RU2088310C1 - Filter for cleaning gas - Google Patents

Abstract

FIELD: cleaning gases of dust in manufacture of building materials. SUBSTANCE: filter includes housing with contaminated and cleaned gas chambers, hopper, upper and lower shutters with grainy filtering material contained between them; shutters are mounted between chambers. Contaminated gas chamber is provided with horizontal grid having projections and plate made from flexible material which are secured to projections and to lower shutter. EFFECT: enhanced efficiency. 2 cl, 3 dwg

Description

 The invention relates to the cleaning of contaminated gases from dust, in particular, in the production of building materials.

Known granular filter for separating dispersed particles from gas [1] comprising a housing with inlet and outlet nozzles for granular material and gas; a filter element made in the form of blinds with a granular material moving between them and forming an input from an output chamber with the walls of the housing. The blinds are made in the form of two concentrically mounted rows of plates placed in obliquely installed packages. The plates of the outer rows are L-shaped and mounted with a narrow plane perpendicular to the flow of the gas to be cleaned. Adjacent plates of the outer and inner rows are installed at an angle exceeding the angle of repose of the granular material by 3-10 ^o C.

 When filling the apparatus with fine grains, its resistance increases. The use of coarse-grained material significantly reduces the degree of purification, although pressure losses during the passage of contaminated gas through the layer are reduced. Uneven movement of the granular material in the filter element does not allow to maintain a constant filtration rate over the entire layer of material, which also reduces the efficiency of gas purification. It should be noted a significant energy consumption for the constant supply of granular material to the filter and for its removal.

 The closest technical solution for the totality of signs is a granular filter for gas purification [2] containing a housing with chambers of contaminated and purified gas, louvres, between which granular material is placed, a hopper. Louvre lattices are installed between the chambers of the polluted and purified gas at an angle exceeding the angle of repose of the granular material. The louvre elements of the grate from the side of the contaminated gas chamber are made in the form of plates adjacent to its side walls, the lower ends of which are made of elastic material.

 When the contaminated gas passes through the granular material, large dust particles are completely trapped, and some fine dust is not retained by it and is transported further along with the purified gas. Theoretically, a high degree of cleaning and trapping of almost all dust can be achieved using fine grains, however, in real conditions, the aerodynamic resistance of the apparatus will be significant, which in turn will cause a sharp increase in operating costs. Therefore, such a technical solution practically does not find application. The constant movement of the granular material under the action of gravity leads to the formation of a layer flow, which is characterized by a variable value of the filtration rate. Changes in the filtration rate in a granular material significantly reduces the efficiency of cleaning dusty gases. The layered flow of granular material also leads to the fact that part of its volume during the cleaning process is practically not saturated with trapped dust and is removed from the filter while it is still in working condition. This causes an increase in the consumption of granular material. It should be noted that it is necessary to constantly supply granular material to the apparatus, and then, after it is saturated with dust, transported from the filter, and significant energy consumption occurs.

 The proposed design of the granular filter allows to increase the efficiency of gas purification from dust by providing preliminary coagulation of dust particles and creating a stationary mode of operation of the granular material in the filter, at which the filtration rate is constant throughout the layer of material. Preliminary coagulation of dust particles allows even with normal grain size, usually used in filters of this type, and therefore, with a small aerodynamic drag, to clean the gas from fine dust. The stationary mode ensures complete dust saturation of the entire volume of the granular material, and therefore the minimum consumption of the latter. As a result of reducing the consumption of granular material, as well as the short duration of its entry into the filter, the energy consumption for material transportation is reduced.

 This is achieved by the fact that the granular filter for gas purification comprises a housing with contaminated and purified gas chambers, a hopper, granular material placed between the main louvres installed between the contaminated and purified gas chambers at an angle exceeding the angle of repose of the granular material, while the louvre the grill on the side of the contaminated gas chamber consists of plates, the lower ends of which are made of elastic material. The difference from the prototype is that the filter is equipped with an additional grating located in the contaminated gas chamber with protrusions to which the elastic plates of the louvre grating are attached at their lower ends, while the additional grating is separated from the louvre by a distance shorter than the length of the elastic plates. It is advisable to make the blinds of the lattice of the purified gas chamber rotary.

 When an additional grate is located in the chamber of dusty gas at a distance shorter than the length of the elastic plates, pliable surfaces are created that undergo an intense oscillation under the influence of the incident gas flow. Oscillation of elastic plates promotes coagulation of dust particles colliding with their surfaces. When particles are enlarged, their heavier fractions are deposited in the hopper, and the remaining part is easily retained by medium-sized granular material. Preliminary coagulation of dust particles and stationary operation of granular material increase the efficiency of gas purification. The stationary mode of operation of the granular material also provides a more complete saturation with dust and a reduction in the cost of electricity for its supply to the filter and removal.

 In FIG. 1 shows a grain filter, a General view in section; in FIG. 2 same, top view; in FIG. 3 element of the scheme of fastening the axes of the louvre grille to the mechanism for turning the blinds

 The filter consists of a housing 1 with chambers of contaminated 2 and purified gas 3, louvres 4 with an angle of inclination greater than the angle of repose for this granular material 5. The louvre 4 of the chambers of contaminated gas 2 consists of plates 6, the lower part of which is made of elastic material and attached to the protrusions 7 of the additional louvre lattice 8. The additional lattice 8 is fixed in the housing 1 at a distance from the lower louvre lattice shorter than the length of the elastic plates. The louvre lattice 4 of the purified gas chamber 3 can be made of rotary blinds 9 with rotation axes 10. The blinds 9 of the lattice 4 are rigidly connected to the rotation axes 10, the ends of which are fixed in the walls of the housing 1 with the possibility of rotation. Each axis is provided with a key 11 perpendicular to its surface, connected to the rail 12 by means of a rod 13. For the particulate material 5 to enter the filter, a loading hopper 14 with a cover 15 is provided, and a guide tray 16 with a cover 17 is used to remove the particulate material saturated with dust. For deposition of coarse dust at the bottom of the filter is a hopper 18.

 Dusty gas enters the lower part of the housing 1 and passes through an additional grill 8, and then between the elastic plates 6. The implementation of the elastic plates 6 of thin-sheet rubber or polymer film, contributes to the formation of malleable surfaces. Since the additional grating 8 is located in the housing 1 at a distance shorter than the length of the elastic plates 6 from the louvre lattice 4 of the contaminated gas chamber 2, oscillating movements will be experienced along the plate 6 when the gas flow is incident. When dust particles hit the surface of the oscillating plates, they briefly stick to the indicated surface, during which new incident particles, colliding with the first, coagulate. After coagulation, large particles of dust under the influence of gravity are deposited in the hopper 18, and the lungs, together with the gas stream, pass through the louvre lattice 4 and are retained in a stationary layer of medium-sized granular material 5. The purified gas through the louvre grille 4 enters the chamber 3 and then is removed from the filter.

 Improving the efficiency of purification of contaminated gas in this apparatus is achieved due to the following factors. As a result of preliminary coagulation and the action of gravity, part of the dust is deposited in the hopper 18, unloading the work of the granular material 5 and contributing to an increase in the period of its stay in the filter. The other part of the dust particles after the specified enlargement process when passing along with the gas in the layer is easily retained by the material with an average grain size. The stationary mode of operation of the granular material provides a constant filtration rate over the layer, which also increases the efficiency of gas purification. The increase in the service life of the granular material in the filter and the stationary mode of its operation causes a decrease in the cost of electricity spent on the supply of grains to the apparatus.

 The filling with granular material of the space between the louvres 4 occurs in the following order. When the cover 14 of the guide tray 13 is closed, granular material 5 is fed into the hopper 11. After filling the indicated space, the supply of granular material is stopped and the hopper 11 is closed by the cover 12 to ensure the tightness of the filter. When the granular material 5 is saturated with dust, the lid 14 of the guide tray 13 opens and the granular material is removed from the filter by gravity and then sent to the technological process for the production of building materials. To prevent clogging by the grains of the louvre lattice 4 the chambers of purified gas 3 the axes of the louvres 9 are turned with the help of the lath 12. Moving the lath 12 in the horizontal direction deviates from the vertical position of the keys 11 and rotates the axes 10. At the same time, the louvres 9 occupy a vertical position and grains that penetrate into the space between adjacent blinds 9, under the influence of gravity are poured and removed from the filter. The next filling of the filter with granular material 5 is performed with the cover 14 of the guide tray 13 closed, after the blinds 9 of the louvre lattice 4 of the purified gas chamber 3 are installed in the working position.

Claims (2)

 1. Granular filter for gas purification, comprising a housing with chambers for contaminated and purified gas, a hopper and lower and upper louvres with granular filter material located between them, installed between the chambers, characterized in that it is provided with a horizontal horizontal chamber in the chamber for contaminated gas a grill with protrusions and plates of flexible material, the lower ends of which are attached to the protrusions, and the upper ends to the lower louvre grille, and the length of which is greater than the distance between the horizontal lower louvre.  2. The filter according to claim 1, characterized in that the blinds of the louvre lattice of the purified gas chamber are made rotary.

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