JP2006061809A - Method for recovering fire extinguishing chemical and its apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make materials with a high concentration of sulfur utilizable in a burning apparatus under an oxidizing atmosphere, and to provide an apparatus for recovering fire extinguishing chemicals containing an alkali hydrogencarbonate and an alkali carbonate. <P>SOLUTION: The apparatus for recovering the fire extinguishing chemical is characterized in that an apparatus for depositing and recovering a sulfate by extracting part of an exhaust gas under an oxidizing atmosphere from the burning apparatus is equipped with a monitoring means for monitoring the sulfur content of a raw fuel used in the burning apparatus and a means for charging fire extinguishing chemicals containing sodium carbonate or the like taken out from a fire extinguisher in response to the sulfur content, thereby enabling the raw fuel with a high sulfur content to be burned. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a method for recovering a sulfate derived from a fire-extinguishing agent containing an alkali hydrogen carbonate and an alkali carbonate, and more particularly, a fire-extinguishing agent characterized in that it can be calcined with a raw fuel having a high sulfur concentration. It is related with the recovery method and its apparatus.

A part of the fire extinguisher that has become unusable due to the pressure drop of the pressurized gas, etc. is being recycled by the waste fire extinguisher processor. Or, the current situation is that it is discarded as it is and reuse is hardly progressing. One of the reasons is that there has been no reuse technology that uses fire extinguishing agents easily and constantly.

  That is, the conventional method of reusing a fire extinguishing agent is limited to recycling use in which the fire extinguishing agent is exclusively regenerated and filled in the fire extinguisher again. Patent Document 1 relates to a recovered powder fire-extinguishing agent containing ammonium phosphate and ammonium sulfate as main components and containing additives, and Patent Document 2 relates to a protein foam fire-extinguishing agent, and a fire-extinguishing agent containing an alkali carbonate and an alkali bicarbonate. There is no disclosure regarding the recycling of.

On the other hand, in a firing apparatus under an oxidizing atmosphere using a material with high sulfur concentration as a raw fuel, this operation is usually limited unless a SOx reduction treatment is performed using a special desulfurization apparatus or the like. . For example, with respect to SOx, it is necessary to clear a predetermined regulation value, and the total amount is regulated for each office. Furthermore, while there is no levy system for NOx emissions, SOx is charged according to the amount of emissions even if the regulation value is cleared. Moreover, in the cement baking apparatus using calcium carbonate as a raw material, the cement baking furnace itself functions as a kind of desulfurization apparatus by reacting with quick lime derived from calcium carbonate and SOx derived from raw fuel having a high sulfur concentration. However, when using high sulfur content as raw fuel, it is necessary to install a desulfurization device, etc., for the calciner that does not use calcium carbonate or calcium oxide as a raw material. This is an indispensable situation. As described above, firing apparatuses that are difficult to use as a raw material such as calcium carbonate are general waste combustion treatment equipment, firing equipment for detoxifying sludge, artificial aggregate firing furnace, boiler firing equipment, etc. Occupies most of the baking equipment.

Therefore, in order to use raw fuel, particularly high-sulfur concentration fuel (for example, delayed oil coke) that leads to discharge of high-concentration SOx, etc., these calcining devices require special desulfurization equipment. It can be said that the actual situation is that there are considerable restrictions on the choices.

Conventionally, a material having a high sulfur content as a pretreatment has few means capable of removing the sulfur content by chemical and physical means, and the substantial use of this pretreatment is difficult. As a result, if SOx emission is not taken into consideration, even a firing apparatus that can be appropriately used as a raw fuel must be abandoned. The present invention has been made to enable reuse of waste extinguishing chemicals and diversification of raw fuels in the firing process.
JP 2003-70935 A JP 2000-63845 A

The present invention has been made in view of the above circumstances, and enables use of a material with a high sulfur concentration in a baking apparatus under an oxidizing atmosphere, and in addition, a fire extinguisher containing an alkali hydrogen carbonate and an alkali carbonate. It is an object of the present invention to provide a method and apparatus for recovering a pharmaceutical agent.

A method of extracting a part of exhaust gas from a calcination apparatus in an oxidizing atmosphere and depositing and recovering sulfate, depending on the sulfur content and / or exhaust sulfur oxide content of the raw fuel used in the calcination apparatus. A fire-extinguishing agent recovery method characterized in that a fire-extinguishing agent containing sodium carbonate and / or sodium bicarbonate taken out from a fire extinguisher is introduced into the above-mentioned calcination device to enable firing of raw fuel having a high sulfur content. (Claim 1) An apparatus for extracting a part of exhaust gas from a calcination apparatus in an oxidizing atmosphere to deposit and recover a sulfate, wherein the sulfur content of the raw fuel used in the calcination apparatus and / or Monitoring means for monitoring the amount of sulfur oxide discharged, and sodium carbonate and / or sodium bicarbonate taken out from the fire extinguisher in accordance with the sulfur content and / or the amount of sulfur oxide discharged A fire extinguishing agent recovery device (Claim 2), characterized in that the raw fuel having a high sulfur content can be fired.

In this specification, “raw fuel used in firing equipment” includes raw materials to achieve the purpose of firing furnaces such as limestone, clay, earthenware waste, soil, general waste, industrial waste, etc. Point. When the firing device includes a boiler combustion furnace, since the firing device is used for the purpose of generating heat energy from combustion for steam generation, it can be said that there is no equivalent to the raw material, but in general, the ash content in the fuel is fired. As a result, what is calcined is included in the fuel. These are also responsible for the scale in the boiler. The “raw fuel used in the calciner” includes combustible waste such as heavy oil, pulverized coal, and waste plastic. In the present specification, “recovery” has a meaning generally understood by those skilled in the art, and “separation only”, “removal only”, or “separated” or “removed” as valuable compounds. Including getting. In the present specification, the “low melting point compound” includes sodium chloride, potassium chloride, sodium sulfate, potassium sulfate, heavy metal chlorides and sulfates, and the like. "A part of the extraction gas" means that in general baking equipment, the general baking process is the main, and in cooperation with peripheral equipment such as calcining furnaces, it is usually in principle to extract all of it. It is because it is not obtained. However, it does not eliminate the case where “all” is extracted when possible or necessary.

According to the present invention, in a method of extracting a part of exhaust gas from a firing device and recovering sulfate, the fire is extinguished in the firing device according to the SOx content expected to be generated from materials used in the firing device. There is provided a method for recovering a fire extinguishing agent, characterized in that a fire extinguishing agent containing sodium carbonate and sodium bicarbonate taken out from a container is introduced to enable firing of a material having a high sulfur concentration. In addition, when the method of the present invention is used for a baking apparatus including a boiler, or the present invention is a baking apparatus including a boiler, it has been found that an effect that is not seen other than that of reducing the adhesion of scale can be obtained. . This is thought to be the result of a decrease in the ash that grows the scale.

DESCRIPTION OF EMBODIMENTS Embodiments of a fire extinguishing chemical recovery method and apparatus according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a conceptual diagram showing an outline of an embodiment of an aggregate firing apparatus for carrying out a fire extinguishing chemical recovery method and apparatus according to the present invention.

An aggregate firing apparatus 100 according to this embodiment includes a rotary kiln 101 and an aggregate cooler 102 as main components for firing the aggregate.

Here, by describing the operation of the aggregate firing apparatus 100 including the embodiment of the fire extinguishing chemical recovery apparatus according to the present invention, the fire extinguishing chemical recovery method and recovery apparatus according to the present invention are described. Will be explained. In the present embodiment, first, the granulated molded body hopper 110 and the fire extinguishing agent hopper 111 are put into the rotary kiln.

The granulated molded body can be molded by various methods. One feature of the present invention is that a fire extinguishing agent is charged into the baking apparatus. This is because SOx and sodium are combined in the firing process of the raw materials and the like, and the SOx fixation is facilitated by the formation reaction of sodium sulfate. In an oxidizing atmosphere furnace, sulfur contained in the raw material or the like can be recovered as SOx and further recovered as sodium sulfate.

In this embodiment, a fire extinguishing agent is added as a sodium compound. The control of the input amount from the hopper 111 will be described later. Examples of fire extinguishing agents that can be used include sodium bicarbonate and sodium carbonate. Two or more compounds can be used in combination. As described above, a fire extinguishing agent taken out from a fire extinguisher that has become unusable is effective.

The raw materials pulverized by the crusher 112 are mixed by the mixer 113 and temporarily stored in the storage silo 120. And according to the processing condition of the aggregate baking apparatus 100, it inputs into the raw material input part 121. FIG.

The raw material reaches the rotary kiln 101. The rotary kiln 101 includes a burner 122. The burner 122 is fed with main fuel such as heavy oil and pulverized coal and auxiliary fuel such as waste plastic, and burns it to burn the artificial aggregate. The artificial aggregate discharged from the rotary kiln 101 enters the cooler 102 and is cooled. These are a series of firing steps for the artificial aggregate.

In the present embodiment, the concentration of sulfur and chlorine in the raw material and fuel, chlorine concentration, concentration of alkali metal such as sodium, alkaline earth metal such as sodium, and the like are further increased by fluorescent X-rays (especially those having an energy dispersive detector). The calcium concentration is monitored, the chemical reaction by the raw fuel is determined, and the amount of fire extinguishing agent input is determined by the following formula. That is, the number of moles calculated by 1 <(2SO _x -Na etc. + Cl-2Ca) / number of Na moles in the charged drug <1.2. Here, Na, etc., in the case where there are other alkali metals or alkaline earth metals, consider this, and Ca is only the one that reacts with SOx due to incomplete chemical reaction with the raw fuel. Consider. Moreover, it is necessary to consider the redox state of sulfur present in the raw fuel. Specifically, for example, it is necessary to specify x of SOx, but x can be represented by 3 if it is an oxide. If there is any other state, a coefficient corresponding to this is set. In some cases, sulfur may exist as negative ions or as a simple substance. When the value obtained by dividing the number of moles calculated by this formula by the number of moles of Na in the input drug is less than 1, SOx fixation is insufficient, and the number of moles calculated by this formula is the Na mole in the input drug. When the value divided by the number exceeds 1.2, the sodium component becomes excessive, which may hinder the purpose of the firing furnace. Furthermore, when these values cannot be determined because the chemical reaction equation is complicated, a method not based on this equation can be used. At this time, the amount of SOx in the exhaust gas is measured with a normal monitoring device, and the amount of the digestive drug introduced per unit time is determined in accordance with the amount of SOx per unit time in the exhaust gas. Similarly, when SOx is generated without completing the chemical reaction, the amount of fire extinguishing agent to be input is determined by analyzing the exhaust gas. The amount of fire extinguishing agent determined in this way is put into the crusher 112.

Next, the process of recovering sodium sulfate from the extracted exhaust gas will be described in the present embodiment. First, the extracted exhaust gas is sent to the heating device 130. The extraction operation is performed using an extraction device such as an extraction probe (not shown). The extracted exhaust gas is usually in a temperature range of 400 to 700 ° C. In the heating device 130, this is heated to a temperature of 1100 to 1500 ° C.

By heating in this way, the low melting point compound is transferred from the dust side mainly composed of the raw material component to the vaporized gas component. The exhaust gas is then sent to the cyclone 131. Here, solid-gas separation is performed, and the dust is returned to the firing step. Here, the low melting point compound is contained in the gas component. Accordingly, the returned dust contains almost no low melting point compound. Low melting point compounds may include potassium, sodium, and metal chlorides and sulfates such as copper, zinc, lead, and vanadium.

The extracted exhaust gas containing the low melting point compound is sent to the bag filter 132. Before this, cooling gas is fed in and cooled to a temperature of 120 to 600 ° C. Then, the low melting point compound is separated by the bag filter 132. The separated low melting point compound is recovered from the lower recovery port and sent to the heavy metal recovery device 133. As the heavy metal recovery device 133, a device generally used by those skilled in the art, such as a wet refining device, can be employed. For example, the recovered dust-like low melting point compound is washed with water, and acid / alkali elution, sulfide precipitation, etc. are appropriately combined and separated as a metal refining raw material containing a zinc component, a copper component, and a lead component.

The gas component of the extracted exhaust gas that has passed through the bag filter 132 is returned to the raw material charging unit 121 again. When the temperature of this gas is 350 ° C. or higher, it contributes to increasing the efficiency of the entire apparatus.

The calcining apparatus 100 includes a waste heat recovery boiler 140, collects the waste heat of the exhaust gas, and then exhausts the exhaust gas from the chimney 142 through the bag filter 141.

Other Embodiments Although the alkali sulfate recovery method and apparatus according to the present invention have been described with respect to the embodiment of FIG. 1, the present invention is not limited to these embodiments.

For example, the aggregate firing furnace is a rotary kiln in the embodiment of FIG. 1, but other types of firing furnaces such as a moving bed such as a vertical kiln or a fluidized bed firing furnace may be used. Moreover, even if it is a baking apparatus provided with the calcining furnace and / or the suspension preheater, this invention can be implemented. Further, instead of heating with the heating device of FIG. 1, a combustible material may be put into the inlet hood and burned, and the gas temperature of the inlet hood may be raised to 1100 to 1500 for extraction. Furthermore, the input position of the alkali carbonate or the like from the digestive agent may not be directly input to the crusher 112 but may be from the raw material input unit 121 as long as it is a powder. The fire extinguishing agent may be mixed with fuel and introduced into the combustion furnace from the burner. Moreover, you may flow in with the inflow air to a burner.

It is a conceptual diagram explaining the outline | summary about one Embodiment of the artificial aggregate baking apparatus containing the collection | recovery apparatus of the fire extinguishing chemical | medical agent which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Artificial aggregate baking apparatus 101 Rotary kiln 102 Cooler 110 Raw material hopper 111 Extinguishing chemical hopper 112 Crusher 113 Mixer 120 Storage silo 121 Raw material input part 122 Burner 130 Heating device 131 Cyclone 132 Bag filter 133 Heavy metal recovery device 134 Alkali salt recovery device 140 Waste heat recovery boiler 141 Bag filter 142 Chimney

Claims (2)

A method of extracting a part of exhaust gas from a calcination apparatus in an oxidizing atmosphere and depositing and recovering sulfate, depending on the sulfur content and / or exhaust sulfur oxide content of the raw fuel used in the calcination apparatus. A fire-extinguishing agent recovery method characterized in that a fire-extinguishing agent containing sodium carbonate and / or sodium bicarbonate taken out from a fire extinguisher is introduced into the above-mentioned calcination device to enable firing of raw fuel having a high sulfur content. . A device that extracts a portion of the exhaust gas from the calcination device in an oxidizing atmosphere and deposits and recovers the sulfate, and monitors the sulfur content and / or the exhausted sulfur oxide content of the raw fuel used in the calcination device. And means for introducing a fire extinguishing agent containing sodium carbonate and / or sodium bicarbonate taken out of the fire extinguisher into the calcining device according to the sulfur content and / or the amount of sulfur oxide discharged. A fire extinguishing chemical recovery apparatus characterized by comprising a raw material fuel having a high sulfur content.

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