How Shot Blasting Machine Works

by Engr. Kh. Mashiur Rahman | Apr 23, 2016 | Finishing

Shot Blasting Machine

Shot blasting machine is special equipment designed and produced for individual customer. It is a machine for cleaning structure steel. It strongly blast the original condition steel parts to remove surface rust, welding slag and scale, making it show uniform metal color and improve coating quality and corrosion prevention effect. The equipment is mainly composed of former auxiliary chamber, shot blasting machine, roller conveyor mechanism projectile cycle apparatus, maintenance platforms, dust removal system and electrical control system components.

Shot blasting machine Design

The main design idea:

• Based on experience, we use roller shot blasting machine. The models are available from the truck or driving feed rollers directly, can work, high efficiency, operational safety of workers. But also take into account the surface cleaning and steel profiles and structural parts.
• For customers work information, we designed an opening device width, height 1700mm. 1520mm diameter steel pipe feeding a time. Projectile body to ensure overall coverage.
• In the sealing chamber at both ends of the installation of equipment wear-resistant steel sheet clip to prevent projectiles spill. To ensure that the work site without projectile.
• roller spacing device designed to 1000mm, to ensure the carrying capacity of 1T / m. And the installation of the spacer rollers to prevent rolling steel pipe rollers to ensure security.
• 6 sets with 11kw motor direct-attached blasting device, the device is turned on, placed in a steel rollers to 1.2-1.6m /min speed through the blasting zone. When steel hanging out roller can be tilted through pipe, steel pipe dumping projectile to collect balls spiral, which will help the projectile recovered.

Shotblasting main advantage：

• Company department completely using three-dimensional design for shotblasting, to avoid any defects and omissions in the design.
• Product design, each year more than hundreds of sets of roller cover shotblasting machinery manufacturing industry fields.
• Main designers as head of the entire project is responsible for the design of the product quality, production process, delivery,installation and after-sales service, etc., to provide clients with integrated one-stop service.

Technical Support for Shotblasting Machine：

• The position of shotblasting wheels arranged on blasting cabinet is confirmed by a 3D blast simulation system.
• Every non-standard machine drawing is documented to convenient maintenance of shotblasting mc.
• All blast wheels are tested 60 minutes on load condition to assure quality.
• Direct blast wheel with high efficient and high speed is used to improve cleaning effect.
• Durable material.
• It adopt pneumatic system to avoid hurting people and abrasive waste.
• Cabinet adopt SPMn13 protective plates, working life up to 13000 hours. Wear resistant and convenient for replacing.
• Safety interlocks ensuring worker’s safety.
• Sub-control rooms distributed in front and end. Sealed rubber plate stops overflow of
•  
• Environmental cartridge dust collector ensuring the efficiency up to 99.5%
• High quality of imported electric appliances, Guarantee the quality of equipment for shotblasting mc.

Shotblasting Machine Maintenance :

Machine Safety

a). All transmission parts have cover and safety warning sign.

b).In operation position and its opposite position, there are emergency stop buttons.

c).Safety interlocks for abrasive feed, blasting and maintenance area.

Sealing problem, dust extraction position

We design multi layers of labyrinth sealing. Near the door, on top of cabinet, there are dust

extraction port which will suck dust away easily.

Anti-run back device of bucket elevator

In order to prevent bucket elevator run back in case of sudden stop or power failure,

causing damage to the machine, the bucket elevator has anti-run back mechanism. Housing of

bucket elevator also has protective liner.

Environment protection problem

In order to prevent tiny abrasive sucked into dust collector, we design an abrasive settlement cabinet to settle down abrasive with size of 0.05mm. We design two steps dust remove, finally dust concentration of exhausted air will be controlled under 85 mg.

Material used on Shot Blasting Machine

• Shot Blasting Machine chamber uses 8mm thickness steel plates, and the protection liner for direct
• blasted area is 10mm thickness SPMn13 steel tiles.
• Front and back chamber uses 5mm thickness steel plates, near blast chamber area, we
• install 65Mn steel plate for protective purpose.
• Bucket elevator and separator use 4mm thickness steel plates.
• Roller use diameter 121mm seamless steel pipe, thickness 6mm.
• Metal ducting for dust collector,2mm thickness steel plates.
• PL frequency inverter is Mitsubishi or Omron, other electric components use CHINT or

Each part structure of Shot Blasting Machine

Shot Blasting Machine roller conveyor shot blasting machine is composed of shot blasting chamber , attaching shot blasting chamber , blast wheel assembly , abrasive recycle system ,dust removal system and electrical control components .

Roller conveyor system: The roller conveyor system includes inlet ,blast chamber roller and outlet roller. Each section of roller use frequency changing motor to drive

• The inlet and outlet roller all use high quality seamless steel tube and shaft head welded together. The roller is machined after welding to keep enough load capacity and co axis.
• The roller shaft is welded by high quality carbon steel seamless steel pipe and hardening and tempering spindle head .outline and installing dimensions are processed after welded , to ensure the bearing , and concentricity .
• Shot blasting chamber indoor is tested by computer dynamic simulation ,completely avoid the blast wheel direct throwing and abrasive secondary bounce hit , although the rollers are equipped with easily changeable wear-resisting sheath .
• Automatic control all rollers, frequency speed changing. Manual control for each section of
• rollers separately for adjusting and maintenance.
• Inlet roller and outlet roller is driven independently, frequency speed changing

Front and back chamber: Attaching shot blasting chambers are steel plate and structural steel welding structure . They together with the cleaning chamber form lenient workpiece cleaning space .attaching chamber internalwall (close to the shot blasting chamber) adopts wear-resisting rubber sheet to protect , all guard plates can be changed easily and conveniently .

Inside the front and behind sealing chamber has multichannel sealing curtain , form maze sealing structure , which is convenient to replace and repair . The device is sealed tightly ; since the dust collector exhaust fan , inside the chamber form a certain negative pressure , no dust escape .

Principle projectile of Shot Blasting Machine :

The arrangement of blast wheel is simulated by computer. There are 6 blast wheels on both upper and bottom of the cabinet to give through blasting of work pieces. Blast wheels adopt transverse blasting theory. The blasting direction formed a 90 degree angle with steel plate marching direction. Axial direction and work piece formed a proper angle to get a perfect blasting effect and avoid abrasive accumulating on the surface of steel plate.

Feature of Shot Blasting Machine：

It is the welding structure of the steel plate and structural steel , which has sufficient

strength and rigidity . chamber body shape , size and blast wheel installation location are confirmed through the 3D optimization and dynamic simulation , to unsure the workpiece cleaning effect , and maximize the efficiency of the equipment . Cleaning chamber uses 10mm thick SPMn13 , which has good wear resistance and durable service . the guard plate hold-down nuts are made of high chromium cast . The bottom of the inside chamber is equipped with grating , the main throwing area upper the grating is equipped with high chromium special wear-resisting cast iron plates with holes , avoid the abrasive destroy grating , hopper and the lower screw conveyor , which has a long lifetime .

Blast wheel base and the wall adopts locating pin and hole bolt to fix . And between the blast wheel and chamber uses high-quality shock-reducing rubber pad . SPMn13 plate（thickness 10mm） high manganese steel is the best choice in the field of against the strong impact , high pressure material wear ,under the action of large impact or greater contact stress , high manganese steel plate surface produce the work hardening ,surface hardness raises from HB200 to HB500 rapidly , which can produce the high wear-resistant surface layer , and the inner layer of the steel plate austenite still maintain the good impact toughness. High manganese steel plate has two biggest characteristic : First , the larger the outside impact , the higher its own surface wear-resistance ; second is along with the wear of the surface hardening layer , the new producing hardening will continuously form . In recent years , with the rapid development of the modern industry and science , high manganese steel has become the first choice of wear-resistant material for the maglev train , drilling robot , new tanks and other advanced equipment .Many new materials and modern surface engineering technology can not compared with high manganese steel on the cost and efficiency .

Blast wheel: The equipment is mainly composed of abrasive ,belt pulleys , bearing ,motor etc. This machine is a total of six sets of shot blasting machines, using my company’s high-efficiency blast wheel. The shot blasting machine is completely manufactured by our company. Each shot blasting related artifacts to run at an angle, ensure the workpiece is to conduct a comprehensive clean-up shot blasting, and to cover all the work on the basis of need to clean up, to minimize the empty projectile throwing, to maximize the projectile utilization, reduce clean up indoor wear protective plate

Shot Blasting Process:

As shown, double disc riveted together, constitute the impeller body., equipped with eight leaves on the impeller impeller body and points with maru “located in the center of the blast wheel installed on the driven by motor spindle. Hood is lined with a guard board, directional set mounted on the casing and into the tube. At work, projectile by tube into the shot. With synchronous rotating blades for points maru “makes the projectile velocity.Projectile by directional flying out of the window, set to the orientation on the outside of the high-speed rotating blade, is leaf further accelerated, the projectile to clean up on the surface of work piece. Because points round pill and synchronous rotating blades ensures the projectile to the blade of no vibration, thus reduced the wear and tear of the blade.

Shot blasting process Feature:

• High efficiency: special impeller structure, blasting efficiency reaches 16-19 kg/min•kw.
• Protective liner and sealing: the top cover has cast iron and wearable rubber two layers
• protection and sealing.
• Low noise：blast wheel bottom has cushioning rubber, which can reduce vibration.
• Runner wheel uses 40 Cr material carburized and quenched. After processed, the
• runner need to be under balance detection.
• To keep precision and good balance when it rotate in high speed, all key machining
• parts are done by CNC center.
• Eight blades are very easy to remove, only need 5 to 10 minutes to replace 8 pieces of
• At the same time, you can also check the abrasion status of impeller and control
•  
• Material of blades, control cage, impeller is high chrome alloy, which has long service life.
• The weight difference each piece of blade is less than 8 grams, which keeps the wheel have
• good balance performance.
• It uses two dish impeller wheel, compact and high throw ability.

Adjust the projectile area

New blasting prior to use must be adjusted correctly oriented sets window position, so as much as possible projectile thrown projectile to clean up the surface of the workpiece is to ensure that the cleaning effect, reducing the interior walls of the clean-up of wear parts wear

Abrasive recycling purifying system: Abrasives circulation purification system by the circulatory system and separation purification system, the two parts divided into pill hopper, tube slide pill, projectile controller (shot blasting,) screw conveyor, bucket elevator, separator, and shot supplements and so on. Projectile controller of the system, screw conveyor, bucket elevator and pill sand separator settings in the electronic control system interlock: After the process does not work, before the process cannot run, thus avoiding clogging occurs due to projectile equipment failure.

Screw conveyor

Screw conveyor is made by the cycloid reducer, helical axis, transmission cover, bearings and other components. It is a standard pill sand horizontal conveyor equipment, shot blasting machine is an important part of the circulatory system of the projectile. Screw conveyor for my company serialization component, versatility, interchangeability, stable and reliable performance. Working to ensure that the entire screw shaft concentricity after welding.

This part uses helical blades 16Mn material, both inside and outside circles being processed by a special process stretching, pitch, outer dimensions are very precise, improve the service life.

Bucket elevator:

Bucket elevator is composed of cycloidal pin gear speed reducer, upper and lower barrel, transported rubber belt, hopper, enclosed barrel, and expanding device etc The elevator is adopted bend welding structure. Maintenance gate is equipment to convenient hopper replace and maintenance. The front door and side door under the lower shell have installed movable door, to easy for the repair of lower transport device, clean the clocked abrasives.

The abrasive dropped to the separator at the force of gravity In the process of working, the hopper in the transport belt brings the abrasives from the bottom, and drop at the gravity. Using polyester transport belt, squirrel cage roller, intermediate slightly protruding, which not only improves the lifting friction between the belt and pulley, avoiding the old light pulley slippage, but also reduces the lifting belt pretension force, extending the life of lifting tape. And can prevent the projectile stuck in between the lower pulley and the belt so the belt deviation phenomenon, flowing from the projectile between the spokes and the belt. Bottom shaft on the lifting having pulse wheel, can detect the tracking work status. Hoist not turn once or slippage failure, timely feedback signals to the PLC process alarms to ensure the safe operation of the equipment.

Abrasive separator

Using advanced three full curtain overflow induction weight automatic adjustment type separator,introduction of Swiss GF + DISA technology .

Working principle of Shot Blasting Machine

Abrasive mixture lifting to the drum sieve by bucket elevator,drum sieve inside and outside has spiral blades.Inside sprial blade making the large pieces discharge;abrasive,sand and dust mixture after sieved then push by outside sprial blade,then form a flow curtain,by adjusting the weight position,so abrasive can be fully separated.

Applicable scope of Shot Blasting Machine

The best separation projectile diameter from φ0.7 ~ φ1.5, the separation efficiency of 99.5% or higher.

Abrasive distribution system

The company patent technology of pneumatic projectile gate, relying on the cylinder to remote control blasting quantity. It can prevent motor burn out due to common controller closed lax, shot blocked, the projectile empty and hurtful phenomenon.

Dedusting system：

JD series of high rapping bag filter is my company absorbing foreign advanced technology,design and manufacture a new generation of highly efficient filter. Mainly used for large-scaleworkshop, shot blasting equipment, environmental dust. The effect of dust: dust emissionconcentration is less than equal to 95mg / m3, well below the JB / T8355-96 andGB16297-1996 “air pollutant discharge standards”.

Dusting method：Dusting collector use economical and practical test for the prolonged rappingbag-type dust collector, the filter has a low wind speed, high filtration precision, good cleaningeffect and so on.

We use the most advanced and reasonable secondary dust removal mode and unique and effective structure:

First step: abrasive settlement cabinet located on top of the machine, connected with air washseparator. This step is to solve the problem that the pipe may accumulate abrasive.

Second step: most effective & economic cartridge type pulse blow dust collector. It has features as low filtering air velocity, high filtering precision and good dust cleaning.

Filter shell made of welded steel plate processing, access door seal to ensure the dust gas to purify the air chamber, the filter body is composed of a single filter bag and support.The system

including the settling chamber, the blower, fan and fan pipe, dust collector and the connection between the host pipe, etc.Reach more than 95%  dust removal efficiency, emissions acuities were 80 mg/m3, accord with GBJ4-73 industrial “three wastes” emissions standards, the main fan power 22 kw, dust bag adopts special needle felt filter material sewing, bag can be easily removed for cleaning and using.

Electric system for Shot Blasting Machine

• All use the Japanese Mitsubishi PLC control, Omron or manual and automatic operation can be realized
• Conveyor speed is controlled by inverter, can stepless speed regulation.
• The entry of the production line, shot blasting room access door and other important parts, are equipped with safety interlock switch device. Chamber blasting of underground foundation pit is also equipped with lamp power socket, easy access lighting.
• Using ammeter displays current of shot blasting machine;
• This system to realize centralized control of shot blasting cleaning machine. The system can be based on user require the use of the programmable controller (PLC) as the core
• This system main power supply adopts 3 ~ 380 v ac power, control circuit adopts single-phase 220 v ac power, to control transformer will be 380 v voltage drop is 220 v to the control circuit after use;
• The system has a relatively complete fault alarm function, help operators or maintenance personnel to quickly find the fault point, reduce downtime, improve working efficiency.
• Electrical and electronic control cabinet design, production in line with international electrical specifications and safety standards.
• Circulatory system of the whole equipment, including hoisting machine, separator, automatic detection device for the spiral conveyor and so on, when some seams or jammed,
• can automatically alarm and inform the fault parts, can make the maintenance personnel to repair.
• It not only can be single move, can according to the chosen way of strengthening any open one shot blasting machine.

Don Lee,

Sales Manager,

Qingdao Antai Heavy Industry Machinery Co.,ltd

Address：No.867 Century Avenue,Jiaonan.Qingdao

Tel：400-617-7706

Tel：0532-88138566 FAX：0532-88138577

Website：http：//www.qdantai.com