JPH10183233A - Heat insulating skid pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the amount of heat transfer from a furnace to a coolant and to simply improve the unit requirement of fuel in the furnace by coating the outer peripheral surface with refractory heat-insulating material and forming heat-insulating layer composed of synthetic resin, etc., on the inner peripheral surface of a heat insulating skid pipe flowing the coolant in the inner part. SOLUTION: In the skid pipe 2 laying a skid rail 1 arranged e.g. in a walking beam type heat treatment furnace, this outer peripheral surface is coated with the refractory heat-insulating material 3 composed of monolithic refractory and also, the coolant 12 is flowed in the inner part and the skid rail 1 and the skid pipe 2 are cooled and protected. On the peripheral surface of the heatinsulating skid pipe 2, further, the heat-insulating layer 11 of epoxy resin, etc., is formed. The thickness of this heat-insulating layer 11 is suitably decided according to the heat-insulating capacity of the refractory heat-insulating material 3, the heatresistant temp. of the heat-insulating layer 11, etc. By this method, the heat transfer quantity from the furnace to the coolant is reduced without changing the material, and the thickness of the heat-insulating material and cooling loss calory is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-insulating skid pipe disposed in, for example, a walking beam type heat treatment furnace.

[0002]

2. Description of the Related Art In a walking beam type heat treatment furnace, as shown in FIG. 2, a skid rail 1 or a skid button (hereinafter simply referred to as "skid rail 1") for supporting a steel material is provided on a skid pipe 2. is set up. Then, for the purpose of protecting the skid rail 1 and the skid pipe 2 from the atmosphere temperature in the furnace, the outer periphery of the skid pipe 2 is covered with a refractory heat insulating material 3 and a cooling medium 4 is allowed to flow through the skid pipe 2 for cooling. I have.

However, in order to protect the skid rail 1 and the skid pipe 2, the inside of the skid pipe 2 is covered with a refractory heat insulating material 3 as a reaction of flowing a cooling medium into the skid pipe 2. There is a problem that the amount of heat in the heat treatment furnace is carried away by the flowing cooling medium. The amount of heat removed is usually 10 to 15% of the heat input to the combustion furnace. However, since the temperature potential is low, effective heat recovery cannot be performed, which is one of the causes of deterioration of fuel consumption. .

In order to solve the above-mentioned problem, the amount of heat transfer from the furnace to the cooling medium may be reduced. One method for achieving this is to increase the thickness of the refractory heat insulating material to increase the heat transfer. It is conceivable to reduce the amount.

[0005]

However, if the thickness of the refractory heat-insulating material is increased, the outer diameter of the skid pipe becomes larger, so that the portion where the radiant heat is blocked is increased (shadow effect), so that the material to be heated may be damaged. The heat transfer is suppressed and the heating efficiency is deteriorated, causing the heat uniformity and the unit fuel consumption to deteriorate. On the other hand, in order to reduce the amount of heat transfer while keeping the outer diameter of the skid pipe constant by changing the material of the refractory heat insulating material, it is necessary to remove all the walking beams, and construction in the heat treatment furnace has to be carried out on a large scale. Become. In addition, there is a problem that the skid pipe itself needs to be replaced, and the equipment cost is enormous.

[0006] There are also a double-insulated structure disclosed in Japanese Utility Model Publication No. 61-40766 and a skid beam having a triple-insulated structure disclosed in Japanese Utility Model Application Publication No. 63-106751. Since the focus is on the reduction of the heat loss due to cooling, no significant reduction in the heat loss due to cooling is observed.

Further, Japanese Patent Application Laid-Open No. 62-222016 proposes a method in which a fuel gas passage is provided on the outer peripheral surface of a water cooling pipe to block heat transfer to the water cooling pipe and preheat fuel gas. The skid pipe used in this method has a complicated structure, and the fuel gas pipe becomes hot, and there is a risk that the fuel gas leaks from a weld or the like.

The present invention has been made in view of the above-mentioned conventional problems, and reduces the amount of heat transferred from the inside of a furnace to a cooling medium without increasing the outer diameter of a skid beam, thereby reducing the heat loss of cooling. It is an object of the present invention to provide a heat-insulating skid pipe capable of reducing the temperature.

[0009]

In order to achieve the above-mentioned object, a heat insulating skid pipe of the present invention has a heat insulating layer formed on an inner peripheral surface of the skid pipe. By doing so, the amount of heat transferred from the inside of the furnace to the cooling medium is reduced without increasing the outer diameter of the skid pipe.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION
The heat insulating layer is formed on the inner peripheral surface of the skid pipe whose outer peripheral surface is covered with a fire-resistant heat insulating material. In the heat-insulating skid pipe of the present invention, by forming a heat-insulating layer on the inner circumferential surface of the skid pipe, the material of the fire-resistant heat insulating material covering the outer circumferential surface of the skid pipe can be changed, or the thickness of the fire-resistant heat insulating material can be changed. Without increasing the thickness, the amount of heat transfer from the inside of the furnace to the cooling medium can be reduced. Further, since there is no need to increase the outer diameter of the skid pipe, there is no adverse effect due to the shadow effect.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A heat insulating skid pipe according to the present invention will be described below with reference to an embodiment shown in section in FIG. In FIG. 1, reference numeral 11 denotes a heat insulating layer of, for example, epoxy resin formed on an inner peripheral surface of a skid pipe 2 installed in a walking beam type heat treatment furnace. The amount of heat transfer from the inside of the furnace to the cooling water 12, for example, flowing through the skid pipe 2 is reduced by the coated refractory heat insulating material 3 made of, for example, an amorphous refractory.

The heat insulating layer 11 and the refractory heat insulating material 3
The material is not limited to an epoxy resin as long as the amount of heat transfer from the furnace to the cooling water 12 can be reduced. For example, a synthetic resin such as polyethylene, mortar, heat-insulating castable, or the like may be used.

The thickness of the heat-insulating layer 11 is appropriately determined according to the heat-insulating ability of the refractory heat-insulating material 3 and the reduction ratio of the heat transfer amount. It is appropriately determined according to the heat resistant temperature of the heat insulating layer 11 and the heat resistant temperature of the skid pipe. For example,
When the heat insulating layer 11 is made of a synthetic resin, the heat resistant temperature of the synthetic resin is about 100 ° C.
The temperature is determined so as to be 00 ° C or less.

When the heat insulating layer 11 is made of mortar or heat-insulating castable, these have a high heat-resistant temperature.
The temperature of the skid pipe 2 whose strength decreases at 00 to 350 ° C. is determined to be 300 ° C. or less.

Incidentally, a skid pipe (outer diameter of a walking beam type heating furnace (nominal capacity: 450 T / H, fuel: coke oven gas)) in which the outer peripheral surface is coated with a refractory heat insulating material of irregular refractory with a thickness of 75 mm. 165.2 mm, thickness 1
When a heat insulation layer made of epoxy resin is lined on the inner peripheral surface of 8.2 mm) with a thickness of 5 mm, compared with a case where the heat insulation layer of epoxy resin is not lined, the heat loss of cooling is about 3 times.
It has been reduced by 0%, and the unit fuel consumption has improved by about 5%.

In this embodiment, the adiabatic skid pipe installed in the walking beam type heating furnace has been described. However, the adiabatic skid pipe of the present invention is not limited to the one installed in the walking beam type heat treatment furnace, but may be a pusher type heating furnace or the like. Needless to say, it may be installed at Further, not only the heating furnace but also other heat treatment furnaces have the same effect.

[0017]

As described above, the heat-insulating skid pipe of the present invention has a structure in which a heat-insulating layer is formed on the inner circumferential surface of a skid pipe whose outer circumferential surface is covered with a refractory heat-insulating material. Change the material of the refractory heat insulating material that covers the outer peripheral surface of the skid pipe by the formed heat insulating layer, or increase the thickness of the refractory heat insulating material while keeping the outer diameter of the skid pipe the same size. In addition, the amount of heat transfer from the inside of the furnace to the cooling medium can be reduced. Therefore, the unit fuel consumption is improved by reducing the heat transfer amount.

[Brief description of the drawings]

FIG. 1 is a sectional view of a heat insulating skid pipe of the present invention.

FIG. 2 is a sectional view of a conventional heat insulating skid pipe.

[Explanation of symbols]

 2 Skid pipe 3 Fireproof insulation 11 Heat insulation layer

Claims (1)

[Claims] 1. A heat-insulating skid pipe characterized in that a heat-insulating layer is formed on an inner peripheral surface of a skid pipe whose outer peripheral surface is covered with a refractory heat-insulating material.