How to install and debug the rotary automatic sandblasting machine?

Detailed guide for installation and commissioning of rotary automatic sandblasting machine

Rotary automatic sandblasting machine, as an efficient equipment in the field of industrial surface treatment, is widely used in scenes such as batch derusting, deburring and strengthening treatment of parts. The standardization of its installation and debugging directly affects the stability of equipment operation, sand blasting uniformity and service life. The following provides a complete installation and debugging process and matters needing attention in combination with the practical standards of mechanical processing industry:

First, preparation before installation

(1) Site requirements

The site should be flat and firm, and the bearing capacity of the ground should not be less than 1.2 times of the total weight of the equipment (the total weight of the conventional medium-sized rotary sandblasting machine is about 2-5 tons), so as to avoid vibration and displacement when the equipment is running; The drainage slope (3-5) should be reserved on the ground to facilitate the discharge of sand blasting wastewater, and at the same time, the ground sand control treatment should be done well (wear-resistant rubber pad can be laid or concrete wear-resistant layer can be poured).

The space of the site should meet the requirements of equipment operation and maintenance: a passage of ≥ 1.5m is reserved around the equipment, and a space of ≥ 0.8m is reserved at the top (easy to overhaul the sand blasting gun and rotary mechanism); The ambient temperature shall be controlled at-5℃-45℃, and the relative humidity shall be ≤85%, so as to avoid short circuit of electrical components and agglomeration of sandblasting media caused by wet environment.

It is necessary to stay away from inflammable and explosive articles and precision equipment (such as CNC machining centers and testing instruments), and protective isolation belts and warning signs should be set in the sandblasting area to prevent people from being injured by sand splashing.

(2) Foundation construction

Small rotary sandblasting machine (capacity ≤50kg/h) can be directly placed on the flat ground, with rubber damping pad with thickness ≥20mm at the bottom; Medium-sized and above equipment (handling capacity > 50kg/h) needs to be poured with concrete foundation, the foundation size is 200mm×200mm larger than the equipment base, the concrete strength grade is not lower than C30, and the anchor bolts (specifications match the installation holes of the equipment base) are embedded in the foundation, and the height of the foundation surface exposed from the top of the bolts meets the equipment installation requirements (usually 30-50mm).

After the foundation is poured, it shall be maintained for 7 days or more, and the equipment shall not be hoisted until the strength reaches the standard, so as to avoid the deformation of the equipment caused by the foundation settlement.

(3) Inspection of equipment and accessories

After unpacking, check whether the equipment main body, rotary table, sandblasting gun set, dust collector, sand circulation system and electrical control cabinet are complete, check whether the accessories (such as sandblasting pipe, nozzle, sealing ring, anchor bolt and tool kit) are in good condition according to the equipment list, and mainly check whether the bearings of rotary mechanism and the nozzles of sandblasting gun are damaged or deformed during transportation.

Check whether the terminals of electrical components (such as frequency converter, contactor and travel switch) are loose and whether the cable insulation layer is damaged; Check whether the pneumatic system (such as cylinder, solenoid valve and gas pipe) leaks, and whether the sand bin and separator are rusted or sundries.

(4) Preparation of auxiliary facilities

Power supply: the corresponding power supply line (conventional 380V three-phase five-wire system, power 15-30kW) shall be configured according to the power of the equipment, and the line section shall meet the current requirements (for example, ≥6mm² copper core cable shall be selected for 30kW equipment), and an independent circuit breaker (capacity 1.5-2 times of the rated current of the equipment) and a grounding device (grounding resistance ≤ 4ω) shall be equipped.

Air source: dry and clean compressed air is connected, and the air pressure is stabilized at 0.6-0.8MPa, and the air supply volume should meet the equipment requirements (usually 0.8-1.5 m/min). An oil-water separator and a pressure reducing valve should be installed at the air source end to prevent moisture and oil stains from entering the sandblasting system, resulting in sand agglomeration and nozzle blockage.

Sandblasting medium: Sand materials (such as quartz sand, brown corundum and glass beads) that meet the equipment requirements shall be selected, and the particle size shall be matched with the nozzle aperture (the conventional nozzle aperture is φ3-φ8mm, and the particle size of sand materials is 0.1-1.2mm). The sand materials shall be dry and free of impurities, and the water content shall be ≤2%. Large particle impurities and caked sand materials shall be removed by screening in advance.

Second, the installation process

(1) Equipment hoisting and positioning

When lifting equipment by forklift or crane, lifting tools (such as wire rope and sling) that meet the weight of the equipment should be selected, and the lifting point should be selected to specify the lifting lug position of the equipment base, so as to avoid directly lifting the rotary table or sandblasting gun set and prevent the deformation of the parts; Keep the equipment stable during hoisting to avoid collision.

Place the equipment on the foundation or at the designated position, and adjust the levelness of the equipment: use a spirit level to detect the vertical and horizontal levelness of the equipment base, with an error of ≤0.2mm/m, realize the levelness calibration by adjusting the height of the anchor bolt or increasing or decreasing the damping pad, and tighten the anchor bolt after calibration (locking with double nuts to prevent loosening).

(2) Component assembly

Installation of the rotary table: hoist the rotary table to the designated position of the main body of the equipment, align the connecting flange, and uniformly tighten the connecting bolts (the bolt specifications need to match, and the tightening torque meets the requirements of the equipment manual); Check the rotation flexibility of the rotary table, make sure that there is no jamming and abnormal sound when rotating manually, install a limit device and adjust the limit stroke to ensure that the rotary range of the table meets the design requirements.

Installation of sandblasting gun set: according to the requirements of sandblasting process, fix the sandblasting gun on the gun rack, and adjust the angle (usually 30-60 included angle with the workpiece surface) and distance (100-200mm conventional distance) of the sandblasting gun to ensure that the sandblasting covers the whole surface of the workpiece; Connect the sandblasting pipe, and fasten the joint with clamps to ensure that there is no air leakage or sand leakage.

Installation of sand circulation system: connect the sand bin, separator and conveying pipeline to ensure that the pipeline connection is sealed and there is no leakage; Install sand supply device and material level gauge, adjust the sensitivity of material level gauge, and ensure that the alarm can be given in time when the sand material is insufficient.

Installation of dust catcher: connect the dust catcher with the exhaust port of the equipment sandblasting room, and the connecting pipeline should be well sealed to avoid dust leakage; Fix the base of the dust collector, connect the power supply of the dust collector and the pulse dust removal system, and check whether the filter bag of the dust collector is firmly installed and whether the dust removal mechanism moves flexibly.

(3) Electrical and pneumatic system connection

Electrical connection: according to the electrical schematic diagram of the equipment, connect the power cord to the electrical control cabinet, and connect the electrical components such as motor, frequency converter, travel switch and sensor. When wiring, it is necessary to distinguish between phase wire, neutral wire and ground wire to ensure firm wiring and correct phase; Check the insulation of electrical circuit (measured by megger, insulation resistance ≥1MΩ) to avoid short circuit fault.

Pneumatic connection: connect the compressed air pipeline to the pneumatic system of the equipment, and connect the cylinder, solenoid valve, pneumatic valve and other components. Wrap the raw material belt or install a sealing ring at the pipeline interface to ensure good sealing; Turn on the air source, test whether all pneumatic components operate normally, and adjust the running speed and stroke of the cylinder to ensure that it meets the work requirements.

(4) Installation of safety devices

Install protective door and safety interlock device: the protective door should be tightly closed, and the safety interlock device should be sensitive and reliable to ensure that the equipment cannot be started when the protective door is not closed; Install the emergency stop button (red, eye-catching position) to ensure that the power supply and gas supply of the equipment can be quickly cut off in an emergency.

Install dust detection and alarm device: install dust concentration sensor in the sand blasting area, and when the dust concentration exceeds the national standard (≤ 10 mg/m), it can alarm in time and start the dust collector to strengthen dust removal; Install noise protection device, the noise of equipment operation should be controlled below 85dB, and a sound insulation cover should be installed if necessary.

Third, the debugging process

(1) No-load debugging

Electrical system debugging: turn on the power supply and check whether the indicator light and instrument display of the electrical control cabinet are normal; Start the control program to test whether the running direction of each motor (rotary motor, sand blasting pump motor and dust removal motor) is correct, and there is no reversal or abnormal sound; Test the speed regulation function of the frequency converter, adjust the speed of the rotary table (conventional speed is 5-20r/min), and observe the stability of the speed, with no obvious fluctuation.

Pneumatic system debugging: start the pneumatic system, and test whether the actions of each cylinder and solenoid valve are coordinated, and there is no jamming or air leakage; Adjust the air pressure of the sandblasting gun, and adjust the working air pressure to 0.4-0.6MPa through the pressure reducing valve (adjusted according to the sand type and process requirements) to test whether the switch action of the sandblasting gun is sensitive.

Commissioning of rotary table: start the rotary table and run it continuously for 30 minutes, and observe the rotation uniformity of the table, without shaking or sticking, and the speed error is ≤ 5%; Check the accuracy of the movement of the limit device, and when the workbench runs to the limit position, it can stop in time and run reversely (or give an alarm).

Debugging of dust collector: start the dust collector and test whether the pulse dust removal system works normally and the dust removal effect of filter bag is good; Check the dust emission concentration of the dust collector exhaust port to ensure that it meets the environmental protection standards and there is no obvious dust leakage.

(2) Load debugging

Sand filling: add a proper amount of sand blasting medium to the sand silo, start the sand circulation system, and test whether the sand conveying is smooth and free from blockage and accumulation; Adjust the separation effect of the separator to ensure that unqualified sand materials (too large or too small particles) can be effectively separated, and the sand materials returned to the sand silo meet the use requirements.

Trial spraying of workpieces: select the workpieces that are consistent with the actual production specifications, place them on the rotary table, and fix them firmly (to avoid the displacement of workpieces during sandblasting); Start the equipment, carry out trial spraying according to the preset process parameters (sandblasting pressure, table speed and sandblasting time), and observe the sandblasting effect:

Uniformity of sandblasting: check whether the sandblasting marks on the surface of the workpiece are uniform, and there is no leakage or overspray, and there is no obvious color difference or roughness difference locally;

Surface quality: measure the surface roughness of the workpiece after sandblasting (Ra1.6-6.3μm as required by the routine, and adjust it according to the process requirements), and check whether the workpiece is deformed or damaged (such as corner cracking and surface scratches);

Sand consumption: record the sand consumption per unit time to ensure that it is within a reasonable range (no abnormal loss).

Parameter optimization: adjust the process parameters according to the test blasting effect. For example, increasing the sandblasting pressure can increase the surface roughness, reducing the rotation speed of the workbench can improve the sandblasting uniformity, and adjusting the angle of the sandblasting gun can avoid excessive sandblasting at the corners of the workpiece; Repeated debugging until the preset process requirements are met.

(3) Continuous running test

Run continuously for 2-4 hours, simulate the actual production conditions, and observe the running state of the equipment;

Equipment stability: no obvious vibration and abnormal sound, no looseness of connecting bolts of various parts, no leakage of sandblasting pipe and gas pipe;

Temperature monitoring: monitoring the temperature of motor, bearing, frequency converter and other components, with motor temperature ≤75℃ and bearing temperature ≤80℃ without overheating;

Sand material circulation: the sand material circulation system runs normally, without blockage and material breakage, and the separation effect of the separator is stable;

Safety device: test whether the safety interlock device and emergency stop button are sensitive and reliable, and can stop quickly in case of sudden failure.

After the operation, check the wear of all parts of the equipment, such as the degree of nozzle wear (the wear exceeds 10% of the aperture and needs to be replaced), whether the sandblasting pipe is damaged, whether the bearing of the rotary table is abnormal, etc., and deal with the problems found in time.

IV. Precautions for Installation and Debugging

Operate in strict accordance with the equipment instructions and industry standards. It is forbidden to change the equipment structure, electrical circuit or process parameters without authorization. If adjustment is needed, it must be confirmed by technicians.

Personal protective equipment (PPE) should be worn during installation and commissioning, such as safety helmet, protective glasses, dust mask, sand control gloves and impact shoes, to avoid personal injury caused by sand splashing and dust inhalation.

Before commissioning, operators should be trained to familiarize themselves with the equipment structure, working principle, operation flow and safety precautions, so as to avoid equipment failure or safety accidents caused by misoperation.

During the operation of the equipment, it is forbidden to open the protective door or reach into the body to contact moving parts (such as rotary table and sand blasting gun), and it is forbidden to carry out overhaul and maintenance operations during the operation of the equipment.

Regularly check the quality of sand, replenish new sand in time, clean up caked sand and impurities, and avoid nozzle blockage and sand blasting effect decline due to sand problems; Clean the filter bag of the dust collector regularly to ensure the dust removal effect and avoid the potential safety hazard caused by dust accumulation.

After the installation and debugging is completed, it is necessary to fill in the installation and debugging record form, and record the information such as equipment model, installation date, debugging parameters, trial spraying effect, existing problems and treatment results, and file them for future reference.

Five, common faults and treatment methods

The rotation of the rotary table is stuck: the reasons may be loose anchor bolts, levelness deviation of the table, bearing wear or foreign body blockage; Treatment: Fasten the anchor bolt, recalibrate the levelness, check the bearing wear (replace the bearing if necessary), and clean up foreign objects.

No sand is ejected from the sandblasting gun: the reasons may be the lack of sand in the sand bin, the caking of sand materials blocking the pipeline, air leakage in the sandblasting pipe and insufficient air pressure; Treatment method: replenish sand, clean up the blocked pipeline, tighten the interface of sandblasting pipe, and adjust the pressure of air source to the specified range.

Uneven sandblasting: The reasons may be improper angle or distance of the sandblasting gun, too fast rotation speed of the workbench and uneven sand particle size; Treatment method: adjust the angle and distance of the sand blasting gun, reduce the speed of the workbench, and screen the sand with uniform particle size.

Dust leakage of dust collector: the reasons may be the damage of filter bag, poor sealing of pipeline interface and failure of pulse dust cleaning system; Treatment: replace the damaged filter bag, seal the pipeline interface, check the pulse ash cleaning system (such as solenoid valve and blowpipe), and repair the faulty parts.

Electrical system failure (e.g. motor does not start, frequency converter gives an alarm): The reasons may be power failure, loose wiring, sensor failure, and incorrect parameter setting of frequency converter; Solution: Check the power supply voltage and wiring, replace the fault sensor and reset the inverter parameters.

Through the above-mentioned standardized installation and debugging process, it can ensure that the rotary automatic sandblasting machine can be put into normal operation quickly and give full play to its efficient and stable surface treatment ability. In the subsequent use process, it is necessary to maintain the equipment regularly to prolong the service life of the equipment and ensure the stability of the production process.