JP2009011889A - Exhaust gas deodorization treatment system for coating drying furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust gas deodorization treatment system for a coating drying furnace by means of a room temperature treating (oxidizing ) high in atmospheric warming prevention effect and safety by minimizing the discharge of CO<SB>2</SB>and VOC. <P>SOLUTION: The deodorization treatment system comprises: a first treatment of cooling and water-solubilizing the exhaust gas from the coating drying furnace by spraying water mist in a tar removing filter 1 and collecting tar and gas by the filter; a second treatment of dehumidifying water-soluble moisture treated in the first treatment in a dehumidifying unit 2; a third treatment of removing the tar particles and smoke in the gas dehumidified in the second treatment by an electrostatic precipitator 3; and a fourth treatment of decomposing malodor components in the gas treated in the third treatment 3 and deodorizing by a photocatalytic deodorizing apparatus 4 to reduce CO<SB>2</SB>and VOC. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a deodorizing treatment system for malodorous gas discharged from a paint drying furnace.

  In order to deodorize odorous gases emitted from the drying furnace for automobile bodies and other painted products, direct combustion deodorizers and regenerative deodorizers are the mainstream, and high temperature combustion (750 ° C to 850 ° C) is used to oxidize and decompose odors. (Deodorized).

  In the above conventional deodorization treatment, the energy (fuel) cost required for combustion is enormous, maintenance is difficult in the painting process of the equipment due to high temperature combustion, and there are concerns about safety during maintenance, In addition, it is expensive. In addition, air pollution related to suspended particulate matter and photochemical oxidants is serious, and one of the causes of suspended particulate matter and photochemical oxidants is the volatility of organic compounds that become gases in the atmosphere. It is necessary to suppress emission of the volatile organic compound (VOC), which is a generic name. The exhaust gas of the paint drying furnace contains volatile organic compounds (VOC) of toluene and xylene, and it is necessary to suppress the emission thereof.

Today, global warming prevention measures have become an important issue, and there has been a problem in the automobile industry and related industries where there is no deodorization method that should replace the high-temperature combustion method that emits a large amount of CO2.
JP 2001-310150 A JP 2002-331223 A Japanese Patent Laid-Open No. 7-8746

  An object of the present invention is to provide an exhaust gas deodorization treatment system for a coating drying furnace by room temperature treatment (oxidation) with high safety and prevention of atmospheric warming while minimizing CO2 and VOC emissions.

  In order to achieve the above object, according to the present invention, the exhaust gas of the coating drying furnace is cooled and water-soluble by mist spraying of water with a filter for removing paint and trapping the gas and gas with the filter. A first treatment, a second treatment for dehumidifying the first treated water-soluble moisture by a dehumidifying unit, and a third for removing dust particles and smoke in the gas dehumidified by the second treatment by an electric dust collector. The third treatment gas is subjected to a fourth treatment for decomposing and deodorizing odor components by a photocatalyst deodorization apparatus to deodorize and reduce CO2 and VOC.

  According to the present invention, the exhaust gas of the coating drying furnace is deodorized and CO2 and VOC reduction treatment is performed at room temperature by oxidative decomposition to greatly reduce the processing energy (fuel) cost and facilitate maintenance in the painting process. It has the effect of ensuring safety.

  The best mode for carrying out the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a filter for removing the first treatment, 2 a dehumidifying unit for the second treatment, 3 an electrostatic precipitator for the third treatment, and 4 a photocatalytic deodorizing device for the fourth treatment.

  The present invention includes a first treatment in which exhaust gas from a paint drying furnace is cooled and water-soluble by spraying water with a mist spray filter 1 and trapped with the filter, and the first treated water-soluble moisture is dehumidified. A second process for dehumidifying in the unit 2; a third process for removing dust particles and smoke in the gas dehumidified by the second process by the electric dust collector 3; and a photocatalyst deodorizing for the third processed gas. An exhaust gas deodorization treatment system for a paint drying furnace characterized in that CO2 and VOC are reduced by performing a fourth treatment of decomposing and deodorizing odor components in the device 4.

  The scavenging filter 1 is provided with a water mist spraying device and a filter, and this filter is suitably a rotary grease filter or a demister filter with extremely small pressure loss and high heat resistance, corrosion resistance, and removability.

  In this first treatment filter, the high-temperature exhaust gas containing malodorous and harmful substances generated by the chemical reaction by baking at a high temperature (220 ° C.) in the coating drying furnace is instantly cooled by water mist spraying. Then, at the moment when the latent heat is taken away, it becomes water-soluble and then traps and gas bonded to water molecules are captured by a filter. At this time, the water-solubilized spider falls from its own weight. Thus, conventionally, a solvent such as a chemical is required for cleaning the cured resin, but this first treatment has the advantage of self-cleaning action.

  By using a rotary grease filter or a demister filter as the filter in the dust removing filter 1, the rotary grease filter has cleanliness and safety that does not allow fire-inducing factors (oil mist) to flow in, and the removal rate is 99.72%. Static pressure (the final static pressure is 127 Pa / surface speed is 1.1 m / sec. In addition, the demister filter is formed by knitting a thin metal wire into a knitted shape, and alternately superposing several sheets of this as a set. Because of the space ratio of 90% or more, the pressure loss is extremely small, the heat resistance and the corrosion resistance are excellent, and the collection efficiency is high.

  In the dehumidifying unit 2 in the second process, the water-soluble moisture is dehumidified because the water is solubilized in the first process. Due to this dehumidification, the drain water at the time of cooling also contains dust and odorous substances and is discharged.

  In the electrostatic precipitator 3 of the third treatment, smoke in the gas is extinguished and particles of ani (containing odor) are captured. At this time, the water-solubilized particle will fall by its own weight and drain.

  In the photocatalyst deodorizing apparatus 4 of the fourth treatment, by irradiating the photocatalytic titanium oxide (TiO2) filter with ultraviolet rays, active oxygen is generated and the exhaust gas components are decomposed, resulting in harmless water and carbon dioxide gas. Decomposes and deodorizes odor components (organic compounds, etc.).

  The exhaust gas of the coating and drying furnace that has undergone the first to fourth treatments eliminates smoke, removes spider, and deodorizes to discharge harmless water and reduced CO2 and VOC. Incidentally, CO2 was reduced by about 75%.

  As the dehumidifying unit 2, the electric dust collector 3, and the photocatalyst deodorizing apparatus 4 other than the first treatment dust removing filter 1, existing devices that are commercially available are used.

  As described above, the present invention treats the deodorizing treatment of malodorous gas discharged from the coating drying furnace at room temperature instead of high temperature combustion as in the prior art, so the equipment cost and the amount of CO2 and VOC generated are greatly reduced. The cost of processing energy is remarkably reduced, maintenance in the painting process is facilitated, safety at the time of maintenance is ensured, and there are advantages that contribute to global warming prevention measures.

Block diagram showing the system of the present invention

Explanation of symbols

1 Smear filter 2 Dehumidification unit 3 Electric dust collector 4 Photocatalyst deodorization device

Claims (1)

  A first treatment for cooling and water-solubilizing the exhaust gas of the paint drying furnace by a mist spray of water with a filter for removing dust and capturing the dust and gas with a filter, and dehumidifying the water-humidity treated with the first treatment with a dehumidifying unit. The second treatment, the third treatment for removing dust particles and smoke in the gas dehumidified in the second treatment with an electric dust collector, and the third treated gas for decomposing odor components with a photocatalyst deodorizer An exhaust gas deodorization system for a paint drying furnace, characterized by performing a fourth process for deodorizing and deodorizing to reduce CO2 and VOC.

Images