JPH0641845U - Jet type crusher - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a crushing device capable of producing extremely fine particles of a combustible material such as coal in which substantially no undesirable impurities are present. [Arrangement] An arc crusher as a whole, a sizing unit communicating with the crusher to form a primary classifier, and a descending chimney connecting the sizing unit to the crushing chamber are provided. Furthermore, a jet type pulverizer equipped with a secondary classifier, a first tertiary classifier and a second tertiary classifier.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a jet-type crushing device that uses a circulating gaseous fluid as a crushing medium, that is, an atomizing medium, and more specifically, crushes or atomizes relatively large-sized particles such as coal. It is particularly relevant to this type of crushing device.

[0002]

[Prior art]

 The jet-type grinders described above have been commonly used to date for processing relatively small sizes. Many attempts have been made to utilize such jet mills for coarse particles such as coal, but these have not been obtained because of the inability to obtain a product of sufficient fineness to use coal instead of oil or gas. The attempt was not entirely satisfactory. This is because it was difficult to separate not only large coal particles but also impurities such as ash, pyrite, aluminum oxide, and silica. It is highly necessary to eliminate pyrite, not only because of these particles, but because the major constituents of the sulfur component in the raw coal are contained entirely within the pyrite particles. It is also desirable to eliminate ash containing clay, kaolin, silica, etc. not only because it inhibits the combustion of coal but also because it adheres to the boiler pipe and produces slag.

[0003]

[Problems to be solved by the device]

 Therefore, an object of the present invention is to provide a crushing device capable of producing extremely fine particles of a combustible material such as coal which is substantially free of undesirable impurities.

Another object of the present invention is to utilize a jet type crusher of standard type to obtain the above-mentioned very fine particles without substantial alteration and without substantial undesirable impurities. It is to provide a crushing device.

[0005]

【Example】

 Referring in more detail to the drawings in which like reference characters indicate like parts, FIG. 1 generally illustrates a jet mill 12 including a lower inlet or grinding chamber 14, an ascending chimney 16 and a descending chimney 18. A crushing device designated by 10 is shown. An angled or tangential inlet nozzle 20 is located at the bottom of the grinding chamber 14 which is an inlet chamber from a manifold 22 which receives a gaseous fluid such as air, steam, etc. from a source (not shown) via a conduit 24. . The gas is introduced into the manifold and converted by the inlet nozzle 20 into a sonic or supersonic low-pressure jet, which produces a high-velocity flow in the grinder as it flows into the grinding chamber. The material to be crushed is inserted into the crushing chamber through the hopper 26 and is passed by a gaseous fluid under pressure from a conduit 28 into a collar 30 with a hole in the hopper surrounding the down spout of the hopper. Sometimes accelerated.

The particles being processed are trapped in the rising gaseous vortex in the grinding chamber and from the rising chimney 16 to the arc-shaped sizing section 32 which is the primary classifier in the upper part of the grinder. There is centrifugal stratification of the particles as they pass through each other due to mutual impact and thus the heavy and coarse particles are light and fine while the fine particles are rotating towards the central or inner peripheral edge. It remains on the periphery.

During the particle falling stroke in the falling chimney, the heavy particles on the outer peripheral edge fall down the lower chimney as they are and are mixed with new material supplied from the hopper 26 and sent to the grinding chamber 14 for further grinding. However, the light particles on the inner peripheral edge flow into the outlet duct 34 communicating with the secondary classifier.

In order to be able to carry out the present method more economically, a very high production amount of a crusher using a high load is required. At such high loads, a coarse or heavy partial flow at the outer periphery spreads and the product exiting the grinder via the outlet duct 34 will have more heavy particles than would be used at low loads. Many of these heavy particles usually contain undesirable impurities such as ash, pyrite, aluminum oxide, silica, etc., so the product exiting the mill will generally be inadequate in this respect.

The product is made more thorough by the use of a secondary classifier 36 having an upper portion 38 and a lower portion 40. The secondary classifier 36 is a relatively low speed classifier, and the circulating flow is weaker than the flow in the primary classifier formed by the particle size dividing section 32 of the jet type pulverizer 12. In the classifier 36, the heavy and coarse particles move along the wall of the classifier and fall into the receiving body 42 below the classifier, while the fine and light particles form an upward vortex flow generated in the center of the classifier. Ascends and passes through the outlet pipe 44.

The upper portion 38 of the secondary classifier 36 is wider than the lower portion 40, and the spiral ledge 46 separates the upper portion 38 and the lower portion 40. Below the inlet of the conduit, this shelf is such that the width of the shelf in the radial direction of the classifier 36 is largest at the inlet, and the direction of fluid flow is around the longitudinal central axis of the classifier 36. The width of the shelf in the radial direction at the position of about 225 ° (135 ° in the opposite direction) is the smallest, The shape is such that its radial width is gradually narrowed along the flow direction of the fluid, and it is arranged so as to extend along the horizontal plane (see FIG. 2).

The spiral ledge 46 acts as an initial classifier for the heaviest particles exiting the outlet duct 34. The heaviest particles are on the outer periphery as they pass through the upper portion 38 and are trapped by the shelves, with these particles flowing over the outermost perimeter of the shelves with their heaviest exiting through slots 48. Draw a vortex along this shelf until. The size of this slot is adjustable by a slidably adjustable plate 50. The lighter particles on the inner circumference of the shelf enter the conduit 52 through which the jet mill 12 grinds the particles in a mixture with the new material entering the mill from the hopper 26. It moves to the inside of the crushing chamber 14. The passage of particles through the conduit 52 is accelerated by the gaseous fluid under pressure flowing through the conduit 54 into a collar 56 with a tangential nozzle that causes the gaseous fluid to flow downward through the conduit 52.

The various fluid conduits include adjustable shut-off valves illustrated at 58, 60, and 62 in the individual conduits described thus far and at 64 and 66 in the conduits described below. ing. The outlet pipe 44 is equipped with a multi-position switching valve 68, from which a conduit 70 leading into the first tertiary classifier 72 emerges. Above the multi-position switching valve 68, the guide pipe 74 leads from the outlet pipe 44 to the three-way switching valve 76. The exhaust pipe 78 leads from one side of the three-way switching valve 76 to a collecting or dispensing station (not shown). The outlet pipe 80 connects the three-way switching valve 76 with the upper part of a relatively immobile second tertiary classifier 82 whose diameter is smaller than that of the secondary classifier 36.

If it is desired to pass the fine particles from the second tertiary classifier 82 through the outlet pipe 44 to another processing or distribution region, the multi-position switching valve 68 is adjusted to adjust the conduit 74 and the outlet pipe. The connection between 44 is opened and the two-way switching valve 76 is adjusted to connect the conduit 74 to the exhaust pipe 78. If it is desired to mix the discharged particles from the second tertiary classifier 82 with the particles from the secondary classifier 36, the particles upward through the outlet tube 44 mixed with the flow from the exhaust tube 78. The multi-position switching valve 68 and the three-way switching valve 76 are opened so that the current flows. If it is desired to direct the discharged particles from the secondary classifier 36 into the first tertiary classifier 72 either in itself or in a mixture with the discharged particles from the second tertiary classifier 82. The multi-position switching valve 68 is adjusted to connect the outlet pipe 44 to the conduit 70 and to have three paths depending on whether the particles from the second tertiary classifier 82 should be mixed with the particles from the secondary classifier 36. The switching valve 76 is opened or closed. In the alternative, the multi-position switching valve 68 is adjustable to achieve only communication between the second tertiary classifier 82 and the first tertiary classifier 72.

The second tertiary classifier 82 is in the receiver 84, and heavy particles flow from the classifier 82 into the receiver 84. The gate 86 at the bottom of the receiver 84 can be dropped onto the conveyor 88 to remove particles. These last particles are mainly ash, pyrite and other impurities and are removed from the equipment.

A nozzle 90 connected to a gaseous fluid source under pressure by a conduit 92 is provided above the second tertiary classifier 82. The conduit 92 is provided with an adjustable shutoff valve 94. The pressurized fluid in conduit 92 can be regulated by a shutoff valve 94 or shut off entirely. If an inappropriate amount of the desired fine particles escapes from the slots 48, the pressurized fluid from the nozzle 90 acts as a dynamic barrier that prevents these fine particles from flowing out through the slots. This pressure can be increased to the point where the lighter particles can flow back into the secondary classifier 36. However, the fluid pressure never increases sufficiently to act as a barrier to large particles passing through the slot with great force, so that these large particles pass through the slot into the second tertiary classifier. Within 82.

When the multi-position switching valve 68 is adjusted to open to the conduit 70, the first tertiary classifier 72 to which the discharged fine particles are directed from the outlet pipe 44 is a relatively stationary centrifugal type.

The particles directed into the first tertiary classifier 72 are either lentthanized and stored as a fluid mixture or mixed with oil to create a coal / oil mixture that flows directly to a burner for combustion. Used for.

Very light particles are discharged from the first tertiary classifier 72 through the upper outlet tube 98 and these discharged light particles can be used for a desired purpose. The heavy but still light particles received from the conduit 70 are in the immobile receiver 100, from which they fall into the mixing chamber 102. The mixing chamber 102 is equipped with a paddle 104 on a shaft 106 operated by an electric motor 108. The spray nozzle 110 is connected to an oil source (not shown) by a conduit 112. The outlet conduit 114 is connected to the outlet spout 116 by the shutoff valve 66 described above.

In operation, particles from the receiver 100 are mixed in the mixing chamber 102 with the injection of oil from the spray nozzle 110, and the resulting liquid product 118 is passed through the outlet conduit 114 and the outlet spout 116. To be removed.

FIGS. 3 and 4 illustrate a modification of the present invention, in which the same as the case of the second third classifier 82 and the second classifier 36, in the same plane as the second classifier. Instead of a third classifier, the third classifier is located below the second classifier with the upper parts of the two classifiers overlapping locally.

This modified structure is shown in FIGS. 3 and 4 by a secondary classifier 120 that is generally similar to the secondary classifier 36 except that the shelf 122 is provided with slots 124. is there. The third classifier 126 is generally similar to the second third classifier 82, except that its wide upper end is partially below the wide upper end of the second classifier 120. It is positioned below the secondary classifier 120.

In the configurations shown in FIGS. 3 and 4, the heavy particles not only on the outer periphery of the secondary classifier but also on its entire shelf flow into the tertiary classifier. This drop is sometimes advantageous because the particles are heavy, although the size and weight of all particles on the shelves vary. Furthermore, falling objects depend not only on centrifugal force but also on gravity.

An upward barrier 128 may optionally be provided over a suitable distance from the slot 124, which guides particles on the shelf, the particles on the shelf only from the shelf tip where the barrier 128 is not provided. The inside of the classifier 120 falls downward.

If desired, both the horizontal and vertical slots shown at 48 and 124 can be used together.

[Brief description of drawings]

FIG. 1 is a side elevational view, partially in elevation and partially in cross-section, of a jet milling apparatus embodying the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is an enlarged cross-sectional view of a modified form of the secondary classifier.

4 is a sectional view taken along line 4-4 of FIG.

[Explanation of symbols]

 10 Crushing device 12 Jet type crusher 14 Crushing chamber 16 Ascending chimney 18 Descent chimney 32 Sizing unit 36 Secondary classifier 44 Outlet pipe 72 First and third classifier 82 Second and third classifier

Claims (8)

[Scope of utility model registration request] 1. A generally arc-shaped crusher having a crushing chamber for mutually pulverizing particles in a vortex flow of a gaseous fluid, and in a circulating flow of particles and a gaseous fluid in communication with the crusher. , A large particle in the outer peripheral area, a small particle in the inner peripheral area, a sizing section forming a primary classifier that stratifies by centrifugal force, and for returning the large particle to the crushing chamber for further pulverization In the descending chimney connecting the sizing section to the crushing chamber, and in the circulating flow of the particles and the gaseous fluid in communication with the sizing section, the heavy particles are in the outer peripheral area, and the light particles are in the inner peripheral area. In the region, an outlet for small particles communicating with the inlet of the secondary classifier that is stratified and separated by centrifugal force, and a region from the inside of the secondary classifier corresponding to the circulation center of the circulating flow to the first tertiary Light particles extending to the classifier And a shelf disposed in the secondary classifier below a region corresponding to the outer peripheral portion of the circulating flow for capturing heavy particles, and an outlet for heavy particles in the secondary classifier. A second tertiary classifier in communication with the secondary classifier, wherein the heavy particle outlet causes heavy particles at the outer peripheral portion of the circulating flow to flow out to the second tertiary classifier. A jet-type crushing device, which is disposed in the path of the circulating flow. 2. The jet mill according to claim 1, wherein the shelves are provided with upright barriers adjacent to the outlets of the heavy particles. 3. The jet pulverizer according to claim 1, wherein the outlet for the heavy particles is arranged on the wall of the secondary classifier above the shelf and adjacent to the shelf. 4. The jet type crushing apparatus according to claim 1, wherein the shelf extends along a horizontal plane from the inlet to a position distant from the inlet. 5. The jet type crushing device according to claim 4, wherein the shape of the shelf is formed in an arc shape. 6. The shelf is formed to be gradually narrowed to a position farther from the entrance.
The jet-type crushing device described in 1. 7. The secondary classifier and first tertiary classifier selectively communicate with means for mixing particles discharged from the secondary classifier and first tertiary classifier with liquid fuel. The jet-type crushing device according to claim 1, wherein 8. The jet type crushing apparatus according to claim 7, wherein the liquid fuel is oil.