JPH0352617A - Method for preventing dew condensation in dry deodorizing device - Google Patents

Abstract

PURPOSE:To prevent the corrosion of an air heater, to surely heat gas to be treated to a prescribed temp. and to prevent dew condensation in a dry deodorizing device by heating the gas to be treated by mixing with air heated with the air heater and by introducing the heated gas into the dry deodorizing device. CONSTITUTION:When gas contg. malodorous components is deodorized by a dry process, the gas A to be treated is heated by mixing with air heated with an air heater 4 and the heated gas is introduced into a dry deodorizing device 3. The corrosion of the air heater 4, especially the heater element can be prevented and an expensive corrosion resistant material is made unnecessary. Since the humidity of the gas is lowered by dilution with the heated air, dew condensation on the surface of an adsorbent, etc., in the deodorizing device is surely prevented, the service life of the adsorbent is considerably prolonged and temp. control is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for preventing condensation in a dry deodorizing device that adsorbs and removes odor components from gas containing certain odors. [Conventional technology] Conventionally, gases containing odorous components such as hydrogen sulfide, mercabutane, and ammonia are generated from human waste and sewage treatment plants, paper mills, and various chemical plants, and it is necessary to deodorize the odorous components in the gases. A dry deodorizing device (hereinafter referred to as a deodorizing device) filled with an adsorbent such as activated carbon or zeolite is used for the treatment. In the above-mentioned deodorizing equipment, especially in winter, the water content in the gas to be treated is close to saturation, so water condenses on the inside of the equipment and on the surface of the adsorbent, resulting in a decrease in the adsorption capacity of the adsorbent and a shortened service life. There is a risk that Therefore, conventionally, as shown in FIG. 3, after introducing the gas A to be treated into the mist separator 1 to remove particles such as mist,
Measures are taken to prevent dew condensation by directly heating the gas with a gas heater 7 to raise the temperature by about 2 to 5 degrees Celsius, lowering the relative humidity, and introducing it into the deodorizing tower 3 with a fan 2. [Problem to be solved by the invention] In the conventional dew condensation prevention method in which the temperature of the gas to be treated is directly raised using a heater, the inside of the heater is exposed to high temperature and high humidity conditions, so hydrogen sulfide contained in the gas to be treated is The heater is easily corroded by corrosive gases such as, and the heater element in particular is at an even higher temperature, so it is not possible to use a heater element made of economical material such as stainless steel, and the corrosion resistance of titanium is considered. Although expensive special materials are used, corrosion accidents still occur. The present invention aims to provide a method for preventing dew condensation in a deodorizing device, which does not cause corrosion problems and can reliably raise the temperature of the gas to be treated to a predetermined temperature to prevent condensation.

[Means to solve the problem]

The gist of the present invention, which was made in view of the above circumstances, is to provide a method for deodorizing a gas to be treated containing odor components by a dry method, in which heated air is mixed into the gas to be treated to raise the temperature, and then a dry deodorizer is used. This is a method for preventing dew condensation in deodorizing equipment, which is characterized by introducing it into a deodorizing device. (Function) By heating air with no risk of corrosion using an air heater and mixing the resulting heated air into the gas to be treated that contains corrosive odor components, the gas to be treated that causes corrosion can be removed. The temperature of the gas to be processed is raised and the relative humidity is lowered without passing it through a heater. In addition, by introducing the gas to be treated with reduced relative humidity into the deodorizing device, dew condensation on the adsorbent surface is prevented and odor components are adsorbed and removed. (Example) The method of the present invention will be explained in detail below based on the drawings.

Fig. 1 is a system diagram of one embodiment of the present invention, Fig. 2 is a system diagram of another embodiment, and Fig. 3 is a system diagram of a conventional method. In each figure, the same numbers are used for the same equipment. Reference numeral 1 denotes a mist separator for removing mist, dust, etc. entrained in the gas to be treated A containing a certain amount of odor. 2 is a fan that introduces the gas A to be treated into the deodorizing tower 3. 3 is a deodorizing tower which is a deodorizing device that is filled with an adsorbent such as activated carbon or zeolite and adsorbs and removes a certain amount of odor.Usually, a fixed bed type filled with adsorbent in layers is used, and the gas to be treated A is absorbed by the adsorbent. The chamber is equipped with an inlet for the gas A to be treated at the bottom and an outlet for the gas B from which odor components have been removed at the top so that the gas to be treated can flow upward through the layer. The present invention is applicable to the deodorizing tower 3 as long as it is a dry method, such as a fluidized bed type in which the packed adsorbent is fluidized, or a moving bed type in which the adsorbent is continuously supplied and discharged.

4 is a heater for air C, and an electric heater equipped with a heater element 5 is preferable due to ease of temperature control and maintenance, but even a heat exchange type heater using a heating medium such as steam, Heating may also be done using a burner. As the heater 7 for the gas to be processed A used in the conventional method, an electric heater equipped with a heater element 5 is mainly used. A blower 6 mixes heated air C into the gas A to be treated. 8 is a heat insulating material that covers the equipment, piping, etc. so that the heating line is cooled by the outside temperature and moisture does not condense. Conventionally, in a method for deodorizing a gas A to be treated that contains a certain amount of odor, as shown in FIG. After being directly heated with a gas heater 7 to raise the temperature by about 2 to 5°C, it is introduced into a deodorizing tower 3 with a fan 2. Therefore, since the inner wall surface of the heater 7 and the heater element 5 are exposed to the high temperature and humid atmosphere inside the gas heater 7, they are not affected by the odor contained in the gas A to be treated or by corrosive gases such as hydrogen sulfide in the gas. It is highly susceptible to corrosion and is easily corroded. In FIG. 1 showing an embodiment of the present invention, air C heated by an air heater 4 is mixed into the gas to be treated A at the front stage of the fan 2 to heat the gas to be treated A. , and in another embodiment shown in FIG. 2, the gas is mixed into the gas A to be treated after the fan 2.

Therefore, the heater 4 does not come into contact with corrosive components and is not affected by them. In addition, the heating temperature of the gas to be processed A is 2 to 2 as before.
The amount of heated air C mixed in and the temperature are controlled to adjust the temperature to about 5°C, but usually the mixed amount is about 10 voj% of the total gas amount.
It is adjusted accordingly. In an embodiment of the invention, the fan 2
If there is enough air flow, use the embodiment shown in Figure 1.
If there is not enough room for the fan 2, it is preferable to use the embodiment shown in FIG. 2, although the installation area will be large. However, it is not limited to these. [Effects of the Invention] Although the amount of gas to be processed in the deodorizing device increases slightly due to the mixing of heated air, the present invention prevents corrosion of the heater, especially corrosion of the heater element, and eliminates the need to use expensive corrosion-resistant materials. In addition, since the humidity is lowered by the dilution of air, dew condensation is less likely to occur, and dew condensation is reliably prevented on the surface of the adsorbent in the deodorizing device, greatly extending the life of the adsorbent. In addition, great effects such as easy temperature control can be obtained.

[Brief explanation of drawings]

Fig. 1 is a system diagram of one embodiment of the present invention, Fig. 2 is a system diagram of another embodiment, and Fig. 3 is a system diagram of a conventional method. 1; Mist separator, 2; Fan, 3; Deodorizing tower, 4;
Air heater, 5; Heater element, 6; Blower, 7;
Gas heater, 8; Heat insulating material, A; Gas to be treated, B; Processing gas, C; Air.

Claims (1)

[Claims] Preventing condensation in a dry deodorizing device, in a method of deodorizing a gas containing odor components by a dry method, characterized in that the gas to be treated is mixed with heated air to raise its temperature and then introduced into the dry deodorizing device. Law.