JPS6148513A - Material preheating method and regenerator for preheating material - Google Patents

Abstract

PURPOSE:To economize the energy for preheating materials with a simple installation by charging the high-temp. material into a regenerator provided with a regenerating material and absorbing the heat released from the high-temp. material into the regenerating material then charging the low-temp. material into the regenerator. CONSTITUTION:The high-temp. material 4 heated to a prescribed temp. right after a heat treatment is charged into the regenerator 1 constituted by covering the outside circumferential surface with a heat insulating material 3 such as ceramic fibers, disposing the regenerating material 2 having large heat capacity such as bricks or concrete on the inside circumferential surface and providing hearth rolls 5 for carrying in and out of the material. The heat released from the above-mentioned material 4 is thus absorbed in the material 2 to increase the temp. thereof. The material 4 is thereafter ejected from the regenerator and in turn the low-temp. material is charged therein so that the heat retained by the material 2 is absorbed into the low-temp. material to preheat economically the low-temp. material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for preheating materials such as steel and a heat storage chamber for preheating in order to save energy in industrial facilities such as heat treatment furnaces for steel materials.

[Prior Art and its Problems] Various attempts have been made to save energy in industrial stools. For example, in a combustion furnace, there is a method for recovering the heat of exhaust gas by forming a preheating chamber in the flue and heating the material to a constant temperature in the preheating chamber before charging the material into the furnace. Although this method can be applied to combustion furnaces, there is a problem in that it cannot be applied to other industrial facilities that do not emit waste gas. On the other hand, a large amount of heat is released from high-temperature materials immediately after heat treatment, but in the past, this heat was wasted into the atmosphere, especially in small-scale equipment, and it is difficult to utilize it effectively. Ita.

[Means for Solving the Problems] Therefore, in the material preheating method of the present invention, a high-temperature material heated to a predetermined temperature is charged into a heat storage chamber in which a heat storage material is provided on the surrounding wall, and the heat released by the high-temperature material is charged. is absorbed by the heat storage material, and then a low temperature material is charged into the heat storage chamber so that the heat of the heat storage material is absorbed by the low temperature material.

In addition, the material preheating heat storage chamber of the present invention forms an airtight jacket on the surrounding wall, and the heat storage chamber absorbs or releases the heat of the material charged into the room by absorbing or releasing its own latent heat into the jacket. It is characterized by being made by enclosing a material.

[Example 1] The heat storage chamber 1 shown in Fig. 1 has a solid heat storage material 2 with a large heat capacity such as brick or concrete arranged on the inner peripheral surface, and the outer peripheral surface is covered with a heat insulating material 3 such as ceramic fiber. A hearth roll 5 is provided on the bottom surface for easy charging. A high-temperature material 4 immediately after heat treatment is charged into the heat storage chamber 1, and the temperature of the heat storage material 2 is increased by radiant heat or the like released from the high-temperature material. The binuclear high temperature material 4 is extracted, a low temperature material is charged in its place, and the heat storage material 2 is
The low-temperature material is preheated by absorbing the heat held by the low-temperature material into the low-temperature material. Furthermore, if the inner surface of the heat storage material 2 is coated with silicon carbide or the like with a high degree of blackness, it will activate heat radiation with indoor materials and increase the heat transfer efficiency! I can do that.

[Example 2] In the example shown in FIG. 2, the bottom wall and ceiling wall of the heat storage chamber 1 are made of a heat-resistant material such as a heat-resistant metal material or a heat-resistant material such as ceramics in a mesh-like, honeycomb-like, porous, etc. A plate-shaped air permeable solid 6.6 formed of
is installed, and the blower 8 is operated to blow the gas in the heat storage chamber 1 to 1!
I'm trying to make it a circle. By doing so, when the high-temperature material 4 is charged into the room, the high-temperature gas that has come into contact with the high-temperature material will heat the gas-permeable solids 6, 6 as it flows through the gas-permeable solids 6, 6. Therefore, the breathable solid 6.
The heat storage material 2 is heated by the radiant heat emitted from the heat storage material 6 .

Therefore, by arranging the air permeable solid in this way, the heat transfer efficiency between the high temperature material 4 or the low temperature material and the heat storage material 2 can be improved.

[Example 3] The material preheating heat storage chamber shown in this example uses sodium nitrate (NaNO3) as a heat storage material. Sodium nitrate is solid at room temperature, but melts at 308°C and can store 63Kcal/Kg of heat of fusion. Therefore, it is suitable for preheating when heat treating steel materials. In this case, as shown in FIG. 3, an airtight jacket 9 made of stainless steel containing sodium nitrate 2 as a heat storage material is formed, and its outer peripheral surface is covered with a ceramic fiber heat insulating material 3.

However, a wire coil 14 at 800°C is placed in the heat storage chamber 1 of the lever.
When 0 kg was charged, the heat released from the wire coil was actively absorbed, and the wire coil was able to be cooled to 450° C. after about 25 minutes. As a result of charging 140 kg of a wire rod coil at 20° C. into the double nuclear heat storage chamber 1, the wire rod coil could be preheated to 120° C. in about 50 minutes.

It goes without saying that the heat storage material is preferably a material that can store a large amount of heat per unit volume. In addition, as in this embodiment, the state reversibly changes from solid to liquid or from liquid to solid near the desired preheating temperature, and absorbs or releases latent heat such as its own heat of fusion or heat of vaporization, thereby further accumulating heat. You can increase the amount. For example, sodium hydroxide (NaOH
) has a melting point of 320℃, a heat of fusion of 71.9Kcal/Kg,
Borax (B203) has a melting point of 450°C and a heat of fusion of 78.1
Kcal/Kg and lead (PB) have a melting point of 327° C. and a heat of fusion of 5.5 Kcal/Kg, so using these substances as a heat storage material is also effective in preheating steel materials.

[Effects of the invention] The heat of the high-temperature material immediately extracted from the heating chamber can be stored and used to preheat the low-temperature material to be heat-treated next, so it is a fairly simple equipment, regardless of the type of industrial use. Energy saving can be achieved. In addition, a heat storage chamber designed to absorb or release latent heat has the advantage that the amount of heat stored at the melting point, ti, or boiling point is significantly large, so that heat can be transferred and received more effectively to the material.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a heat storage chamber showing Embodiment 1 of the present invention;
FIG. 2 is a longitudinal sectional view of a heat storage chamber showing a second embodiment, and FIG. 3 is a longitudinal sectional view of a heat storage chamber showing a third embodiment. ]...Heat storage chamber, 2...Heat storage material, 3...Insulating material, 4...High temperature material. Figure 1 Figure 2 Figure 8 - Go to 2 -

Claims (1)

[Claims] 1. A high-temperature material heated to a predetermined temperature is charged into a heat storage chamber with a heat storage material provided on the surrounding wall, and after the heat released by the high-temperature material is absorbed by the heat storage material, the low-temperature material is charged. A method for preheating a material, characterized in that the heat storage material is charged into the heat storage chamber and the heat of the heat storage material is absorbed into the low temperature material. 2. An airtight jacket is formed on the surrounding wall, and a heat storage material that absorbs or releases the heat of the materials charged into the room by absorbing or releasing its own latent heat is enclosed in the jacket. A heat storage chamber for preheating materials.