JP2012500377A - Heat treatment plant - Google Patents

Abstract

[Solution]
A first processing section for heating a workpiece or medium to be processed to a first processing temperature; a temperature adaptation section for bringing the workpiece or medium to a uniform temperature; and the workpiece or medium to a second processing temperature. A heat treatment plant comprising a second processing section to be transitioned, wherein at least a majority of the temperature adaptation section is uniform with the workpiece or medium transitioning to a uniform temperature substantially by retroreflection of its own thermal radiation. Lined with a reflective material that reflects the heat radiation of the workpiece or medium to maintain temperature.
[Selection] Figure 1

Description

  The present invention relates to a plant for various heat treatments. The heat treatment plant includes a first processing section that heats a workpiece or medium to be processed to a first processing temperature, a temperature adaptation section that provides a uniform temperature for the workpiece or medium, and a second workpiece or medium. And a second processing section for transitioning to the processing temperature.

  Furnace with a temperature-adaptive section has been used in the oldest kind of production plant in the history of technology and has been refurbished many times over the centuries. In many “classical” production methods, such as the production of ceramic and glass products, and metallurgy, products that are manufactured or processed at high temperatures to give specific properties, in particular special material structures, It is important to maintain at a low temperature for a predetermined period before reheating if necessary, or before cooling in a shorter time.

  Previous development has often focused on increasing productivity and tailoring parameters to the special quality requirements of the product being produced. However, especially in the last few decades, increasing energy efficiency has also been a reason for the development of plants and methods.

  In addition to keeping the temperature profile constant, this wall is often made thicker to increase energy efficiency by avoiding significant heat loss in the post-processing section walls of common types of furnaces. If appropriate, a material having a high heat resistance and / or a large heat capacity is used as a construction material. This increases the “thermal mass” during construction. Such a construction business is expensive because of the large amount of materials used and at the same time the cost is high, and since the thermal mass is large, a high time constant is required for control.

  In view of the foregoing, it is an object of the present invention to provide an improved plant of the type described above, to provide a plant that is cost effective for construction and easy to control, and to provide a corresponding method. .

  The object is achieved by a plant having the features of claim 1 and a method having the features of claim 11. Useful improvements of the subject matter of the invention are described in the dependent claims.

  With respect to energetically separating the temperature adaptation section from its upstream and downstream sections, the present invention essentially abandons the traditionally prioritized thermal insulation for workpiece temperature adaptation. Take advantage of reflections from the walls into the interior of the temperature adaptation section. The invention further includes coating a large portion of the section with a material with optimized reflective properties (hereinafter also referred to as a lining).

  As used herein, “workpiece” means any solid processing object. In other words, it means not only individual parts, but also, for example, a wire-like or strip-like material or compound material that extends substantially infinitely. In addition, “medium” is particularly used to mean a paste-like or liquid-like treatment object, and in some cases, means a gaseous treatment object or a treatment object material having free flow. To do.

  The solution proposed here has significant technical and economic advantages compared to conventional furnace structures. First, a technical explanation will be given of what results directly from abandoning the majority of the thermal mass. Abandonment of the majority of the thermal mass is made possible by the solution proposed here, i.e. by allowing the temperature to be controlled rapidly in the temperature control chamber. However, those skilled in the art will appreciate that the above advantages also include problems. As thermal mass is reduced, temperature stability with respect to changes in the temperature of the workpiece or the surrounding environment is reduced, so high speed control is not only possible, but is required if there is a high demand for temperature stability. However, today, high-speed control is not a problem with the latest processing control system including a sensor and an actuator capable of high-speed operation, and can be easily realized from the viewpoint of cost.

  In this specification, a “thermally lightweight” configuration is proposed for the post-processing section and the temperature control chamber associated therewith. However, by adopting such a configuration, a mechanically lightweight configuration can be obtained. Therefore, the raw materials used and the construction cost are relatively small. Further, the mechanically light-weighted configuration also provides an advantage that assembly and disassembly can be performed in a short time, and the producer can immediately respond to the customer's request. The refurbishment of a conventional furnace may take weeks or months, but the construction of the post-processing section of the plant according to the invention is basically completed in a few days (although of course depending on the size) It is possible to make it.

  The temperature adaptation section of the plant proposed here can basically omit the active heater or, according to a preferred embodiment, the active heater only in a small area of the temperature control chamber. Is provided. Compared to a plant with at least a post-processing section and a temperature-adaptive section where heat utilization efficiency from the workpiece is low, construction and operating costs are further reduced.

  As mentioned above, the furnace proposed here is sensitive to temperature changes caused by heat being supplied from the workpiece to the post-processing section or the surrounding environment. Thus, according to a preferred embodiment, the temperature control chamber is provided with a low power control heater to correct the temperature. The maximum output of the heater is at least an order of magnitude less than the heating output required to achieve a uniform temperature or uniform temperature range.

  Since the control heater needs to be dimensioned to accommodate only expected temperature fluctuations, implementing it also increases cost efficiency. Considering the functions specific to the control heater, it is important to respond quickly and finely adjust in order to meet the demands of each user. In this regard, it is preferable that the above-described active heater or control heater performs temperature control with substantially no inertia.

  According to a useful refinement of the inventive idea, furthermore, the heating in which the first and / or second processing section has an active heater and the majority of the inner wall is lined with a reflective sheet material. Having a furnace chamber; Specifically, such a configuration allows the furnace chamber to be thermally insulated at least mostly by a reflective sheet material. Optionally, thermal insulation is facilitated by a cooling gas flow that flows along the reflective sheet material. In other words, the “insulation principle” that is fundamental to the construction of the temperature adaptation section is also applied to at least one of the main processing sections and the corresponding furnace chamber.

  As a reminder, cooling with any air or gas flow may be used in the temperature adaptation section if necessary. In particular, such a configuration requires that the temperature of the outer surface of the temperature adaptation section be kept below a predetermined temperature limit based on the predetermined safety requirements, which limits the reflection characteristics of the wall. This is a case that cannot be achieved simply by optimization. Specifically, a gas circulation cooling system may be provided that generates a cooling gas flow and flows along the back surface of the lining material, and flows over the workpiece surface after the gas is heated.

  According to another preferred embodiment of the invention, the heaters of the first and / or second processing section and / or the optional temperature adaptation section heater are a near infrared (NIR) radiant heater or infrared ( IR) radiation heater is included. Heating furnaces equipped with IR or NIR emitters are already known techniques and are used in related industrial fields. In particular, such a system has been developed and provided by the Applicant and is the subject of earlier applications filed by the Applicant for the purpose of protecting the rights. For this reason, a more detailed description of the above-mentioned type of heating element and its incorporation into the latest heat treatment plant will be omitted.

  According to one embodiment of the present invention, the above-described material for coating or lining the temperature control chamber is a highly reflective sheet-like composite material having a reflectivity of 97 on a sheet-like metal substrate. More than 5% coating, on which a corrosion-resistant coating made of transparent oxide or glass is provided. Specifically, the substrate constituting the sheet-like composite material having very high reflectivity may be formed of aluminum, an aluminum alloy, stainless steel, or ceramics. The coating may be substantially formed from very high purity aluminum or silver having a purity of 99.99% or higher. In particular, if the solution proposed herein is utilized in ultra-high temperature processing, according to one embodiment, the reflectivity is very high to prevent the outer surface or lining of the temperature control chamber from overheating and deforming. The back surface of the highly sheet-like composite material is dark, particularly black, for the purpose of improving heat radiation.

  According to embodiments of the present invention, it is also advantageous to optically close the temperature adaptation section and, optionally, the furnace chamber in almost all respects, as long as it is feasible with respect to the furnace attachment / detachment process. can get. By adopting such a configuration, it may be appropriate to use the locking means on the input side and / or the output side. For this reason, it is preferable to minimize the dimension of the opening for attachment / detachment.

  In connection with the above, it may be more reasonable for the temperature control chamber to have an inlet area and an outlet area through which the workpiece or medium to be processed passes. Optical density means may be provided in the entrance area and the exit area so that heat does not leak. Specifically, the optical density means includes inlet and / or outlet bevels or curved surfaces that are at least partially coated with a reflective material. More specifically, the inlet and / or outlet slope may be provided with adjusting means for adjusting the inclination angle, and the inlet and / or outlet slope is divided into a plurality of portions, each of which has an inclination angle. May be different and optionally separately adjustable.

  Furthermore, it has been mentioned above that the reflective material that reflects the supplied heat basically forms only the walls of the temperature control chamber, without the addition of a heat retaining outer wall and / or an insulating outer wall. Such a configuration is obtained by, for example, shaping a reflective material, particularly a highly reflective composite material into a sheet shape or a plate shape according to a predetermined outer shape of the temperature control chamber, and forming a sheet shape or a plate on the support structure. It may be realized by suspending or stretching a plate-like highly reflective composite material.

  However, according to another embodiment, specifically, the sheet-like reflective material mounted on the support structure is provided in front of the outer wall of the temperature control chamber and / or in front of the outer wall of the furnace chamber. Are spaced apart by a distance of. This embodiment is particularly effective when a conventional heating furnace configuration is modernized by applying the present invention, or at least when the conventional configuration principle and parts are used. Furthermore, this embodiment is useful when a “huge” outer wall is desired depending on the circumstances specific to each application.

  According to a first practical application, the heat treatment plant is configured to perform heat treatment and / or drying and hardening treatments on rolled steel products, in particular coil coatings. According to another practical application, the heat treatment plant is characterized in that it is configured to thermally temper and / or dry and cure the coating of plastic or ceramic products.

  According to a method of using a heat treatment plant according to another important embodiment of the present invention, the paint coating on the substrate is dried and cured. Finally, without mentioning whether the examples mentioned are sufficient, we will describe the generation or acceleration of chemical reaction processes by heat in the workpiece or medium, especially in the fluid flowing through the furnace. .

  The residence time of the workpiece to be adapted in the temperature adaptation section, or one point of material that continues indefinitely, or one point of the media, of course, is uniform to reach the first processing temperature. It depends on the relationship with temperature, transport speed, heat radiation capacity, and other factors. According to a useful embodiment of the invention, it is between 0.5 and 10 seconds, in particular between 1 and 5 seconds.

Advantages and usefulness of the present invention will become apparent by referring to the description of embodiments described below in conjunction with the drawings. The drawings are as follows.
It is a schematic longitudinal cross-sectional view which shows the plant which concerns on the 1st Embodiment of this invention. It is a schematic longitudinal cross-sectional view which shows the plant which concerns on the 2nd Embodiment of this invention.

  FIG. 1 is a diagram showing a heat treatment plant 1. The heat treatment plant 1 is built on a stand 3 and includes an outer wall 5. The upper part of the outer wall is cooled by a gas flow 7 flowing between the outer wall and the inner wall 9. Above the bottom 5a of the heat treatment plant, a transport channel 11 is provided at a position separated by a certain distance. In the transport channel 11, the bulk material 13 to be processed is transported in the direction indicated by the arrow A.

  The heat treatment plant 1 includes a first treatment section 1A having a first treatment temperature PT1, a temperature adaptation section 1B that maintains the temperature of the bulk material 13 as a uniform temperature TX, and a predetermined temperature, and a second treatment. And a second processing section 1C that maintains the temperature as the temperature PT2. In the first processing section, a plurality of NIR radiators 15, each of which is associated with a reflector 15 a, are provided below the upper inner wall 9 and are arranged in the direction of the bulk material 13. The temperature adaptation section has a planar reflector 17 disposed below the inner wall (ceiling 9), and the second processing section 1C has a conventional IR radiator that emits medium and long wavelength infrared radiation. A plurality of 19 are provided.

  The reflector 17 provided in the temperature adaptation section 1B has a multilayer structure, and includes a ceramic support plate 17a, a highly reflective Ag coating 17b, and a glass corrosion-resistant coating 17c. For convenience of illustration, the reflector is not shown in the actual size. In addition to the reflector 17, two low power NIR radiators 21 are provided in the temperature adaptation section to fine tune the uniform temperature TX.

  FIG. 2 is a diagram illustrating a multi-stage heat treatment plant 101 that individually processes a plurality of workpieces. A part of the structure of the heat treatment plant is the same as that of the heat treatment plant 1 shown in FIG. 1, and reference numerals are assigned according to those of FIG. 1, and description of common parts is omitted.

  Similar to the heat treatment plant 1 shown in FIG. 1, the heat treatment plant 101 has a uniform temperature TX * as a whole with the first treatment section 101A of the first treatment temperature PT1 *, or the uniform temperature TX *. Is provided with a temperature adaptation section 101B that is being adapted to a second processing section 101C with a second processing temperature PT2 *. The workpiece 113 is transported in the heat treatment plant in the direction indicated by the arrow A * on the conveyor belt 111, and a two-stage process is performed with temperature equalization in between.

  Similarly, the first processing section 101A includes a plurality of NIR radiators 115 each associated with a reflector 115a for the purpose of rapidly heating the surface of the workpiece and performing heat treatment. Is provided. A cooling zone having a spray nozzle 118 is formed in the second processing section 101C. The spray nozzle 118 injects coolant onto the workpiece 113 to cool the workpiece 113 to the second processing temperature.

  In the heat treatment plant 101, sections 101A, 101B, and 101C have separate housings 105A, 105B, and 105C, respectively. In the heat treatment plant, only the bottom surface 105a is continuous. A reflective coating 117 is provided inside the central housing 105B, reflecting most of the heat radiation of the workpiece 113 conveyed from the first processing section 101A without adding any heating means. It can be adapted to the uniform temperature TX * (similar to the heat treatment plant 1 of FIG. 1 without a control heater).

  The embodiments of the present invention are not limited to the above-described aspects and embodiments, and a plurality of modifications can be conceived with the ability of those skilled in the art. In particular, the features recited in the claims can be combined in various ways to the extent technically possible, and all possible combinations are intended to be included within the scope of protection of the present invention.

Claims (15)

A first processing section for heating a workpiece or medium to be processed to a first processing temperature;
A temperature-adaptive section for bringing the workpiece or the medium to a uniform temperature;
A second processing section for transitioning the workpiece or the medium to a second processing temperature;
At least a majority of the temperature adaptation section is such that the workpiece or the medium transitions to and maintains the uniform temperature substantially by retroreflection of its own thermal radiation. A heat treatment plant lined with a reflective material that reflects the heat radiation of the medium.   The temperature-adaptive section is substantially realized by one of the absence of additional insulation means and the use of a material with a heat capacity, which is mainly achieved by the reflective material. The heat treatment plant according to claim 1.   The heat treatment plant according to claim 1, wherein the reflective material is mounted on a support structure, and is disposed in front of an outer wall of the temperature adaptation section and separated by a predetermined distance.   The heat treatment plant according to any one of claims 1 to 3, wherein the reflective material includes a plate made of aluminum or stainless steel, or a plate made of ceramics.   The reflective material is provided with a coating having a reflectance of 97.5% or more on a sheet-like metal substrate or ceramic substrate, and the corrosion resistance formed from a transparent oxide or glass on the coating. The heat treatment plant according to any one of claims 1 to 4, wherein a coating is provided.   2. An active heater disposed only in a small region of the temperature adaptation section and at least one of a low output control heater intended only for temperature correction is disposed. The heat treatment plant according to claim 5.   The heat treatment plant according to claim 6, wherein the heater includes an IR radiation heater or an NIR radiation heater.   The heat treatment plant according to claim 6 or 7, wherein the active heater performs temperature control with substantially no inertia.   The temperature adaptation section is provided with an inlet region and an outlet region, and the inlet region and the outlet region are provided with optical density means so that heat does not leak. The heat treatment plant according to any one of claims 1 to 8, comprising a slope or a curved surface of at least one of an inlet and an outlet, which is coated with the reflective material. The temperature adaptation section, and optionally at least one of the first processing section and the second processing section comprises a gas circulation cooling system;
The gas circulation cooling system generates a cooling gas stream to flow along the back surface of the temperature adaptation section and optionally at least one of the first processing section and the second processing section. Then, after the cooling gas is heated, the heat treatment plant according to any one of claims 1 to 9, which flows on the surface of the workpiece or the medium. A method of heat treating a workpiece or a medium, comprising:
The workpiece or the medium is heated to a first processing temperature in a first processing section, brought to a uniform temperature in a temperature adaptation section, transitioned to a second processing temperature in a second processing section, and Processed at the second processing temperature;
Transitioning the workpiece or the medium to the uniform temperature and, if necessary, maintaining the workpiece or the medium at the uniform temperature substantially includes a first processing section and a second processing section. A method realized only by the retroreflection of the radiation characteristic of the reflecting wall of the temperature adaptation section which is arranged between the processing section.   The method according to claim 11 realized as at least one of a method of thermally tempering a coating of a plastic product or a ceramic product and a method of drying and curing.   12. The method of claim 11 realized as a method of drying and curing a primer or paint coating on a metal substrate.   12. The method of claim 11, realized as a method of generating or accelerating a chemical reaction process by heat in the workpiece or the medium.   15. The work piece or the medium according to any one of claims 11 to 14, wherein the workpiece or the medium resides in the temperature adaptation section for a period of 0.5 to 10 seconds, in particular for a period of 1 to 5 seconds. The method described.

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