JPS59500063A - Preheating furnace for long materials - 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] Preheating furnace for long materials The present invention applies to long materials such as bars, ingots, billets and other metal materials. In particular, it relates to a preheating furnace for elongated materials of aluminum or aluminum alloys. preheat Furnaces are made of particularly thin-walled refractory materials, which are joined together or individually removable. It has a furnace tunnel composed of a steel furnace shell, and this furnace tunnel has a burner and a high temperature furnace. configured to be heated by a heating device such as a hot gas nozzle that penetrates the furnace shell; The heating device was carried into this furnace tunnel along the longitudinal direction of the furnace tunnel. By being directed at the material, it heats the material directly. The above preheating furnace can also be used for preheating It has an exhaust gas duct located at the top of the furnace.

In the known preheating furnace of the type described above (West German Patent No. 1.807504) In some cases, a thin-walled furnace shell is incorporated as part of the preheating furnace structure without insulation. There is. Therefore, heat is lost through thermal radiation, particularly from the outer wall of the furnace shell. The exhaust gas is , is sucked into the exhaust gas duct through the slot at the top of the furnace tunnel.

Heat is lost from the furnace tunnel to the exhaust gas duct.

For this reason, known preheating furnaces have low efficiency. Furthermore, the known preheating furnace It is complicated and It's expensive.

The object of the invention, as specified at the beginning of the specification, is to energy can be used more efficiently than before due to its simple and compact structure The purpose is to provide a preheating furnace.

In order to address the above objects, the present invention provides a preheating method as specified at the beginning of the specification. In the furnace, the furnace tunnel is integrated into the exhaust gas duct covered with insulation. Exclusion The insulation of the gas ducts is suitable for keeping the new grain in the furnace tunnel small (at least in its central part It is desirable to cover from the sides. That way, the lower part of the furnace shell can be used for assembly and maintenance of the furnace shell. There is no hassle in either.

According to the invention, energy is utilized very well. The reason for this is that exhaust gas From the furnace tunnel, for example, through the upper gap between multiple furnace shells arranged vertically. This is because the heat is transferred to the exhaust gas duct without losing heat. Advantages of the invention and so that the upper center of the furnace tunnel is separated only by the exhaust gas duct, i.e. insulation without using any means.

The lower part of the furnace tunnel is insulated to facilitate assembly and maintenance. do not have. In the present invention, the amount of heat lost by thermal radiation from the lower part of the furnace shell is relatively small. I discovered that. As mentioned above, removing insulation from the bottom of the furnace shell can cause e.g. assembly consisting of a furnace, support frame for the furnace shell, and a conveyor for preheating the material This has the advantage that there is space left to accept and interact with the aggregate. many.

The insulation material may protrude upwardly from the support frame or may be attached to the furnace shell. It may be shaped to fit on top.

One aspect of the invention is particularly easy to assemble and disassemble; The material is supported by a support member fixed to the support frame of the preheating furnace, and this support having a removable upper insulation member disposed above the member, while a lower part of the insulation The heat insulating member supports the furnace shell from the side and also insulates the furnace shell. do.

According to a preferred embodiment of the invention, lower and upper burner rows are provided around the furnace tunnel. The upper burner row passes through a removable insulation member. , and the lower burner row is located in the lower part of the furnace shell, which is not insulated. death Each insulating member through which the burner penetrates constitutes the furnace shell, and is connected to this insulating member. It has the same length as the opposing block.

If only the bottom burner row is required, these burners should be placed below the insulation. The exhaust gas duct opens into the inside of the furnace tunnel, and the exhaust gas duct is a removable integral structure. Become. If the preheating furnace is configured in this way, it is recommended to replace all or part of the furnace shell. The exhaust gas duct can be removed as a whole for ease of use, especially in the furnace shell. assembly, maintenance or replacement becomes easy.

In modern preheating furnaces of the type described so far, the high-temperature exhaust gas is Pass through a gas duct to the preheating zone of a preheating furnace or other furnace for preheating the material. (West German Patent Application No. 2.637.646). Economical use is guaranteed. Even in these latest types of preheating furnaces, in particular, There are many advantages to the type in which the gas serves to heat the upstream preheating furnace. Upstream preheating The furnace operates through at least one fan and a small fan placed along the material to be preheated. Transport the exhaust gas to at least one row of slotted nozzles and spray this exhaust gas onto the material. It is constructed so that it can be used.

According to the present invention, the inside of the preheating furnace is divided into several heating control zones, and these This is particularly advantageous if the heating control zones communicate through a common exhaust gas duct. many. When the respective heating control zone is closed according to the rated temperature The - heating control zone is connected to other heating control zones even if they are connected by an exhaust gas duct. Not affected by the control zone. All guided gases are routed over a common exhaust gas duct. After passing through the section longitudinally, it is transferred to a preheating zone or used to preheat the material. In order to fully utilize the heat capacity of the fuel, an upstream preheating furnace can be used as described above. It is desirable to transport the The upstream preheating furnace described above has a preheating furnace connected to the downstream furnace. As part of a lamp group consisting of a thermal furnace and multiple preheating furnaces upstream of this preheating furnace. It is positioned as such.

A preferred embodiment of the present invention will be further described based on cross-sectional views of two preheating furnaces implemented. will be explained in detail.

In the drawing, FIG. 1 shows a first embodiment of a preheating furnace according to the present invention, and the line I--I in FIG. FIG.

FIG. 2 is a cross-sectional view of the same location in the second embodiment.

FIG. 3 shows a lamp group consisting of a preheating furnace and an upstream heating furnace according to a modification of the present invention. FIG. 3 is a partially sectional side view.

FIG. 4 shows a group of lights connected upstream having the preheating furnace shown in FIG. 1 or 2. FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3 in the heating furnace.

The illustrated preheating furnace has a support frame 10 made of steel.

A double running conveyor chain 13 is installed in the lower space of the preheating furnace. A heavy conveyor chain 13 conveys a force such as a bar or billet--J. A carrier 12 is added. The above double running conveyor chain 1゜3 is a double running conveyor chain. The material is separated in a cylindrical furnace tunnel 15 made up of several semi-cylindrical furnace shells 14. Push forward intermittently. In their lower part, the furnace shells 14 are mounted on carrier rails 16. It is pivotably supported by a There is.

In the embodiment shown in Figure 1, the longitudinal direction of the furnace is perpendicular to the drawing. A furnace in which a burner row consisting of a plurality of premix burners 18 is arranged in a row. Provided for the shell 14. The burner 18 has a burner nozzle 20, which The burner nozzle 20 is inserted into a cylindrical furnace tunnel through an opening 21 formed in the furnace shell 14. 15 and acts directly on the material. The burner 18 preheats materials with different diameters. When the material surface is well utilized for heat transfer and the temperature gradient is They are arranged so as to be rotationally symmetrical in the cross section. burner nozzle 2o , adjusted to obtain the desired temperature gradient.

Instead of the burner 18, a hot gas nozzle acting directly on the material 1 may also be used. Ma In addition, air heated by known electrical means may be used as the hot gas. Can be done.

Exhaust gas rises from the furnace tunnel 15 and passes through the left and right furnaces at the attachment point of the spacer 17. The exhaust gas pipe passes through the longitudinal slot (30) formed by the shell 14 and passes directly through the vertical passage. This leads to section 32. From this exhaust gas duct 32, the exhaust gas flows into the preheating section for the material 1. (not shown) and, for example, to be sucked by a fan (not shown). It is retained upstream of the preheating furnace. The exhaust gas duct 32 has a heat insulating material. child Among the heat insulating materials, a lower heat insulating member 54 extends over the entire length of the preheating furnace. this The lower heat insulating member 54 is disposed leaving a gap for the furnace tunnel 15 to be disposed. At the same time, it is in contact with the central portion of the furnace shell 14 from the outside. Lower insulation member 54 are supported by carrier beams 52, and these carrier beams 52 are It is fixed on a support frame lo. The main parts of the exhaust gas ducts 3 and 2 are composed of two It is separated by a vertical insulation member 56. Therefore, the upper insulation member 58 of the insulation material is integral with the vertical insulation member 56.

In the embodiment of FIG. 1, both the vertical insulation member 56 and the upper insulation member 58 are connected to the preheating furnace. It extends the entire length. Therefore, these vertical insulation members 56 and the upper section Thermal member 58 can be removed as a unit. The furnace shell 14 has a lower insulation member 54 It is held from the side by However, spacer 17 was removed. Therefore, the furnace shell 14 has a capacity relative to each fulcrum provided on the carrier rail 16. It can be easily pivoted inward and removed separately for replacement.

The above-mentioned heat insulating material is composed of, for example, two layers of heat insulating material. The inner layer has good insulation effect, but , is made of ceramic fiber with poor heat storage effect, while the outer layer is made of ceramic fiber with poor heat storage effect. It is made from mineral fibers.

In addition to the row of burners 18 arranged on the lower side, the embodiment shown in FIG. Only in the point that one row of burners 19 is arranged for each row of furnace shells 14, as shown in FIG. This is different from the embodiment. A throttle valve 24 is provided in the fuel supply line 23, and this The upper burner 19 is adjusted with the lower burner 18 as a reference by the throttle valve 24. Ru.

For the added 190 rows of upper burners, the lower insulation member 54 and the exhaust gas duct It is necessary to position the vertical heat insulating member 59 between the main part of the seat 32 and the main part of the seat 32. Vertical section The heating member 59 is divided into a plurality of parts corresponding to the furnace shell 14. Lower insulation part The material 54 extends over the entire length of the preheating furnace. The main parts of the exhaust gas duct 32 are , has insulating members 60, 62 and 64, and these insulating members 60, 62 and 64 have , are joined together and can therefore be removed as one piece. Furnace shell 14 In order to replace the insulation elements 60, 62 and 64 must be lifted. . Therefore, as in the case of the embodiment shown in FIG. In order to be able to exchange the paired furnace shells 14 by Thermal member 59 must be removed. The embodiment shown in FIG. Although it has a slightly more complicated configuration than the example described above, this makes material 1 more uniform. It is unavoidable in order to heat it all at once.

The right half 90 of FIG. 3 shows the side surface of the preheating furnace shown in FIG. 1 or 2. , the left half of Figure 3 shows the upstream preheater heated by the exhaust gas discharged from the preheating furnace. Shows a thermal furnace. To heat the upstream preheating furnace, the exhaust gas duct 32 The opening 33 opens at the right end surface 34 of the upstream preheating furnace 40 (the third (see figure). Details of the upstream preheating furnace 40 are shown in FIG. Through the opening 33 is connected to the exhaust gas duct 32 and is provided with a heat insulating material 42 similar to the heat insulating material of the preheating furnace 90. Inside the furnace 41, which is protected by Annular zones 47 and 48 are provided. Each circulation zone 47 or 48 has exhaust gas Exhaust gas is sucked from the duct 32 in the direction of arrow F in Fig. 3, and two rows of slot-shaped The material is sprayed through the nozzle 44. The nozzle 44 is configured to converge toward the material. Located on both sides. The material 1 is transported by a double running conveyor chain 13 to each It is sent in the transport direction T inside the processing chamber 45 in the circulation zone 47 or 48. Double above Traveling conveyor chain 13 passes through both preheating furnaces 40 and 90. material 1 is sent in the transport direction T, the exhaust gas is sucked from the processing chamber 45 by the fan 43. It is exhausted and recycled again or discharged through the discharge pipe 46.

In circulation zones 47 and 48, which are continuous from right to left in FIG. A gradually decreasing temperature gradient in the opposite direction to direction T is established. Temperature in each circulation zone The material is inserted in such a way that it can be controlled, similar to this multi-stage exhaust gas guide. It's for the system. Therefore, the heat capacity of the exhaust gas is optimally utilized. There is. Thus, the preheating furnace shown in FIGS. 3 and 4 is particularly economical, i.e. In particular, it is characterized by low heating costs.

IG 1

Claims (1)

[Claims] 1. Long materials, such as bars, ingots, billets and other metal materials, especially A preheating furnace for long materials of aluminum or aluminum alloy, the preheating furnace being , particularly thin-walled refractory furnaces, joined together or individually removable It has a furnace tunnel composed of a shell, and this furnace tunnel is used for the burner and high-temperature gas. configured to be heated by a heating device that penetrates the furnace shell, such as a nozzle, etc. , the heating device is carried into this furnace tunnel along the longitudinal direction of the furnace tunnel. The preheating furnace heats the material directly and heats the material directly. Furthermore, in the case where the exhaust gas duct is installed in the upper part of the preheating furnace, The tunnel (15) is incorporated into the exhaust gas duct (32) having insulation material. A preheating furnace featuring: 2. The preheating furnace according to claim 1, wherein the exhaust gas duct) (32) is disconnected. The heating material flows from at least the outside of the central part of the furnace tunnel (15) into the furnace tunnel (15). 5), which is characterized by covering a plurality of furnace shells (14). 3. The preheating furnace according to claim 1 or 2, wherein the heat insulating material is supported by a support member (52) fixed on the support frame (10) of the furnace; In addition, a removable heat insulating member (54, 56 and 58; 59, 60. 62 and 64), and the lower insulation member (5 4) is characterized in that it laterally supports the furnace shell (14) and insulates it. 4. The preheating furnace according to claim 3, which is placed on the support member (52). The plurality of lower heat insulating members (54) are connected to other heat insulating parts forming the exhaust gas duct. (56 and 58; 59, 60. 62 and 64) can be individually removed. What makes it unique? 5. Claims provided with lower and upper burner rows and arranged around the furnace tunnel. 4. The preheating furnace according to item 3 or 4, wherein the burner (19) in the upper burner row is The burners (18) of the lower burner row penetrate the removable heat insulating member (59) and It is installed in the lower part of the furnace shell, which is not heated, and the burner (19) passes through it. Each heat insulating member (59) has the same length as the corresponding furnace shell among all the furnace shells. characterized by. 6. The preheating furnace according to claims 1 to 4, wherein all rows of burners are disconnected. Below the heating material, it opens into the furnace tunnel (15) and an exhaust gas duct. (32) is constructed as one unit and can be freely removed. 7. A preheating furnace according to one of claims 1 to 5, which comprises: The insulation consists of at least one inner layer of ceramic fibers and at least one outer layer of mineral fibers. % indicates that it contains layers. a. At least one row of strips arranged along the material and blowing exhaust gas onto the material. The rotary nozzle has an upstream pre-stage for transporting the exhaust gas through at least one fan. A group of lamps in which a thermal furnace is heated by the exhaust gas of the preheating furnace according to claims 1 to 7. The exhaust gas duct) (32) is located in the furnace (41) of the preheating furnace (40) in a substantially uniform manner. They are arranged in rows, and a fan (43) is provided inside the furnace, and the inside of the furnace is covered with a heat insulating material ( 42), and furthermore, the exhaust gas duct) (32) is located at its front end (33), characterized in that it opens into the furnace interior (41).