Sources and characteristics of waste gas from building sanitary ceramics industry Waste gas from building sanitary ceramics industry can be roughly divided into two categories. The first type is process exhaust gas containing productive dust. The temperature of this type of exhaust gas is generally not high, mainly from crushing, sieving, granulating and spray drying in the preparation of blanks, glazes and pigments; the second type It is a kind of high-temperature flue gas produced during the production of various kiln firing equipment. The flue gas contains carbon monoxide, sulfur dioxide, nitrogen oxides, fluoride and soot. These exhaust gases have large emissions, many emission points, high levels of free silica in the dust, and high dust dispersion in the exhaust. The dust in these exhaust gases is basically close to or belongs to ultrafine dust. Therefore, in a single-stage dust removal system, inertial dust collectors and intermediate-effect cyclones are not suitable. If a cyclone is required, a high-efficiency cyclone must be selected. . If we only look at the particle size of the dust, wet dust collectors, bag dust collectors, and electrostatic precipitators are all suitable dust removal equipment for the building sanitary ceramic industry exhaust gas purification system.
Exhaust gas treatment technology during molding process
(1) The dust removal system of manual friction brick press is generally best equipped with two or one manual friction brick press equipped with a dust removal system. Dust removal equipment can use cyclone separator, carbon chloride impulse type dust removal unit, water bath dust collector and bag dust collector. However, due to the high degree of dust dispersion in the dust generated by each smoke point of the brick press, and the dust concentration is not large, the cyclone separator is not suitable, and it is less used in actual projects; carbon chloride impulse The type of dust removal unit is not used much, because the single unit of this type of dust collector has a large air volume, the resistance loss of the unit is large, and the water consumption of the constant flow type is large, which will cause water waste and the transfer of pollution. . The dust removal systems of manual friction brick presses are more commonly used with water bath dust collectors and bag dust collectors.
(2) Dust removal system of automatic brick press The automatic brick press has a large output, more dust discharge points, and a larger air volume. Therefore, it is reasonable for a single automatic brick press to independently set a dust removal system. Automatic brick press can use pulse bag dust collector, impulse dust collector.
(3) Dust removal system of sanitary ceramic glaze spray cabinet The dust removal system of sanitary ceramic glaze spray cabinet is set up with a single dust removal system, so that different glazes can be recycled separately. Dust removal system for sanitary ceramic spray cabinet. At present, wet dust collectors such as water bath dust collectors are mostly used.
Treatment technology of exhaust gas during auxiliary material preparation and processing
(1) Treatment of waste gas in the preparation process of the casket In the preparation process of the casserole, dust-containing exhaust gas is generated in each step of blank processing, molding and firing. However, due to the coarse particles, high water content and small output of semi-dry pressed powder, most enterprises have not adopted exhaust gas control measures. When the raw material of the box bowl is coarsely crushed by a jaw crusher and crushed by a wheel mill, a large amount of dust-containing exhaust gas is generated. This pollution source shall be provided with a closed exhaust air purification system. When the powder is sieved, dusty exhaust gas is also generated. The sieve should be hermetically sealed and equipped with a local exhaust hood and dust removal equipment. The dust removal can be dry or wet, such as a bag dust collector or a water bath dust collector.
(2) Treatment of dust-containing waste gas during the preparation of semi-aqueous gypsum ① Raw material preparation Dust treatment and treatment The dust generated when the jaw crusher is used to coarsely crush large pieces of natural gypsum shall be provided with an external dust hood at the feeding port of the jaw crusher. The collected dust-containing exhaust gas can be collected separately, and it can also share a dust removal system with Raymond mill tail gas. Dust removal equipment can be used bag filter.
② Hemihydrate gypsum preparation dust treatment The gypsum dust exhaust gas with a large moisture content is produced during the preparation of hemihydrate gypsum. The exhaust gas can be pre-heated and insulated by using dry hot air and used as a bag-type dust collector for back blowing dust removal. In addition, dehydration can be carried out in a larger particle state to reduce dust during the frying process.
(3) Gypsum mold dust-containing exhaust gas treatment The dust in the gypsum mold dust-containing exhaust gas is semi-aqueous gypsum powder, which will condense and harden when it encounters water. Therefore, it is more suitable to use dry dust collector for the dust. The particle size of the dust after cooking is very small, about 96% of the particle size is less than 5 μm, so cyclone dust collectors should not be used for dust removal equipment. Pulse bag dust collectors can be used.
Burning waste gas treatment technology
(1) Treatment of dust removal in front of sanitary ceramics before the kiln. Generally, the water removal precipitator is used in the dedusting equipment of the ventilation and dedusting system for sanitary ceramics before entering the kiln. Because the dust concentration generated by the cleaning of sanitary ceramics before the kiln is generally only about 100mg / m3, it is only necessary to add a certain amount of water to the dust collector to ensure its required constant water level and keep the dust removal efficiency stable. The amount of mud removed by the dust collector is not large, and only regular mud removal is required.
(2) Treatment of kiln coal burning flue gas In order to reduce the emissions of kiln exhaust gas, coal can be converted into gas and then supplied back to porcelain kiln as fuel; a centralized gas generating station can also be established at a large ceramic base, Provided goods to various ceramic factories. In addition, bag-type dust collectors can be used in the smoke exhaust of coal-fired tunnel kiln in ceramic factory to eliminate smoke and dust.