JPH04263786A - Operating method of fluidized bed type heating and cleaning furnace - Google Patents

Abstract

PURPOSE:To control the peak value of the amount of organic gas, much amount of which is generated temporarily, when parts, to which organic substance is adhered, are treated in a fluidized bed type heating and cleaning furnace. CONSTITUTION:A fluidized bed type heating and cleaning furnace 1 is operated by a method wherein the supplying amount of gas 6 for fluidized bed is controlled only in an period except a time when parts to be treated are charged and when the same are extracted upon cleaning the parts, to which organic substance is adhered, by heating in the fluidized bed furnace to regulate a heat transfer rate to the parts to be treated and reduce the temperature rise of the parts.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of operating a fluidized bed heating and cleaning furnace.

0002

2. Description of the Related Art Conventionally, a fluidized bed heated cleaning furnace has been used to remove organic substances such as plastics, paints, oils, and solvents adhering to metal parts or ceramic parts. In this case, the treatment material is generally charged into a fluidized bed maintained at 150° C. to 700° C., and the attached organic matter is removed by thermal decomposition or vaporization.

0003

[Problems to be Solved by the Invention] By the way, as mentioned above, the organic matter removal treatment is carried out by charging the organic matter into a high-temperature fluidized bed. Then, as shown in FIG. 4, it immediately thermally decomposes or vaporizes, and a large amount of organic gas (flammable gas) is generated at once. Therefore, the generated gas may burn abnormally in the fluidized bed, causing the furnace temperature to rise rapidly and damaging the processing material or the cleaning furnace itself. Further, the generated gas is incinerated in a gas treatment device (fume incinerator), but since the large amount of gas generated at one time must be incinerated, the gas treatment device not only becomes larger, but also the generated gas Since the amount fluctuates greatly, there have been various problems such as unstable processing of the generated gas. All of the above problems are due to the fact that a large amount of generated gas is generated at once. therefore,
An object of the present invention is to provide a method for operating a fluidized bed heating and cleaning furnace that can solve the above problem by lowering the peak value of the generated gas using a simple method.

0004

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention, when heating and cleaning parts with organic matter adhering to them in a fluidized bed furnace, reduces the amount of fluidizing gas supplied at times other than when charging and extracting materials to be treated. The heat transfer rate to the treated material is controlled only during this period.

[0005]

[Example] Next, the operating method according to the present invention will be explained with reference to the drawings. FIG. 1 shows a fluidized bed heating and cleaning furnace that performs the operating method according to the present invention. 1 is a furnace body formed by a heat insulating layer 2, and fluidized particles 3 such as alumina particles are stored in the furnace body 1. A retort 5 is provided, and a gas dispersion means 6 for blowing out a fluidizing gas, for example, air, is disposed in the lower part of the retort 5. In addition, 7
is a blower driven by the sequence control described below. Further, the furnace body 1 is provided with a burner 8, and the supply amount of combustion air and fuel gas is controlled by a temperature setting device 9 so that the inside of the furnace body 1 reaches a set temperature. .

Furthermore, the exhaust gas outlet 5a provided in the upper part of the retort 5 is connected to the burner 8 side of the furnace body 1 through a pipe 10 having a circulation fan 11, and the exhaust gas is discharged by a cyclone 12 disposed in the middle of the pipe 10. After the fluidized particles 3 inside are removed, the organic gas in the exhaust gas is incinerated within the furnace body 1. In other words, the furnace main body 1 is a gas processing device (
Also serves as a fume incinerator. The gas treatment device may be installed separately from the furnace body 1, but if the furnace body 1 is used for both purposes as in the embodiment, the entire device can be made smaller and the equipment cost can be reduced. can do.

Reference numeral 13 denotes a cooling air jetting plate that blows cooling air from a blower 14 onto the side wall of the retort 5, and controls the amount of cooling air jetted by opening and closing a control valve 16 in response to a signal from a temperature setting device 15. The temperature of the fluidized bed 4 is maintained at a predetermined temperature. Further, 1a is a lid body that opens and closes the upper opening of the retort 5, and this lid body 1a has a
A steam supply pipe 17 is attached to supply steam into the retort 5 to prevent explosions caused by generated organic gas.

[0008] Next, a method of operating the fluidized bed heating and cleaning furnace having the above structure will be explained. First, the fluidized particles 3 in the retort 5 are heated by burning the burner 8, and a fluidizing gas such as air is supplied from the gas dispersion means 6 to form a fluidized bed 4 at a predetermined temperature corresponding to the attached organic matter. Then, the processing material to which organic matter has adhered is charged into the fluidized bed 4 by opening and closing the lid 1a. After charging, for a predetermined period of time, for example, FIG.
The rotation of the blower 7 is slowed down or stopped by sequence control until the temperature range where a large amount of organic gas is generated in (see figure). In other words, it is known that the relationship between the heat transfer coefficient of the fluidizing gas and the fluidized particles in the fluidized bed 4 is such that as the flow rate of the fluidizing gas increases, the heat transfer coefficient rapidly increases, and then decreases after reaching a maximum value. ing. Therefore, immediately after charging the processing material, the supply amount of fluidizing air is reduced or stopped as described above, and the heat transfer coefficient of the fluidized particles 3 is raised more slowly than in the conventional method. The decomposition or vaporization rate is kept lower than that of conventional products, preventing the sudden generation of large amounts of organic gas (see Figure 3).
.

[0009] In the above description, a case has been described in which the supply amount of flowing air is controlled by controlling the rotational speed of the blower 7, but it may also be controlled by adjusting the opening degree of an on-off valve. Further, the organic gas in the exhaust gas discharged from the fluidized bed 4 is incinerated within the furnace body 1, and the organic gas in the exhaust gas discharged from the fluidized bed 4 is incinerated in the retort 5 together with the combustion gas of the burner 8.
is heated and then discharged outside the furnace.

0010

[Effects of the Invention] As is clear from the above explanation, according to the present invention, when a treatment material with organic matter attached is charged into a fluidized bed, the supply amount of fluidizing gas is reduced or stopped. Since the rate of temperature rise of the treated material is reduced to suppress the generation of large amounts of organic gas during this period, the gas treatment device (combustion chamber) can be made smaller than conventional ones. Moreover, since a large amount of organic gas is not generated at a time, the risk of damage due to abnormal combustion of organic gas is reduced accordingly, and organic gas can be processed in a stable state.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a fluidized bed heating and cleaning furnace for carrying out the operating method of the present invention.

FIG. 2 is a diagram showing a supply pattern of fluidizing air.

FIG. 3 is a graph showing the state of organic gas generation when the operating method of the present invention is adopted.

FIG. 4 is a graph showing the state of organic gas generation in a conventional operating method.

[Explanation of symbols]

1 Combustion chamber 4 Fluidized bed 5 Retort 6 Gas dispersion means 7 Blower

Claims (1)

[Claims] Claim 1: When heating and cleaning parts with organic matter attached in a fluidized bed furnace, the supply amount of fluidizing gas is controlled only during periods other than when charging and extracting the processing material to improve the heat transfer rate to the processing material. 1. A method of operating a fluidized bed heating and cleaning furnace, characterized by adjusting.