JP2005049083A - Method and device for dry incineration and heat recovery of malodor component-containing low-heating value waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device capable of perfectly performing deodorization and removal of dioxin with excellent thermal economic property in dry incineration and heat recovery of a malodor component-containing low-heating value waste. <P>SOLUTION: The device and method are adapted to dry-incinerate the malodor component-containing low-heating value waste D and obtain hot water and/or steam W1 by indirect heat exchange of the resulting dry incineration waste gas with water W. In the method and device, ordinary-temperature air A is indirectly heat-exchanged with dry incineration exhaust gas G1 which is not indirectly heat-exchanged yet with the water W or dry incineration exhaust gas G2 after it is indirectly heat-exchanged with the water W, and heated so as to be usable as air A1 for the dry incineration of the malodor component-containing low-heating value waste D, whereby the temperature of the dry incineration exhaust gas G1 not indirectly heat-exchanged with either the water W or the ordinary temperature air A is raised to a value for decomposing and extinguishing the dioxin included therein. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

Detailed Description of the Invention

  The present invention performs, for example, incineration of malodorous component-containing low calorific value waste that generates malodor, such as chicken manure, and has a high nonflammable content and low calorific value, and heat recovery from the incineration exhaust gas. In addition, the present invention relates to improvement of a low heat generation waste incineration, a heat recovery method and an apparatus thereof configured to obtain steam.

  In recent years, the breeding of chickens for meat and eggs has become large-scale, and the treatment of large amounts of chicken manure has become a major problem. As a method for treating chicken manure, there are methods such as composting and incineration. Composting is the most desirable in terms of effective use of chicken manure, but the reality is that there is not enough demand to accept it, and there is a limit to expecting it alone.

  Recently, an incineration process using a rotary kiln and the like, and effective use of the heat generated from it have been proposed and implemented in part, but in any form during the incineration process, carbon monoxide, hydrocarbons and chlorine (chloride) If hydrogen is present, dioxins are generated. In order to prevent these occurrences, (1) high temperature (800 ° C. or higher, preferably 850 ° C. or higher), (2) sufficient at that temperature so that combustion is performed well and unburned content is reduced. Both a good residence time (2 seconds or more) and (3) good contact with sufficient air (high air ratio, sufficient stirring and mixing) are essential.

  However, chicken manure has a lot of incombustibles, and even if moisture is removed, it has a low calorific value, and it is large and fluctuates over time. When incineration is carried out, there is a problem that the temperature of the incineration exhaust gas necessary for the decomposition and disappearance of dioxins cannot be secured stably.

  One of the causes of the above problems is the removal and reduction of moisture, which includes drying of chicken dung by contact with incineration exhaust gas. According to this, chicken dung contains malodorous components, and a large amount of exhaust gas containing malodors is present. There is another serious problem in the environment of being discharged. As countermeasures, deodorization by recombustion of dry exhaust gas and deodorization with chemicals have been proposed and implemented. However, there is no added value from them, and economics are increased with the addition of fuel, chemicals, and equipment. There is a problem that it decreases.

  On the other hand, the applicant already said, “Waste is dried by air indirectly heated by incineration exhaust gas, and the dry exhaust gas mainly composed of air is used as incineration air of the dried waste, and malodorous components are contained. "A structure configured to burn and deodorize in a high-temperature atmosphere" has been proposed (see Patent Document 1). However, this is intended until deodorization, but dedioxins are not mentioned.

      Japanese Patent Application No. 2001-169773 (

Claims

Claim 1

And Figure 1)

  Furthermore, even if the incineration exhaust gas temperature above the value necessary for the decomposition and disappearance of dioxins is stably secured, then when the heat recovery proceeds further and the temperature falls within a certain range (for example, 300 to 500 ° C.), There is a problem that dioxins are re-synthesized from a substance generated by the decomposition and disappearance of the dioxins. At that time, the metal compound acts as a catalyst.

Problems to be solved by the invention

  Therefore, the present invention has been made to eliminate the above-mentioned disadvantages of the prior art, and is completely deodorized and dedioxin-free in the dry incineration and heat recovery of low-calorific value waste containing malodorous components, and thermoeconomic. It is an object to provide an excellent method and apparatus.

Means for solving the problem

In order to achieve the above object, the invention of claim 1 is characterized in that the malodorous component-containing, low calorific value waste D is dry-incinerated, and hot water or / and / or by indirect heat exchange between the dry-incinerated exhaust gas and water W. Containing malodorous components configured to obtain steam W1, dry incineration of low calorific value waste, heat recovery method,
The air A at normal temperature is indirectly heat exchanged with the dry incineration exhaust gas G1 that has not yet indirectly exchanged heat with the water W or with the dry incineration exhaust gas G2 after it has indirectly exchanged heat with the water W, and contains the malodorous component and has a low calorific value. By heating the waste D as air A1 for dry incineration, the temperature of the dry incineration exhaust gas G1 that has not yet indirectly exchanged heat with either the water W or the air A at room temperature is the dioxins contained therein. It is configured so that it can be increased to a value that decomposes and disappears.

  In addition to the structure of the invention of claim 1, the invention of claim 2 is such that the temperature of the dry incineration exhaust gas G3 after indirect heat exchange with the water W and air A at room temperature is the dry incineration exhaust gas G3. It is kept in a range in which dioxins are not re-synthesized from substances contained by decomposition and disappearance of the dioxins.

The invention according to claim 3 is a method for producing hot water or / or by indirect heat exchange between the dry incineration exhaust gas from the dry incineration unit 10 and the water W together with the dry incineration unit 10 in which the malodorous component-containing, low calorific value waste D is dry incinerated. And a malodorous component containing indirect heat exchanging unit 20 configured to obtain steam W1, dry incineration of low calorific value waste, heat recovery device,
The temperature of the dry incineration exhaust gas G1 from the dry incineration unit (10), which has not yet indirectly exchanged heat with water (W) or air at normal temperature (A), is increased to a value at which dioxins contained therein decompose and disappear. The air A at normal temperature indirectly exchanges heat with the dry incineration exhaust gas G1 that has not yet indirectly exchanged heat with the water W or with the dry incineration exhaust gas G2 after it has indirectly exchanged heat with the water W, and contains the malodorous component, A second indirect heat exchange unit 30 configured to be heated as air A1 for drying and incinerating the low calorific value waste D is provided.

  According to the invention of claim 1 or 3, the air A at normal temperature (in claim 3 in the dry incineration unit 10 in claim 3) is subjected to dry incineration of waste containing low odor components and low calorific value (in claim 3). Dry incineration exhaust gas G1 (from the buffer incineration unit 10) or (in claim 3, exhaust gas G2 from the indirect heat exchange unit 20) (in claim 3, the second indirect heat exchange unit 30) indirect heat exchange, the malodor The component-containing, low calorific value waste D is heated as air A1 for dry incineration, whereby the temperature of the dry incineration exhaust gas G1 is a value at which dioxins contained therein decompose and disappear (for example, 800 ° C. or higher, The temperature is preferably increased to 850 ° C., and deodorization which can be performed at a temperature lower than that of the dedioxins is completely performed, and no special deodorization equipment is required.

  Note that the order of indirect heat exchange with the dry incineration exhaust gas G1 is, as described above, the water W (in the indirect heat exchange section 20 in claim 3) or the second indirect heat in claim 3. Any of the bad odor component content (in the exchange unit 30) and the air A for dry incineration having a low calorific value D may be first, and is not particularly limited. Moreover, of course, even if the waste D to be treated has a lower calorific value based on the dry amount and the moisture content increases, most of the waste D (in the indirect heat exchange section 20 in claim 3). This can be dealt with by reducing the heat recovery amount of the water W and increasing the heat recovery amount of the air A.

  According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the temperature of the dry incineration exhaust gas G3 is not re-synthesized from the substance generated by the decomposition and disappearance of the dioxins contained therein. Since it is kept within the range, re-synthesis of dioxins is prevented.

  The embodiment of the present invention will be described with reference to FIG. 1. For example, a foul odor component-containing low calorific value waste D (hereinafter abbreviated as a waste D) containing moisture and malodorous components such as chicken manure and having a large amount of incombustible and low calorific value. However, it is first led to the drying unit incineration unit 10, contacts with the air A1 for dry incineration described in detail later, is dried, and the moisture and malodorous components contained therein are vaporized and incinerated.

  If it explains supplementarily, drying of the waste D will advance also by receiving heat, such as the flame accompanying the incineration of the below-mentioned waste D, and the radiation | emission other than by contact with a part of air A1 for dry incineration. . The dried waste D then contacts and reacts with the remaining dry incineration air A1 and releases a large amount of heat, thereby forming a flame and providing heat to the surroundings, thereby continuing the combustion. The incineration is completed with the ash K left.

  At that time, combustible components and vaporized malodorous components in the waste D react with oxygen contained in the air A1 for dry incineration that has come into contact with the waste D, change mainly into water vapor and carbon dioxide, and are vaporized by drying. It becomes the dry incineration exhaust gas G1 deodorized together with moisture and other inactive components and is discharged from the dry incineration unit 10.

  Here, the dry incineration air A1 will be described in detail. Separately from the dry incineration unit 10, the dry incineration exhaust gases G1 and G2, the water W, and the air A at room temperature exchange heat, respectively, and warm water or / and steam, respectively. W1 and indirect heat exchanging units 20 and 30 for obtaining high-temperature dry incineration air A1 are provided. In the figure, the dry incineration exhaust gas G1 is first led to the (first) indirect heat exchange section 20, and after leaving it, it becomes the dry incineration exhaust gas G2 so as to be led to the second indirect heat exchange section 30. However, any of them may be first, and the order is not particularly limited. G3 is a dry incineration exhaust gas from the indirect heat exchange unit 30.

  For simplification, each part is shown as a block in FIG. 1, and a pump, fan, transporter, dust collector, etc. are required for transporting fluids such as water supply and ventilation, transporting solids, and collecting dust. However, their illustration is also omitted. As a form of the dry incineration unit 10, any of a rotary cylinder type, a mechanical stirring type, a fluidized bed type, an air current transportation type, an aeration type, etc. can be applied as long as it is a direct heating type.

  Further, the amount and temperature of the dry incineration air A1 supplied to the dry incineration unit 10 through the second indirect heat exchange unit 30 are sufficient for incineration of the waste D, and the drying caused thereby. It is necessary that the temperature of the incineration exhaust gas G1 is increased to a value (for example, 800 ° C., preferably 850 ° C.) at which dioxins contained therein decompose and disappear.

Here, for specific explanation, for example, waste D is a chicken manure whose composition and calorific value are as shown below, and the waste D is operated at a moisture content of 37% and an air ratio of 2.0. In this case, the horizontal axis and the vertical axis respectively calculate the water content of the waste D supplied to the dry incineration unit 10 and the air ratio (air amount) for dry incineration, and the contour lines of the temperature of the obtained dry incineration exhaust gas G1. Is as shown in FIGS. That is,
・ Composition: Dry standard (%)
C: 41.88 H: 6.01 N: 3.58 O: 33.34
S: 0.28 Ash content: 14.93
・ Heat generation amount: Dry basis (MJ / kg)
High calorific value 16.79 Low calorific value 15.47

  As is apparent from the figure, when each condition fluctuates ± 10% (within the rectangle indicated by the broken line), as shown in FIG. 2, when the air A1 for dry incineration is at room temperature (15 ° C.), About half (slightly) the temperature of the dry incineration exhaust gas G1 falls within the range of 800 ° C. (preferably 850 ° C.) or higher. On the other hand, as shown in FIGS. 3 and 4, when the temperature of the air A1 for dry incineration is 100 ° C. and 150 ° C., respectively, the temperature of the dry incineration exhaust gas G1 is 800 ° C. (preferably 850 ° C.) or more. It is understood that deoxygens and deodorization can be easily realized by entering most (about half) in the former and all (most) in the latter.

  Needless to say, even if the heat generation amount of the waste D to be treated is reduced based on the dry amount and the water content is increased, most of the waste is caused by the dry incineration air A1 by the second indirect heat exchange unit 30. The required temperature of the dry incineration exhaust gas G1 can be secured by increasing the heat recovery amount and increasing the temperature.

  In addition, even if the water content is so high that the temperature of the dry incineration exhaust gas G1 cannot be secured, the illustration is omitted, but the waste D or the warm water previously obtained by the indirect heat exchange unit 20 is omitted. / And pre-dried by steam W1. As a result, a part of the evaporated water is not brought into the dry incineration unit 10 and the amount of heat heated to the temperature of the dry incineration exhaust gas G1 is reduced, so that the temperature of the dry incineration exhaust gas G1 is increased accordingly.

  In addition, the temperature of the dry incineration exhaust gas G3 from the second indirect heat exchange unit 30 after undergoing indirect heat exchange with the water W and the air A at room temperature needs to be maintained at 500 ° C. or higher. Thereby, even if the metal heat transfer surface of the heat exchange units 20 and 30 upstream of the second indirect heat exchange unit 30 and the dry incineration exhaust gas come into contact with each other, the temperature of the dry incineration exhaust gas is decomposed by the dioxins. Since the dioxins are kept in a range (500 ° C. or higher) where the dioxins are not re-synthesized from the substance generated by disappearance, the re-synthesis of the dioxins is prevented. In addition, this dry incineration exhaust gas is normally rapidly cooled by a water spray so that dioxins may not be re-synthesized.

The invention's effect

  As described above, according to the invention of claim 1 or 3, in the dry incineration of the malodorous component-containing, low calorific value waste D (in claim 2 in the dry incineration section 10), water W, air A at normal temperature Since the temperature of the dry incineration exhaust gas G1 that has not yet undergone indirect heat exchange with any of the above is increased to a value at which dioxins contained therein decompose and disappear (for example, 800 ° C or higher, preferably 850 ° C), Deodorization, which may be lower than that temperature, is completely performed, and no special deodorization equipment is required.

  According to the invention of claim 2, in addition to the effects of the invention of claim 1, the temperature of the dry incineration exhaust gas passing through the both indirect heat exchange parts 20, 30 is included in the decomposition and disappearance of the dioxins contained therein. Since the dioxins are kept in a range where the dioxins are not re-synthesized from the generated substance, the re-synthesis of the dioxins is prevented.

  FIG. 3 is a block process diagram illustrating a first exemplary embodiment of the present invention.   Chicken manure supplied to the dry incineration unit 10 on the horizontal axis and the vertical axis, respectively, in the case of dry incineration by chicken incineration with a moisture of 37%, air at a temperature of 15 ° C. and an air ratio of 2.0 It is a graph which shows the contour line of the temperature of the dry incineration exhaust gas obtained by trial calculation about the water | moisture content and air ratio.   It is a graph which shows the contour line of the temperature of dry incineration waste gas when other conditions are the same as FIG. 2 except being 100 degreeC of the air for dry incineration.   It is a graph which shows the contour line of the temperature of dry incineration waste gas when other conditions are the same as FIG. 2 except being 150 degreeC of the air for dry incineration.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Dry incineration part 20 Indirect heat exchange part 30 Indirect heat exchange part A Room temperature air A1 Dry incineration air D Odor component containing low calorific value waste G1 Dry incineration exhaust gas G2 Dry incineration exhaust gas G3 Dry incineration exhaust gas K Ash W Water W1 Hot water or steam

Claims (3)

Malodorous odor component, low calorific value waste (D) is dried and incinerated, and hot water or / and steam (W1) is obtained by indirect heat exchange between the dried incineration exhaust gas and water (W) Containing ingredients, dry incineration of low calorific value waste, heat recovery method,
Dry incineration exhaust gas (G1) in which air (A) at normal temperature has not yet indirectly exchanged heat with water (W) or incineration exhaust gas (G2) after indirect heat exchange with water (W) and indirect heat Both water (W) and room temperature air (A) are still heated by being exchanged and heated to be usable as air (A1) for dry incineration of the malodorous component-containing, low calorific value waste (D). Dry incineration exhaust gas (G1) that has not undergone indirect heat exchange is raised to a value at which dioxins contained in it are decomposed and disappeared. Collection method. The temperature of the dry incineration exhaust gas (G3) after indirect heat exchange with water (W) and air at normal temperature (A) is contained in the dry incineration exhaust gas (G3), and the substance generated by the decomposition and disappearance of the dioxins The method according to claim 1, wherein dioxins are kept in a range where they are not re-synthesized. Malodorous component-containing, low calorific value waste (D) with dry incineration part (10) in which dry incineration is performed, and hot water or water (W) by indirect heat exchange between the dry incineration exhaust gas and water (W) from the dry incineration part (10) And / or a malodorous component containing, indirect heat exchange section (20) configured to obtain steam (W1), dry incineration of low calorific value waste, heat recovery device,
The value of the dry incineration exhaust gas (G1) that has not yet indirectly exchanged heat with water (W) or room temperature air (A) from the dry incineration unit (10) at which the dioxins contained in it decompose and disappear So that the air (A) at room temperature is not yet indirect heat exchange with water (W), or the dry incineration exhaust gas (G2) after indirect heat exchange with water (W). ) And a second indirect heat exchange section (30) configured to be heated to be usable as air (A1) for dry incineration of the malodorous component-containing, low calorific value waste (D). It is characterized by comprising a malodorous component-containing, low calorific value waste incineration and heat recovery device.

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