JPS58200988A - Method of promoting heating and heating furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for heating objects to be heated in a heating chamber with a wide gas core and a trowel. This article relates to a heat transfer promotion method that completely improves heating efficiency by radiation.

Improving thermal efficiency has always been considered since ancient times, and recently, as general energy conservation issues have been widely discussed, interest and demand for effective use of heat have become particularly strong.

In order to improve the thermal efficiency of a heating furnace, efforts are being made to reduce the amount of heat dissipated from the furnace zone, entrances and exits of objects to be heated, etc., reduce heat loss due to exhaust gas, and recover such heat.

Increasing the amount of heat transferred to the heated object in the heating furnace directly contributes to one of the main purposes of the heating furnace.

There are three modes of heat transfer: conduction, convection, and radiation, which are the most effective since the M degree of the exhaust gas is also lowered, but convection heat transfer is predominant in the heat transfer of fluids, especially gases. This is because general fluids have low thermal conductivity, so conductive heat transfer is smaller than convective heat transfer, and fluids have a small emissivity when radiating heat, so radiant heat transfer is smaller than convective heat transfer.

However, in general, in systems containing high-temperature objects, radiation heat transfer often contributes to a larger proportion of the total heat transfer than convective heat transfer, and radiation accounts for more than 90% of the total. This is normal for heat transfer due to

Therefore, even in systems containing fluids, even if ′! In the case of heat transfer from combustion gas to the heated object, there are examples in which the rate of radiation heat transfer is greatly increased compared to convective heat transfer by increasing the effective gas thickness by increasing the inner volume of the furnace. There are fluids such as dried air that have very little emissivity, and there are cases where it is difficult to use radiation heat transfer, which is originally the most effective method for heat transfer at high temperatures.

Furthermore, when designing a heating furnace to improve radiation heat transfer efficiency, it may not be possible to obtain an appropriate effect due to the shape and size of the object to be heated, the structure of the furnace, and the positional relationship on the object.

Therefore, in such heat transfer, a third object as a radiator is interposed in the heat transfer system such as high-temperature exhaust gas, and heat transfer between the fluid and the object is performed mainly by convective heat transfer, and the heat transfer between the object and the heated object is performed mainly by convection heat transfer. A heat transfer method is known in which the heat transfer area of the system is apparently increased by performing heat transfer by radiation heat transfer. This method takes advantage of the fact that the fluid has a fairly high permeability.

An example of this is a commonly used heating furnace 4, which uses a furnace chamber as a third object to promote heat transfer between the exhaust gas and the object to be heated. To make this phenomenon more active, as mentioned above, a radiator is provided as a third object apart from the high-temperature gas flow, generally the furnace zone 2.

As the radiator in this case, generally known are objects having a large number of pores, objects made of bundled thin wires, wire meshes, and other objects having appropriate air permeability.

It has been confirmed that the intervention of such a radiator is effective in improving the heat transfer efficiency of the system, and its active use will attract attention in the future.

In view of these points, the inventors of the present invention have conducted various studies and studies on the use of radiators, and have made improvements up to the present.The present invention was discovered as part of this effort. This has succeeded in further increasing the heat transfer efficiency.

That is, the present invention is a heating acceleration method in which a radiator is provided in a high-temperature gas flow path and a radiator facing the object is provided in a high-temperature gas flow path, and the radiator is moved. This article focuses on a heating furnace that enables heating.

The purpose of the present invention is to significantly increase the heating efficiency of the radiant because the heat transfer rate by gas is extremely low among the heating that the radiator receives by convection and radiation heat transfer from high-temperature gas (combustion gas). Promote heat transfer to the radiant by improving the convection heat transfer effect that has been inhibited.
It is necessary to fully demonstrate the effect.

There are various types of heating furnaces to which the heating method of the present invention can be applied; examples include Y industrial furnaces (glass, ceramics, cement, etc.), metal furnaces (steel, non-ferrous metals, etc.), and garbage incinerators. It is a furnace used to give heat to an object to be heated, such as a generation furnace, or it may be a furnace in which the object to be heated itself generates heat, such as a generation furnace.

Furthermore, since the present invention effectively utilizes radiation heat transfer, it is most suitable for heating using a high temperature gas, for example, 1000° C. or higher, or melting gas as a heat source.

In a preferred single-deaf mode according to the present invention, the heat transfer area of the surface of the radiator facing the object to be heated is made as large as possible, and power is distributed so as to exhibit the radiation effect. The arrangement with respect to the flow direction of the high temperature gas is as follows.

In other words, the radiator is placed parallel to the flow direction of the high-temperature gas as will be described later, so that the influence of the movement of the radiator on the gas flow is minimized, and the turbulence of the gas flow is minimized. The idea is to make the radiant move so that it does.

In a further preferred embodiment, the radiator +17. l: Purpose of writing (・To make people move in unison, i' v4) 1411
') is to use a rod-shaped body as a radiator.

The present invention will be explained below with reference to the drawings.

FIG. 1 shows an example of a typical conventional heating furnace, in which a combustion burner is installed and high temperature combustion gas is sent to a heating chamber 2 and circulates in the direction of arrow A within the heating chamber. Inside the heating chamber 2, there is a heated object 3, such as a brick (ceramic),
Glass, metal, etc. are accommodated and transferred through the heating furnace by conveyor rolls 4.

Here, the object to be heated 3 is heated mainly by the flame radiation of the 4ii gas and the solid radiation through the furnace wall 5, but by distributing the radiator 6 to an appropriate potential in the heating chamber It is possible to improve radiation efficiency.

The present invention is an improvement in a heating furnace using a radiator as described above, and FIG. 2 shows a typical series thereof.

In Fig. 2, Q' is provided inside the heating chamber 2! ″L/CI,
Heated object 5 such as 1lIQ1L/CI, 1lIQ1 body 6
When υ0 heats up, for example, it rotates in the direction of arrow B. Here, the high-temperature gas flows approximately in the direction of arrow C from the burner port, passes through the flow channel 8 of the partition plate 7 provided at the upper part of the heating chamber, passes through the flue 9 formed between the furnace wall and the partition plate, and flows in the direction of arrow A. It will be distributed.

The usage of the radiator 6 will be explained with further reference to FIG. 3. The radiator 6 is provided in the heating chamber 2 in two stages, upper and lower, and covers almost the entire widthwise area.

This movement of the radiator is easily possible by extending the drive shaft 10 to the outside of the furnace wall νζ and connecting it to the motor 11.

A specific shape of a radiator suitable for use in the embodiment shown in FIG. 2 will be described with reference to FIGS. 4 and 5.

As shown in FIG. 4, the drive shaft 10, which itself has a radiation function, has a plurality of approximately disk-shaped radiating plates 12 formed in parallel in the axial direction, and the outer periphery of the radiating plates 12 is provided with a sandy cut. Designed to further improve radiant heat transfer.

FIG. 5 is similar to FIG. 4, but instead of forming a radiant radiator 12, a large number of rod-like bodies 13 are attached to the disk.

Each of these radiators 6 has a large contact area with the high-temperature gas and has a large radiation effect on the heated object, and even when rotated to increase the convection heat transfer effect during heating, the flow of the high-temperature gas is greatly increased. This is a very advantageous implementation without any disturbance.

That is, since the radiator 6 is arranged parallel to the gas flow direction, it is less likely to inhibit the flow from becoming circular.

Here, when the radiator (the drive shaft, plate-shaped body, rod-shaped body, etc. that constitute the radiator, and their assembly) is parallel to the gas flow, it means that the radiator and its constituent parts face each other in the direction of gas flow. This means that the area should be as small as possible compared to the area facing the oil pressure direction, or in other words, the gas flow should not be cut off as much as possible.

In Figures 4 and 5, arranging the projector so that the gas flow direction is 1°K from the drive axis greatly increases the gas flow with the radiation plate 12. Although this is not preferable as it may cause interference (cutting), such a problem can be avoided even if the arrangement shown in FIG. 5 is similar. In other words, the use of a radiator consisting of a rod-shaped body and an assembly thereof as shown in Fig. 5 provides resistance to gas flow regardless of the direction of gas flow (no matter how it is arranged in the direction of gas flow). It is the most advantageous radiator because it has as little as possible.

FIG. 6 shows another example of application, in which a radiator 6 as shown in FIG. This is a book in which the heating element is rotated in the direction of arrow B during heating.

Even in this case, the radiator 6 is in a +r plane parallel chain position with respect to the flow direction of the gas, so this is a preferred embodiment.

FIG. 7 shows another example of application, in which power is distributed within the heating furnace (chamber) 2 by hanging the radiator 6 through the ceiling portion 5, which is the furnace wall.

As a specific embodiment of the hanging type radiator 6 as shown in FIG. 7, those shown in FIGS. 8 and 9 are suitable.

@ In both Figures 8 and 9, the drive shaft 10 also serves as a hanging bolt.
and a plurality of rod-shaped bodies 13 or plate-shaped bodies 13', and it is appropriate to use them properly depending on the direction of gas flow.

In the present invention, the means for imparting motion to the radiator is generally preferably carried out via a drive shaft connected to a drive source provided outside the heating furnace (chamber), but gas If the flow velocity is relatively high, the radiator can be structured so that it can be moved by the gas flow without applying external force, but the relative velocity between the radiator and the gas flow will be delayed. Therefore, the effect other than the special chirping is small.

In the present invention, it is difficult to determine how effectively the radiators should be interlocked in terms of wind and air, but it is complicated due to complex factors such as the design of the caloric furnace, operating conditions, the amount of material to be heated, and the structure and shape of the arranged radiators. However, in the examples of using radiators as shown in Figures 4, 115, 8, and 9, the rotation speed of the drive shaft is 50 to 500 rpm.
, α5~b seems to be obtained as the circumferential speed.

Furthermore, the material of the radiator used in the present invention is 100%
It needs to be durable enough to be used in a heating furnace that handles high-temperature gases such as 0° C. or higher, and is preferably made of ceramics. Specifically, it is selected from materials that can be easily obtained as a sintered body having high heat resistance, high strength, and a relatively small coefficient of thermal expansion, such as cordierite, zircon, zirconia, mullite, alumina, aluminum titanate, silicon nitride, and silicon carbide. It is better to do so.

As described above, in the heating method and heating furnace of the present invention, a radiant is provided in the heating furnace (chamber) using high-temperature gas and is moved toward the object to be heated.
The convection heat transfer between the high-temperature gas and the radiant is promoted, and the heat absorption of the radiant increases accordingly.As a result, the radiant enhancer fully demonstrates the effect of improving radiation efficiency, and has achieved great success. It is expected to improve heat transfer efficiency by up to 50% in various heating furnaces, depending on the conditions, and its industrial value is great.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of a conventional heating furnace, Fig. 2 is a sectional view of the main part of a heating furnace showing an embodiment of the present invention, and Fig. 3 is a cross-sectional view showing an example of a conventional heating furnace. FIGS. 4 and 5 are perspective views showing embodiments of the radiator used in the present invention, and FIGS. 8 and 9 are perspective views showing other embodiments of the radiator used in the present invention. In the drawings, 2 is a heating chamber (furnace), and 5 is a tortoise. Reference numeral 5 denotes a furnace wall, 6 a radiator, 10 a drive shaft, and 12 and 13 a radiant plate-like body and a radiant rod-like body constituting the radiator, respectively. -1'7)! 1 1', J)￥I 2nd year old

Claims (1)

[Claims] 1. In a method of heating an object with high-temperature gas,
1. A method for promoting heating, comprising providing an object to be heated and a radiator facing the object in a high-temperature gas flow path, and causing the radiator to move. 2. The method according to claim ta1, wherein the radiant is moved to increase convective heat transfer from the high temperature gas to the radiant, thereby enhancing the radiation effect from the radiator to the object to be heated. 5. The method according to claim 1 or 2, wherein the radiator is provided parallel to the flow direction of the high-temperature gas, and the MJ is moved so that the resistance given to the gas flow is as small as possible. 4. The method as set forth in claim 51, wherein the projectile is caused to move so that the resistance exerted on the gas flow is as small as possible, regardless of the direction of the gas flow. 5. A method according to claims 1 to 41, in which the radiator is rod-shaped or a combination thereof. 6. The method according to any one of claims 1 to 5, wherein the radiator is made of ceramics. 7. Method 8 above (from claim 6), in which the radiator is moved by a drive source provided outside the gas flow path. 8. A heating furnace for an object to be heated, characterized in that a radiator is provided in the high-temperature gas in the furnace, facing the object to be heated, and a drive mechanism for moving the radiator is attached to the radiator. ? The heating furnace according to claim 8, wherein the radiator is arranged parallel to the flow direction of the gas. 10. The heating furnace according to claim 8 or 9, wherein a rod-shaped body or a combination thereof is used as the radiator.