JP2000288348A - Deodorization apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a direct combustion type or catalytic combustion type deodorization apparatus with high deodorization efficiency, high heat recovery ratio, a compact size, and a low apparatus cost per treatment quantity. SOLUTION: This deodorization apparatus is provided with a heat source part 1 in the center, an inflow route 3 for guiding an object gas to be treated into the heat source part 1, and a discharge route 4 for discharging the gas treated in the heat source part 1. In this case, the flow-in route 3 and the discharge route 4 are arranged adjacently to each other through a spiral metal wall 7 while surrounding the heat source part 1. An inflow inlet 5 and a discharge outlet 6 are formed in the outer circumferential part.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a deodorizing apparatus for treating odors of various gases generated from factories and residential areas caused by VOCs (volatile organic compounds) that cause global warming and environmental pollution.

[0001]

2. Description of the Related Art Combustion type deodorizers include a catalytic combustion type and a direct combustion type. The former is a method in which a gas to be treated is passed through a heated honeycomb structure or the like carrying a noble metal catalyst such as Pt to oxidize, decompose and deodorize at a relatively low temperature of 300 to 400 ° C.

On the other hand, the latter is a flame-combustion cracking furnace of 700 to 800
This is a method in which the gas to be treated is directly oxidized and decomposed at a high temperature of ° C to deodorize.

[0003] In either method, a heat exchanger is provided independently of a deodorizing device or a deodorizing furnace, and heat is exchanged between the treated gas and the gas to be treated to recover energy.

[0004] In this case, the recovery rate deteriorates due to heat radiation from the entire apparatus, and is limited to about 50 to 60% at most. In addition, the installation area of the entire apparatus including the heat exchanger becomes large, and the size of the apparatus is reduced. Is difficult.

Further, when powder is generated when the gas to be treated is decomposed or when powder is brought in from the outside, the powder may accumulate in the apparatus and the gas passage may be blocked. . Therefore, maintenance work such as removal of the powder in the apparatus must be frequently performed, which is troublesome.

[0006] As a new technology, there is a regenerative (repetitive) deodorizer. This is a method in which the positions of the combustion burner and heat exchanger are placed symmetrically via a cracking furnace and used repeatedly at certain time periods.The heat recovery rate is said to be around 90%, There is a disadvantage that the whole apparatus becomes complicated and the process becomes complicated.

Further, the apparatus itself becomes large-scale, and a small turn corresponding to the degree of odor generation (for example, VOC emission amount) cannot be obtained.
The investment amount is high and it is hard to say that it is a universal type device.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention relates to a direct combustion type and catalytic combustion type deodorizing apparatus which has (1) a large deodorizing effect, (2) a large heat recovery rate (small energy consumption), (3) The equipment volume is small and compact. (4) There is little maintenance work such as cleaning of gas passages.
An object of the present invention is to provide a deodorizing apparatus in which the apparatus price is small with respect to the amount of gas to be processed per unit time.

[0009]

According to a first aspect of the present invention, there is provided a deodorizing apparatus comprising: a heat source section provided with an electrothermal or flame type heat source; and an inlet for guiding a gas to be treated to the heat source section. A cylindrical deodorizing device provided with a passage (3) and a discharge passage (4) for discharging the gas processed in the heat source unit (1), wherein the heat source unit (1) is provided in a central part, The inflow path (3) and the discharge path (4) are spirally arranged adjacent to each other around the heat source section (1).
(3) is separated from the discharge path by a metal wall (7),
An inlet (5) serving as an inlet of the inflow path (3) and a discharge port (6) serving as an outlet of the discharge path (4) are provided on the outer peripheral portion.

According to this, the gas to be treated passes through the spiral (swirl) inflow passage (3) from the outermost inlet to the heat source (1) at the center, and is decomposed near this heat source. After the treatment, it is discharged from the outermost discharge port (6) through a spiral discharge path (4).

The gas to be treated and the treated gas come into contact with each other over a plurality of turns of the spiral via the metal wall (7) serving as a partition. Therefore, a large heat transfer area can be secured,
Heat exchange is performed efficiently.

The apparatus of the present invention has a temperature gradient in the radial direction of a columnar apparatus, and the temperature difference between the gas and the inlet temperature decreases as approaching the outer periphery. The temperature drops, and the retained thermal energy is transferred to the gas to be treated, so that the deodorizer has a high heat recovery rate.

[0013] Since the heat source section (1) at the center is surrounded by the inflow path (3) and the discharge path (4), less heat is wasted to the periphery of the apparatus, and this point also consumes energy. It contributes to reducing the amount.

According to a second aspect of the present invention, there is provided the deodorizing apparatus according to the first aspect, wherein the metal wall (7) serving as a partition wall between the inflow path (3) and the discharge path (4) is made of iron or an iron alloy (for example, SUS) or Al. , Cu
Or made of an alloy of Al and Cu, and the thickness of the metal wall (7) is
The lower end of the metal wall (7) is fixed to the bottom plate (8) by welding, and the top plate (10) is attached to the upper end of the metal wall (7) via packing. It is characterized by having.

The metal material used for the apparatus and its thickness are specified in consideration of heat transfer and corrosion prevention. In addition, by simplifying the inflow path and the discharge path, and by integrally surrounding the pyrolysis zone of the gas to be treated with a structure having a heat exchange function, the overall volume of the apparatus can be made compact, preventing heat radiation,
In addition, a heat insulation function is provided by having a heat exchange function.
As the iron alloy, for example, a SUS material or the like can be used.

According to a third aspect of the present invention, in the deodorizing apparatus according to the first or second aspect, a water washing mechanism (12) capable of washing the wall surface of the metal wall (7) with running water is provided.

When powder to be treated is decomposed or accompanied by powder from the outside, the powder may adhere to the wall surface of the spiral passage and hinder heat transfer. In such a case, if a water spray mechanism is provided on a top plate or the like at the top of the apparatus in order to avoid this, it is possible to perform automatic maintenance for cleaning the wall surface of the metal wall by spraying water as needed.

According to a fourth aspect of the present invention, in the deodorizing apparatus according to the first, second, or third aspect, the air for thermal decomposition can be introduced into the heat source portion, or the air for thermal decomposition can be introduced into the inlet. It is characterized in that it can be mixed into the gas to be processed before reaching.

In some cases, the deodorizing effect can be positively enhanced by mixing the gas to be treated and the combustion air before introducing the gas to be treated into the heat source section at the center of the device or the device. is there. Further, by blowing the combustion air into the heat source portion, the air flows in a turbulent state in the discharge path, so that the deodorizing effect and the efficiency of heat exchange can be further enhanced.

According to a fifth aspect of the present invention, in the deodorizing apparatus according to the fourth aspect, a plurality of projections are provided on a wall surface of the metal wall.

When the projection is provided on the wall surface of the metal wall,
The protrusions enhance the stirring and mixing of the gas to be treated and the processing air, and can positively generate turbulence. As a result, the heat exchange effect and the heat transfer effect are enhanced.

According to a sixth aspect of the present invention, there is provided the deodorizing apparatus according to the first, second, third, fourth, or fifth aspect, wherein the oxidative decomposition of the organic compound is promoted on the surface of the ceramic material serving as the base material. It is characterized in that a honeycomb structure supporting a catalyst is installed in a heat source section.

If a honeycomb structure in which a ceramic material is used as a checker in the heat source portion and a catalyst for accelerating the oxidative decomposition of an organic compound such as Pt or Pd is supported on the surface thereof, a catalytic combustion mechanism is added. It is possible to reduce the decomposition temperature and to save the fuel for oxidative decomposition.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to preferred embodiments.

FIG. 1 is a transverse sectional view showing the concept of a VOC direct combustion type deodorizing apparatus according to the present invention, and FIG. 2 is a longitudinal sectional view.

A heat source section (1) is provided in the center space, and an electric heater or a flame combustion burner is mounted as a heat source. In the figure, a plurality of electric heaters (2) are suspended and fixed to a heat source section top plate (9). An example is shown.

A metal wall (7) serving as a partition wall is formed by winding a SUS iron plate having a thickness of 0.5 to 3 mm and surrounding the heat source portion (1) in a spiral shape with a wall interval of 5 to 20 mm.

The lower end of the metal wall (7) is fixed to the bottom plate (8) by welding. The top plate (10) has a groove corresponding to the upper end of the metal wall (7), and is fixed or welded so that the upper end of the metal wall fits into this groove via packing to prevent gas leakage. I do. The heat source top plate (9) and the top plate (10) have a structure that can be opened and closed or fixed by welding with a washing nozzle for internal cleaning or maintenance of the heat source.

In the figure, (3) is an inflow path, (4) is a discharge path, (5) is an inlet provided on the outer peripheral portion, and (6) is a position symmetrical with the inlet (5) on the outer peripheral portion. It is a discharge port provided in.

It is considered that the number of gas passages made of metal walls is desirably about 6 to 20 layers in consideration of the size of the apparatus and the heat exchange efficiency, but the diameter of the apparatus is calculated from the wall gap and the number of layers. If the heat source diameter is 300mm, if the wall spacing is 5mm and there are 20 layers, (5 × 20) × 2 + 300 = 5
00mm If the wall spacing is 20mm and there are 20 layers, (20 x 20 x 2) + 300 = 11
00 mm.

Actually, it is considered that the size of the apparatus is practically up to about 1000 mm in diameter.

Here, when calculating the total area of the metal wall when the outer diameter is 720 mm and the heat source section is 400 mm using 12 layers, the average diameter of the spirally wound metal wall is [(0.
72−0.4) /2+0.4], so the circumference at the location of the average diameter is [(0.72−0.4) /2+0.4] π = 1.76 m.

Since there are 12 layers, the total length of the metal wall is 1.76
× 12 = 21.1m.

[0034] When the height of the apparatus to 1.2 m, total area of 21.1 × 1.2 = 25.3 ^2, and becomes an apparatus having a very large heat transfer area.

Now, the total air volume including the air of the gas to be treated is 5
Assuming m ³ / min, the residence time at the heat source is
Since the heat source part volume is [(0.4 / 2) ² π] × 1.2 = 0.15 m ³ , (60/5) × 0.15 = 1.8 sec.

That is, since the residence time of the cracking furnace of a generally used direct-burning type deodorizer is 1.5 to 2 seconds,
Under the above assumed dimensions, the apparatus of the present embodiment is about 5 m ³ / min.
For air volume processing.

The wind speed at the above assumed dimensions is (5 m ³ / mi) since the gas passage cross-sectional area is 0.02 × 1.2 = 0.024 m ^2.
n) (1 / 0.024 m ² ) = 208.3 m / min = 3.5 m / sec, which is considerably smaller than 10 m / sec of a normal direct combustion type. Therefore, if the residence time of the heat source part can be shortened depending on the type of the gas to be treated, the processing air flow rate is more than 5 m ³ / min and 10 to 15 m ³ / min.
To the extent possible.

In the apparatus of the present invention, since both the gas on the inflow side and the gas on the discharge side are completely countercurrent, and the gas passage is enclosed, the heat recovery efficiency is high, the heat loss is small, and the heat generated by decomposition is added depending on the type of gas to be treated. The heat energy to be supplied to the heat source can be greatly reduced.

The temperature of the heat source section is the same as that of a normal direct combustion type deodorizer.
Although the operation is performed at 700 to 800 ° C., since the heat recovery efficiency of the apparatus of the present invention is high, the energy consumption reaches the target at 10 to 20% of the supply load, and the energy saving effect is large.

In consideration of safety against heat generation, it is preferable to provide an emergency external discharge valve at the heat source. For example, it is possible to control so that the release valve is opened when the temperature becomes higher than the set temperature of the heat source section by, for example, 50 to 100 ° C. or more.

If there is a risk of introducing the powder, a water spray mechanism is provided on the top plate (10) or the like of the apparatus in order to avoid such a situation. Good. (12) is a watering pipe connected to the internal space of the top plate (10). Watering pipes on the underside of the top plate (10)
A number of water injection holes are provided for jetting the water sent from (12). (13) is an openable and closable drain port provided at the bottom of the apparatus for draining the water after washing together with the powder at that time.

In the figure, (11) is a processing air introduction pipe. In order to enhance the deodorizing effect, it is effective to mix the gas to be treated and the processing air at a stage before the gas to be treated is introduced into the heat source section at the center of the device or the device.

Further, by blowing the processing air, the gas moves in a turbulent state also in the discharge path, and the deodorizing effect can be further enhanced. Further, when the gas passes through the discharge path in a turbulent state, the high-temperature gas constantly comes into contact with the metal wall, so that the temperature difference between the gas in the inflow path and the gas in the discharge path through the metal wall increases, thereby further increasing the heat recovery rate. it can.

If a plurality of projections are provided on the wall surface of the metal wall as necessary, the projections enhance the agitation and mixing of the gas to be treated and the processing air, so that turbulence can be positively generated. . For example, dm ² per 20 a metal projection on the metal wall
It is conceivable that about 200 pieces are fixed by welding.

"Example 1" A VOC containing exhaust gas from a lithography process in a semiconductor manufacturing plant was deodorized.

The basic configuration of the deodorizing apparatus used is as described above. In this embodiment, a space of 300 mmφ is provided in the center,
At the center thereof, twelve electric heaters having an electric capacity of 0.9 kw and having a nichrome heating element inserted in a 0.8 mm long straight I-type Fe / Ni alloy sheath were installed.

Then, in a form surrounding the heat source space
A gas passage of 18 layers with a thickness of 3 mm of SUS316 with a wall interval of 20 mm was provided. The height of the device is 1.2 mm and the outer diameter is 1.1 mm.

The processing air was introduced into the heat source from the outside, and a checker was provided at a position 40 cm above the bottom of the heat source space. A checker is a type of turbulence generator having a cross-sectional shape in which openings and closures are alternately arranged in a checkered pattern.For example, when processing air is introduced into the heat source, the flow is By generating a vortex when passing through the checker, the gas to be processed and the processing air are efficiently stirred and mixed. Further, even when the processing air is not introduced into the heat source section, the checker acts as a baffle plate to obtain a gas stirring effect.

The checker mounting position is not particularly limited.
The upper portion, the central portion, or the lower portion of the heat source portion may be used, and when an electric heater is used, the heat source portion may be attached so as to penetrate the heater.

Although not performed in the embodiment, a honeycomb structure in which, for example, alumina is used as a base material as a checker and a catalyst for accelerating the oxidative decomposition of an organic compound such as Pt or Pd is supported on the surface of the heat source is provided as a checker. Then, a structure taking into account the catalytic combustion system can be taken into account, the decomposition temperature can be reduced, and the fuel for oxidative decomposition can be saved.

While maintaining the center space temperature at 830 ° C., VO
The gas containing C was introduced from the inflow port with a fan at a flow rate of 5 m ³ / min from the inflow port, and was discharged from the discharge port. When a steady state was reached, gas analysis and temperature measurement were performed, and the following results were obtained.

[0052]

[Table 1] The rest is all external air.

The gas to be treated was introduced at 25 ° C., and the outlet temperature of the treated gas was 125 ° C. The heat recovery rate of this device was [(830-125) / (830-25)] x 100 = 87.5%.

During the deodorization treatment, the load of the electric heater was shifted at about 75% due to the heat generated by the combustion of the gas to be treated.

[Embodiment 2] A place where the electric heater in the first embodiment is installed is replaced with a city gas 13A in place of the electric heater.
A gas-burning burner using the same was provided. The conditions were set so that the heat source space temperature was maintained at 800 ° C. Others are the same as the first embodiment.

In this case, the gas to be treated containing VOC is sent at a flow rate of 5 m ³ / min as described below, and 0.01 m ³ / min of external air is introduced into the heat source for complete combustion of LPG. After the steady state, the gas concentrations at the inlet and outlet and the temperature of the treated exhaust gas were measured.

[0057]

[Table 2] The rest is all external air.

[0058]

As described above, according to the present invention, there is provided a deodorizing apparatus capable of recovering energy with high efficiency by exchanging heat between a gas to be treated and a treated gas in deodorizing a gas body. Can be. As a result, energy consumption in the deodorizing step is reduced, and the apparatus itself has a compact structure and a small occupied area, thereby contributing to a reduction in equipment costs. Further, maintenance work such as cleaning inside the apparatus is reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the concept of a deodorizing device of the present invention.

FIG. 2 is a longitudinal sectional view showing the concept of the deodorizing device of the present invention.

[Explanation of symbols]

 (1) Heat source (2) Electric heater (heat source) (3) Inlet (4) Outlet (5) Inlet (6) Outlet (7) Metal wall (8) Bottom plate (9) Top plate of heat source ( 10) Top plate (11) Treatment air inlet pipe (12) Sprinkling pipe

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[Procedure amendment]

[Submission date] March 23, 1999 (1999.3.2
3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0047

[Correction method] Change

[Correction contents]

Then, in a form surrounding the heat source space
A gas passage of 18 layers with a thickness of 3 mm of SUS316 with a wall interval of 20 mm was provided. The height of the device is 1.2 m and the outer diameter is 1.1 m.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0056

[Correction method] Change

[Correction contents]

In this case, the gas to be treated containing VOC is sent at a flow rate of 5 m ³ / min as described below, and external air of 0.01 m ³ / min is further introduced into the heat source for complete combustion of the city gas 13A. After a steady state, the gas concentrations at the inlet and outlet and the temperature of the treated exhaust gas were measured.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4C080 AA09 BB02 KK02 MM07 QQ11 QQ13 QQ14 4D002 AB02 BA05 CA07 DA70 EA02 EA09 GA01 GB20 HA03 4D048 AA17 AA20 AA22 AB01 BA30Y BA31Y CC21 CC52 CC53 CC54

Claims (6)

[Claims] 1. A cylindrical deodorizer having a heat source section having an electric or flame heat source, an inflow path for guiding a gas to be treated to the heat source section, and a discharge path for discharging gas processed in the heat source section. The heat source is provided at a central portion, the inflow passage and the discharge passage are spirally arranged adjacent to each other around the heat source portion, and a metal is provided between the inflow passage and the discharge passage. A deodorizing device, wherein the deodorizing device is partitioned by a wall, and an inflow port serving as an inlet of the inflow path and a discharge port serving as an exit of the discharge path are provided on an outer peripheral portion. 2. A metal wall serving as a partition wall between the inflow path and the discharge path is made of iron or an iron alloy or Al, Cu or an alloy of Al and Cu, and the thickness of the metal wall is 0.5 to 3 mm. 2. The deodorizing device according to claim 1, wherein a lower end of the metal wall is fixedly welded to a bottom plate, and a top plate is attached to an upper end of the metal wall via a packing. 3. The deodorizing apparatus according to claim 1, further comprising a water washing mechanism capable of washing a wall surface of the metal wall with running water. 4. An air for thermal decomposition treatment can be introduced into the heat source part.
4. The deodorizing apparatus according to claim 1, wherein air for thermal decomposition treatment can be mixed into the gas to be treated before reaching the inlet. 5. The deodorizing apparatus according to claim 4, wherein a plurality of projections are provided on a wall surface of the metal wall. 6. A heat source unit having a honeycomb structure in which a catalyst for promoting the oxidative decomposition of an organic compound is supported on a surface of a ceramic material serving as a base material. The deodorizing device according to claim 4 or claim 5.