JPH078035Y2 - Horizontal mill trunnion seal structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a trunnion seal structure for a horizontal mill.

[Prior Art] As shown in FIG. 2, a hollow trunnion 4 fitted in a trunnion bearing 3 is integrally connected to both ends of a cylindrical body 2 of a rotatable horizontal mill 1 in the direction of an axis l. There is. Inside the trunnion 4, a cylindrical tube 5 for sending heated air to the cylindrical body 2 and a trunnion tube 7 accommodating a coal feeding screw conveyor 6 surrounding the cylindrical tube 5 are inserted. The trunnion tube 7 is set so that the trunnion tube 7 does not rotate.
The part protruding from the outside is supported and fixed.

Since the trunnion pipe 7 is inserted into the trunnion 4 as described above, a gap 8 is formed between the trunnion 4 and the trunnion pipe 7 as shown in FIG. Since the pulverized coal which is communicated with the outside through the gap 8 may be leaked to the outside, a trunnion seal structure 9 is provided at the end of the trunnion 4 to prevent the leakage of the pulverized coal to the outside. There is.

The trunnion seal structure 9 is fixed to the end face of the trunnion 4 in the direction of the axis l, is rotatable with the seal ring 10, and is attached to the outer periphery of the trunnion pipe 7 concentrically with the trunnion pipe 7, and A cylindrical lid-shaped seal box 12 having an opening 11 on the side facing the seal ring 10 and an outer peripheral portion on the opening side of the seal box 12 communicates with the internal space of the cylindrical body 2 through a gap 8. Attached to the fixed flange 13 and seal ring
A ring-shaped gasket 14 formed of asbestos or the like that can come into contact with the end face of the trunnion tube 7 in the direction of the axis l, and a ring-shaped backing made of an elastic material capable of pressing the gasket 14 as shown in FIG. 4 to the end face of the seal ring 10. It is composed of a metal plate 15 and a ring-shaped pressing plate 16 for pressing the gasket 14.

In order to press the gasket 14 against the seal ring 10 on the backing plate 15, a plurality of tongue pieces 18 are formed on the inner peripheral side 17 and are radially formed by cutting at a predetermined interval in the circumferential direction.

In the figure, 19 is a coarse powder separator and 20 is a baffle plate.

In the horizontal mill 1, coal is sent to the cylindrical body 2 by the screw conveyor 6, and the coal is crushed in the cylindrical body 2. The coal pulverized into the required fine powder is carried to the coarse powder separator 19 through the gap between the trunnion pipe 7 and the cylindrical pipe 5 by the heated air blown from the cylindrical pipe 5 into the cylindrical body 2.

During operation of the horizontal mill 1, the seal ring 10 rotates together with the cylindrical body 2 and the trunnion 4, but the trunnion tube 7, seal ring 12 and gasket 14 do not rotate, so the seal ring 10 slides on the gasket 14. Move.

On the other hand, a part of the heated air introduced into the cylindrical body 2 entrains pulverized coal and enters the seal box 12 through the gap 8, but a gasket 14 is provided on the opening side of the seal box 12, and the gasket 14 is Seal ring with a constant force by the back metal 15
Since it is pressed against 10, heated air containing pulverized coal does not flow out.

Further, when the horizontal mill 1 is operated, heated air is introduced into the cylindrical body 2, so that the cylindrical body 2 and the trunnion 4 thermally expand and move to the seal box 12 side. 15
And the pressing force of the seal ring 10 against the gasket 14 becomes larger than that before the thermal expansion of the cylindrical body 2 and the trunnion 4.

[Problems to be Solved by the Invention] However, the conventional backing metal 15 has an inner peripheral side 17 of the backing metal 15.
Since the tongue piece 18 has a wide pressing surface and a large sealing effect of pressing the gasket 14, the tongue piece 18 has a large sealing surface because the tongue piece 18 is formed by cutting the tongue piece 18 in the circumferential direction at required intervals. Because of the large elastic force of the gasket, the gasket with the backing plate 15 accompanies the thermal expansion of the trunnion 4 and the trunnion tube 7.
The pressing force of 14 against the seal ring 10 becomes too large, and the gasket 14 is rubbed against the seal ring 10 and worn, which shortens the life of the gasket 14.

The present invention has been made in view of such circumstances, and an object thereof is to provide a backing metal having a wide pressing surface and a small elastic force.

[Means for Solving the Problems] The present invention is to attach a seal ring to an axial end face of a hollow trunnion connected to an axial end of a cylindrical body,
A trunnion tube supported so as not to rotate inside the trunnion is inserted into the trunnion, and the inside of the trunnion tube is communicated with the inside of the cylindrical body and the inside of the trunnion, and an axial end surface of the trunnion. A trunnion seal box having an opening formed on the side facing the, and a ring-shaped gasket capable of contacting the end face of the seal ring with the opening of the trunnion seal box and the gasket on the end face of the seal ring. In a trunnion seal structure of a horizontal mill provided with a ring-shaped backing metal which can be attached, a plurality of tongue pieces are formed by radially cutting the inner circumferential side of the backing metal in the circumferential direction at required intervals to form a plurality of tongue pieces. The present invention relates to a trunnion seal structure of a horizontal mill, characterized in that the width of the middle part of the backing metal in the radial direction is smaller than the width on the inner peripheral side.

[Operation] Since the gasket is pressed against the seal ring by the pressing force of each tongue piece of the backing metal, the inside of the cylindrical body and the trunnion is sealed from the external space.

With the thermal expansion of the trunnion and the trunnion tube, the flexure of the backing metal of the trunnion seal structure increases, but the pressing force generated by the tongue does not increase so much, and the wear of the gasket decreases.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a backing metal used for the trunnion seal structure of the horizontal mill of the present invention.

On the inner peripheral side 17 'of the backing plate 15' made of elastic material,
A tongue piece 18 'is formed by inserting notches 21 radially cut at a required interval in the circumferential direction, and an inner circumference is provided between a required position on the inner circumference side 17' of the tongue piece 18 'and a notch 21 base end portion 22. A paddle portion 23 having a width narrower than that of the side 17 'is formed.

When the backing metal 15 'described above is used as the backing metal 15' of the trunnion seal structure 9 of the horizontal mill 1 shown in FIGS. 2 and 3, the required position of the paddle portion 23 of the backing metal 15 'is the inner circumference. Since it is formed narrower than the side 17 'and the elastic force of the paddle portion 23 is small, the trunnion 4 and the trunnion pipe 7 are thermally expanded, and the seal ring 10 interposes the gasket 14 on the tongue piece of the backing plate 15'. Even if 18 'is pressed, the reaction force by the backing metal 15', that is, the pressing force is not so large, and therefore the pressing force of the gasket 14 against the seal ring 10 is not so large, so that the gasket 14 is less likely to wear and its life is extended.

Further, since the inner peripheral side 17 'of the paddle portion 23 is usually formed in the same manner as the conventional one, the gasket 14 can evenly press the seal ring 10.

The trunnion seal structure of the horizontal mill according to the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] As described above, according to the trunnion seal structure of the horizontal mill of the present invention, even if the trunnion and the trunnion tube are thermally expanded, a large pressing force is not generated on the backing metal, so that the pressure applied to the gasket is reduced. Therefore, it is possible to obtain the excellent effect of reducing the wear of the gasket and extending the life of the gasket.

[Brief description of drawings]

FIG. 1 is a partially enlarged front view showing a backing metal used in a trunnion seal structure according to an embodiment of the present invention, FIG. 2 is a schematic front view of a horizontal mill, and FIG. 3 is a sectional view of a trunnion seal structure in a horizontal mill. FIG. 4 is a partially enlarged front view showing a conventional backing metal. In the figure, 1 is a horizontal mill, 2 is a cylindrical body, 4 is a trunnion,
7 is a trunnion tube, 9 is a trunnion seal structure, 10 is a seal ring, 12 is a seal box, 14 is a gasket, 1
5'denotes a backing metal, 17 'an inner peripheral side, and 18' a tongue.

Claims (1)

[Scope of utility model registration request] 1. A trunnion tube having a seal ring attached to an axial end surface of a hollow trunnion connected to an axial end portion of a cylindrical body, the trunnion tube being supported in the trunnion so as not to rotate in the trunnion. Through, through the outer periphery of the trunnion tube, the inside communicates with the inside of the cylindrical body and the inside of the trunnion, and a trunnion seal box having an opening formed on the side facing the axial end face of the trunnion is fixed. In a trunnion seal structure of a horizontal mill, the opening of the trunnion seal box is provided with a ring-shaped gasket capable of contacting the end surface of the seal ring and a ring-shaped backing metal capable of attaching the gasket to the end surface of the seal ring. A plurality of tongues are formed by radially cutting the inner peripheral side of the backing metal in a circumferential direction at a required interval to form a tongue-shaped backing metal part in the radial direction. Horizontal mill trunnion seal structure is characterized in that smaller than the width of the inner circumferential side width.