JPH078826A - Air seal for central discharge opening of rotary mill - Google Patents

Abstract

PURPOSE:To provide an air seal for the central discharge opening of a rotary mill capable of giving uniform pressure over the whole seal part, having a simple constitution and easy in maintenance work. CONSTITUTION:An annularly worked pipe 15 is fitted to an annular flange 11 placed at the outer periphery of the mill through an annular sliding plate 9 in the vicinity of the central discharge opening of the mill 1 main body (rotary part). The outer peripheral part of an annular sealant 8a made by laminating a felt plate 16 and an elastic material 17 is fixed on the side face of a fixing cover 7 covering the periphery of the central discharge opening. Sealing is kept since the elastic material 17 is exerted so that the felt plate 16 constantly presses the pipe 15. 18 shown in a figure is the supply opening of a lubricant for lubricating a contact part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a central discharge air seal for discharging pulverized material of a rotary mill.

[0002]

2. Description of the Related Art As an example of a raw material mill used in a cement factory, there is a closed circuit dry pulverization type double rotator mill capable of simultaneously drying and pulverizing raw materials, a part of which is shown in FIG. 3 (a) is a front view of the central portion, and FIG. 3 (b) is a sectional view taken along the line AA of FIG. 3 (a).

Although not shown, raw materials such as limestone, clay, silica stone, and iron raw materials are mixed at a constant ratio and supplied to the drying chamber of the mill 1. The dried raw material is roughly crushed in the first crushing chamber 2 and then discharged from the central discharge port 4 through the raw material discharge side 5 and sent to the separator by the basket elevator (not shown). In the separator, it is classified into coarse powder and refined powder, the refined powder is transported to a silo, and the coarse powder is mainly supplied to the crushing chamber 2 (a part of which is sent to the crushing chamber 1). The pulverized raw material is again discharged from the central discharge port 4 via the raw material discharge side 5, and is again supplied to the separator via the basket elevator, so that the raw material flow constitutes a closed circuit.

The air seal of the central exhaust port 4 of the prior art is
As shown in FIG. 3 (b) and FIG. 2 which is an enlarged cross-sectional view taken along the line BB of the ◯ part in FIG. 3 (b), both sides (only one side is illustrated) near the central discharge port 4 of the mill 1 main body. Is provided with an annular slide plate 9 provided on an annular flange 11 which is fixed around the outer periphery of the mill. These are the parts that rotate with the rotation of the mill 1 main body.

On the fixed side, a fixed cover 7 having a U-shaped cross section is provided so as to surround the periphery of the mill 1 so as to cover the central discharge port 4, and both side surfaces of the fixed cover 7 (only one side is shown in the figure). It is composed of a plurality of holding metal fittings 10, one end of which is fixed to the inner peripheral edge of (a), and an annular seal plate 8 made of a thin steel plate. Further, the holding metal fitting 10 is composed of a holding plate 13, a seal plate holding portion 14, a felt 12, and the like.

The outer periphery of the annular seal plate 8 is the fixed cover 7.
Is fixed to the inner peripheral edge of the retainer, the inner peripheral portion of which is locked by a plurality of pressing metal fittings 10, and the felt 12 at the tip of the pressing metal fitting 10 is fixed.
The annular slide plate 9 is pressed through the air gap between the cover 7 and the mill 1 main body to form an air seal. Further, the bending reaction force of the seal plate 8 and the bending reaction force of the holding plate 13 are applied to this pressing force by adjusting the screw tightening position.

[0007]

However, the air seal of the above construction has the following problems. (1) The outer periphery of the seal plate made of an annular thin steel plate is fixed to the cover 7, but the inner periphery of the seal plate is formed only by the felts 12 of the press fittings 10 provided at several places. Since the structure is pressed by 9, the sealing effect is not guaranteed in a place where the pressing metal fitting 10 is not provided. That is, it is almost impossible to make the bending reaction force of the sealing plate uniform over the entire circumference of the mill, and if the sealing plate is thickened in order to improve the sealing effect,
Further, it becomes difficult to make uniform, and if it is made thin, cracks are likely to occur.

(2) If the number of the holding metal fittings 10 is small, it is not possible to uniformly press the felt 12 against the sliding plate 9 over the entire circumference of the mill, and if the number is large, the adjustment becomes complicated and the operation and maintenance becomes complicated. Become. (3) It is difficult to understand the wear state of the felt and it takes time to replace it. (4) When the felt is worn, the flange and the felt pressing portion are brought into metal contact with each other and are worn with each other, and particularly, the flange surface is significantly worn.

The present invention solves the above-mentioned problems and makes it possible to perform highly accurate air sealing by applying a uniform pressing force over the entire sealing portion, and further, with a simple structure and maintenance work. It is an object of the present invention to provide an easy air seal for a central outlet of a rotary mill.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is an annular flange fixedly provided on the outer peripheral surface of the mill body on both sides of the center of the mill in the vicinity of the raw material discharge port so as to surround the outer periphery of the mill. , An annular slide plate attached to the base, a fixed cover having a U-shaped cross section for covering the outer peripheral surface of the raw material discharge port, and an outer peripheral portion of the annular seal plate fixed to the inner peripheral edges of both side surfaces of the fixed cover. Along with the inner periphery of the fixed cover, it is applied to an air seal for a rotary mill central discharge port provided with a plurality of seal plate retainers for pressing the inner peripheral portion of the seal plate against the annular sliding plate. The means was taken. That is, a metal rod processed into an annular shape is fixed to the annular sliding plate, and the sealing plate is composed of a laminated body of an annular felt plate and an annular elastic body that presses the felt plate against the pipe. At the same time, an air seal for the central discharge port of the rotary mill is provided, in which the pressing member is provided with a lubricant supply port for preventing wear of the felt plate.

[0011]

Since the present invention is constructed as described above, the elastic body presses the felt plate against the annular pipe that constantly rotates, and the elastic surface of the metal rod processed into an annular shape with respect to the rotation axis of the mill is slightly deformed. It is possible to absorb the inclination even if it occurs, and the sealing performance is improved over the entire sealing portion.

Further, since the pressing metal fitting is provided with a lubricant supply port to lubricate the contact portion between the pipe and the felt plate, the wear of the felt plate can be reduced. A circular steel rod, a polygonal steel rod such as a hexagon, and a pipe are suitable as the metal rod processed into an annular shape, but a pipe is most preferable in terms of processing and cost.

[0013]

FIG. 1 shows an embodiment of the present invention. In this embodiment, an annular pipe 15 is used as the annular metal rod. As the rotating part, the annular processing pipe 15 is attached to the annular sliding plate 9 provided on the annular flange 11 which is fixed around the outer periphery of the mill near the central outlet of the mill 1. On the other hand, the fixed portion has the inner peripheral portion of the annular sealing material 8a mounted on the inner peripheral edge of the fixed cover 7. In the present application, the annular seal member 8a is formed by laminating the felt plate 16 and the elastic plate 17 formed of a rubber belt that uniformly presses the felt plate 16 against the annular pipe 15. This rubber belt can use a part of the discarded conveyor belt. With this configuration, the felt plate 16 can press the circular pipe 15 over the entire circumference, and the air between the cover 7 and the mill 1 main body can be satisfactorily air-sealed.

In the present application, the lubricant supply port 18 is provided to reduce the wear of the felt plate 16. Reference numeral 19 is a holding metal fitting for the lubricant supply port 18. In order to compare the effects of the present invention and the conventional example, the oxygen concentration between the inlet and outlet of the mill was measured, and it was found that the leak rate was significantly reduced and the sealing effect was improved.

[0015]

The present invention has the following excellent effects. (A) The sealing surface can be uniformly sealed over the entire circumference, and the sealing effect can be improved. (B) Since the structure is simple, inspection is easy, and since waste material can be used, maintenance costs can be reduced.

(C) Since the seal portion absorbs the fluctuation of the rotating surface of the circular pipe, the assembly accuracy of the seal contact portion may be lower than the conventional one. (D) Since the lubricant is supplied to the contact surface, wear of the felt can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view of a cross section of an embodiment of the present invention.

FIG. 2 is an explanatory view of a cross section of a conventional technique, and is an enlarged cross sectional view taken along the line BB of FIG. 3B.

FIG. 3 is an explanatory view of an air seal attachment structure.
FIG. 3A is a front view of the center of the mill, and FIG. 3B is FIG.
3 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

 1 Mill 2 Grinding 1 Chamber 3 Grinding 2 Chamber 4 Discharge Port 5 Raw Material Discharging Side 6 Gas Discharging Side 7 Cover 8, 8a Seal Plate 9 Sliding Plate 10 Holding Metal Fitting 11 Flange 12 Felt 13 Presser Plate 14 Seal Pressing Part 15 Circular Ring Processing Pipe 16 Felt plate 17 Elastic plate 18 Lubricant supply port 19 Metal fittings

Claims (1)

[Claims] 1. A ring-shaped sliding plate attached to a ring-shaped flange fixedly provided on the outer peripheral surfaces of the mill body on both sides near the raw material discharge port at the center of the mill so as to surround the outer periphery of the mill, and the raw material discharge port. A fixed cover having a U-shaped cross section for covering the outer peripheral surface, and an outer peripheral portion of an annular seal plate fixed to inner peripheral edges of both side surfaces of the fixed cover, and an inner peripheral portion of the seal plate on the inner peripheral edge of the fixed cover. In an air seal for a central outlet of a rotary mill equipped with a plurality of seal plate pressing fittings for pressing the annular slide plate, an annular processed metal rod is fixed to the annular slide plate, and the seal is attached. The plate is composed of a laminated body of an annular felt plate and an annular elastic body that presses the felt plate against the pipe, and the pressing metal fitting is provided with a lubricant supply port for preventing wear of the felt plate. An air seal for the central outlet of the rotary mill.