The impact of casting production on the environment is huge. According to different pollution forms and components, different measures can be taken to effectively control and control the environmental pollution.
1. Cupola flue gas treatment
At present, for the flue gas produced by cupola, there are many kinds of desulfuration and dedusting equipment at home and abroad. The efficiency, performance, stability, equipment investment and operation cost of the equipment are different. Generally speaking, the price of imported equipment is about 2-3 times that of domestic equipment, and the operation cost is doubled. The effect of desulfuration and dedusting is slightly higher, and the domestic equipment adopts the most advanced technology, The integrated equipment of dust removal and desulfurization produced by some famous environmental protection equipment companies in China is a combination of four processes, i.e. spray cleaning, atomization absorption, liquid film mass transfer and impact turbulence, so that gas-liquid solid can be fully contacted, reacted and separated, so as to achieve the purpose of high-efficiency desulfurization and dust removal.
The common features of these devices are:
(1) Scientific and compact structure;
(2) Wear resistance, corrosion resistance, high temperature resistance and long service life;
(3) Dedusting and desulfurization are carried out at the same time, with strong adaptability, allowing gas volume to fluctuate more than 30%, and stable operation;
(4) Strong operability and convenient maintenance and management.
Technical performance index:
(1) Dust removal efficiency ≥ 95%;
(2) Smoke emission concentration < 100 mg / m3;
(3) Lingeman blackness of flue gas ≤ level 1;
(4) Desulfurization efficiency ≥ 75%;
(5) Sulfur dioxide emission concentration ≤ 700 mg / m3.
The scheme can be used by 1 × 3 × cupola or 2 × 4 × cupola at the same time. The features of the scheme are small area, low investment, low operation cost, and the treated flue gas can reach the discharge standard.
2. Control of cleaning the dust of roller
Shot blasting roller has many points, and the dust contains iron powder. The ratio is large and the concentration is high. Using ordinary cyclone separator and single wet or dry method to remove dust, not only the effect is not ideal, but also because of the large amount of dust, it is difficult to maintain and manage. This paper introduces a simple and easy dedusting technology with less investment, good effect, very low operating cost and convenient management.
The process is to use the characteristics of large dust ratio and fast settlement, and build an attached span equal to the workshop in length, 3 m in width and 2 m in height outside the cleaning workshop. As a dust settling room, a tap water pipe with small holes is installed on it. When cleaning out the dust, spray a little water.
Two dust discharge doors are opened outside the settling chamber for the tipper to enter and exit during dust discharge. Two ordinary back blow bag dust collectors are installed outside the settling room, which can achieve good dust removal effect.
In addition, for the sand treatment system, as long as several key equipment such as the sand remover, crusher, roller screen and elevator are installed with dust cover, the exhaust pipe is connected outside the dust cover, collected into a main pipe, enters into the reverse blow bag dust remover, and a 45 kW exhaust fan is installed outside, the purpose of dust removal can be achieved.
3. Noise control of mechanical equipment
The noise control of the mechanical equipment in the foundry workshop should be different according to the characteristics of the equipment and different places.
3.1 Noise control of blower and air compressor
A muffler is installed at the exhaust port of the fan, a sound insulation cover is installed for the fan, motor and compressor, and the walls in the blower room and air compressor room are used for sound absorption. Sound insulation doors are used, and damping materials are applied to the air supply pipes .
3.2 Noise control of molding machine and desander
The vibrating surface of the shaker moulding machine moves into the cylinder, the noise is shielded, and damping materials are used; the ceramic jigging mechanism adopts the non box modeling and injection molding, and the sand machine adopts the movable steel plate cover, and the inner layer of the cover is coated with sound-absorbing materials, which is dust-proof and sound insulation.
4 Concluding remarks
There are many aspects of environmental pollution in foundry, and there are many technologies and equipment that are suitable for environmental treatment in foundry. The first principle to be followed when choosing technology and equipment is: reasonable technology. Its main contents include: advanced index, economic energy saving, mature technology and convenient maintenance. As long as we grasp the above points, we can make a more comprehensive and objective choice and find the most suitable process equipment.
All the process equipments introduced are both feasible and available. At present, they have been running well in the foundry and achieved good environmental and economic benefits. Practice has proved that as long as the environmental protection process is selected reasonably, the foundry can also be built into a garden type factory.