JPH01304916A - Large-sized heating furnace for organic material product - Google Patents

Abstract

PURPOSE:To accelerate the rise time speed of temperature of a product by adding a means for radiating far infrared radiation to a means for jetting hot air to the product during the period of heating the product. CONSTITUTION:In order to accelerate the temperature rise of a product 2, the hot air around 170 deg.C is fed from air supplying ducts 14, 15. The hot air is introduced uniformly into a furnace from the ports provided on an inner wall 5, floor plate 8 and lower ceiling 7, as the result, the air temperature in the furnace rises up uniformly and gradually. While, the inner wall 5, floor plate 8 and the lower ceiling 7 are heated by the hot air passing through a side wall space 10, under floor space 9 and ceiling space 11, and become a temperature of 170 deg.C, after that, extreme infrared radiation is radiated from the furnace inside surface thereof (the inner wall 5, floor plate 8 and the lower ceiling 7 are made of alumite which is a material with a high radiation rate of far infrared radiation). The product 2 is heated by the heat transfer as well as the far infrared radiation, and the temperature rises up rapidly. At the time when the surface of the product 2 becomes approximately to the required temperature of 130 deg.C, the temperature of the hot air is lowered.

Description

[Detailed Description of the Invention] Purpose of the Invention To improve the hot air blowing device in a hot air blowing heating furnace used to heat large products made of organic materials such as plastics or rubber, and to improve heat transfer between the hot air and the surface of the product. The purpose of this is to provide far-infrared radiation from the surrounding furnace material, shorten the rise time for heating up the product, and uniformly heat the entire product.

Problems to be Solved by the Prior Art and the Invention Some products made of organic materials such as plastic or rubber require heat treatment after molding. The large product (hereinafter referred to as the product)
A steam blowing furnace is sometimes used as a large heating furnace for heating. In that case, for example, if the product temperature is raised to about 130℃, the vapor pressure will be 2.
This will require more than atmospheric pressure (gauge). Therefore, a pressure-resistant heating furnace must be used, which requires a large pressure-resistant steam furnace and a large investment in equipment.

For this reason, hot air blown heating furnaces are often used. In this case, the capital investment is small, but because the heat transfer coefficient between the hot air and the product surface is small, the rise time for raising the temperature of the product is long.
It becomes an obstacle to work rationalization and energy saving. Moreover, it is very difficult to operate to uniformly raise the temperature of the entire product.

Means for Solving the Problems The present invention is a large-scale heating furnace using hot air blowing, in which the furnace is structured as described below in order to shorten the temperature rising time of the product and uniformly raise the temperature. be. In other words, the side walls, floor, and ceiling of the furnace are almost entirely double-layered, and the space between the double-layered structures is used as a hot-air passageway, with most of the passageway (
For example, 80 to 90%) is used as an air supply passage, and the remaining part is used as an exhaust passage. The outside of each hot air passage is thermally insulated, and a large number of small holes are uniformly bored in the inner partition wall so that hot air can be uniformly blown into the furnace. The inner partition wall may be made of a material with a high far-infrared emissivity (for example, an alumite plate), or the inner surface of the furnace may be coated with a paint with a high far-infrared emissivity. As a result, far-infrared rays will be abundantly radiated to the product inside,
In addition to heat transfer between hot air and products, far-infrared irradiation accelerates the rise in temperature of products. The air exhausted from the exhaust passage is sent to the air heater, heated, and returned to the furnace in the same manner as in a general heating furnace.

In this way, the hot air enters the furnace uniformly, so there is no unevenness in the temperature inside the furnace, and the inner partition wall of the hot air passage located all over the inside of the furnace has a high temperature equal to that of the hot air, so far infrared rays are abundantly emitted from the inner surface of the partition wall. This radiation is absorbed by the product, increasing the temperature rise.

Example Examples will be described in detail below.

FIG. 1 is a cross-sectional view of the embodiment, and FIG. 2 is a longitudinal cross-sectional view thereof.

In FIGS. 1 and 2, 1 is a heating furnace main body, 2 is a product to be heated, and 3 is a cart for supporting the product.

The heating furnace body l has a double structure as shown in the figure. That is, the side walls have a double structure of an outer wall 4 and an inner wall 5, and the ceiling has an upper tenben 6.
It has a double structure with a lower ceiling 7 and a space 9 under the floorboard 8.
It has a double structure. Spaces with double side wall structure (hereinafter referred to as side wall spaces) 10 and 13. Underfloor space9. The space 11 of the double ceiling structure (hereinafter referred to as ceiling space) is entirely a hot air passage. The side wall space is divided into upper and lower parts by a partition 12, with the lower side wall space 10 serving as a hot air supply passage and the upper side wall space 13 serving as an exhaust passage. Underfloor space9. The ceiling space 11 is used as a hot air supply passage.

The side wall space 10 receives hot air from the air supply duct 14,
Hot air is supplied to the underfloor space 9 from the side wall space 10. Hot air is supplied to the ceiling space 11 from an air supply duct 15. One air heater (not shown) in the supply air duct 14゜15
Hot air is supplied by branching from the A side wall space for exhaust (hereinafter referred to as exhaust space) 13 communicates with an exhaust duct 16, and the air exiting from the exhaust duct 16 is sent to the air heater (not shown) and circulated therein.

Inner wall of side wall space 10 5. The lower ceiling 7 and the floorboard 8 have a large number of small holes uniformly drilled over the entire surface. The situation is shown in Figure 3. FIG. 3 shows a very small portion 21 of the plate, in which small holes 22 are uniformly bored. Also, small holes of appropriate size are made all over the inner wall 17 of the exhaust space 13 so that air can be sucked in evenly.

In this way, the air heated by the air heater passes through the air supply duct) 14.15 to the side wall space 10 and the underfloor space 9. Enter the ceiling space 11, the inner wall 5, the floor plate 8. It uniformly enters the furnace through a small hole in the lower ceiling 7. The air then uniformly passes through the small holes in the inner wall 17 and enters the exhaust space 13, and further passes through the exhaust duct 16 and returns to the air heater. In this way, the air circulates and the inside of the heating furnace 1 is heated. Air circulation is performed by a fan (not shown) provided in the middle of the exhaust duct or the air supply duct.

All parts of the furnace body 1 and ducts that come into contact with the outside air are insulated to reduce heat loss. This situation is shown by thick lines in FIGS. 1 and 2. Also, inner wall5. Floorboard 8. A situation in which hot air uniformly enters the furnace through small holes in the lower ceiling 7 is shown by small arrows 18, and a situation in which hot air is uniformly exhausted from small holes in the inner wall 17 of the exhaust space 13 is shown by small arrows 19.

Also, the inner wall 5. Floorboard 8. Lower ceiling7. The inner wall 17 is made of a material with a high far-infrared emissivity (for example, an alumite plate), or the inside surface of the furnace is coated with a paint with a high far-infrared emissivity so that far-infrared rays can be radiated abundantly.

A product 2 to be heated is placed in a heating furnace 1 on a cart 3. 20 indicates the entrance door. For example, product 2 is vertical and horizontal.

(or diameter) length is approximately 2 to 1 ion, and wall thickness is, for example, approximately 10 to 100 mm.

A case where the product 2 is heated to, for example, 130°C will be explained.

When heating in the above-mentioned heating furnace, it is sufficient to circulate the air with an air circulation fan and heat it with an air heater before feeding it.

Initially, the temperature of the product 2 is room temperature, so to accelerate the temperature rise, hot air of around 170°C is sent from the air supply duct) 14.15.The hot air is sent to the inner wall 5. Floorboard 8. Since the air enters the furnace uniformly through the small holes in the lower ceiling 7, the temperature of the air inside the furnace increases uniformly and sequentially. One-way wall5. Floorboard 8. The lower ceiling 7 is a side wall space 10. Underfloor space9. 170 heated by hot air passing through the ceiling space 11
℃, and the inner surface of the furnace has a high emissivity of far-infrared rays, so far-infrared rays are radiated abundantly. The cart 3 supporting the product 2 has a frame structure so as not to block far infrared rays. Since the far infrared rays penetrate deep from the surface and warm the product 2, the product 2 is heated by the far infrared rays in addition to heat transfer.
Temperature rises rapidly. In particular, it takes a short time for the deep part of the product 2 to reach a predetermined temperature, and when the surface of the product 2 reaches the required 130°C, the temperature of the hot air is lowered to 130°C. Even if the surface of product 2 reaches 130°C, the internal parts do not reach 130°C at the same time, but the temperature of the hot air is increased to 130°C.
If the temperature is kept at 130°C for a suitable period of time, the entire product 2 will reach 130°C. Then, the temperature is maintained at 130° C. for the necessary time to complete the heat treatment.

With this device, the temperature of the product 2 can be increased much faster than with a conventional hot air blowing furnace, and the amount of heat consumed is small, and the entire product 2 is heated without unevenness in temperature, resulting in good results in heat treatment.

Up until now, we have explained that the walls, floor, and ceiling are all double-layered and emit far-infrared rays over the entire surface, but if you do not need such strict uniform temperature, you can partially have a single-layered structure. (for example, omitting the double structure of the ceiling).

In addition, although the exhaust passage 13 has been described as being located at the top of the side wall, it may be located at the bottom of the side wall, on the ceiling, under the floor, or any other convenient location.Furthermore, in the explanation of the embodiment, the heating temperature was set at 130°C, but this may vary depending on the product. It is sufficient to operate at an appropriate temperature each time.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of the present invention, FIG. 2 is a longitudinal cross-sectional view of the same, and FIG. 3 is a plan view of a portion of plate materials constituting the inner wall, floor plate, and lower ceiling of the heating furnace. l... Heating furnace body, 2... Large organic material product, 3...
- Trolley, 4... External wall, 5... Inner wall, 6... Upper heaven valve, 7... Lower ceiling, 8... Floor plate, 9... Underfloor space,
10... Space with side wall double structure, 11... Space with double ceiling structure, 12... Partition, 13... Exhaust passage, 1
4゜15...Air supply duct, 16...Exhaust duct, 1
7...Inner wall, 18.19...Air passage arrow, 20.
...door, 21...part of the board that makes up the inner wall, lower ceiling, and floorboard, 22...small hole drilled in the board. that's all

Claims (1)

[Claims] In hot air blowing heating furnaces used to heat large products made of organic materials such as plastic or rubber, the side walls and
The floor and ceiling are almost entirely double-layered, with most of the double-walled structure serving as an air supply passage and the rest as an exhaust passage, with the exhaust passing through a circulation fan and an air heater into the air supply passage for circulation. A large number of small holes are made almost uniformly in the inner partition wall of the air supply passage and the exhaust passage so that hot air can be uniformly supplied into the furnace and exhausted, and the inner partition wall has a far infrared emissivity. By making the furnace using high-quality materials or by coating the inner surface of the furnace with a paint with high far-infrared emissivity, far-infrared rays can be radiated abundantly inside the furnace, and large organic products inside the furnace can be heated. A large-sized organic material product heating furnace characterized by shortening the temperature rise time to reduce heat consumption and maintaining a uniform temperature of the large-sized organic material product.