Steel drum production Environmental Protection - Dustproof

In recent years, the metallic steel drums as a branch of the packaging industry, has been greatly developed. But also produce a lot of environmental pollution. In today's increasing demands for high environmental protection, steel drums and processing enterprises, not only in the production process to be executed IS09000 standard, also must perform IS014000 standard. Environmental pollution is not only present in the steel drum itself, but also exists in the production process and the use of the process of the steel drums, so development of green packaging to reduce environmental pollution will be the direction of the development of China's steel drums.

, Most of the production line in China's steel drum production milling process, steel drums outside surface of the cleaning process and the painting process. The barrels are edging process is a process barrel body welding barrels before the butt seam welding while processing side processing is to take the side of the barrel physique welding seam at pretreatment before seam welding, its main purpose is Lower take the side of the thickness, quality assurance process in order to facilitate the after; followed in order to eliminate ride the edge of the oxide, grease, facilitate seam welding. Domestic the cooperage enterprises mainly adopt the technology is edging that a 4-8 group grinder butt edges grinding, cooperage industry called the edging process. Seen edging production will be shocked, because where the working environment is too harsh, deafening noise, the diffuse dust flying, a toxic gas cloud of cigarette smoke ... the noise from the friction of the wheel and the steel plate; dustunder the grinding wheel and steel grinding particles; flue part is the product of the adhesive under high temperature grinding wheel within a part of the result from the drums surface oil at high temperature vaporization.

The cleaning step is after the completion of the drums manufactured before painting pretreatment step. It is hanging hanging with the steel drums and operated by the conveyor belt, preheat the drying room, and then spray containing the chemical liquid high-pressure water into the spray chamber, cleaning the grease and corrosion of the steel drum surface. Then spray water softening chemical solution to clean, and then drying the painting process. Which solution due to the structural characteristics of the drums themselves, steel drums, on the edge of the spray water addition is not clean, the drums after pretreatment, always with some solution out after the drying process, at the outlet mist and mist. These aerosol and mist contains a lot of harmful chemical ingredients, it will spread to the drying room air.

The painting process itself is a source of pollution of the environment, the concentration of harmful gases in the paint shop has already several times more than the normal air.These harmful gases from the fumes of paint mist and paint drying, spray paint produced in Environmental Protection, called the fog of dust and soot.

Such a work environment, why not for corrective actions it? This is because most of the cooperage economic efficiency of enterprises are not very good, while the use of edging the process works well, and does not require much investment; the former cleaning and painting process after a series of change is built with investment, the process is also The effect is also very good.

So, how can a small investment to reduce production processes smoke, fog, dust and dust? Or let us take a look at how they are formed.

, Smoke, fog, dust and dust generation and harm

Edging production process, full of a lot of smoke in the air workshop. Smoke and dust are tiny particulate matter. The dust is the particulate waste is formed due to the friction force between the grinding wheel and a multi-plate. Smoke is by the organic substances in the oil on a steel plate and the grinding wheel by the friction heat generated by vapor condensation, especially in the processing of the galvanized sheet, zinc heat oxidized into zinc oxide particles in the flue gas most harmful. The particulate material into the air, wherein greater than 10 microns in diameter, due to gravity quickly settle, but only relatively stable in the air in the vicinity of the grinding wheel a high concentration of coarse particles, the fine particles will be longer floating in the air particulate matter can wheel motor drive system failure, human disease. People smoke filled environment also affect efficiency.

The dust is mainly excess paint after painting into the air, it is improperly adjusted by the gun or spray disc or part into the air in order to meet the technical requirements. If the adjustment is not high enough, it will generate the leakage point or edge of the spray is not completely defective. Of suspended small paint particles in the gas, the particle diameter is generally relatively small, wherein the part of the particle diameter larger than 10 microns, by gravity settling to the ground in a short time; the majority less than 10 microns in diameter particles will be floating in the air for a long time, the formation of fog dust.

Into the drying room the steel drum spray paint, baking, baking temperature about 150 ℃, so just finished spraying the paint's wet steel drums into the drying room, will produce smoke, this smoke contains a lot of The rubber water ingredients into the atmosphere will cause pollution sources. This smoke is known as soot.

Fog dust is the general term of droplets suspended in the gas. It is formed due to the condensation of the steam, the liquid spray, atomizing and chemical reaction processes. Mist, mist, alkali mist, oil mist, and all belong to the fog of dust. These are mainly generated in the drums of cleaning pretreatment.

Inhaled particulate matter, the disease may cause pneumoconiosis, alveolitis, tuberculosis, bronchitis, occupational asthma, poisoning, such as cancer. In addition, the particulate matter can affect lung function, some particulate matter can cause dermatitis and conjunctivitis.

, Workshop dust control measures

Production workshop, even take control of soot, dust, fog and dust measures, it is inevitable that some of soot, dust and fog dust flying with air diffuser dust in the working environment, and some is deposited on the surface of the roof beams, wall, equipmentetc.. Accumulated to a certain extent, due to the mechanical vibration, and other reasons, it may then fall, suspended in the air, and spread to the breathing zone of workers. Floating dust sometimes soot concentrations much higher than the day-to-day operations.

Dust workshop in order to avoid the above situation, the best installation of ceiling and roof beams not exposed, no pipes, wiring below the ceiling; wall, window frames, but also not easy to accumulate dust streamlined structure ; flooring and wall joint best should have proper arc for easy cleaning.

In the short term there will be a lot of dust accumulation on the ground of the workplace, the lattice structure can be used on the ground, its lower part with a the local suction device vacuuming or using recycled water vacuuming.

Workplace equipment layout and dust control. If the equipment is reasonably arranged, the channel size appropriate to facilitate the full implementation of dust control measures. At design time, you should strive to make the process system to simplify and enhance continuity, minimize soot deposition opportunities.

Dust generating equipment and the equipment does not produce dust should be divided in two different workshop, or to limit the spread of dust, to minimize the impact of the dust of the other working environment completely isolated with a partition wall.The general steel drum manufacturer has the workshop divided into paragraphs, front-end for the next meal mill Punta. Used the partition separated to prevent dust diffusion.The middle of the rolling, spot welding, seam welding, flanging, bulging tendons, seaming and leak testing. After paragraph spray, cleaning, drying, painting and drying.The middle of a through workshop, last paragraph as a closed unit.

Spray paint drying room layout according to their characteristics, in addition to adsorption equipment installed in the shop over the ventilation equipment following dug trench benefits of water, covered with grill plate. Remember the ditch not compact with cable channel, otherwise it will cause a short circuit, and the ground is often kept moist.In addition, painting rooms, operating rooms should be closed, the timing input to its internal fresh air.

Edging process characteristics, being in the same process can achieve the effect of technology should be distributing smoke the least technical; economy can not be ignored, but should not only consider the direct economic, and according to the smoke caused by hazards are integrated economy into consideration to select the production technology. Dust control measures can be taken in terms of production technology:

1 Select pollution grinding wheel

In the past, many manufacturers very consider edging the grinding wheel material harmful, so using harmful free silica material, should be paid to the choice of better quality and less environmental pollution silicon carbide, boron carbide, white fused alumina and other raw materials instead. Good quality grinding wheel in Shanghai, Zhejiang and other places, there are many foreign-invested enterprises, production, and life expectancy is several times that of the original old-fashioned wheel. It is very wearable, grinding the physique of an equal number of barrels, the dust generated should be many times lower than the original, but the price is relatively modest.

2, to improve production technology and equipment

The process will produce dust completely sealed, and will be able to prevent the spread of smoke to the operating environment, but due to operational reasons completely sealed reality. It is generally confined hood also implement local inhale clean air flow to cover the airtight cover, to prevent dust stream to escape.

Apart from the dust of equipment confined or semi-confined, also can turn on the surrounding environment of the workers in the distribution of dust environment enclosed. Completely prevent pollution measures example, in large distributing soot workshop, take difficulties, the the workers operating chamber airtight, fresh air or oxygen to the indoor blower.

3, the use of automation and mechanization processing

Using putschism (robot) for remote operation, and have a significant role in the prevention of dust hazards, so that workers do not need to be directly involved in distributing the operation of the soot, and can realize a completely closed and absorb dust. Into the device internal overhaul, maintenance workers must wear protective clothing, with a protective cover. Doing so may encounter high concentrations of dust, causing much harm to the human body.

, Commonly used in the dust removing method

The commonly used method of dust ventilation and dust removal method and local inhale dust removal method.

(A), ventilation a comprehensive ventilation, whirlwind law.

1, a comprehensive ventilation and dust removal method

General ventilation to control dust, mainly gently clean air, continuous production sites air harmful substances fishing? Short, so that does not exceed the allowable concentration, so called dilution ventilation. A full ventilation are generally much larger than local inhale air volume, so better the local the inspiratory economy. Steel drums the the edging workshop and more comprehensive ventilation to control smoke.Grinding wheels generally have eight, and more dispersed, process, operation, it is difficult to set the local suction device. This dust removal method is really just the concentration of harmful substances? Short, and no purification dust, from the point of view of environmental protection is unscientific. The control of the discharge of the exhaust gas should be dependent on a variety of control techniques and purification apparatus.

Cyclone

The cyclone is the use of centrifugal force generated by rotation of the dusty gas, the dust particles separated from the gas out of the process. The cyclone has a simple structure, small footprint, low investment, easy operation and maintenance, consume little pressure available a variety of materials, direct recovery of dry dust particles.Cyclone with the tapered end of the outer cylinder, intake manifold, exhaust pipe, cone, dust box, dust discharge valve is composed of five parts. Exhaust pipe to the formation of the inner cylinder into the outer cylinder, intake manifold with cylindrical tangent, the lower part of the outer cylinder is a cone, the lower part of the cone is the dust box.

The dust stream after entering from the intake port (14 ~ 24m / s) at a high speed, due to the limit of the outer cylinder cover and the inner and outer cylindrical wall, forcing airflow do top-down outer rotary circulation movement in the airflow formed during the rotation of the great centrifugal force. Under the action of centrifugal force, the dust particles in the gradually dumped to the outer wall, the the rotational drop under the action of gravity along the outer wall surface, until the dust box. Rotation decrease the outer cyclone due to the cone shrinkage of pooled, falling gradually to the center to a certain extent, begin to return to rise; airflow Usually bottom-up rotational movement is formed, generally referred to as the trip flow. Within the cyclone does not contain large particles of dust, it is relatively clean and can be discharged to the atmosphere through the inner tube. However, since the inner and outer swirler mutual interference and penetration, it is easy to sink to the bottom of the dust particles is brought up caused by the secondary precipitator flying phenomenon. Spirits, improve collection efficiency in order to reduce the secondary, often set up in the lower part of the cone gas barrier dust exhaust device. Precipitator internal dust streams movement is very complex, it is not only a circular motion, the radial movement and the axial movement, but also in the process of settlement of dust, the line speed change and centrifugal acceleration and changes, therefore, should the cyclone work in large quantities oversimplify. In addition, research and use at the axis of the cyclone is more than in the vacuum state, and should therefore be avoided the dust exhaust pipe to the operation of any air leakage between the dust box, in order to guarantee its collection efficiency.

(B) local inhale dust

Local inhale harmful substances emitted to the workers breathing zone air before it sucked from the generating source near. Local getter device is provided by the suction hood, pipes, air purifier, the fan is composed of four parts. Used for vacuuming, the air purifier is the precipitator.

Dust suction means excluding Housing, the outdoor air should be fed in a controlled state workshop, replacing the air discharge, but should pay attention to this problem, especially in the case of large suction than otherwise, affect the vacuum effect occurs indoors is not easy to maintain a comfortable temperature so that the workers or blow cold air workers. The supplemental air volume at least equal to the amount of the total air discharged from the the inspiratory ventilation system from the workshop, preferably a little more in order to minimize air leakage around the building.

Must be heated make-up air in the winter and summer, will have to cool down, so the local suction system should be designed to minimize the amount of suction Note: under the premise of ensuring the suction effect, or recycled air, but without circulating airendanger the health of workers as a prerequisite.

Containing soot air sucked by local suction system, you need to go through the dust purification before entering the atmosphere. Conventional precipitator with a mechanical precipitators, scrubbers, fabric filters and electrostatic precipitators four, each of which there are many different types. Can be selected according to the situation. At present, most of the steel drum factory has chosen this local inhale dust removal method. Precipitator, the upper shelf in the drying room, each window and are equipped with axial fans, enter the amount of fresh air to the workshop. However, the current situation, most of the manufacturers are sucked out harmful gases directly discharged into the atmosphere, rarely purification, so more and more serious environmental pollution caused by. So the the IS014000 standard certification in steel drums enterprise imperative.

Fourth, strengthen production management, source reduction

In addition to the adoption of technical measures in order to prevent the generation of soot, dust, fog, dust and other harmful substances, should also strengthen production management, its contents include: maintain its premises in a clean environment, and maintain a dust-proof equipment intact, often measured dustproof effects and dust education and training.

Practice has proved that the dust generated in the production environment, even if dust control measures taken, it is inevitable that some dust flying out a long time, some of the dust will be attached to the window, wall, surface of the device, as well as lighting.Regular cleaning should be deposited dust. Cleaning dust with a damp mop, vacuum cleaner, blowing suction sweep away cars, such as tools and equipment.

And production equipment, dust equipment should meticulously maintained, strengthen maintenance to ensure that it can often play a good role. Should be done to check table lists must check the premises, at regular intervals, itemized check for abnormalities.Abnormal, you should investigate the cause, make the necessary repairs, replacement and supplement, and to make the maintenance records.

About the effect of dust, through technical determination should be monitored.Determination of the content is mainly soot concentrations of the operating environment and the technical performance of the various dust-proof equipment. This should be measured frequently found the problem solved.

Dustproof work to do, but also to deal with the education and training of workers for dustproof, its contents should generally include: the hazards of smoke, about regulations, dust, dust the use and maintenance of the equipment and the management of the operating environment. In addition, technical personnel engaged in dust-proof work should also be carried out specialized training and training on smoke control and smoke detection method.

In recent years, at home and abroad has appeared in a variety of new welding technology and welding edge process, that people still recognize the environmental impact of the edging. The new welding process using a butt welding, welding, there is no need to take the edge, to just butt both sides leaving a gap of 0.3 ~ 0.5mm, melt fusion welding method, both sides are welded together. New side of the weld process the edge milling process, cleaning processes, fully automated high-frequency welding process. Edge milling process eliminates noise and dust, is a more adapted to the transition process of the general small cooperage plant; relatively simple and feasible.The cleaning process also eliminates noise and dust, but because it is the butt edge of hydrochloric acid and other oxides and grease corrosion, often accompanied with toxic and harmful gases, but also cleaning liquid, or to protect the environment unfavorable it is not advocated high speed steel barrel making machine. Automatic high frequency welding process due to the characteristics of the advanced nature of its welder, welding side generally does not require rigorous treatment can be welded, the removed treatment processes, thus reducing the labor intensity, reduce production costs, environmental pollution has also improved . Welded steel drums and updating process.

About the process of cleaning, drying, painting, although there are many ways, but from the point of view of environmental protection, are less than ideal, and needs further exploration. But from another aspect to improve working conditions, plant some flowers such as the pollution of the workshop on the windowsill in the factory area, afforestation, use of natural conditions dustproof, clean shop air is an economical and reasonable measures . Also meet the entertainment rest, beautify the environment.