JPS6250755B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rapid heating/cooling furnace that can rapidly raise and lower the temperature inside the furnace.

[Prior Art] In the past, as an example of this type of furnace, there was one whose main part was shown in FIG. 4A. In order to minimize the heat capacity of the furnace wall due to the required temperature characteristics, the furnace of this example has two heat reflecting plates 20 and 21 using radiation resistance in the heat insulation structure separated by a gap. A water cooling pipe 22 is arranged in the gap. A heat-resistant plate 23 is provided on the inner side of the furnace than the heat-reflecting plate 21 with a gap therebetween, and a ceramic fiber 24 is pasted on the inner surface of this heat-resistant plate as a heat insulating material. Further, a plurality of insulators 25 are placed on the heat-resistant plate 25 so as to be located on the inner surface side of the ceramic fiber.
Heating wires 26 with a small diameter are attached to the insulators and supported by these insulators to avoid increasing the heat capacity of the furnace body.
are arranged.

As another example of a furnace, the main part of which is shown in FIG. Some had heating wires 28 with a small diameter buried.

FIG. 5 shows an example of temperature rise/fall characteristics of a conventional furnace configured as described above, in which the temperature fall time is significantly longer than the temperature rise time.

[Problems to be solved by the invention] Conventional furnaces of the above type have focused on reducing the heat capacity of the furnace body in order to achieve rapid temperature rise and fall, and have neglected heat loss from the furnace walls. Therefore, heat loss during temperature rise was large and thermal efficiency was poor. Also, the temperature lowering time was not short enough. Furthermore, the furnace of the type shown in FIG. 4B has the disadvantage that, since the heat insulating material forming the furnace wall is exposed to the outside, the working environment is likely to be contaminated by debris from the surface.

The purpose of the present invention is to provide a rapid heating/cooling furnace that reduces heat loss during heating and improves heating characteristics, significantly reduces cooling time, and does not cause environmental pollution from the furnace wall. be.

[Means for Solving the Problems] The configuration of the present invention for solving the above problems will be described below with reference to FIG. 1 and FIGS. 2A and 2B, which correspond to embodiments.

The rapid heating/cooling furnace of the present invention is composed of an inner wall 1 and an outer wall 2 that form a gap G between them. A furnace body 3 having an outlet 5, a heater 8 provided inside the furnace body 3, a cooling means 9 for cooling the furnace body 3, and a heat insulating material supply hopper connected to the insulating material inlet 4. 12, and the insulation material outlet 5
When the temperature of the furnace is rising, the heat insulating material storage tank 15 is charged into the gap G of the furnace body 3 from the hopper 12 through the heat insulating material inlet 4 to fill the gap G, and when the temperature is falling, the heat insulating material storage tank 15 is connected to The granular heat insulating material 7 is discharged from the gap G through the heat insulating material outlet 5 and stored in the heat insulating material storage tank 15.

In addition to the above configuration, the rapid heating/cooling furnace of the second invention of the present application is connected between the heat insulating material storage tank 15 and the heat insulating material supply hopper 12, and is housed in the heat insulating material storage tank 15. Granular insulation material 7
The apparatus is equipped with a heat insulating material circulation pump 19 that transfers the heat insulating material to the heat insulating material supply hopper 12.

[Operation of the Invention] The rapid heating/cooling furnace configured as described above charges the granular heat insulating material 7 from the hopper 12 through the heat insulating material inlet 4 into the gap G between the inner wall 1 and the outer wall 2 when raising the temperature of the furnace. power is supplied to the heater 8. As a result, the heat insulation effect of the furnace body 3 during temperature rise becomes extremely good, heat loss is reduced, and the temperature inside the furnace increases rapidly. Next, to lower the temperature of the furnace, power supply to the heater 8 is stopped, and the granular heat insulating material 7 is discharged from the gap G through the heat insulating material outlet 5 and stored in the tank 15. As a result, the heat insulation effect of the furnace body 3 is significantly reduced, good heat radiation is performed, and the temperature inside the furnace is rapidly lowered.

Further, in the furnace of the second invention of the present application, the tank 15
The granular heat insulating material 7 accommodated in the hopper 12 is transferred to the hopper 12 by a pump 19. As a result, the granular insulation material 7
, hopper 12 → furnace body 3 → tank 15 → hopper 1
The heat insulating material 7 for the furnace body 3 is circulated through the path of
This makes charging and discharging extremely efficient.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings. In FIG. 1, 1 is an inner wall made of quartz or stainless steel with one end closed and the other end open, and 2 is an outer wall made of stainless steel provided to cover this inner wall with a gap G.
A furnace body 3 is formed by the inner wall 1 and outer wall 2 described above. 4 is a heat insulating material inlet provided at the top of the outer wall 2, 5 is a heat insulating material outlet provided at the lower end side of the furnace body 3, and 6 is a pot provided at the bottom of this outlet. Reference numeral 7 designates a hollow so-called shirasu balloon (diameter 0.5 to 2 mm) as a granular heat insulating material with good fluidity, which is inserted into the gap G between the inner wall 1 and the outer wall 2.
Reference numeral 8 indicates a heater formed in a substantially cylindrical shape inside the inner wall 1, and reference numeral 9 indicates a water cooling pipe as a cooling means disposed on the outer periphery of the outer wall 2. 10 is a support stand for the furnace body 3;
Reference numeral 1 denotes an inlet/outlet for the object to be heated, which is opened in this support stand. Reference numeral 12 denotes a heat insulating material supply hopper disposed at a higher position than the insulating material inlet 4, and the lower open end of this hopper is connected to the insulating material inlet 4 by a pipe 14 having a pot 13 in the middle. ing. 1
5 is a heat insulating material storage tank connected to the tank 6 by a pipe 16, and 17 is a water-cooled heat exchanger disposed in the middle of the pipe 16. 18 is a pipe connecting the tank 15 and the hopper 12; 19;
is a heat insulating material circulation pump installed in the middle of this pipe.

In the furnace of this embodiment configured as described above, water is constantly supplied to the water cooling pipe 9 during operation to cool the outer wall 2 and prevent an increase in ambient temperature. Then, when operating the furnace, by energizing the heater 8,
Due to the good heat insulation effect of the heat insulating material 7, the temperature inside the furnace rises rapidly, and the object to be heated inserted into the furnace is heated well. In order to lower the temperature inside the furnace after this heat treatment is completed, the power supply to the heater 8 is stopped and the heater 8 is turned off.
3 and open the pot 6, the granular heat insulating material 7 charged into the gap G between the inner and outer walls as shown in FIGS. 1 and 2A passes through the pipe 16 and into the heat exchanger 17.
The heat is cooled by the water and enters the tank 15, and the gap G between the inner wall 1 and the outer wall 2 becomes hollow without the heat insulating material 7, as shown in FIG. 2B. This allows for better heat dissipation from inside the furnace to the outside.
The temperature inside the furnace drops rapidly. The granular heat insulating material 7 housed in the tank 15 is sucked up by operating the pump 19 and passed through the pipe 18 to the hopper 1.
Transferred to 2.

For the next heat treatment, the heat insulating material 7 in the hopper 12 is heated by closing the hopper 6 and opening the hopper 13.
from the insulation material inlet 4 to the inner wall 1 through the pipe 14.
and the outer wall 2, and after filling the gap with the heat insulating material 7, power is supplied to the heater 8 to raise the temperature of the furnace.

Next, to describe specific data in this example, in a furnace in which the inner wall 1 has a height of 75 cm and a diameter of 28 cm, the outer wall 2 has a height of 82.5 cm, a diameter of 43 cm, and a gap G between the inner and outer walls is 7.5 cm, the heating power is When the temperature was set to 12 KVA, the temperature rise and fall characteristics shown in Figure 3 were obtained. As can be seen by comparing this temperature rise/fall characteristic with the characteristics in Figure 5, the temperature rise time is 4/5 that of the conventional one, and the temperature fall time is 1/5 of that of the conventional one.
Each has been shortened to .

In the above embodiment, the inner and outer walls are cylindrical, but the furnace wall is not limited to this shape. Further, the heat exchanger used in the above embodiment may be omitted depending on the case.

Furthermore, although water-cooled pipes were used as the cooling means in the above embodiments, any suitable air-cooling means may be used.

[Effects of the Invention] As described above, the rapid heating/cooling furnace of the present invention uses a furnace body having a gap between the inner wall and the outer wall, and charges granular heat insulating material into the gap when raising the temperature of the furnace. Therefore, the insulating effect of the furnace body during temperature rise is extremely good, heat loss is reduced, and the temperature inside the furnace can be rapidly raised. Furthermore, when lowering the temperature of the furnace, the granular heat insulating material is discharged from the gap, which greatly reduces the heat insulation effect of the furnace body and improves heat dissipation, allowing the temperature inside the furnace to drop extremely rapidly. be able to. As described above, since the furnace of the present invention can raise and lower the temperature inside the furnace at an angular velocity, the productivity of heat treatment work can be improved. Further, in the furnace of the present invention, since the heat insulating material is not exposed to the outside, there is no possibility of contamination of the working environment due to peeling and scattering of the heat insulating material.

Furthermore, according to the invention of claim 2,
Since the granular insulation material in the insulation storage tank is transferred to the insulation material supply hopper by a pump,
By circulating the heat insulating material from the hopper to the furnace body to the tank to the hopper, the heat insulating material can be loaded into and discharged from the furnace body extremely efficiently.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an overview of an embodiment of the present invention, FIGS. 2A and B are sectional views of main parts showing the presence or absence of heat insulating material in the furnace body of the same embodiment, and FIG. 3 is a cross-sectional view of the same embodiment. Figures 4A and 4B are cross-sectional views of main parts showing the outline of different configurations of conventional rapid heating and cooling furnaces, and Figure 5 is a diagram showing the temperature raising and cooling characteristics of a conventional furnace. FIG. 3 is a characteristic curve diagram showing an example. 1...Inner wall, 2...Outer wall, G...Gap, 3...
Furnace body, 4... Insulating material inlet, 5... Insulating material outlet, 7... Granular insulating material, 8... Heater, 9... Water cooling pipe as cooling means, 12... Insulating material supply hopper, 15...Insulating material storage tank, 19...Insulating material circulation pump.

Claims (1)

[Claims] 1. A furnace body consisting of an inner wall and an outer wall that form a gap between them, communicating with the gap, having a heat insulating material inlet at one end and a heat insulating material outlet at the other end. , a heater provided inside the furnace body, a cooling means for cooling the furnace body, a heat insulating material supply hopper connected to the heat insulating material inlet, and a heat insulating material connected to the heat insulating material outlet. When the temperature of the furnace is rising, the storage tank is charged into the gap of the furnace body through the insulating material inlet from the hopper to fill the gap, and when the temperature is decreasing, it is discharged from the gap through the insulating material outlet. and a granular heat insulating material accommodated in the heat insulating material storage tank. 2. A furnace body consisting of an inner wall and an outer wall that form a gap between them, communicating with the gap and having a heat insulating material inlet at one end and a heat insulating material outlet at the other end, and an inner side of the furnace body. a heater provided in the furnace, a cooling means for cooling the furnace body, a heat insulating material supply hopper connected to the insulating material inlet, a heat insulating material storage tank connected to the insulating material outlet; When the temperature rises, the material is charged into the gap of the furnace body through the insulating material inlet from the hopper to fill the gap, and when the temperature decreases, it is discharged from the gap through the insulating material outlet to the insulating material storage tank. granular insulation contained in;
A heat-insulating material circulation pump connected between the heat-insulating material storage tank and the heat-insulating material supply hopper and configured to transfer the granular heat-insulating material contained in the heat-insulating material storage tank to the heat-insulating material supply hopper. A rapid heating/cooling furnace featuring: