JPS61197910A - Waste material combustion method removing hydrogen chloride and its device - Google Patents

Abstract

PURPOSE:To enable to simply remove hydrogen chloride without providing a large scale attached facilities, by a method wherein alkali agent is spouted to gas containing hydrogen chloride which is generated by burning combustible wastes, and to make generate chloride in the gas, and to make pass ash layers of particle remnants. CONSTITUTION:In a dry distillation furnace 1, thrown in wastes 20 are stacked in the furnace, and after ignition, these are dry distillated at the 500-600 deg.C by the air which is supplied from an air dispersion pipe 10 and passed a fire grate 9, and hydrogen chloride is generated from wastes by heat decomposition and dry distillated gas which contains hydrogen chloride enters in a reaction chamber 4 through a gas passage 5, and, for instance, slaked lime powder is spouted from an alkali agent spouting output 13, and calcium chloride is generated by reacting with hydrogen chloride, and goes down accompanied by gas. In the mean while, ash layers 21 of particle remnants after dry distillation are transferred to the side of the reaction chamber 4 by a screw conveyer 11, and calcium chloride and soot etc. accompanied by dry distillation gas are filtered and classified when passing by ash layer 21' of particle type remnants, and ash layers of particle remnants which caught these, fall in an ash take out box 18, and are discharged outside by opening a damper 19.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention removes hydrogen chloride from the carbonization gas when combustible waste is burned and carbonized to produce gas or incinerated to release exhaust gas. The present invention relates to hydrogen chloride removal combustion in which purified non-corrosive gas is extracted, or incineration exhaust gas is released into the atmosphere as harmless.

(Conventional technology) Municipal dust and various industrial wastes often contain substances that generate hydrogen chloride when burned, such as vinyl chloride and chloroprene rubber, and when used as a heat source as carbonized gas, they corrode various equipment. Also, when incinerated, there is a problem in that it pollutes the atmosphere.

As a prior art for removing this hydrogen chloride, Japanese Patent Application Laid-open No. 54
-37378 publication, and JP-A-54-150865
Although it is disclosed in the Japanese Patent Application Publication No. 54-373 of the former
Publication No. 78 adopts a fluidized incinerator, introduces lime powder into the upper space of the furnace, causes a contact reaction with hydrogen chloride in the furnace, and causes the hydrogen chloride to adhere to the surface of the lime powder as calcium chloride.
The lime powder with calcium chloride attached is then removed outside the furnace using a dust collector such as an electrostatic precipitator or a multi-cyclone. Calcium compounds are supplied directly to the input point of the material supply hopper and immediately undergo a dry reaction with hydrogen chloride generated from the waste layer, but in this case as well, the reaction is accelerated in a high temperature atmosphere, similar to the prior art described above. However, electrostatic precipitators were installed in the flue leading to the chimney, and hydrogen chloride was separated and removed outside the incinerator.

(Problem to be Solved by the Invention) When recovering thermal energy from waste by carbonization, conventional mechanical stoker furnaces perform gasification by carbonization of waste and combustion of generated gas almost simultaneously and without distinction. In order to be exposed,
Gasification and combustion are not performed completely, and soot and unburned phosphorus remain in the exhaust gas, which is undesirable. Therefore, for heat recovery from waste, it is recommended to install a two-stage device in which the process involves carbonizing the waste to obtain gas, and then combusting the generated gas in a separately provided burner.

When burning combustible waste containing vinyl chloride, chloroprene rubber, etc., for example, when vinyl chloride is burned in the presence of oxygen, it reacts as follows to generate hydrogen chloride.

C! H2OHCl+D02→HOJl'+2002+H
20 To remove hydrogen chloride generated in this way, 1)
There are two methods: a wet method in which salts are absorbed in water or an alkaline solution, 2) a semi-dry method in which salts are reacted with an alkali solution and recovered as a solid, and 3) a completely dry method in which salts are reacted with an alkali powder and recovered as a solid. Of these, the wet method can remove 30 to 40% by water injection, and the alkaline solution can remove 85 to 95% at low temperatures. This requires dual facilities such as waste liquid treatment equipment, which increases construction costs, and there are also problems such as chlorides and soot adhering to the waste heat recovery equipment, reducing heat transfer efficiency and corroding the equipment. Ta. In addition, in the semi-dry method and fully dry method, gas is purified outside the furnace by installing an electrostatic precipitator in the flue from the combustion furnace to the chimney, but this also requires large-scale equipment and poses problems. there were.

(Means for Solving the Problems) Therefore, in view of the above-mentioned problems of carbonization furnaces or incinerators, in order to solve the problems, the present invention has been developed to easily chlorinate the This was developed to provide a method and device for capturing and removing hydrogen as chlorides such as calcium chloride. The agent is ejected to generate chloride in the gas,
The chloride-carrying gas is passed through the ash layer of granular residue in the furnace to capture and remove the chloride, and a partition wall is installed in the furnace with an alkali agent spout at the top to separate the combustion chamber and this. A reaction chamber is formed that communicates with the ash layer, and an ash extraction device is installed in the lower part of the furnace, and a gas outlet is opened in the reaction chamber through the ash layer of the granular residue, and a hydrogen chloride removal waste combustion device is connected to the ash layer box. It is.

(Operation of the Invention) In the present invention, hydrogen chloride generated during carbonization or combustion of waste reacts with an alkali powder, such as slaked lime, as shown in the following equation.

2HOJ? +0a(OH)r”oaO12+2H20 The produced calcium chloride is captured by passing through the ash layer of the granular residue in the furnace and discharged together with the ash, eliminating the need for ancillary equipment such as electrostatic precipitators and multi-cyclones of the prior art. It is something to do.

In other words, there is a gas passage above the combustion furnace, and the lower part is divided into a large-capacity combustion chamber and a small-capacity reaction chamber by a partition wall that allows the transfer of the granular residual ash layer. Gas accompanied by chlorides such as calcium chloride that ejects and reacts with hydrogen chloride and falls is transferred from the combustion chamber by an ash removal device such as a screw conveyor or pusher, and is retained on a fine ash layer support filter. It passes through the ash layer of the granular residual agglomerates, and the space between the residual agglomerates becomes an effective filtration flow path, and chlorides such as powdered calcium chloride are captured by IP.In the case of carbonization, only the purified gas is passed through the combustion furnace in the latter stage. (not shown), and in the case of incineration, it is released into the atmosphere.As shown in the example, the partition wall faces the combustion chamber, so the temperature becomes high, maintaining the reaction chamber at a high temperature, and promoting the reaction. . Chlorides such as calcium chloride captured in the ash layer of the granular residue are discharged from the ash removal box together with the ash content.

(Embodiment) The figure is a cross-sectional explanatory diagram showing an embodiment of the present invention in which carbonization gas is obtained by carbonization combustion of combustible waste. 2 into a large-capacity carbonization chamber 3 and a small-capacity reaction chamber 4, and the chambers are communicated with a gas passage 5 at the top and a top outlet passage 6 at the bottom, and a damper 7 is provided at the top of the furnace. A waste input device 8 is provided, and the entire lower part of the carbonization chamber is covered with Rosdol 9. An appropriate number of air dispersion pipes 10 for combustion are placed below it, and a screw conveyor or An ash removal device 11 such as a pusher is arranged until it reaches the side wall 12 of the reaction chamber.

In the upper part of the reaction chamber, a plurality of alkali agent jet ports 13 are opened as appropriate, and in the lower part, an ash layer supporting filter 14, which is narrower than the spacing between the Rosdol 9, is spread, and below that, a gas outlet 15 is opened.
An ash removal box 18 having an inclined side wall 17 is provided on the side wall 12 via a damper 16, and a damper 19 provided on the box 1B blocks outside air.

The alkaline agent spout may be provided in the carbonization chamber if measures are taken to prevent clogging.

In the carbonization furnace 1 having the above configuration, the input waste 20 containing chlorides such as vinyl chloride and chloroprene rubber was deposited in the furnace, and after being ignited, it was supplied from the air distribution pipe 10 and passed through the Rosdol 9. Approximately 500~ depending on the air
The waste is carbonized at 600°C, and hydrogen chloride is generated by thermal decomposition, and the carbonized gas containing this enters the reaction chamber 4 through the gas passage 5. For example, slaked lime powder is passed through the alkali agent spout 13.
It ejects from the water, reacts with hydrogen chloride to produce calcium chloride, and descends along with the gas.

On the other hand, the ash layer 21 of the granular residual mass after carbonization is transferred to the reaction chamber side by the screw conveyor 11, and here the carbonization gas descending through the reaction chamber 4 is transferred to the ash layer 21' of the granular residual mass and the fine particles supporting this. Passes through the ash layer support filter 14 and exits at the outlet 1
5 to the subsequent combustion chamber (not shown), but the calcium chloride and soot entrained by the carbonized gas are separated as they pass through the ash layer 21' of the granular residue, and the captured granules The remaining ash layer falls into the ash removal box 18, and is discharged to the outside by opening the damper 16. The presence of the fine ash layer supporting filter 14 is effective in ensuring an ash layer at all times, and chloride-entrained gas does not pass through the flue.

In the above explanation, slaked lime was used as the alkaline agent, but it goes without saying that quicklime, magnesium hydroxide, soda ash, etc. can also be used. The ash removal work should be carried out after the amount of dust in the furnace has decreased. If the ash layer in the reaction chamber becomes too high due to the transfer of the ash layer and the gas passage resistance becomes large, open the damper 16 and remove the ash. The ash is dropped into the box 18, and when the ash layer decreases, the damper 16 closes to convert the ash layer to an appropriate height, and the ash removal operation can be adjusted in this way.

(Effects) The present invention injects an alkali agent into high-temperature combustion gas containing hydrogen chloride to generate chlorides such as calcium chloride in the gas, and the combustion gas accompanied by the chlorides is used to remove granular residual agglomerates in the furnace. This is a hydrogen chloride removal waste combustion method that captures and removes the chlorides through an ash layer, and an apparatus in which a reaction chamber is formed by dividing the furnace with a partition wall, so the reaction chamber has one side that is the partition wall of the high-temperature combustion chamber. In addition to being maintained at a high temperature, the existence of this reaction chamber lengthens the gas flow path and keeps the gas residence time longer than in the case of taking gas immediately from a conventional incinerator that spews out an alkaline agent. The longer the reaction time, the more the hydrogen chloride removal reaction is promoted.

In addition, if the alkali agent spout is installed above the reaction chamber, the alkali agent will be ejected in parallel with the gas flow, reducing the ejection resistance and lowering the ejection pressure, preventing clogging. If equipment, air dispersion pipes, etc. are buried in the ash layer, they will not be directly exposed to flames and can withstand long-term use.

Furthermore, since the combustion gas passes through the ash layer of the granular residue, the entrained chlorides such as calcium chloride and soot are eliminated and captured by the granular residue ash layer, making it possible to use large-scale equipment such as conventional electrostatic precipitators. Furthermore, since the combustion gas does not contain hydrogen chloride, corrosion due to hydrogen chloride can be prevented even if a heat recovery waste heat boiler is installed in the latter stage. Since post-processing equipment and the like are not required, the equipment becomes simpler, the equipment cost becomes cheaper, and maintenance becomes easier, which has great effects.

[Brief explanation of the drawing]

The drawings are explanatory cross-sectional views of one embodiment of the present invention, in which FIG. 1 is an explanatory longitudinal cross-sectional view, and FIG. 2 is a partially cutaway plan view showing the internal structure. ]... Carbonization furnace, 2... Partition wall, 3... Carbonization chamber, 4... Reaction chamber, 5... Gas passage,
6...Tendo outlet passage, 8...Waste input device, 9
...Rosdol, 10...Air distribution pipe, 11...
- Ash extraction device, 13... Alkaline agent spout, 14... Ash extraction support filter, 15... Gas outlet, 18... Ash extraction box, 20... Waste, 21.21' ...Ash layer of granular residual mass.

Claims (2)

[Claims] (1) An alkali agent is injected into the gas containing hydrogen chloride generated by burning combustible waste to generate chloride in the gas, and the gas accompanied by the chloride is removed from the ash of granular residue in the furnace. Hydrogen chloride removal waste combustion method that captures and removes chloride through a layer. (2) A partition wall is provided in the furnace equipped with an alkaline agent spout at the top to form a combustion chamber and a reaction chamber communicating with the combustion chamber.An ash removal device is installed at the bottom of the furnace, and the reaction chamber is filled with ash of granular residue. A hydrogen chloride removal waste combustion device with a gas outlet opening through the bed and communicating with the ash removal box.