The dedusting system is composed of a collecting hood, an air inlet pipe, a dust collector, an ash discharging device, a blower, an electric motor, a silencer and an exhaust chimney. The utility model utilizes the power generated by the fan to purify the dust containing gas from the dust source through the exhaust pipe into the dust removing device, and the purified gas is discharged through the exhaust chimney; the recovered dust is discharged by the ash discharging device.
1, the division principle of dust removal system
When designing a decentralized or centralized dust removal system, the following should be carried out and systematic division shall be carried out.
When the same production process and the fugitive dust are not far apart, a system should be set up.
Dust spots with different dust types at the same time, when the process allows different dust mixed recovery or no dust recovery value, can also be set up a dust removal system.
In the following circumstances, a system shall not be integrated:
(a) when two or more or more than two dust or dust gases are mixed, they can cause combustion or explosion;
(b) dust laden gases of varying temperature, which may cause condensation in the duct and dust collector when mixed.
2 、gas collection vacuum hood
(1) the position of the dust collecting hood
Setting the dust suction hood shall keep the negative pressure in the cover evenly, and the dust laden airflow can be effectively prevented from escaping inside the cover, and the powder is not sucked out. If the crushing, screening and transportation are not available, the dust hood shall be kept away from the dusty airflow center to prevent a large amount of powder from being sucked out. The distance between the belt conveyor feeding point suction hood and the discharge chute of two adjacent sides should be 0.75 ~ 1.5 times the length of the chute, but not less than 300 ~ 500mm; 0.6 times the cover from the surface of the tape machine height of not less than the width of the tape machine. When the discharge chute and the belt conveyor incline to feed, the dust cover should be arranged in front of the chute; when the discharging chute is perpendicular to the belt conveyor, the dust cover shall be provided at the front and rear of the chute.
When the heat material is processed or transported, the dust absorption cover shall be positioned at the top of the sealing device, or the upper and lower exhaust dust collecting cover is arranged at the feeding point and the receiving point.
Dust hood should not be close to open holes (such as operating hole, observation hole, outlet, etc.), so as not to inhale the air outside the hood. The dust screen must be provided for the dust collecting cover of the belt conveyor, and the dust screen can be made of rubber belt and canvas belt.
The location of the dust hood should not affect the operation and maintenance. A piece of pipe connected with the cover is best laid vertically so as not to clog the pipe.
(2) the form of air collecting vacuum hood;
To make the air inside the hood even, umbrella cover is usually adopted.
When the large volume sealed cover and silo ventilation, generally no suction powder of worry, the wind can be directly connected to the tube or large volume sealed cover bin.
3 、dusty gas pipeline
In the dust removal system, the dusty gas pipeline (dust removal pipeline) before the dust collector can be arranged in a branch pipe network or a collecting pipe network.
(1) the collecting pipe network and the collecting pipe network are divided into two kinds: horizontal and vertical. The level set on the map, from the top or side access duct connection, collection pipe section wind speed is 3 ~ 4m/s, suitable for producing dust distribution equipment in the same plane, and the horizontal distance between the great occasion. Set vertical pipe connecting wind pipe connecting pipe section in the tangent direction, set speed is 6 ~ 10m/s, suitable for dust production equipment distribution in multi platform, and the horizontal distance is not the occasion.
The main characteristics of the collecting pipe network are:
(a) the collecting pipe has coarse purification function, and the lower part shall be equipped with dust removing valve and dust conveying equipment;
(b) system resistance is easy to balance;
(c) pipe connection is convenient;
(d) when the air volume changes, the system is relatively stable.
(2) layout form of branch network in branch pipe network. The air duct can be laid vertically, horizontally or obliquely; the angle between the air pipe and the horizontal plane shall be greater than 45 degrees when it is tilted. When the above requirements are not met, the small slope or horizontal laid pipe sections shall be shortened as far as possible and measures taken to prevent dust accumulation shall be taken.
Heat preservation measures shall be designed for pipes containing high temperature dust gas and high relative humidity and easy to dew. The pipe through the high temperature dust containing gas must be considered compensation measures of thermal expansion, the appropriate part of the natural compensation turn or in the pipeline setting compensator; the corresponding pipe support should also consider the stress generated by thermal expansion.
The steel pipe with round steel shall be adopted in the dust removing pipeline, the joints and joints should be tight, and the welding pipelines shall be leak tested by kerosene.
Dust removal pipeline should be clear. When the underground air duct is adopted, the concrete or brick can be used for masonry, the inner surface is smoothed with mortar, and a cleaning hole is arranged in the air duct.
For explosive gas containing dust, explosion proof valves shall be installed on the pipeline and shall not be laid underground.
4, dust collector
For dry dust collector with high relative humidity and easy to dew, a heat insulating layer shall be provided. If necessary, heating measures shall be taken in the dust collector.
The dry dust collector used for purifying explosive dust or gas should be arranged on the negative pressure section of the system. The dust collector shall have explosion proof valves.
Cloth bag dust collector with dust, fibers and chips with explosion hazard for explosion lower than or equal to 65g/m3. If necessary, dry dust collector should be made of non sparking material; if bag filter is used, antistatic filter bag and explosion proof electromagnetic pulse valve should be equipped.
For the purification of bag type dust collector dust explosion hazard, should be arranged in the production workshop, and from the external windows holes should not be less than 10m; or arranged in a separate building within the dust collector should be continuous cleaning, and the air is <1500m3/h, ash storage capacity of <60kg.
A dry dust collector for purifying combustible dust, fiber and debris which has a lower explosive limit greater than 65g/m3, shall be arranged in a separate room when installed in the production plant.
The dust removal system has danger of explosion, the dry dust collector shall be installed in people or short time there are a lot of people stay in the room (such as the human body information room, conference room) below, as in the above room adjacent layout, separated by application of refractory solid wall.
The selection of wet dust collector in the northern area, should consider the heating or insulation measures to prevent dust and water supply and drainage pipeline freezing.
The dust collector used in high pressure conditions, the structure should be negative pressure resistant measures, and the shell should be more strict with.
The gas containing dust by dust purification, directly discharged indoors, must use high efficiency dust collector, ensure the gas is discharged into the indoor dust concentration does not exceed the national health standards.
5 、dust conveying device and dust treatment
The dust of dust collection dust or discharge of sewage recycling, according to production conditions, dust collector, dust type value and convenient maintenance and management and other factors must take proper recycling or disposal measures; technology allows, should be included in the process of recycling.
Dust discharged from wet dust collector should be recycled after treatment to reduce water consumption and avoid water pollution.
Under the condition of high negative pressure, the dust collector shall be provided with two series unloading devices, and the two ash discharging valve shall be opened to discharge dust at the same time.