JPS6364669B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for sealing a connecting portion of a passage through which gas passes, such as an exhaust gas duct.

For example, a duct that passes combustion exhaust gas discharged from a combustion device is divided into several parts due to its structure.
This connection is often designed to facilitate installation and to absorb thermal stresses. FIG. 1 shows an example of this stress absorption method. Reference numeral 3 denotes a bellows, which is arranged at the connection between the ducts 1a and 2a. Both ends of the bellows 3 are attached to the ducts 1a and 2a via a seal member 4, and are fixed to these ducts by fixing means such as bolts 5. Both ducts 1a and 2a are deformed by the heat of the exhaust gas G passing through them, and the deformation of both ducts occurs in the XX' direction at this connection point.
It appears as a displacement relative to the YY′ direction or the combined direction. The bellows 3 absorbs the displacement while maintaining the airtightness of the connection between the ducts 1a and 2a. However, since the bellows absorb stress by deforming itself, it is easily damaged, and when the temperature of the gas passing through the bellows is high, the materials for forming the bellows are significantly limited and expensive. Furthermore, since the bellows are usually stuck to the duct, there is also the problem that it is difficult to remove or replace the bellows if the bellows are damaged.

Next, instead of using such a bellows mechanism, it was considered to retain water at the duct connection and seal with this water, but since the water evaporates rapidly, it must be constantly replenished, and furthermore, the S content in the exhaust gas is reduced. It is difficult to put it into practical use because problems such as the reaction between water and water produce sulfuric acid, which accelerates the corrosion of ducts.

Furthermore, connections using sand instead of water were developed in 1983.
It is known as No. 4648 (Figure 2). However, in this case, if the pressure inside the duct and the pressure outside the duct are unbalanced, high-temperature gas will flow through the sand and leak. Flexible and heat resistant airtight means are provided. However, this structure corresponds to the bellows structure described above, and there is a need for a simpler and more effective device.

In view of the above-mentioned problems, the object of the present invention is to have a simple structure, maintain high airtightness, facilitate vertical and horizontal relative displacement of the duct connection, effectively absorb thermal stress, and shorten the service life. The purpose is to provide a long sealing device.

In short, this invention forms a groove at one almost vertical end of a gas passage such as an exhaust gas duct, fills this groove with particulate matter such as sand, and forms a seal wall at the other end of the duct. By inserting this seal wall into the granular material packed layer, gas is sealed by the seal wall and the granular material filled layer, and gas flows inside the duct onto the surface of the granular material packed layer on the outer periphery of the seal wall. Since there is a layer of material that softens depending on the gas temperature, the sealing wall 8a and the groove 6
It is constructed to ensure sufficient airtightness between the outer circumferential walls of a and to absorb relative displacement of the duct connection portion.

An embodiment of this invention will be described below.

First, the structure of a conventional connecting portion having an annular groove for accommodating sand or the like will be explained with reference to FIG. Reference numeral 6 denotes a groove structure, with a groove 6a formed in its upper part, and the entire groove structure 6 is attached to the upper end of the duct by strong means such as welding. By attaching the groove structure 6, a groove 6a is formed on the outer peripheral edge of the upper end of the duct 2. 7 is this groove 6
It is a granular material such as sand (silica sand) filled in a. Since this particulate material seals the gas as described later, it is necessary that the particle size is small enough to prevent the passage of gas, and that it does not change in quality due to the heat of the gas passing through the gas passage. It is. For this reason, in addition to the above-mentioned sand, fine cement clinker and the like are suitable.

Next, reference numeral 8 denotes a seal wall structure, and this seal wall structure 8 itself is fixed to the outer periphery of the lower end portion of the duct 1 in the same manner as the groove structure 6 described above, and a seal wall 8a is formed and arranged at the tip thereof. This sealing wall 8a is inserted into the packed bed of granules 7.

In the above description, the groove 6a and the seal wall 8a are formed as part of the groove part structure 6 and the seal wall structure 8, respectively, and these structures 6 and 8 are attached to each duct 2 and 1 to form a part of each duct. Grooves and seal walls were formed. This is intended to facilitate modification of existing ducts, increase productivity, and reduce cost.This invention is not limited to this type, and the end portion of each air duct may be bent. The grooves and sealing walls may be formed integrally with these air passages from the beginning by molding.

In the device having the above configuration, the connecting portion of the ducts 1 and 2 is connected to the seal wall 8a and the particulate matter in the groove 6a.
The ducts are hermetically sealed by the packed bed of granules 7, and the relative displacement between the two ducts is absorbed by the packed bed of granules.

Next, an embodiment of the present invention will be explained with reference to FIG. In the above structure, if a layer of a material such as asphalt 9 that is softened by the temperature of the gas passing through is formed on the surface of the packed layer at the outer peripheral portion of the seal wall 8a, it is possible to form a layer of a substance such as asphalt 9 on the surface of the layer in the sand portion inside the groove and on the surface of the layer of the seal wall 8a. A substance that softens at the temperature of the gas inside the duct is located between the inner surface of the outer circumferential wall of the groove 6a and is adhesively connected to these walls, so it can be used instead of a bellows etc. to keep the sealing part airtight when the passing gas temperature is relatively high. In addition to being able to maintain a higher level of performance, displacement of both ducts can be effectively absorbed.

By carrying out this invention, since sealing is performed using a layer filled with granular materials, the structure of the sealing portion can be simplified while maintaining high sealing performance.

Further, since the seal portion is formed by inserting the seal wall into the granular material-filled layer, the gas passage can be attached and removed without any modification to the seal portion.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an exhaust gas duct showing a conventional blow sealing method, and FIG. 2 is a sectional view of a gas passage showing an embodiment of the present invention. 1, 2...Duct, 6...Groove structure, 6a...
...Groove, 7...Particles, 8...Seal wall structure, 8
a... Seal wall.

Claims (1)

[Claims] 1. When forming a substantially vertical gas passage through which high-temperature gas flows by connecting two ducts, a groove is formed at the upper end of the lower duct and heat-resistant granules are filled in this groove. , a sealing wall is formed at the lower end of the upper duct, and this sealing wall is inserted into the packed layer of granules to absorb the relative displacement of the duct in the vertical and horizontal directions and to maintain the airtightness of the duct connection part. What is claimed is: 1. A sealing device for a duct, characterized in that a layer of a substance softened by the temperature of gas flowing in the duct is formed on the surface of the particulate material filling layer on the outer periphery of the seal wall.