Dusty packing machines, or are in asiiriruemy housing, or provided with an annular suction of pneumatic clamping the neck of a paper bag. In the latter case, the amount removed by suction of air should be not less than 1000 m3 / h at a suction. At the conclusion of the packaging machine to cover the amount of exhaust air is determined by the speed in the doorway, which is taken equal to 1,2-1,4 m / sec.
Sewing machine for packaging bags is also a source of dust emission. Dust from this machine is possible with the help of a suction panel. The amount of air removed panel recommended within 600-800 m3 / h each. Machine.
As in the previous case, in the production of lithopone particularly toxic emissions are observed. Basic naughty is dust raw materials - barytes, coal, zinc-containing raw materials; and dusty and the finished product, especially calcined lithopone. All of these dust toxic.
In addition to dust emission, the production of lithopone is characterized by heat from the furnace and dried, as well as minor gassing. Of the latter the most significant evolution of gases should be recognized, particularly carbon monoxide from the recovery furnace. Quite significant breakthroughs of sulfur dioxide from prokalochnyh furnaces. There are also release vapors, gases and hollow droplets from the reactors for the dissolution of zinc-containing materials and cleaning solution. In addition, we observe the formation of acid fumes from hot solutions in the reaction of lithopone.
Factories producing lithopone, usually consist of three main departments: sernistobarievogo, zinc and lithopone.
In sernistobarievom shop restores a heavy spar to barium sulfide leaching and nlava water. Reduction proceeds in a rotary kiln with a gas
heating. In the process stands out carbon monoxide, mogutnaya burst into the room through leaks of the drum and still differs! furnace. The device is local exhaust, mechanical traction can be considered mandatory. Speed in the slot floor suction ring should be about 4 m / sec.
Rotary kilns are usually cooling drum. When pouring the mixture burned in the cooling drum is seen dusting.
Fragmentation of heavy spar and charcoal and mixing - and dusty processes. Dust heavy spar, which is slightly reduced, to not exclude dust formation. To reduce such may apply moisturizing and gidroobespylivanne mostly pneumatic.
Baked batch dusts more than crude, but wetting is inapplicable here, as barium sulfide is soluble in water. Dusting occurs during transport of the charge and when it is loaded into vyschelachivatelnye aids. To combat the dust foci pyleobrazovanpya cover in aspiriruemye cover type cabinet. Aspirated and all transportation device: elevators, augers and, of course, the crusher. The amount of air removed by aspiration, are determined by conventional methods, taking into account non-toxic dust and its low volatility (with the exception of the burnt charge).
Barium sulfide leaching is allocated a small amount of hydrogen sulfide, which is not so poisonous, however distasteful because of the smell. Therefore, you should provide vyschelachnvatelnye aids local suction directly from the apparatus itself. The design speed in the openings inspection by the charging hole is recommended to take at least 1 m / sec. Considering dust emission during loading and high temperature in the apparatus. Can be considered open two hatches out of five.