JP2007085716A - Heat exchanger for closed vertical composting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive and easily-maintained heat exchanger for a closed vertical composting device in view of problems wherein an inner tube used for heat exchange in the closed vertical composting device is high in machining cost because the surface is mounted with pleat-like fins or a wavy metal plate, and heat transmission is poor if the welded or joined state of the pleat-like fins or wavy metal plate is bad, and strict maintenance and inspection are required because impurities in exhaust gas enter clearances of the pleat-like fins or the like to degrade heat exchange efficiency. <P>SOLUTION: In this heat exchanger, a flexible metal tube is used as the inner tube through which outside air passes. Compared with an ordinary tube, a surface area is large, and since no fins are mounted, machining is easy, and maintenance is easy without impurities entering the clearances. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat exchanger of an apparatus for producing compost by sealing organic matter such as livestock excrement, food residues, and raw garbage into a vertical fermentation tank.

  The closed-type composting apparatus has been used as a composting apparatus for organic substances such as livestock manure because it has a small installation area and is easy to deodorize. In the sealed vertical composting device, heat exchange is performed between the exhaust gas whose temperature has been increased by the fermentation heat generated in the tank and the fresh air sent into the tank, and the fresh air whose temperature has been raised in advance is supplied. In some cases, it is possible to create favorable conditions for fermentation. In this case, heat exchange is performed by allowing the outside pipe to pass through a plurality of branched inner pipes before entering the fermenter, and passing the exhaust gas from the sealed vertical composting apparatus outside the inner pipe. Is normal. In order to increase the efficiency of heat exchange, a large number of bowl-shaped metal fins or corrugated metal plates are attached to the surface of the inner tube, and the contact area with the exhaust gas from the closed composting device that passes outside the inner tube A method of increasing the heat exchange time with the exhaust gas by increasing the path length of the inner tube through which fresh air passes by bending or spiraling the inner tube, and further bending or spiraling A composite method in which a large number of fins or corrugated metal plates are provided in the ventilation path is employed.

  The method of mounting a large number of hook-shaped fins or corrugated metal plates on the inner tube surface of the above-mentioned prior art has a high processing cost, and the welding or joining state of the corrugated fins or corrugated metal plates is bad There was a problem that heat transfer to the hooked fin or the corrugated metal plate was poor. In addition, when the exhaust gas passage route is bent or spiraled to increase the exhaust gas passage route length, moisture in the exhaust gas accumulates in the heat exchanger as condensed water, and floating substances are generated and difficult to remove. The inside of the tube is clogged.

  By using a flexible flexible metal tube for the inner tube through which fresh outside air passes, the surface area can be secured, the processing is easy, and the surface is smooth, so that it is difficult to get dirt and as a result, water clogging hardly occurs.

  The heat exchanger for a sealed vertical composting apparatus of the present invention can be manufactured at low cost and is easy to maintain when used.

  A description will be given with reference to FIG. 1 of a schematic diagram of a heat exchanger conventionally used. Hot exhaust gas from the sealed vertical composting apparatus 1 is introduced from the sealed vertical composting apparatus 1 through a normal hose or a metal pipe into the heat exchange chamber 3 through the exhaust gas inlet 2 of the heat exchanger. In the heat exchange chamber 3, an inner pipe 4 through which fresh outside air to be sent to the sealed vertical composting apparatus 1 passes is provided.

  Fresh outside air enters the inner tube 4 of the heat exchanger from the outside air inlet 5, is discharged from the outside air outlet 6, and is introduced into the fermenter via the air intake 7 in the sealed vertical composting apparatus 1. The exhaust gas that has entered the heat exchange chamber 3 from the exhaust gas inlet 2 passes between the inner pipes 5, exchanges heat, raises the temperature of fresh outside air, and then passes through the exhaust gas outlet 8 as it is or via a deodorization tank. Released into the atmosphere. Although not shown for the schematic view, the exhaust gas flow is devised so as to stay in the heat exchange chamber 3 for a long time so as to increase the contact time with the inner pipe surface in order to increase the heat exchange efficiency.

  In order to increase the surface area and increase the efficiency of heat exchange, the inner tube 5 has a plurality of branched metal fins or corrugated metal plates attached to the surface of the inner tube 5 to increase the surface area and increase the heat exchange efficiency. A method for increasing the contact area with the exhaust gas from the sealed composting apparatus 1 that passes outside, or by increasing the path length of the inner tube through which fresh air passes by bending or spiraling the inner tube. In addition, a method of increasing the heat exchange time with the gas, and a combined method of providing a large number of fins or corrugated metal plates in a bent or spiraled ventilation path are employed.

  The method of attaching a large number of hook-shaped fins or corrugated metal plates to the inner tube surface with a heat exchanger conventionally used in such a structure is expensive in processing costs, and is made of hook-shaped fins or corrugations. If the metal plate is poorly welded or joined, there is a problem that heat transfer to the corrugated fin or the corrugated metal plate is poor.

  In addition, when the inner pipe is bent or spiraled to increase the exhaust gas passage path length, the moisture in the exhaust gas accumulated in the heat exchanger accumulates between the complex structures of the inner pipe and floats in the exhaust gas. It is difficult to remove because of the mixture.

  The heat exchanger of the present invention is shown in FIG. Although not shown, the exhaust gas from the sealed vertical composting apparatus enters the heat exchange chamber 3 from the exhaust gas inlet 2 and is discharged from the exhaust gas outlet 8. In the illustrated example, a partition plate 9 is installed in the heat exchange chamber 3 so that exhaust gas stays in the heat exchange chamber 3 for as long as possible to increase the heat exchange efficiency. However, the method of retaining the exhaust gas is not limited to this method. In the figure, the exhaust gas port 8 is located at the upper part of the heat exchange chamber 3 for the sake of illustration, but it is more effective to install it slightly below in order to extend the residence time of the exhaust gas.

  Fresh outside air enters from the outside air inlet 5 and is branched into a plurality of inner pipes 4 by the outside air diverting duct 10 near the outside air inlet 5, exits from the outside air outlet 6 via the outside air merging duct 11, and becomes a sealed vertical composting apparatus. Supplied. In FIG. 2, the outside air diverting duct 10 and the outside air merging duct 11 are shown in a rectangular parallelepiped shape, but are not limited to this shape.

  The inner tube 4 is composed of a plurality of flexible flexible metal tubes. The flexible metal hose is arranged such that continuous mountains or independent mountains whose surfaces rise in a spiral shape are stacked, and has a larger surface area than a normal pipe. If a large number of corrugated fins or corrugated metal plates are attached to a normal pipe, the construction cost will be high, and if the welded or joined state of the metal plates is poor, heat transfer to the corrugated fins or corrugated metal plates will be poor. There are drawbacks, but flexible hoses do not. The shape, quantity, and arrangement method of the flexible metal hose are not particularly limited.

  Exhaust gas from the sealed vertical composting device is used for heat because the sealed vertical composting device is mainly used for livestock manure, so many impurities are often mixed in the exhaust gas. When passing through the heat exchange chamber 3, it is mixed into the dew condensation water. When the inner tube 4 is constructed so as to be fitted with a large number of bowl-shaped fins or corrugated metal plates, or when it has a complicated branch structure, impurities enter the gap and heat exchange efficiency decreases, and the strict Maintenance / inspection is required.

  On the other hand, flexible hoses have a larger surface area than ordinary pipes and are not equipped with fins, etc., so impurities do not enter gaps, and even with a complicated branch structure, impurities are not mixed easily and maintenance is easy. It is.

Schematic diagram showing an overview of heat exchangers used in the past Overall view including a partial cross section of a heat exchanger for a sealed vertical composting apparatus of the present invention

Explanation of symbols

3. Heat exchange chamber
4 .... Inner pipe
5 .. Open air entrance
6 .... Outdoor exit

Claims (1)

  Heat exchanger for sealed vertical composting equipment using multiple flexible metal tubes as inner pipe

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