JPH11263978A - Apparatus for heat treatment with hot gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently receive heat of a hot gas by a cylindrical unit, effectively heat a material to be treated, shorten the heating time and improve the treating efficiency by using an LNG combustion gas as a heat source and further providing a received heat increasing means on the outer surface of the cylindrical unit. SOLUTION: This apparatus for heat treatment with a hot gas is obtained by forming a heat-treating furnace from a rotatable cylindrical unit 1 having a means for moving the material to be treated while stirring the material to be treated in the interior thereof, a received heat increasing means formed from unevennesses on the outer periphery of the cylindrical unit 1 and a heating cylinder 2 covering the nearly total length of the outer periphery of the cylindrical unit 1 and is capable of feeding the hot gas into the interior of the heating cylinder 2 and heating the material to be treated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating apparatus for supplying an object such as waste to a heating furnace having a rotating cylindrical body, transferring the object in the heating furnace while stirring, and performing heat treatment. The present invention relates to a processing apparatus, and more particularly, to a heating processing apparatus using a hot gas as a heating unit.

[0002]

2. Description of the Related Art General waste (municipal waste, etc.), industrial waste (shredder dust, etc.), ash (incinerated ash, fly ash, etc.), treated media (powder treated with a bag filter, etc.), sludge Instead of burning the object to be treated, such as those containing various organic substances, heat treatment (drying, pyrolysis, carbonization, and incineration) in a steamed state to improve the property and reduce the volume of the object. That is being done.

As a heat treatment method of this kind, there is a method of heat treating waste by a low-temperature carbonization method. In this method, for example, as disclosed in Japanese Patent Publication No. 8-510789, a low-temperature carbonization chamber (pyrolysis furnace) is provided in a rotary furnace, and the low-temperature carbonization chamber converts the fed waste into low-temperature carbonization gas. Is converted to a pyrolysis residue, which is burned in a high-temperature combustion furnace to produce a molten liquid slag and solidified into a glass, and the generated gas is processed and discharged by a boiler, removal filter and gas purification device. I do. The low-temperature carbonization chamber is equipped with a number of parallel heating tubes inside, and heats the waste with the heating tube almost in a state where air is shut off. And moved in the direction of the outlet of the low-temperature carbonization drum.

[0004] As another method, when heat-treating an object to be treated, an appropriate amount of an alkaline additive which easily reacts with a chlorine component is mixed and heat-treated, and the chlorine component is fixed to treated ash to be harmless. There has also been proposed a method of obtaining exhaust gas and removing the chlorine component from the treated ash by washing with water or the like (Japanese Patent Laid-Open No. 9-155).
326).

[0005]

The heating means in the conventional heat treatment apparatus is generally heated by a single heating means.

In the heating means based on the low-temperature carbonization method, a heating gas is introduced into a large number of heating tubes arranged in a rotary furnace to heat the heating tubes. Although there is an advantage that it is easy to perform, since a large number of heating tubes are installed, manufacturing and maintenance become very complicated. Further, it is difficult to maintain stable heat treatment performance over a long period of time.

In addition, in order to increase the heat transmission area, the number of heating tubes must be increased, resulting in a complicated structure.

Further, since the hot gas is introduced only in one direction from the discharge side to the supply side, it takes time to uniformly raise the temperature in the heating furnace to a predetermined temperature from the stopped state of the heating furnace. .

The heating means in the method for fixing the chlorine component to the treated ash is based on electric means such as induction heating from the outside. However, this means increases only when the temperature of the object to be treated is lowered. Although the temperature control has the advantage that it can be performed quickly, the cost for heating is higher than that of gas.

The present invention has been made to solve such a problem.

[0011]

According to the present invention, in order to effectively heat an object to be processed inside a rotating cylinder, a hot gas is used and a heat receiving area from the hot gas is increased.
This is to heat the cylinder effectively by accelerating the temperature rise of the cylindrical body. The concrete means has a supply port for supplying an object to be processed on one end side and a discharge port for discharging the discharge side on the other end side, and a rotatable cylinder disposed at a substantially horizontal position, and an inside of the cylinder. A heating treatment furnace is constituted by means for stirring and transferring the object to be treated from the supply port side to the discharge port side, and a heating means for externally heating the cylindrical body, wherein the heating means comprises an outer periphery of the cylindrical body. A heating cylinder is provided to form a sealed space between the heating cylinder and the outer periphery of the cylindrical body, and a heated gas obtained by a combustion device is introduced into the sealed space to heat the object to be processed, and the outside of the cylindrical body is heated. The heat receiving means for increasing the contact area with the hot gas is formed on the surface.

The heat receiving increasing means may be formed by providing a spiral member, a flat plate member, or a corrugated member on the surface of the cylindrical body, or by forming a plurality of grooves in the circumferential direction of the surface of the cylindrical body to form a concave or corrugated cross section. By increasing the surface area, the heat of the hot gas is efficiently transmitted to the cylindrical body, and the object to be processed inside is effectively heated.

The material of the cylindrical body is formed of an iron-based material.

The hot gas is obtained by burning LNG. LNG
Combustion does not emit harmful substances specified by the Air Pollution Control Law, and can be discharged as it is without the need for exhaust gas treatment.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention.
(A) is a conceptual diagram viewed from the front of the heat treatment apparatus, and (B) is a cross-sectional view of the cylindrical body. In the figure, F _h is the heat treatment furnace, heat treatment furnace F _h, the heating and cylinder 1 rotatable, forming a gas duct on the outer circumference of the cylindrical body 1 by introducing a hot gas cylinder 1 Heating cylinder 2, and a supply port 3 provided at one end of cylindrical body 1 to supply an object to be processed into cylindrical body 1.
And a discharge port 4 provided at the other end of the cylindrical body 1, and the cylindrical body 1 is rotationally driven by a rotation driving unit 5. The rotation driving means 5 includes a driving motor 5a, a driving gear 5b, and a driven gear 5c provided on the cylindrical body 1.
6 is a supply side duct surrounding the supply port 3 side, and 7 is a discharge port 4
2 shows a discharge duct surrounding the side.

The heating cylinder 2 covers the cylindrical body over substantially the entire length of the cylindrical body 1, and heats the entire cylindrical body with a hot gas. Further, on the outer surface of the cylindrical body 1 covered with the heating cylinder 2, a heat receiving increasing means for efficiently receiving heat from the hot gas is provided.

FIG. 2 shows an example of this heat receiving increasing means.
FIG. 2 (A) is an enlarged cross-sectional view of a portion G of FIG.
FIG. 4B shows a case where a spiral projection 1a is provided on the outer surface of the cylindrical body 1 and a plate body having a predetermined width is provided on the outer surface of the cylindrical body 1 at a predetermined interval in a circumferential direction of the cylindrical body. (C), (D) when the plate-like projection 1b formed in accordance with
Is a concave portion 1C or a corrugated portion
This is the case where d was formed.

Reference numeral 8 denotes a combustion device which converts natural gas (LNG) into L
The LNG from the NG tank 8T is burned to generate hot gas. This hot gas is supplied to a heating cylinder 2 provided on the outer periphery of the cylindrical body 1.
After heating the cylindrical body 1, it is discharged through a discharge pipe v or used as another heating source. H indicates a hopper into which an object to be processed and a processing agent are charged.

In the figure, P denotes a dynamic seal such as a mechanical seal, which is provided at the joint between the rotating cylinder 1 and the ducts 6 and 7 and the joint between the heating cylinder 2 and the cylindrical body 1 and inside the duct and heating. Seal the inside of the cylinder.

FIG. 1B is a vertical cross-sectional view of the cylindrical body 1 having a plurality of blades S therein, the workpiece supplied inside by rotation of the cylindrical body, and the workpiece and the processing agent. Is moved from the supply port side to the discharge port side while stirring. In order to make this movement smooth, the supply port side of the cylindrical body 1 may be slightly inclined higher than the discharge port side.

A series of heat treatments is performed by first
The NG is burned to generate a hot gas, which is supplied to the heating cylinder 2.

Next (or simultaneously), a mixture of the object to be treated and the treatment agent, or the cylinder 1 from the hopper H while mixing.
Supply within. The object to be treated is subjected to dry distillation in the cylindrical body 1. The heat-treated object moves to the discharge port side while being stirred by the blades S inside the rotating cylindrical body, is discharged from the discharge side duct 7, and is sent out to a processing device or the like in the next process. The hot gas introduced into the heating cylinder 2 heats the object to be processed through the cylindrical body 1 and then is discharged through the discharge pipe v, and is reused as a heating source in the next step. When the hot gas passes through the inside of the heating cylinder 2, the cylinder receives heat increasing means because the cylinder receives heat increasing means.

Next, the heat treatment apparatus according to the present invention is used to treat an object to be treated such as waste containing a large amount of harmful components such as halogen substances and sulfides by performing a thermal treatment such as thermal decomposition. A case where the present invention is applied to a component-containing material processing apparatus will be described as a second embodiment.

FIG. 3 is a conceptual view of this processing apparatus, in which two heat processing furnaces shown in FIG. 1 are used and an auxiliary electric heating coil is used. This is a case in which a decomposition reaction treatment for detoxifying the treated material is performed, and the volume is reduced by carbonization or the like in the second heat treatment furnace.

In FIG. 3, reference numeral 10 denotes a first heat treatment furnace;
Reference numeral 20 denotes a second heat treatment furnace. First heat treatment furnace 10
Is provided at one end of the cylindrical body 11, a heating cylinder 12 for forming a gas duct around the outer periphery of the cylindrical body 11, introducing a hot gas to heat the cylindrical body 11, and
The cylindrical body 11 is constituted by a supply port 13 for supplying an object to be processed into the cylindrical body 11 and a discharge port 14 provided at the other end of the cylindrical body 11. . The rotation driving means 15 includes a driving motor 15a, a driving gear 15b, and a driven gear 15c provided on the cylindrical body 11.
Consists of 16 is a supply duct surrounding the supply port 13 side, 17 is a discharge duct surrounding the discharge port 14 side, 18
Denotes a heating coil (induction heating or resistor), which is provided on the outer periphery of the cylindrical body 11 on both sides of the heating cylinder 12 in a non-contact and close proximity to the cylindrical body 11 and constitutes a heating means together with the heating cylinder 12.

In the drawing, reference numeral 19 denotes a cylinder for mounting a temperature sensor;
Indicates a dynamic seal.

The second heat treatment furnace 20 has the same basic configuration as the first heat treatment furnace 10 described above. Therefore, the same or corresponding part is designated by the same digit after 20 (for example, 21 is a cylindrical body, 22 is a heating cylinder), and description thereof is omitted.

Reference numeral 30 denotes a hopper, which mixes and throws in the processing object and a processing agent comprising an alkali metal compound, and feeds the mixture from the supply port 13 of the cylindrical body 11 into the cylindrical body 11 through an open / close valve (open / close door) 31. Supply. The material to be treated may be any of solid matter such as general waste and industrial waste, ash, and sludge.

The hopper 30 may have a crushing function and a function of mixing the processing agent, and may mix the processing agent while crushing the solid material. May be mixed and charged.

The cylindrical body 11 of the first heat treatment furnace 10 and the cylindrical body 21 of the second heat treatment furnace 20 are disposed vertically, and the discharge duct 17 of the cylindrical body 11 and the supply of the cylindrical body 21 are provided. The opening 23 is communicated with an opening / closing valve (opening / closing door) 32, and the discharge side duct 27 of the cylindrical body 21 of the second heat treatment furnace 20 is connected to a melting tank 34 via an opening / closing valve (opening / closing door) 33. To discharge the residue after the heat treatment and the reacted treating agent.

Reference numeral 35 denotes a combustion device, for example, when LNG is burned, burns LNG from the LNG tank 36 to generate hot gas. This hot gas is supplied into a heating cylinder 22 provided on the outer periphery of the cylindrical body 21 and heats the cylindrical body 21.
After being fed into the heating cylinder 12 of the cylindrical body 11 through the connecting pipe 37 and heating the cylindrical body 11, it is sent out to the drying means 39 through the discharge pipe 38 and used as heat of the drying means. , And is sent to the combustion means 42 through the pipe 41.

The combustion means 42 is supplied to the gas in the discharge duct 17 of the first heat treatment furnace 10 and the gas in the supply duct 26 of the second heat treatment furnace 20 and is sent from the combustion device 35 to be used for each heating part. The burned gas is burned and sent to the bag filter 40 in the next step.

In the combustion means 42, the gas is burned to remove tar components, and the gas is cooled and sent to a temperature lower than the endurable temperature of the bag filter 40.

In the bag filter 40, after the reaction treatment with the treatment agent, the unreacted treatment agent is sent to the hopper 30 for reuse.
The exhaust gas is sent to an exhaust gas combustion section 43, where the exhaust gas is subjected to combustion processing by LNG or the like, and is discharged from a chimney 44.

Reference numeral 45 denotes a dehydrating means, which solidifies and separates the aqueous solution in the dissolving tank 34, and after the solid matter is dried by the drying means 39,
The liquid discharged to the carbide hopper 46 is neutralized by a water treatment means 47 with a neutralizing agent or the like, and then returned to the dissolving tank 34 for reuse.

Next, a series of processing methods will be described.
First, LNG is burned by the combustion device 35 to generate hot gas, which is supplied to the heating cylinders 22 and 12. If necessary, AC power is supplied to the heating coils 18 and 28 so that the cylindrical body 2
Heat 1,11. Next, (or simultaneously) a mixture of an object to be treated containing a halogen substance and a sulfide and a treatment agent made of an alkali metal compound, or a cylinder 11 of a first heat treatment furnace 10 from a hopper 30 while mixing. Supply within.

In the heat treatment in the first heat treatment furnace 10, after moisture is removed from the object to be treated in advance by a drying means, the temperature and time at which HCl gas and SOx gas are deposited are investigated in advance, and the heat treatment is performed. The properties of the processed material are grasped, and the processing is performed at a temperature (200 ° C. to 350 ° C.) and time that can sufficiently cover the results of the investigation.

The time and temperature are related to the state of the heating furnace (conditions depending on the furnace, such as the size and heating means), the processing amount, the processing time, the processing temperature, and the like. It needs to be done well, and it is necessary to collect and store data.

When the heating in the first heat treatment furnace is not "combustion and incineration" but "steaming and pyrolysis", the harmful HCl gas, SOx gas and the alkali metal compound which are deposited are removed. The contacting reaction with the treating agent can be effectively performed.

In the first heat treatment furnace 10, HC
Decomposed gas containing l, SOx components is generated, but H
Cl and SOx components are added alkali metal compounds,
For example, it reacts with sodium hydrogen carbonate to produce harmless sodium chloride (NaCl) and sulfite (Na ₂ SO ₃ ), and eliminates harmful HCl and SOx from the decomposition gas. Thereby, the detoxification of the HCl and SOx components in the decomposition gas and the detoxification of the residue can be performed at the same time.

After the harmful components are precipitated and detoxified, the object is sent to the supply port 23 of the cylindrical body 21 of the second heat treatment furnace 20 through the duct 17 and the opening / closing valve 32,
Here, the temperature at which the material to be treated is carbonized (carbonization of paper starts at about 350 ° C.) Carbonization by heating to 350 ° C. to 700 ° C. or incineration by heating to 800 ° C. or more to reduce the volume I do. In the second heat treatment furnace 20 in this volume reduction step, H
Since there is no cracked gas containing Cl and SOx components, it is not absorbed by the carbonized or incinerated object.

The volume-reduced material to be processed and the reacted sodium chloride, sulfite and the like are discharged into a dissolution tank 34 via a duct and an opening / closing valve 33. In this melting tank 34,
The reduced volume of the object to be treated, the treated agent after the reaction, and the like are dissolved in water, and this is separated into a solid and a liquid by a dehydrating means 45, and the solid is dried by a drying means 39, and then dried. On the other hand, the liquid is recovered from the hopper 46, and the liquid is recovered by the water processing means 47, and the liquid is returned to the dissolving tank 43 after being treated by injecting a neutralizing agent or the like.

The temperature control means of the first and second heat treatment furnaces is performed as follows. In the first heat treatment furnace 10, a valve (open / close valve or three-way valve) is provided in the communication pipe 37 with the heating cylinder 22 of the second heat treatment furnace 20. Are provided, and the flow rate of the hot gas is controlled by means for selecting the number of used by the valve opening / closing control.
The temperature is controlled by means for controlling the alternating current supplied to the heater or the frequency in the case of induction heating. These controls are performed by measuring the gas concentration of HCl or the like in the duct 17 with a gas
5 or is automatically or manually controlled according to the temperature detected by a temperature sensor provided in the temperature sensor mounting cylinder 19.

The temperature control means of the second heat treatment furnace 20 is substantially the same as that described above.
The control of the NG combustion means becomes main, and the electric heating means assists. These controls are also performed by the HC in the ducts 26 and 27.
The control is performed by reflecting the temperature detected by the gas concentration meters 46 and 47 for measuring the l concentration and the temperature sensor in the temperature sensor mounting cylinder 29.

At this time, the first and second heat treatment furnaces 1
When the hot gas passes through the 0 and 20 heating cylinders, the heat receiving increasing means is provided on the outer periphery of the cylindrical body, so that the heat of the hot gas is efficiently transmitted to the cylindrical body, and the object to be processed is also effectively heated. Done in

When the object to be treated and the alkali metal compound are heat-treated in a heat treatment furnace, the decomposed chlorine gas and sulfur oxide gas react with the alkali metal compound to render the decomposed gas harmless and the residue harmless. Can be performed simultaneously. This is clear from the following experimental investigation by the inventor of the present application.

The experiment was carried out using a solidified fuel (hereinafter, referred to as RDF) containing a sulfur component in an object to be treated as a sample.

The RDF is a product which is solidified so as to be combustible. In a broad sense, (1) kitchen waste (remaining material such as meat, fish head, bone, eggshell, vegetables, fruits, etc., is called "compost") (2) Plastics (polyethylene, polypropylene, polystin, polyvinylidene chloride, etc.) (3) Papers (tissue paper, newspaper, advertising paper, bags, boxes, beverage packs, etc.) (4) ) A solidified mixture of other combustible materials (fibers such as cloth, wood chips, rubber, leather, etc.).

In a narrow sense, (2), (3) and (4) which do not include the compost of (1) are mentioned. This time, RDF without compost was used.

The RDF of such a sample is crushed, and several kinds of substances are selected from the alkali metal compounds according to the present invention.
A comparative experiment was performed using uncrushed RDF.

It should be noted that a generally known processed RD
The sulfur component of F contains about 1.0% by weight, and the plastic RDF contains 0.29 to 0.89% by weight of a chlorine component. In addition, waste paper RDF is 0.2% by weight.
Contains a chlorine component.

In the experiment, a low-oxygen atmosphere was created in a closed vessel equipped with an exhaust pipe and having an opening / closing door, a sample was placed in this closed vessel, heated in an electric furnace, and heated from 250 ° C. to 600 ° C. for 5 hours.
The temperature was held at 0 ° C. for 5 minutes at each temperature, and the HC1 and SO ₂ gas concentrations (ppm) were measured by opening the exhaust pipe at the time of heating and keeping. In addition, the measurement was also performed at 600 ° C to 1000 ° C.

The gas concentration was measured using a detector tube specified in JIS-K0804.

Tables 1 and 2 show the measurement results. H
The Cl gas and SO ₂ gas concentrations were measured values in ten experiments, and Comparative Examples 1 to 3 in Table 2 were the lowest values, and Example 1 in Table 1 was the lowest value.
To 7 indicate the highest values.

Note that "ND" represents "not detected",
It shows that none was detected in 10 experiments.

First, 40 g of the above uncrushed RDF was crushed, and 10 g of NaHCO ₃ was added as a treating agent to the crushed RDF, and those obtained by adding 4 g were referred to as Examples 1 and 2, respectively. Examples 3 and 4 were obtained by adding ₃ g of KHCO ₃ and 3 g of Na ₂ CO ₃ + K ₂ CO ₃ as treating agents to 20 g of the crushed, respectively.
Examples 5 and 6 were obtained by adding 3 g of NaOH and KOH as a treating agent to 20 g of RDF crushed, and further adding 10 g of NaHCO ₃ as a treating agent to 40 g of a lump that did not crush RDF. As Example 7, the HCl concentration and the SO ₂ concentration of each sample were measured. Table 1 shows the results.

[0058]

[Table 1]

Next, a conventionally-processed RDF
Those obtained by using 40 g and 20 g of crushed RDF were referred to as Comparative Examples 1 and 2, respectively, and those obtained by using 40 g of lump without crushing RDF were used as Comparative Example 3.
The HCl concentration and the SO ₂ concentration were measured for each. Table 2 shows the results.

[0060]

[Table 2]

From the experimental results in Tables 1 and 2, the following is considered.

In the case of hydrogen chloride (HCl) (1) In the case of crushing, a very small amount was detected at 400 ° C. in Example 4, but was not detected in other examples, and very good results were obtained.

As can be seen from comparison with Comparative Examples 1 and 2, there is a considerable reduction.

(2) In the case of lumps, the amount was slightly detected as compared with the case of crushing at 350 to 450 ° C., but it was found that it was considerably reduced as compared with Comparative Example 3.

In the case of sulfide gas (SO ₂ ), (1) When crushed, SO ₂ is slightly generated at 400 to 450 ° C., but very good as a whole (Example 1)
~ 6).

It can be seen that Comparative Examples 1 and 2 are considerably reduced.

(2) In the case of a lump, 350 to 45
Although slightly more SO ₂ is generated than when crushed at 0 ° C., it is good as a whole (Example 7).

As can be seen from the comparison with Comparative Example 3, it is considerably reduced.

According to the above experimental investigation, when treating a treated product containing a chlorine component and a sulfur component, harmful HCl
And reacting with SOx to generate harmless chlorides and sulfites,
It was confirmed that HCl and SOx could be detoxified.

Although a similar dechlorination effect can be obtained even at 600 ° C. or higher, it may be determined based on the type of equipment, time, throughput, and the like.

The reason why HCl and SOx can be detoxified by adding an alkali metal compound for the treatment is as follows.
According to the following reaction.

(A) Reaction in the case of HCl The reason why harmful hydrogen chloride is replaced with harmless chloride is produced from the following reaction.

Sodium hydrogen carbonate (NaHCO ₃ ) + (HCl) → (NaCl) + (H
₂ O) + (CO ₂ ) potassium hydrogen carbonate (KHCO ₃ ) + (HCl) → (KCl) + (H ₂ O) +
(CO ₂ ) Sodium hydroxide (NaOH) + (HCl) → (NaCl) + (H ₂ O) Potassium hydroxide (KOH) + (HCl) → (KCl) + (H ₂ O) Especially in the case of hydrogen carbonate Is remarkable, this is because
First, CO ₂ is separated at a temperature lower than the temperature (250 ° C. or higher) at which hydrogen chloride (HCl) decomposes and precipitates, so that an atmosphere state in which the reaction between the remaining NaOH and KOH and the generated HCl can be performed smoothly. It is thought that it is.

That is, when the reaction state is sodium hydrogen carbonate, (NaHCO ₃ ) → (NaOH) + (CO ₂ ) (NaOH) + (HCl) → (NaCl) + (H ₂ O) Potassium hydrogen carbonate (KHCO ₃₎ ) → (KOH) + (CO ₂ ) (KOH) + (HCl) → (KCl) + (H ₂ O), and NaOH, KOH and HCl react rapidly to form harmless chlorides (NaCl, KCl). Is newly generated.

On the other hand, in the case of calcium carbonate (CaCO ₃ ) and slaked lime (Ca (OH) ₂ ), harmless chloride (CaCl) is similarly produced, but the reaction with Ca seems not to be smooth.

NaCl, KCl produced as described above
Is a harmless chloride. In addition to the above substances, N
There are the following sodium-based and potassium-based substances that produce aCl and KCl, and similar effects can be obtained.

Sodium carbonate, potassium carbonate, sodium potassium carbonate, sodium carbonate hydrate, sodium sesquicarbonate, natural soda.

Next, the chlorine-based substance after the treatment was confirmed.

As a result of analyzing the obtained residue, no harmful chlorine-based gas components were detected, and harmless chlorides such as sodium chloride and potassium chloride were detected. Further, the residue was stirred for 10 minutes and washed with water, so that sodium chloride and potassium chloride were dissolved in water and a carbide remained, but no harmful chlorine-based gas component was detected in the carbide.

Therefore, the harmful chlorine components are sodium chloride (NaCl) and potassium chloride (K
Cl), water (H ₂ O), and gas (CO ₂ ), do not generate hydrogen chloride that causes dioxin, and can achieve harmlessness of exhaust gas and residues.

(B) In the case of SOx reaction The reason why the harmful SOx is replaced with a harmless sulfite is evident from the following reaction.

Sodium hydrogen carbonate (NaHCO ₃ ) → (NaOH) + (CO ₂ ) (2NaOH) + (SO ₂ ) → (Na ₂ SO ₃ ) + (H
₂ O) Potassium hydrogen carbonate (KHCO ₃ ) → (KOH) + (CO ₂ ) (2KOH) + (SO ₂ ) → (K ₂ SO ₃ ) + (H ₂ O) Sodium hydroxide (2NaOH) + (SO ₂ ) → Na ₂ SO ₃ ) + (2H
₂ O) potassium hydroxide _{(2KOH) + (SO 2)} → (K 2 SO 3) + (H 2 O) potassium sodium carbonate _{(Na 2 HCO 3 + K 2} CO 3) + (2SO 2) → (Na 2 S
O ₃ ) + (K ₂ SO ₃ ) + (2CO ₂ ) In particular, the effect is remarkable in the case of a hydrogen carbonate system.
First, CO ₂ is separated at a temperature lower than the temperature (300 ° C. or higher) at which the sulfurized gas (SO ₂ ) decomposes and precipitates, so that the remaining alkali metal hydroxide (NaOH, KOH) and the generated SO ₂ It is considered that the atmosphere was such that the reaction could be performed smoothly.

That is, when the reaction state is sodium hydrogen carbonate, (NaHCO ₃ ) → (NaOH) + (CO ₂ ) (2NaOH) + (SO ₂ ) → (Na ₂ SO ₃ ) + (H
₂ O) Potassium hydrogen carbonate (KHCO ₃ ) → (KOH) + (CO ₂ ) (2KOH) + (SO ₂ ) → (K ₂ SO ₃ ) + (H ₂ O), and NaOH, KOH and SO ₂ It reacts quickly to produce harmless chlorides (Na ₂ SO ₃ , K ₂ SO ₃ ). Was produced as described above, Na ₂ SO ₃ (sodium sulfite), K ₂ SO ₃ (potassium sulfite) is a harmless sulfite, in addition to the above substances, likewise, Na ₂
There are the following sodium-based and potassium-based substances that generate SO ₃ and K ₂ SO ₃ , and similar effects can be obtained.

Sodium carbonate, potassium carbonate, sodium potassium carbonate, sodium carbonate hydrate, sodium sesquicarbonate, natural soda.

Next, the sulfide after the treatment was confirmed.

As a result of analyzing the obtained residue, harmful SO was detected.
No x gas component was detected, and potassium metal salts (Na ₂ SO ₃ , K ₂ SO ₃ ), which are harmless sulfites, were detected.

Further, by stirring the residue for 10 minutes and washing with water, the alkali metal salt of sulfite is easily dissolved in water, hydrolyzed to exhibit alkalinity, and (Na ₂ SO ₃ ) + (2H ₂ O) → (2NaOH) + (H ₂
SO ₃ ) (K ₂ SO ₃ ) + (2H ₂ O) → (2KOH) + (H ₂ SO
₃ ) These substances were dissolved in water and carbide remained, but no harmful SOx gas component was detected in the carbide.

Therefore, the harmful SOx components become a part of the residue, such as sodium sulfite (powder) (Na ₂ SO ₃ ), potassium sulfite (powder) (K ₂ SO ₃ ), moisture (H ₂ O),
Gas (CO ₂ ), preventing the generation of SOx gas,
It was confirmed that the detoxification of SOx gas can be realized from the decomposition gas and the residue.

The treating agents used for treating harmful components include: (1) a simple substance of an alkali metal compound, a mixture of plural kinds thereof, (2) the alkali metal compound is a substance of hydroxide or carbonate, and (3) Hydroxides and carbonates are sodium-based and potassium-based substances. (4) The desulfurizing agent is sodium bicarbonate, sodium carbonate, sodium sesquicarbonate, natural soda, potassium carbonate, potassium bicarbonate, sodium potassium carbonate, sodium hydroxide. It has also been found that a single substance selected from the group consisting of, potassium hydroxide, and a mixture of plural kinds are suitable.

Therefore, the contact reaction between the harmful components (chlorine gas and sulfur oxide gas) in the generated decomposition gas and the added treating agent causes the harmful components to be harmless sodium chloride (NaCl, KCl) and sulfite. (Na ₂ SO ₃ , K ₂
Since SO ₃ is replaced and generated, harmful components (chlorine-based gas and sulfur oxide-based gas) can be eliminated from the decomposition gas and the residue, and harmless decomposition gas and harmless residue can be obtained.

The detoxified residue (substance to be treated) is reduced in volume by carbonization or the like in the second heat treatment furnace 20, and is transferred to the dissolution tank 34 together with the harmless sodium chloride and sulfite of the reaction product. Taken out. The sodium chloride and the sulfite can be effectively removed by washing with a solution such as water.

As described above, the decomposition reaction means for decomposing and depositing the harmful components contained in the object to be treated and reacting with the alkali metal compound at the same time, and the means for heating and reducing the volume of the object to be treated thereafter. When performed in another heat treatment furnace, (1) As is clear from the results of the experiment, when the object to be treated such as waste containing chlorine component and sulfur component is subjected to heat treatment, harmful chlorine-based gas and The sulfur oxide-based gas is decomposed and precipitated, but the alkali metal compound and the generated harmful component react to produce harmless salts, so that both the decomposed gas and the residue can be made harmless, and The generated salts in the residue can be removed by a solution such as water, and no harmful components are precipitated in the removal solution, so that the waste can be safely treated.

Therefore, it is possible to effectively remove chlorine-based gas that generates dioxins and sulfur oxide-based gas that promotes air pollution.

(2) In the decomposition reaction step of decomposing and separating harmful substances contained in the object to be treated, the object to be treated and the alkali metal compound of the treating agent are both heated, so that the gas decomposed and deposited and The contact reaction with the agent is carried out quickly and reliably, and forms harmless salts, so that no harmful components are present in the exhaust gas. Therefore, generation of dioxin is prevented.

Further, the flue gas is not corroded and can be safely used as a heat source and a fuel at a high temperature exhaust gas or at a high temperature.

Since the cracked gas is harmless, it can be used as fuel (turbine, boiler, etc.) for reuse.

(3) The volume reduction step of heating the material from which the chlorine-based gas has been removed to reduce the volume is performed in a heat treatment furnace different from the heat treatment furnace in the decomposition reaction step. In the consolidation step, there is no dioxin generated due to harmful components in the residue, so that the dioxin does not adsorb and mix in the residue (carbide, ash), and the residue can be made harmless. Metals and carbides can be extracted from the residue and reused.

[0098]

As described above, according to the present invention, L is used as a heating source.
Since the NG combustion gas is used, and the heat gas is efficiently received by the cylindrical body by providing a heat receiving increasing means on the outer surface of the cylindrical body, the object to be processed can be effectively heated, and the heating time is reduced. It can be shortened and the processing efficiency is improved.

Accordingly, it is possible to shorten the entire processing time from the introduction to the discharge of the object to be discharged, and to increase the processing amount of the object as a whole.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a first embodiment of the present invention.

FIG. 2 is an explanatory view of a heat receiving increasing means of the present invention.

FIG. 3 is a conceptual diagram of a waste treatment facility according to a second embodiment of the present invention.

[Explanation of symbols]

_Fh : Heat treatment furnace 1: Cylindrical body 2: Heating cylinder 3: Supply port 4: Discharge port 5: Rotary drive means 6: Supply duct 7: Discharge duct 8: Combustion device

Claims (5)

[Claims] 1. A rotatable cylindrical body having a supply port for supplying an object to be processed on one end side and a discharge port for discharging the same on the other end side, and disposed at a substantially horizontal position. A heating treatment furnace is constituted by means for stirring and transferring the object to be treated from the supply port side to the discharge port side, and a heating means for externally heating the cylindrical body, wherein the heating means comprises an outer periphery of the cylindrical body. A heating cylinder is provided to form a sealed space between the heating cylinder and the outer periphery of the cylindrical body, and a heated gas obtained by a combustion device is introduced into the sealed space to heat the object to be processed, and the outside of the cylindrical body is heated. A heat treatment apparatus characterized in that a heat receiving increasing means for increasing a contact area with a hot gas is formed on a surface. 2. The heat gas treatment apparatus according to claim 1, wherein the heat receiving increasing means is formed by a spiral projection, a flat projection, or a corrugated projection. 3. The heat gas treatment apparatus according to claim 1, wherein the heat reception increasing means is formed by a plurality of concave or wavy grooves at predetermined intervals in a circumferential direction of the surface. 4. The heating apparatus according to claim 1, wherein the cylindrical body is made of an iron-based material. 5. The heat gas processing apparatus according to claim 1, wherein a gas generated by burning LNG is used as the hot gas.