JPS583193B2 - Energy-saving continuous heating furnace - Google Patents

Description

[Detailed description of the invention] This invention relates to improvements in continuous heating furnaces.

More specifically, the present invention relates to a continuous heating furnace for efficiently and continuously heating an object to be heated with little heating energy.

Continuous heating furnaces are widely used in the electronics industry, metal industry, powder metallurgy industry, ceramic industry, chemical industry, nonferrous metal industry, and other fields for firing, baking, sintering, and various other heat treatments of heated objects. The objects to be heated are diverse, ranging from metals, powder metallurgy, ceramics, to electronic components.

Conventionally, such a continuous heating furnace generally has a heating zone H and a soaking zone U equipped with a heating element along the movement of the object to be heated from the furnace inlet 20 to the furnace outlet 21, as shown in FIG. Instead, it consists of a cooling zone C equipped with intake and exhaust holes as required, and in order to make heat distribution uniform, each zone is divided into a plurality of blocks and each block is equipped with a fan.

If an example of a conventional continuous heating furnace is illustrated in detail in FIG. 2, such a continuous heating furnace has blocks divided by a plurality of baffle plates 3 provided between an outer furnace wall 1 and an inner furnace wall 2. Each block is provided with a heating element 4 symmetrically between the double walls and a seven-ring 5 on the inner surface of the block.

Although the fan may be located on the top, bottom, or side of each block, the drawings illustrate a furnace with a fan on the top.

The heating element 4 is a conventional heating element such as a nichrome wire or a nonmetallic heating element, and is installed depending on the purpose.

The fan 5 is used to circulate the atmosphere and make the temperature inside the furnace uniform.6 The fan 5 is installed between the outer wall 1 and the inner wall 2 at the upper part of the furnace for each block, and when the fan is operated, the inner wall 2 The atmosphere inside rises from the hole 6 in the upper part of the inner wall, is sucked in by the fan, is exhausted by the fan, and is further formed between the outer wall 1 and the inner wall 2 by the outer wall 1, the inner wall 2, and the alignment plate 3. You will be guided to the space where you will be guided.

The atmosphere then comes into contact with the heating element 4 to be heated and descends, and rises again inside the inner wall 2 through the lower opening 7 of the inner wall 2.

The movable frame 10 is of a cart type, a slide type, a set of rollers, a set of conveyors, etc., and can continuously supply the object to be heated.

Even in furnaces equipped with fans other than the top of each block,
Atmosphere flow will be understood in the same way as above.

However, in such a conventional continuous heating furnace, due to its structure, thermal energy is naturally dissipated to the outside of the furnace along with the object to be heated.

Therefore, conventional continuous heating furnaces have a large loss of thermal energy, and a large amount of energy must be consumed in order to obtain the desired heat treatment effect.

An object of the present invention is to effectively utilize the thermal energy conventionally dissipated from the furnace mouth, thereby achieving energy saving in a continuous heating furnace.

The present invention provides a continuous heating furnace in which a fan is provided on the inner surface of each of a plurality of blocks partitioned by a plurality of baffle plates provided between an outer furnace wall and an inner furnace wall forming a double wall. The continuous heating furnace is characterized in that the air baffle plate is installed at an angle so that the center of the surface opposite to the surface provided with the fan is shifted toward the furnace inlet by an appropriate distance with respect to the center of the surface. .

In the continuous heating furnace of the present invention, a swirling atmosphere flow is formed from the furnace outlet toward the furnace inlet.As a means for this, in the present invention, the air baffle plate is installed at an angle as described above.

According to FIGS. 3 and 4, if one embodiment of the present invention is explained by arranging furnaces equipped with fans on the top surface of each block, the center of the top (fan side) of each block of the continuous heating furnace By tilting the baffle plate 8 so that the center of the lower part (hearth side) is shifted toward the furnace inlet by an appropriate distance l, a swirling atmosphere flow is formed from the furnace outlet toward the furnace inlet.

At this time, the opening 7 of the inner wall 2 is also shifted toward the inlet by the distance l.

As a result, when the atmosphere inside the inner wall 2 exhausted by the 5 fans 5 descends through the space formed between the outer wall 1 and the inner wall 2, it is guided by the inclined air baffle plate 8 and flows diagonally.
A part of it is sucked inward through the opening 7 at the bottom of the inner wall 2 by the fan of the next block adjacent to the furnace inlet side.

As a result of such an atmosphere flow occurring throughout each block of the furnace, a swirling atmosphere flow is formed from the furnace outlet 21 toward the furnace inlet 20.

The flow rate of this swirling atmosphere flow from the furnace outlet to the furnace inlet can be controlled by changing the inclination angle of the air baffle plate, that is, by changing the length of the above-mentioned t, by changing the rotation speed of the fan, and by providing an appropriate shielding plate. Alternatively, it can be changed arbitrarily by changing the size of the air conditioning plate.

Although these factors are interdependent, the preferred t
range is 200 to 500 rran, and the preferred fan speed is 200 to 500 rran. The rotation speed is 500-1200 RPM.

Even when the fan is located at a location other than the top surface, the air regulating plate may be similarly arranged corresponding to the fan location.

When the air baffle plate 8 is installed inside the furnace inner wall 2, the same effect can be obtained by installing the air baffle plate so that the inclination of the air baffle plate is shifted by a distance l toward the furnace outlet side, contrary to the above.

Note that the number of air conditioning plates can be increased according to operating conditions.

FIG. 4 shows a specific example of this case, and shows a continuous heating furnace in which two sets of baffle plates are further installed near the fan.

These cases are naturally included within the scope of the present invention, which is characterized in that a swirling atmosphere flow is created from the furnace outlet toward the furnace inlet.

By passing the swirling atmosphere flow from the furnace outlet to the furnace inlet in this way, two parts of the atmosphere drawn into the furnace from the direction of the furnace outlet exchange heat with the high-temperature material to be heated and store heat. It is used to heat the object by passing through the soaking zone and exchanging heat with the object to be heated at a low temperature again in the heating zone.

Therefore, a considerable amount of the thermal energy conventionally dissipated from the furnace outlet can be returned to the heating zone and used effectively, and the energy required for heat treatment of the object to be heated can be reduced.

The energy saving of the continuous heating furnace according to this invention is a great advantage for the national economy at present when resource shortages are being avoided.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a conventional continuous heating furnace, and FIG. 2 is an enlarged sectional view taken along line A--A in FIG. 1. FIG. 3 is a schematic sectional view showing an embodiment of the continuous heating furnace according to the present invention, and FIG. 4 is a partially enlarged view of FIG. 3. Here, 1 is an outer wall of the furnace, 2 is an inner wall of the furnace, 3 and 8 are baffle plates, 4 is a heating element, 5 is a fan, 7 is an opening, 20 is a furnace inlet, and 21 is a furnace outlet.

Claims (1)

[Claims] 1. In a continuous heating furnace equipped with a fan on the inner surface of each of a plurality of blocks separated by a plurality of baffle plates provided between the outer wall and inner wall of the furnace, which form a double wall, the surface of each block equipped with a fan is A continuous heating furnace characterized in that the air baffle plate is inclined and installed so that the center of the surface opposite to the surface provided with the fan is shifted toward the furnace inlet by an appropriate distance with respect to the center.