JP2008188575A - Method for carbonizing and reutilizing volatile residue - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for recovering and reutilizing a large amount of coating residue sludge, produced in spray coating or electrodeposition coating as the final finishing of a coating material for the exterior coating for the final finishing of exterior parts such as car bodies or frames in the final step of products in manufacturing plants in automobile industries or consumer electronic industries, without current treatment such as incineration and disposal as industrial wastes, by a carbonization treatment, which can be said to be a technique opposite to incineration and can not only treat the coating material residue safely and harmlessly but also recover and recycle the coating material residue as a useful resource. <P>SOLUTION: The method for reutilizing a coating material residue and a coating material sludge is characterized in that the residue is first primarily dried, for example, in a drying furnace or a horizontal kiln furnace and is then carbonized in a carbonization furnace using a superheated steam of 280°C or above. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, a large amount of paint residue containing titanium and rare metals is generated as sludge in spraying and electrodeposition coating in the painting process performed immediately before the completion of the product in the manufacturing factory of the automobile industry and the home appliance industry. These paint residues are treated as industrial waste sludge, and finally are incinerated or landfilled. However, it is important not to dispose of them wastefully but to treat them safely and harmlessly. The present invention relates to a treatment method for the purpose of utilizing the residue as an effective resource.

  In the final process of products at manufacturing plants in the automobile industry and the household electrical appliance industry, the final finishing of exterior parts such as car bodies and frames is done by spraying exterior paint or by electrodeposition coating. A large amount of paint residue sludge is generated at the time, and the paint residue is used as an effective resource, not to treat it as a current incineration process or industrial waste, but to treat it safely and harmlessly. In order to recover and recycle, we provide a technology to recover and reuse these residual sludge by carbonization treatment, which can be called the opposite technology of incineration.

In the exterior exterior coating process of automobiles and electrical appliances, due to the nature of the painting work, 1/3 to 1/4 of extra paint, i.e., paint residue or paint soot, is generated as sludge during painting. Residual sludge is either directly incinerated in an incinerator or treated as industrial waste, and there is no prior application literature in patent literature or other studies, especially in exterior coatings such as automobiles and home appliances. Spray paint residue and paint sludge, etc., which contain ignitable substances, such as sludge, are temporarily stored in drums, etc., treated with strict and careful safety, and then incinerated with high costs and labor. It is intended to provide technology for recovering and reusing resources that have been treated as industrial wastes as industrial resources. Problem, such as the friction between the international on rare metal trading, now recovery technology of paint residue is an important problem from the viewpoint of valuable resources secured.

The present invention has been made in view of such problems, and its purpose is not to use the paint residue sludge as a waste, but as a means to collect and reuse it as a resource. By using superheated steam below, it is intended to be recovered and reused after carbonization in an environment where there is little risk of explosion or ignition.

The above problems can be solved by the following means.
1. In order to reuse paint residue and paint sludge, as a pre-treatment, first remove the metallic foreign matter with a magnetic separator to remove impurities contained in the paint residue, and then apply the residue to the crusher as much as possible. After pre-processing so that the thermal effect is uniform by adjusting to a certain size,
2. Next, in order to remove moisture from the sludge, primary drying is first performed in a drying furnace or horizontal kiln furnace. The heat source for drying at this time is not only the direct heating of the burner but also the waste heat of the boiler and the waste heat of the superheated furnace. May be used. At this time, the plastic packaging material and organic waste contained in the residue are first vaporized together with moisture at a furnace temperature of about 120 ° C. or more and about 300 ° C.
3. In the carbonization furnace in the next step, first, superheated steam of 280 ° C or higher is blown into the furnace for a certain period of time, so that the oxygen in the furnace becomes minimal and the atmosphere is close to the reducing atmosphere. After at least 200 ° C. or higher, the paint residue sludge after the drying treatment is put into the furnace.
4. By using superheated steam for the heat treatment process at this time, the combustible pyrolysis gas in the carbonization furnace generated by vaporizing the waste plastic system attached to or contained in the paint residue is also superheated steam. Because it is filled with an inert gas body, it can be processed safely without danger of explosion or ignition even at high temperatures.
5. To that end, first, a saturated steam at 100 ° C. is generated by a boiler, and then the superheated steam at 300 ° C. to 800 ° C. is generated by reheating the saturated steam in a superheated furnace (superheated steam generator). The generated superheated steam is blown into a drying furnace or horizontal kiln furnace maintained at a high temperature under the above-mentioned reducing atmosphere, and at the same time, paint sludge is introduced and exposed to the superheated steam in the reducing atmosphere in the furnace for a certain period of time. Carbonization of the residue proceeds.
6. Next, if the temperature in the carbonization furnace is raised from 300 ° C to around 600 ° C, paper and other foreign substances or other organic contaminants will not have oxygen in the furnace, so they will be vaporized or thermally decomposed to the desired paint. Only the residue can be recovered without being oxidized.
7. In order to reduce costs as a drying heat source in the drying process, waste heat from a boiler or the like may be effectively used until the water content of the sludge is about 20%.

1. Carbonization using superheated steam in a reducing atmosphere without throwing away most of the paint residue that has been treated as waste makes it possible to reuse it as a recycled product that hardly deteriorates or as an extender. In addition, the cost required for carbonization can be less than the disposal cost, and not only the cost can be saved, but also the resources can be used effectively, and it has helped to environmental problems such as the global warming problem of incineration.

The carbonization furnace of the present invention and its embodiments will be described with reference to the drawings.
FIG. 1 is an overall flow diagram. FIG. 2 is an explanatory diagram of an embodiment of a vertical batch according to the present invention.

FIG. 2 shows a vertical batch carbonization furnace, which has a structure in which the periphery of the furnace body cavity and the entire inner walls of the upper and bottom surfaces are surrounded by a heat insulating material. About 30 kg of paint residue sludge, which is a product, is divided into six flat bat containers and directly put into the furnace as it is. Since the exhaust gas from the combustion chamber circulates in the drying chamber, the object to be treated is dried and fed into the next lower carbonization chamber. In this embodiment, the hearth is rotated because it is a vertical type instead of a rotary kiln furnace.

After the paint residue sludge with a water content of about 80% is charged in the drying chamber, the drying chamber inlet 7 is closed and the burner switch 1 is turned on. First, the boiler (saturated steam generator) 6 is turned on simultaneously with heating in the furnace. Warm and produce saturated steam. Saturated steam is injected from the superheated steam injection port at the bottom of the carbonization chamber via the serpentine type superheated steam generator 5 installed on the combustion chamber ceiling of the burner. The temperature is raised to 600 ° C. That is, the superheated steam is converted into superheated steam when the saturated steam generated by the boiler 6 (saturated steam generating apparatus) passes through the superheated steam generating apparatus 5 and is jetted into the carbonization chamber 12 from below.

Oxygen in the furnace was expelled by blowing superheated steam into the cavity, and 30 kg of paint residue sludge was carbonized for about 2 hours in an oxygen-free reducing atmosphere and a superheated steam atmosphere in the temperature range of 400 ° C to 500 ° C. As a result, the paint residue sludge charged into the furnace became muddy in the state of about 1 hour on the way, and the result after 2 hours became a fine powdery carbide in smooth powder. In particular, in terms of odor, butyl alcohol, xylene, toluene and the like having a strong odor were thermally decomposed and odorless. In addition, regarding the resulting carbide as a result of carbonization, 30 kg of paint residue sludge was numerically reduced to 1.5 kg and reduced in weight to 0.5%, but the volume was about 1/10. The carbide was stored in a pail as it was.

Amount of kerosene used in the above carbonization demonstration: 7 liters / hour, 14 liters were used for 2 hours.
Temperature of each part: Control by burner heating section 800 ° C 8) Due to the above carbonization Exhaust gas especially abnormal odors and smoke abnormalities are smokeless and odorless exhaust gas, and there is a possibility that it can be carbonized safely and inexpensively Proven.

As described above in detail, the present invention can be used as a recycle product or a virgin extender, safely and inexpensively without disposing of paint sludge that has been treated as an incineration process or a disposal process at a high cost. It is an innovative technology as well as ensuring innovative new resources that can be recovered and recycled as usable carbides, and it contributes greatly to the rise of new industries.

FIG. 1 is a flowchart of the present invention. FIG. 2 is a schematic diagram of the structure after the verification test of the present invention.

Claims (3)

After vaporizing unnecessary substances such as water-soluble organic substances from paint residues and paint sludge containing dangerous substances such as volatile substances with good ignitability that may ignite even at room temperature below 300 ° C, only the effective substances A dry carbonization apparatus characterized by using superheated steam in a treatment process for dry carbonization recovery. Revolving heaters for drying and carbonization with a space that is kept secret from the outside air, boilers for generating saturated steam, and steam generated by the same boiler are reheated to generate superheated steam. And a drying carbonization apparatus characterized in that after the paint sludge having a moisture content of 50% to 95% is dried by the apparatus, it is carbonized and recovered in a reducing atmosphere with superheated steam and reused. 3. The dry carbonization method according to claim 1, wherein superheated steam at a normal pressure of 280 ° C. to 900 ° C. is used in the dry carbonization treatment.

Images