JPH025954B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applied to an air shaft sealing device, particularly a device called a so-called bowl mill, such as a vertical mill, a vertical crusher, a vertical pulverizer, etc. This invention relates to a floating collar type air sealing device that prevents foreign matter from entering the air.

In conventional clearance type sealing devices, when the vertical main shaft bearing becomes worn, or when tramp iron is present in the pulverized coal, the sealing action rapidly decreases. This type of sealing device still cannot maintain the required service life and requires many costly field corrections, such as increasing the sealing air volume to maintain the pressure differential or adding a housing for heat shielding. is necessary.

Further, in the case of a labyrinth type sealing device, the sealing material may rub against the sides of the labyrinth due to thermal expansion of the seal housing. In such cases, the lip of the seal material wears out quickly, and its mechanical strength and physical properties deteriorate, causing failure. If the seal material rips or the labyrinth track destroys the seal material, the failure becomes definitive.

The latest face-seal types are sophisticated and expensive, and data on their average lifespans are not yet available. However, it is expected that this type of system will require more maintenance than ever before.

The present invention was made in view of the above circumstances, and is suitable for use in places where seal maintenance is not required and where long-term operation is required, and where the operating conditions are extremely poor, such as in a pulverizer drive unit. To provide an air sealing device that can be applied to places where there is no particularly effective dust removal method, can be made by a very general method rather than by any special method, and can be applied to existing equipment. The purpose is to

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below as illustrated in the accompanying drawings.

Figures 1 to 4 show the main parts of an air sealing device according to the present invention applied to a pulverizer.
is the support ring retaining screw 3 (see Figure 2).
installed by. The support rings 2 are interconnected by support ring coupling screws 4 to form an annular shape, as shown in FIG. A split self-centering floating collar 5 is mounted on the top of the support ring 2. Floating color 5 is the second
As shown in the figure, the floating collar combination key 6 and the combination key fixing screw 7 are connected to each other. The coupling key 6 is aligned with the floating collar 5 by a dowel pin 8. The floating collar 5 is held in the position shown only by its own weight (for example, the floating collar weighs about 10.4 kg with a shaft outer diameter of about 28 cm), and no special holding means is used. Preferably, this floating collar 5 is chrome plated on its outer surface 9. An air seal housing 10 is located around the outer periphery of the floating collar 5, and this air seal housing 10 is equipped with at least three floating collar centering rollers 11 (FIG. 1) or floating collar centering studs 12 (FIG. 3). It is equipped with A seal air chamber 13 is provided within the air seal housing 10 . In addition, what is provided above the shaft 1 in FIGS. 1 and 3 is a bowl hub 14 that supports a crushing table of a vertical coal pulverizer.

When the vertical main shaft 1 of the pulverizer rotates,
The floating collar 5 also rotates at the same rotation speed. floating color 5
The force for rotating is the adhesive force (frictional force) existing between the top of the support ring 2 and the corresponding contact surface 15 of the floating collar 5. In the past, when the main shaft 1 started to vibrate due to crushing of the tramp iron or loosening of the bearing, the center position was changed relative to the floating collar 5, but in the present invention, the center position is changed around the floating collar 5. provided at least 3
two centering rollers 11 or wear-resistant studs 12
cancels such disturbances by suppressing the swings. Once corrected, the floating collar 5 will continue to rotate in an axially symmetrical manner.

Engineering clearance between shaft 1 and split support ring 2 and floating collar 5 16, 17,
18 ensures that no contact or wear occurs on the sealing surface 19.

This air sealing device is expected to have a service life that is equal to or longer than the upper radial bearing of the shaft 1.

FIG. 4 shows yet another embodiment of the air sealing device according to the present invention.

According to FIG. 4, the floating collar 5 is a friction shoe 20.
The split support ring 2 is mounted on the top of the split support ring 2 via the support ring 2. In this embodiment, the floating collar 5 is not rotated but is fixed. At least three collar retainers 21 provided in the air seal housing 10 are loosely fitted into the recesses provided on the outer periphery of the floating collar 5, so that the floating collar remains stable even when the shaft 1 and the support ring 2 rotate. Not rotated. The lip seal 22 provided at the top of the air seal housing 10 acts as a centering ring for the floating collar 5, and since the floating collar 5 does not rotate, there is no friction, so the pressure difference in the sealing air is always constant. It will be preserved. Seal air is pumped between the support ring 2 and the floating collar 5 via a passage 23 provided in the floating collar 5. The sealing or shielding here is performed by a wear-resistant friction shoe 20.

FIG. 5 illustrates an overall view of the floating collar type air sealing device according to the present invention applied to a vertical pulverized coal machine.

According to FIG. 5, the coal to be crushed supplied from the raw material supply pipe 26 is moved from the center of the crushing table 24 to the outer circumference of the crushing table 24 by the centrifugal force of the rotating crushing table 24. While
The material is crushed by being caught in the gap between the crushing roll 25 to which a crushing load is applied from the hydraulic cylinder 29 and the crushing table 24. The pulverized fine powder is lifted up by the upward flow of gas supplied from the carrier gas inlet 30 and enters the classifier 27 . The classifier 27 has wings with a certain angle around it.
When the fine powder passes between these wings, it is given a rotational force,
The flow becomes a swirl inside the classification cone 31, where it is separated into fine powder and coarse powder, and the fine powder is formed at the pulverizer outlet 28.
It is discharged outside as pulverized coal. On the other hand, the coarse powder falls through the classification cone 31 and returns to the crushing table 2.
4 and re-ground.

In such a vertical pulverized coal machine, it is necessary to prevent fine powder from entering into the reducer 32 from the sliding part with the rotating shaft 1, but by applying the device according to the present invention, the intrusion of fine powder can be prevented. It can definitely be prevented.

As mentioned above, conventional sealing technologies do not meet the sealing performance requirements and do not satisfy user requirements in terms of availability, flexibility, efficiency, economy, etc., but according to the present invention, The actual contact parts in the seal part are rollers, wear-resistant studs, and wear-resistant friction shoes, and most other parts are made of seal air, so it has a long life and can last for a long time. No maintenance required. Also, since it has a self-dust-proofing and cleaning effect using sealed air, it can be used in harsh environments. Further, since the sealing device according to the present invention does not require any special equipment, it can be manufactured by a general method, and since the structure is not complicated, it can be easily applied to existing equipment.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main part of an air sealing device according to the present invention, FIG. 2 is a plan view of the main part taken along - in FIG. 1, and FIG.
FIG. 4 is a diagram similar to FIG. 1 showing still another embodiment of the present invention, and FIG. 5 is a schematic diagram showing an example of application of the device according to the present invention to a vertical pulverizer. It is a diagram. 1...Shaft, 2...Support ring, 3...Support ring holding screw, 4...Support ring coupling screw, 5...Floating collar, 6...Floating collar coupling key, 7...Coupling key fixing screw, 8...Dowel pin,
9...Outer surface, 10...Air seal housing, 11
...roller, 12...stud, 13...seal air chamber, 14...bowl hub, 15...contact surface, 16,1
7, 18...Clearance, 19...Sealing surface,
20...Friction shoe, 21...Collar retainer, 22
...Lipstick, 23...Aisle.

Claims (1)

[Claims] 1. A support ring attached to a vertical shaft, a floating collar placed on the top of the support ring in a loosely fitted manner with respect to the shaft, and a plurality of floating collars fixedly attached at appropriate intervals around the outer circumference of the floating collar. a device for centering the floating collar; and a seal for supplying sealing air into a gap between the floating collar and the support ring or between the floating collar and a housing holding the centering device. A floating collar type air seal device comprising an air chamber.