system and discharged into the atmosphere. The dust and dirt are stored in the dust cylinder for regular cleaning.
How to calculate the air volume of dust collector in the sandblasting room?
Calculated by cross-sectional area. The method of calculating the cross-sectional area is to multiply the length by the width. It is important to explain here that the length and width are the areas that the ventilation can pass through. If there are other flowing air inlets besides the door, it should be added for rational calculation. ：Air volume=cross-sectional area*wind speed*3600
It’s also important to consider the return on investment (ROI) when building a blast room facility. The amount of blasting done over a given period and the number of employees required both will influence blast room decision-making. Additionally, selecting the proper abrasive requires a thorough consideration of all of the parts that will be blasted. For example, mineral abrasives break down faster than steel grit abrasives but allow for greater flexibility for various blasting needs. Disposal costs also need to be factored in and can vary greatly depending on material and volume.
The operation process of sandblasting room
The most widely used sandblasting room in the field of rust removal of workpieces is the automatic sandblasting room, which is applied to various industries and has the advantages of convenient operation and high production efficiency. The operation process of the automatic sandblasting room equipment is as follows.
- The gas storage tanks, pressure gauges, and valves of the automatic sandblasting room should be checked regularly. The gas storage tank discharges dust once every two weeks, and the filter in the sand tank is checked once a month.
- Check whether the ventilation pipe of the sandblasting equipment and the door of the automatic sandblasting equipment are sealed. Five minutes before work, the ventilation and dust removal equipment must be activated. When the ventilation and dust removal equipment fails, the equipment is prohibited from working.
- Wear protective equipment before work. It is not allowed to operate automatic sandblasting equipment with bare arms.
- The compressed air valve of automatic sandblasting equipment should be opened slowly, and the air pressure must not exceed 0.8MPa.
- It is not allowed to blow dust on the body with compressed air in the automatic sandblasting room.
- When the sandblasting equipment is working, no unrelated persons are allowed to approach. When cleaning and adjusting the operating parts, the machine should be shut down.
- The sandblasting equipment’s operating procedures The sand size should be compatible with the work requirements, generally between ten and twenty, and the sand should be kept dry.
- After the work is finished, the ventilation and dust removal equipment of the automatic sandblasting machine should continue to operate for five minutes and then shut down to discharge indoor dust and keep the site clean.
Maintenance of sandblasting room
In order to make the sand blasting room have a longer service life and prevent possible dangers, we must maintain and maintain the blasting room regularly. So how to maintain the sand blasting room?
The sandblasting room is a kind of equipment that meets the current environmental protection needs. During the use of the equipment, if you want to always maintain the use and environmental performance of the equipment, regular maintenance and maintenance are indispensable.
Sandblasting pipeline, gas path
Check whether the sandblasting hose is damaged and replace it immediately. Check whether the connection is firm, and if there is leakage, eliminate it immediately.
Check the damage, wear and connection of the air pipe to ensure that each joint is sealed reliably. If it is worn, it should be replaced immediately.
Floor recovery system
At work and after get off work every day, check whether there are large impurities in the floor recovery system, if so, it should be removed.
Before going to get off work, check whether the protective glass of the respirator is damaged or whether it affects the processing operation. If it is affected, replace it immediately. Ensure personal safety; check the air filter and air source of the respirator to ensure normal air supply.
Because the glass of the protective clothing is fragile, it should be handled with care during sandblasting. Don’t touch it indiscriminately, and it should be kept stable when not in use.
Blasting gun, nozzle
Check the wear of the gun and nozzle, if it is severely worn or the efficiency of the sandblasting process is significantly reduced, replace it immediately.
Environmental protection sandblasting room Because the nozzle, protective clothing glass, spray gun switch and other parts are fragile, you should hold it gently during sandblasting, do not shake or touch, and keep it steady when not in use.
Sand control valve sand discharge adjustment lever
Check whether the adjusting rod is worn out and must be replaced in advance.
Protective rubber in the room
Check whether the rubber in the room is damaged and whether it is replaced according to the situation.
Door, safety power switch, gun switch
Check whether the gate control safety switch and spray gun switch are sensitive and effective. If the action fails, it should be repaired immediately.
Check the seals, especially the door seals. If they are found to be invalid, they should be replaced immediately.
Check whether the operation control buttons of each device are normal. If an abnormality is found, it should be repaired immediately.
Check the protective glass, ballast and bulb usage of the lamp.
Filter dust box ash box
Clean the dust in the dust box of the filter element and the dust box of the separator before work.
According to the above-detailed understanding of the maintenance and maintenance methods of the environmental protection sandblasting room, the equipment can be used better, the failure of the equipment can be reduced, and the service life of the equipment can be prolonged on the premise of ensuring the efficiency of the equipment.
Whenever workers are sandblasting, the steel sand will hit the surface of the workpiece, and at the same time, the steel sand will splash around, the splashing steel sand will hurt the workers, and the workpiece will produce a lot of dust after descaling, the dust will cause harm to the human respiratory system, so the workers must wear protective clothing and sandblasting helmets whenever they work. Sandblasting suits are used to protect workers. They consist of sandblasting helmets, sandblasting suits, gloves, and breathing filters, with which workers can work safely when they wear them.
Abrasive blasting is the process of cleaning the surface of rough chemical parts by using the impact of steel sand at high speed. Abrasive blasting with sands containing crystalline silica can cause serious or fatal respiratory disease. We use steel grit instead of abrasives containing Silicon dioxide to protecting workers. There are many different types of steel shot, including steel grit, steel shot, cut shot, abrasive shot and stainless steel shot, and the type of shot to be used when blasting is adjusted to suit different needs.