JP2006205027A - Apparatus and method for reducing volume/weight of hydrous organic sludge or the like - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for treating waste such as sludge having high moisture content by using less fuel, wherein the bad smell generated when waste is dried is burned/decomposed together with a dry distillation gas, industrial waste such as sludge is drastically reduced in volume and weight, and sludge having high moisture content is pretreated in a general melting furnace including a gasifying/melting furnace and the melting furnace is operated stably and economically to obtain a molten raw material from which a dried/dry-distilled product being a carbonized material can be produced and used as a reducing agent etc. in the steel industry, namely, to provide a technique capable of not only treating waste but also producing a recyclable product. <P>SOLUTION: This apparatus is provided with: a dryer comprising an inner cylinder and an outer cylinder; a dry distillation furnace which is arranged in the succeeding stage of the dryer and comprises an inner cylinder, an outer cylinder and a central cylinder; a hot air generation furnace for burning the dry distillation gas generated from the inner cylinder of the dry distillation furnace to generate hot air; and a means for introducing the generated hot air into the space between the inner cylinder and the outer cylinder of the dryer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention performs dry distillation by drying high moisture-containing industrial waste such as organic sludge, pruned branches, livestock waste, food waste, etc., and uses the generated dry distillation gas as energy to reduce and reduce the volume. In addition to treating waste and containing harmful dioxins, when detoxifying with chemicals, removing carbide as a product and reusing it as a useful resource, and melting organic sludge with a lot of moisture The present invention relates to a pretreatment method and a treatment apparatus for preventing a steam explosion or the like.

  In recent years, with increasing public interest in environmental issues, technology development has been made to detoxify sludge that occupies about 70% of industrial waste and waste containing high moisture, and to recycle it with less energy. Is required. In addition, the situation that the construction of landfills for waste, etc. cannot be done due to the opposition of the local residents, the shortage of landfills has become a problem.

Especially for sludge, the amount of water contained is often 90% or more, and occupies most of the weight of waste.
Therefore, it is important to separate moisture and reduce the weight of waste. Conventionally, a dehydrator or the like is often used, but in the case of organic sludge, the water content immediately after dehydration is still about 80%.
Heat evaporation is most effective for completely separating water, but for that purpose, a large amount of fossil fuel or electric power is required, and a lot of energy is consumed.
In addition, melting furnaces that are generally used in recent years often cause a steam explosion or poor melting if a large amount of water is contained in the processed material.
Therefore, when the sludge having a high water content is melted, a pretreatment such as dehydration is required, and a method for effectively using the contained organic matter has not been established.
Methods for drying using dry distillation gas are disclosed in JP-A-8-253771, JP-A-9-174031, JP-A-9-210333, and JP-A-11-138133. No method has been proposed for drying and distilling organic sludge having a large water content and recovering it as carbides.

Japanese Patent Laid-Open No. 8-253771 Japanese Patent Laid-Open No. 9-174031 JP-A-9-210333 Japanese Patent Laid-Open No. 11-138133

The present invention is an apparatus and method for treating waste such as sludge having a high water content with less fuel in view of the technical problems as described above, and burns malodor generated by drying together with dry distillation gas, In addition to decomposing, it aims to greatly reduce the volume of industrial waste such as sludge, and it can also be used for pretreatment of general raw materials for melting furnaces including gasification melting furnaces.
In addition, dry-distilled products can be used as reducing agents in the steel industry as carbides, and the purpose is not only to treat waste, but also to provide technology that can manufacture recycled products.
Furthermore, in the case of sludge containing harmful substances, the harmful substances can be decomposed, for example, by mixing with a dioxin decomposition agent.

  In particular, the present invention is a technology that can reduce sludge and the like containing a large amount of water by using a minimum amount of energy, reduce the cost of the treatment, and contribute to the extension of the shortage of final disposal sites.

In order to achieve the above object, the technical gist of the present invention is to provide a dry distillation furnace consisting of an inner cylinder and an outer cylinder, preferably a central cylinder, in a subsequent process of a dryer consisting of an inner cylinder and an outer cylinder. A hot air generating furnace for generating hot air by burning dry distillation gas generated from the inner cylinder is provided, and means for introducing the hot air between the inner cylinder and the outer cylinder of the dryer is provided.
More specifically, a dryer equipped with an inner cylinder made of a rotating cylinder and a dry distillation furnace equipped with an inner cylinder made of a rotating cylinder are installed, and the carbonization gas generated in the carbonization furnace is burned in a hot air generating furnace. In addition, it is characterized in that the sludge thrown into the inner cylinder is dried by an external heating method by the combustion gas generated by co-firing with a burner device installed for the purpose of adjusting the amount of heat.

  In this case, organic sludge and the like can be continuously introduced into the system, and if a stirring blade is provided in the rotating cylinder, the evaporation efficiency of moisture can be promoted.

Here, after the hot air generated in the hot air generating furnace is further passed between the inner cylinder and the outer cylinder of the dryer, and further provided with means for introducing between the inner cylinder and the outer cylinder of the dry distillation furnace, The waste heat from the dryer can be used as a heat source for the furnace.
Moreover, in order to use waste heat more effectively, hot air can also be passed through the center tube.
Since the dried sludge is introduced into the external heating type carbonization furnace using the waste heat, it is separated from the heat source, and it is possible to produce a high quality carbide with less ash.

Carbon dioxide, which is regarded as a problem as a global warming gas generated by combustion of carbon dioxide, is a problem of increasing the carbon dioxide concentration on the earth due to the concept of carbon neutral. It does not cause.
In addition, a means for introducing the exhaust gas after drying generated from the inner cylinder of the dryer into the hot air generating furnace is provided, and the energy can be effectively used when reheated in the hot air generating furnace.
Further, using a volume reduction / weight reduction device, the high water content organic sludge can be dried with a dryer and then carbonized in a carbonization furnace to obtain a carbide.
In the case of raw materials containing harmful substances, for example, those containing dioxins can be rendered harmless by mixing dioxins decomposition inhibiting agents with the raw materials.

According to the present invention, a dry distillation furnace including an inner cylinder and an outer cylinder is provided in a subsequent process of a dryer including an inner cylinder and an outer cylinder, and hot air is generated by burning dry distillation gas generated from the inner cylinder of the dry distillation furnace. Since a hot air generating furnace is provided and this hot air is introduced between the inner cylinder and the outer cylinder of the dryer, organic sludge having a high water content can be dried with a very small amount of fuel and dry-distilled in one system.
Also, malodor generated during drying is combusted and decomposed in a hot air generating furnace and is not released to the outside.

  Hereinafter, referring to FIG. 1, a dry-distillation treatment system and treatment method (volume reduction / reduction of water-containing organic sludge) of organic sludge, pruned branches, livestock waste, food waste, or a mixture thereof according to an embodiment of the present invention will be described. I will explain.

  Industrial waste such as organic sludge, pruned branches, livestock waste, food waste and the like to be treated is input to the quantitative feeder 3. The input method can be a manual input method using heavy machinery, or temporarily store organic sludge, pruned branches, livestock waste, food waste, or other industrial waste in a hopper, etc., and automatically by a belt conveyor or screw feeder. You may throw into the fixed_quantity | feed_rate feeder 3. FIG.

A fixed amount of raw material is charged into the dryer 1 from the quantitative feeder 3.
When industrial waste such as organic sludge containing harmful substances is treated, or when decomposition of dioxins is necessary, it is mixed in a quantitative amount with a chemical for decomposition in a quantitative feeder 3.

The dryer 1 includes an inner cylinder (rotating cylinder) 1a and an outer cylinder 1b, and allows hot air to pass between the inner cylinder and the outer cylinder.
The inner cylinder is a rotating cylinder with an inclination angle of about 1 ° to 2 °, and organic sludge, pruned branches, livestock waste, food waste, etc. by sliding with rotation driven by a drive motor Industrial waste moves in the rotating cylinder for a certain time and is discharged.
The rotating cylinder may be equipped with a lifter for scavenging contaminants or paddle blades.

  A hot air passage wall is provided by the outer cylinder 1b so as to cover the outer wall of the inner cylinder 1a of the dryer 1, and the heat is transferred to the rotating cylinder of the dryer 1 so that the industrial waste such as organic sludge that is the object to be treated is disposed. Heat the thing.

  The temperature of the hot air that is the heating source is 800 ° C. or higher, and is supplied from the hot air generator 6. The hot air is separated from the inside of the rotating cylinder of the dryer 1 and does not mix with the gas generated during drying.

The hot air that has passed between the inner cylinder and the outer cylinder of the dryer 1 and that has been discharged maintains a temperature of about 500 ° C., and is between the inner cylinder (rotating cylinder) 2a and the outer cylinder 2b of the dry distillation furnace 2 described later. To introduce.
When the center tube 2c is provided inside the inner tube of the dry distillation furnace, the hot air is also passed through the center tube.

The dried processed product that has passed through the rotary cylinder of the dryer 1 is discharged from the dryer 1 and introduced into the rotary cylinder of the dry distillation furnace 2 by the screw conveyor 9 in a fixed amount.
The rotating cylinder of the dry distillation furnace 2 is inclined at an angle of 1 ° to 2 °, and moves in the rotating cylinder in the dry distillation furnace 2 for a certain period of time by the sliding caused by rotation.
A lifter or paddle blade for scrubbing contaminants may be mounted in the rotating cylinder.

In the dry distillation furnace 2, an outer cylinder 2b is provided so as to cover the outer wall of the inner cylinder 2a, and a hot-air passage wall is provided, and a central cylinder 2c through which the hot air similarly passes is disposed inside the inner cylinder.
Thereby, the heat heats and dry-distills industrial wastes, such as dried organic sludge which is a process target object.

  Carbide discharged after completion of dry distillation is transported to the product storage 11 by the screw conveyor 10. The screw conveyor 10 is indirectly cooled with water and cools the discharged product. If there is sufficient cooling time to reach the product storage, indirect water cooling is not necessary.

The dry distillation gas generated when the dried raw material passes through the inner cylinder of the dry distillation furnace 2 removes pulverized coal with a cyclone 20 and is introduced into the hot air generation furnace 6. The hot air generating furnace 6 is equipped with a burner 15 for adjusting the amount of heat, and the heavy oil supplied from the heavy oil service tank 7 is supplied to the burner 15 by the oil pump 8.
The cyclone 20 may not be equipped depending on the properties of the raw material.
In the temperature adjustment, the temperature indicator controller 16 controls the amount of raw material charged into the quantitative feeder, and manages the temperature in the rotating cylinder in the dryer 1.
The burner 15 is controlled by the temperature indicating controller 19.

  The generated hot air passes from the hot air passage wall between the inner cylinder 1a and the outer cylinder 1b of the dryer 1 through the hot air passage wall between the inner cylinder 2a and the outer cylinder 2b of the dry distillation furnace 2 and the central cylinder 2c, and as a heat exchanger. 12 is introduced. The exhaust gas that has undergone heat exchange is controlled by a pressure indicating controller 17 installed in order to keep the pressure in the rotating cylinder of the dry distillation furnace 1 constant, and is sucked by the smoke exhaust fan 13 and discharged from the exhaust projection 14 to the outside air. . Alternatively, it is introduced into an existing exhaust gas duct.

Even when producing a carbonized product, a special exhaust gas treatment device for completely burning dry distillation gas is not required.
When organic sludge containing toxic substances, pruned branches, livestock waste / food waste, etc. are used as raw materials, it is better to pass through an exhaust gas treatment device, that is, a rapid temperature reduction tower or a bag filter.

  The high-temperature air heat-exchanged by the heat exchanger 12 is introduced into the rotating cylinder 1 a of the dryer 1. In addition to the heat from the hot air passage wall of the dryer 1, the drying is efficiently performed by the introduced high-temperature air. It is discharged from the rotating cylinder of the dryer 1 together with the evaporated water and separated from the raw material scattered by the cyclone 4.

  The separated gas is introduced into the hot air generating furnace by the exhaust fan 5 as combustion air. The exhaust fan 5 adjusts the outer cylinder temperature of the rotating cylinder by a temperature indicating controller 18. The gas blown by the exhaust fan 5 contains a large amount of moisture, and the oxygen concentration of the hot air generated from the hot air generating furnace is kept low.

  In FIG. 1, TIC: temperature control, PIC: pressure control, INV: inverter control.

A device according to the present invention was prototyped and treated with water-containing organic sludge of 180 kg / h having a water content of 80 kg / h. As a result, 8 kg / h of a product (carbide) having a water content of 0 kg / h was obtained.
Therefore, the raw material is reduced to approximately 4.4% by weight.

  The scale of the present invention is generally applied to about 100 kg / h to 10 t / h for processing.

An example of a sludge treatment plant flow diagram is shown.

Explanation of symbols

1 (External heat type) dryer 1a Inner cylinder (rotating cylinder) of dryer
1b Dryer outer cylinder 2 (external heat type) carbonization furnace 2a Carbonization furnace inner cylinder (rotating cylinder)
2b Outer cylinder of dry distillation furnace 2c Central cylinder of dry distillation furnace 3 Fixed feeder 4 Cyclone 5 Exhaust fan 6 Hot air generator 7 Heavy oil tank 8 Heavy oil pump 9 Screw conveyor 10 Water-cooled screw conveyor 11 Product tank 12 Heat exchanger 13 Exhaust fan 14 Chimney 15 Burner 16 Temperature indicating controller 17 Pressure indicating controller 18 Pressure indicating controller 19 Temperature indicating controller 20 Cyclone

Claims (5)

  In the subsequent process of the dryer consisting of an inner cylinder and an outer cylinder, it is provided with a dry distillation furnace consisting of an inner cylinder and an outer cylinder, and a hot air generating furnace that generates hot air by burning dry distillation gas generated from the inner cylinder of the dry distillation furnace, A water-containing organic sludge volume reduction / weight reduction device comprising means for introducing the hot air between an inner cylinder and an outer cylinder of a dryer.   The apparatus further comprises means for introducing hot air generated in the hot air generating furnace between the inner cylinder and the outer cylinder of the dryer and then introducing between the inner cylinder and the outer cylinder of the dry distillation furnace. Item 1. A device for reducing and reducing the volume of water-containing organic sludge according to Item 1.   The water-containing organic sludge according to claim 1 or 2, further comprising means for introducing exhaust gas after drying generated from an inner cylinder of the dryer into the hot air generator, and reheating in the hot air generator. Volume reduction and weight reduction equipment.   The water-retaining organic sludge volume reduction / weight-reduction apparatus according to any one of claims 1 to 3, wherein the dry distillation furnace has a central cylinder inside an inner cylinder.   A water-containing organic sludge characterized by using the volume reduction / weight-reduction apparatus according to any one of claims 1 to 4 to dry a high water content organic sludge with a dryer and then carbonize it in a carbonization furnace to obtain a carbide. Volume reduction / weight loss method.

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