JP2014213267A - Waste treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste treatment apparatus capable of removing inexpensively and sufficiently an unnecessary matter generated during a heat treatment of waste.SOLUTION: A waste treatment apparatus 1 includes a heating part 10 for heating organic waste containing moisture, and a gas purification part (gas purification means 20, 30, 40) for purifying gas discharged from the heating part 10. The gas purification part includes at least either of spray means for spraying water over the gas and adsorption means made of a porous ceramic sintered body for purifying the gas.

Description

  The present invention relates to a waste treatment apparatus.

Various methods are known for treating organic waste containing water, such as food waste, sewage sludge, and manure from poultry and pig farms.
For example, in Patent Document 1, as a method for treating sludge generated in a sewage treatment plant, a household / large-scale septic tank, or a treatment plant of a food factory, the sludge is carbonized using a continuous carbonization device to produce fuel, fertilizer, water purification Disclosed is a method for making powder coal that can be used as an agent and a soil conditioner.
In Patent Document 2, organic sludge discharged from sewers or the like is heat-treated at a temperature of 400 ° C. to 800 ° C. and in a state in which the outside air blocking property is enhanced (ie, low oxygen state, reducing atmosphere). A method of obtaining sludge carbide is disclosed.

However, when organic waste is treated by the methods described in Patent Documents 1 and 2, an unnecessary substance such as a malodorous substance is generated during the heat treatment, and thus improvement has been demanded.
In Patent Document 3, sludge discharged from a rural settlement wastewater treatment facility, a sewage treatment plant, an organic wastewater treatment facility, etc. is carbonized at 450 to 550 ° C. using a rotary kiln type carbonization furnace, and the resulting carbide is deodorized. Use as an agent is disclosed.
In Patent Document 4, organic waste such as sludge is heated in a low oxygen state to generate carbides, malodorous substances in the gas discharged at that time are treated with a platinum precious metal catalyst, microbubbles. There has been proposed a method of removing by at least one of ozone treatment used and plasma treatment using high-temperature plasma.

JP-A-6-128576 JP 2000-80386 A JP 2006-63105 A JP2013-43149A

However, the sludge carbide described in Patent Document 3 did not provide sufficient deodorizing properties. The unnecessary substance removing method described in Patent Document 4 is expensive and impractical.
Therefore, an object of the present invention is to provide a waste treatment apparatus that can sufficiently remove unnecessary substances generated during heat treatment of waste at a low cost.

In order to solve the above problems, the present invention has the following configuration.
[1] A spraying unit that includes a heating unit that heats organic waste containing moisture and a gas purification unit that purifies gas discharged from the heating unit, and the gas purification unit sprays water on the gas. A waste treatment apparatus comprising at least one of a means and an adsorption means made of a fired porous ceramic body for purifying the gas.
[2] The waste treatment apparatus according to [1], wherein the gas purification unit includes both the spraying unit and the adsorbing unit, and the adsorbing unit is disposed on the downstream side of the spraying unit.
[3] The waste according to [1] or [2], wherein the porous ceramic fired body is obtained by firing a porous ceramic fired body raw material and then firing without drying. Processing equipment.
[4] The waste treatment apparatus according to any one of [1] to [3], wherein the porous ceramic fired body is a granular material.
[5] The water according to any one of [1] to [4], wherein the water supplied by the spraying means includes at least one selected from the group consisting of an acidic substance, a basic substance, and a surfactant. Waste treatment equipment.

  The waste treatment apparatus of the present invention provides a waste treatment apparatus capable of reducing the volume of organic waste containing water and suppressing the emission of malodorous substances generated at that time at a relatively low cost. be able to. Therefore, introduction is easy even in small and medium-sized factories, waste treatment plants, sewage treatment plants, pig farms and poultry farms, and the odor environment in the region can be improved.

It is a schematic diagram which shows an example of the waste apparatus of this invention.

Hereinafter, the waste disposal apparatus of the present invention will be described.
The waste treatment apparatus of the present invention includes a heating unit that heats organic waste containing moisture, and a gas purification unit that purifies gas discharged from the heating unit.
Organic waste containing water is discharged from sludge, poultry, hog raising, and cattle farms discharged from rural wastewater treatment facilities, sewage treatment plants, organic wastewater treatment facilities such as dyeing plants, food factories, and paper mills. Although it is not particularly limited, it may be excrement, waste material discharged from a food processing plant, leftover food from a restaurant, and the like. As the sludge, either undigested sludge or digested sludge can be used.
These organic wastes are preferably dehydrated by a dehydrator such as a filter press, belt press, and centrifugal dehydration so that the water content is 100% by mass or less.

(Heating section)
The heating unit heats and carbonizes the organic waste containing moisture. A carbide obtained by carbonizing organic waste has a large calorific value and is suitable as a fuel.
The form of the heating unit is not particularly limited, and may be, for example, one that heats in a sealed state or one that heats in an open state.
Specific examples of the heating unit include a continuous heating furnace such as a rotary kiln and a roller hearth kiln, and a fractional heating furnace such as a shuttle kiln. Among these, a continuous heating furnace is preferable from the viewpoint of productivity.
More specifically, what is known as a heating device such as sludge is preferable. For example, a heat treatment device described in JP-A-8-155419, a rotary furnace described in JP-A-2000-80386, JP Examples thereof include a carbonization apparatus described in Japanese Patent Application Laid-Open No. 2006-63105 and a heating furnace described in Japanese Patent Application Laid-Open No. 2013-43149. Further, a volatile organic solvent recovery device using induction heating described in JP 2010-75783 A can be used as the heating unit. It is also possible to use the rotary kiln or the like as a heating unit in combination with induction heating.
When organic waste is heat-treated by the heating unit, at least one unnecessary substance selected from the group consisting of malodorous substances, harmful substances and dust is often generated.

(Gas Purification Department)
The gas purification part in this invention is equipped with at least one of the spraying means which sprays water on the said gas, and the adsorption means made from the porous ceramic sintered body which purifies the said gas.
Specifically, the gas purification unit may include both the spray unit and the adsorption unit, or may include only one of the spray unit and the adsorption unit. In terms of a high gas purification rate, it is preferable that both the spraying means and the adsorbing means are provided, and the adsorbing means is disposed downstream of the spraying means.
Further, the spraying means and the adsorption means may each be one or plural.

<Spraying means>
By spraying water into the gas using the spraying means, dust contained in unnecessary substances can be captured in water, and water-soluble components of malodorous substances and harmful substances can be dissolved in water.
The spraying means is not particularly limited as long as water can be sprayed, and examples thereof include a spray nozzle and a jet nozzle.
The spray pattern of the water supplied from the spray means is preferably annular, planar or strip-shaped in order to increase the contact area with the gas.
As will be described later, the water sprayed by the spraying means may include at least one selected from the group consisting of acidic substances, basic substances, and surfactants.

The number of spraying means is preferably two or more. If there are two or more spraying means, water can be sprayed from two or more places, and gas can be passed through a space in which water droplets that are disorderly and turbulently fly in various directions exist. Thereby, the contact opportunity of gas and water can be increased, and mainly dust and water-soluble components can be captured more by water.
Furthermore, in order to increase the contact opportunity between gas and water, it is preferable that the spray directions of the two or more spraying means are different from each other.

A part of the water sprayed by the spraying means may be collected and supplied again to the spraying means using a circulation pump.
Alternatively, a certain amount of sprayed water may be stored, and the gas discharged from the heating unit may be bubbled through the stored water to capture unnecessary substances. In this case, the water sprayed from the spraying means is brought into contact with the gas that has passed through the stored water.

<Adsorption means>
Although the arrangement of the adsorption means is not particularly limited, it is preferable to arrange the adsorption means in a direction that is not parallel to the gas traveling direction because the chance of contact with the gas increases. Furthermore, it is more preferable that the adsorbing means is layered and arranged perpendicular to the gas traveling direction. A plurality of layered adsorption means may be arranged. When a plurality of layered adsorption means are arranged, an air layer may be formed between the layers of the adsorption means, or another gas purification unit may be arranged.
Further, the adsorption means may be filled with a porous ceramic fired body except for the portion where the water supply means is installed.

The porous ceramic fired body constituting the adsorbing means has pores in the micrometer order and pores in the nanometer order. Moreover, what has these pores connected is preferable.
More specifically, the pores formed in the porous ceramic fired body have nanometer-order pores having a pore diameter of 1 nm or more and less than 1000 nm and micrometer-order pores having a pore diameter of 1 μm or more and less than 1000 μm. . Further, it may have pores in the order of millimeters outside this range, and pores of other sizes.

  The pore diameter of the pores can be adjusted by combining the types of raw materials of the fired porous ceramic body and the firing conditions. The pore diameter refers to the major diameter of the pores. The pore diameter of millimeter-order pores is a value measured using a scale after cutting a porous ceramic fired body (cut along the thickness direction in the case of a plate-like material). The pore diameter of nanometer-order pores and micrometer-order pore diameters are measured using an electron microscope after cutting a porous ceramic fired body (cut in the thickness direction in the case of a plate-like material). Value.

  When the porous ceramic fired body has pores in the micrometer order and pores in the nanometer order, it becomes easy to obtain a preferable apparent density and saturated water content described later. For this reason, the contact area with the gas increases, and the performance of removing unnecessary substances becomes higher.

The porous ceramic fired body is preferably obtained by mixing raw materials for a porous ceramic fired body and firing without drying. “Drying” as used herein refers to an operation for setting the moisture content to 1% by mass or less.
By firing without drying, a large amount of moisture contained in the mixture evaporates in a short time during firing, and the porous ceramic fired body is cracked. Due to the cracks at the time of firing, heat is transferred to the inside of the obtained porous ceramic fired body, and pores of the order of micrometers or nanometer size can be formed more. Furthermore, through the cracks in the obtained porous ceramic fired body, water supplied to the porous ceramic fired body, acidic substances contained in the water, and unnecessary substances in the gas enter the porous ceramic fired body. The removal performance can be improved.
The size of the crack in the porous ceramic fired body can be adjusted by the composition of the mixture, the firing speed, the firing time, and the like.

The shape of the porous ceramic fired body may be any of a plate-like material, a columnar material, a spherical material, a massive material, and a granular material, but the resistance to gas flow is reduced and the gas and porous ceramics are fired. Granules are preferred because they can easily increase body contact opportunities.
The particle size of the porous ceramic fired body is preferably 5 cm or less, and more preferably 3 cm or less. If the particle size of the porous ceramic sintered body is equal to or less than the above upper limit, the chances of contact with unnecessary substances can be increased.
On the other hand, the particle size of the granular material of the fired porous ceramic body is preferably 1 mm or more, more preferably 5 mm or more because resistance to gas flow is reduced.

The granular material of the fired porous ceramic body may be prepared by preparing granular materials of various sizes and blending them at an arbitrary ratio. The particle diameter is a value measured by sieving. For example, a granular material having a size of more than 5 mm and not more than 10 mm means a particle that passes through a sieve having an opening of 10 mm and cannot pass through a sieve having an opening of 5 mm.
In addition, when the granular material is large and it is difficult to obtain a sieve, the long side of the granular material may be measured with a caliper or the like to obtain the particle diameter.

The porous ceramic fired body preferably has an apparent density of 0.3 to 1.5 g / ml. The upper limit of the apparent density is more preferably 1.1 g / ml or less, and more preferably 0.8 g / ml or less. Within the above range, the pores in the fired porous ceramic body increase while maintaining the strength of the fired porous ceramic body. Therefore, the surface area of the porous ceramic fired body is increased, and the chance of contact with unnecessary substances in the gas can be increased.
The above apparent density is the bulk density (g) determined from the dry soil mass (g) measured by the three-phase distribution / volumetric weight (actual volume method) in “Soil Standard Analysis / Measurement Method” (Hakutosha). Provisional specific gravity, g / ml).
In addition, the unit of the apparent density when the porous ceramic fired body is large is “g / cm ³ ” based on the measurement method described in Examples.

The porous ceramic fired body preferably has a saturated moisture content of 15 to 100% by mass. About the minimum of saturation moisture content, it is more preferable that it is 30 mass% or more. If the saturated moisture content is within the above range, the pores in the porous ceramic fired body increase while maintaining the strength of the porous ceramic fired body. Therefore, the surface area of the porous ceramic fired body is increased, and the chance of contact with unnecessary substances in the gas can be increased.
The saturated water content of the porous ceramic fired body can also be regarded as the porosity of the porous ceramic fired body.

The porous ceramic fired body may carry at least one selected from the group consisting of acidic substances, basic substances, and surfactants.
Specific examples of acidic substances, basic substances, and surfactants include the following.
Examples of the acidic substance include inorganic compounds such as titanium oxide, silicon dioxide, aluminum sulfate, ammonium chloride, and zinc chloride, and organic compounds such as carboxyl group-containing compounds such as acrylic acid, sulfonic acid group-containing compounds, and phosphoric acid compounds. It is done.
Examples of the basic substance include inorganic compounds such as zinc oxide, magnesium oxide and barium oxide, and organic compounds such as polyamine compounds, dicyandiamide compounds and quaternary ammonium compounds.
Note that amphoteric substances such as zinc oxide and aluminum oxide become basic substances when the target substance to be treated is an acidic substance, and become acidic substances when the target substance to be treated is a basic substance.
Surfactants include anionic surfactants such as carboxylates, sulfates, sulfonates and phosphates, cationic surfactants such as amine salts and quaternary ammonium salts, and fatty acid ethylene oxide. Examples include polyethylene glycol type nonionic surfactants such as adducts, polyhydric alcohol type nonionic surfactants such as fatty acid esters of glycerol, betaine type, amino acid type, and imidazoline type amphoteric surfactants. These surfactants can be used alone or in combination of two or more.
The acidic substance, basic substance, and surfactant preferably have no odor. For example, amphoteric surfactants preferably have a high purity with 10 or more carbon atoms in the alkyl moiety.
A plurality of acidic substances, basic substances, and surfactants may be used in combination, but when an acidic substance and a basic substance are used in combination, a uniform surfactant or the like is used so that they do not bond. It is preferable to maintain a dispersed state.

An example of a method for producing a porous ceramic fired body will be described. However, the manufacturing method of a porous ceramic fired body is not limited to the manufacturing method of the following example.
The porous ceramic fired body manufacturing method of this example is prepared by mixing raw materials for a porous ceramic fired body to prepare a mixture (hereinafter, simply referred to as “mixture”) (mixing step), and molding the mixture. Thus, a molded body is produced (molding step), and the molded body is fired to obtain a porous ceramic fired body (firing step).

The mixing step is a step of obtaining a mixture by mixing raw materials including clay.
As a mixture, the thing containing a foaming agent and clay is preferable, for example, and the thing containing a foaming agent, organic sludge, and clay is more preferable. By using a foaming agent and clay, irregularities in the order of millimeters and micrometers can be formed on the surface of large pores in the order of millimeters, pores in the order of micrometers or porous ceramics fired bodies. Furthermore, by using organic sludge, more micrometer-order pores and even smaller nanometer-order pores can be formed. A porous ceramic fired body obtained by firing such a mixture has pores in which the pores communicate with each other.

A foaming agent foams at the time of baking, For example, well-known foaming agents for ceramics, such as calcium carbonate, silicon carbide, magnesium carbonate, and slag, can be used. Of these foaming agents, slag is preferred. The slag is not particularly limited. For example, slag is generated at the time of cast iron such as blast furnace slag generated during metal refining, municipal waste melting slag generated when melting municipal waste, sewage sludge melting slag generated when melting sewage sludge, and ductile cast iron. Examples include glassy slag such as cast iron slag. Among them, a stable foamed state is obtained because the composition is stable, and cast iron slag having a foaming rate of about 1.5 to 2 times that of other slags. More preferred.
The cast iron slag contains components such as SiO ₂ , Al ₂ O ₃ , CaO, Fe ₂ O ₃ , FeO, MgO, MnO, K ₂ O, Na ₂ O, and the obtained porous ceramic fired body is a base. It has excellent acid substance removability even if it does not carry a functional substance.

  The amount of slag in the blend can be determined in consideration of the moldability of the mixture, for example, preferably 80% by weight or less, more preferably 20 to 75% by weight, and even more preferably 30 to 65% by weight. . Within the above range, the moldability of the mixture can be smoothly and smoothly formed, and the apparent density and porosity (saturated water content) of the porous ceramic fired body can be adjusted to a suitable range.

Organic sludge is sludge containing an organic substance as a main component. Any organic sludge can be used, and activated sludge derived from wastewater treatment such as sewage or factory is particularly preferable. The activated sludge is discharged from a wastewater treatment facility using the activated sludge method through a coagulation / dehydration process. By using such organic sludge, pores on the order of micrometers can be efficiently formed, and pores on the order of nanometers can be formed. By forming nanometer-order pores, the apparent density of the porous ceramic fired body can be reduced, the porosity (saturated water content) can be further increased, and the chance of contact with unnecessary substances can be increased. Furthermore, activated sludge derived from wastewater treatment, which has been positioned as waste, can be used as a raw material.
The water content of the organic sludge is, for example, preferably 10 to 90% by mass, and more preferably 65 to 85% by mass. If it is in the said range, while obtaining a homogeneous mixture, it is easy to maintain favorable moldability.

  Although content of the organic substance in organic sludge is not specifically limited, For example, 70 mass% or more is preferable as content of organic substance (organic substance content) in solid content of organic sludge, and 80 mass% or more is more preferable. The larger the organic content, the easier it is to form micrometer-order pores, and nanometer-order pores. The organic content is a value obtained by measuring the ash content (mass%) of the dried sludge in accordance with JIS M8812-1993 at a carbonization temperature of 700 ° C. and the following equation (1).

  Organic matter content (mass%) = 100 (mass%) − ash content (mass%) (1)

  The average particle diameter of the organic sludge is preferably 1 to 5 μm, more preferably 1 to 3 μm. Since organic sludge is burned off by firing and pores are formed there, pores on the order of micrometers can be formed more easily as the average particle size is smaller, and pores on the order of nanometers can be formed. The average particle diameter is a volume-based median diameter (50% volume diameter) measured by a particle size distribution measuring device (LA-920, manufactured by Horiba, Ltd.).

  The content of organic sludge in the mixture can be determined in consideration of the moldability of the mixture, for example, preferably 1 to 60% by mass, more preferably 5 to 40% by mass, and 5 to 30% by mass. Further preferred. If it is in the said range, a mixture will have moderate fluidity | liquidity and plasticity, a moldability will improve, and it can shape | mold smoothly, without obstruct | occluding a shaping | molding apparatus.

Clay is a mineral material that exhibits clay-like properties that are commonly used as ceramic raw materials.
As the clay, known materials used for ceramics can be used, which is composed of mineral composition such as quartz, feldspar, clay, etc., and the constituent mineral is mainly kaolinite, halloysite, montmorillonite, illite, bentonite, pyrophyllite. The thing containing is preferable. Examples of such clays include cocoon clay. Clay can be blended alone or in combination of two or more. The components contained in these clays are also effective in removing malodorous and toxic substances contained in the gas.

  The clay content in the mixture can be determined in consideration of the strength and formability required for the porous ceramic fired body. For example, the content is preferably 5 to 60% by mass, more preferably 5 to 50% by mass, and 10 to 40%. More preferred is mass%. If it is in the above-mentioned range, the moldability of the mixture can be smoothly formed without sacrificing, and the strength of the fired porous ceramic body can be made sufficient.

The mixture may contain an optional component as long as the effects of the present invention are not impaired. Examples of optional components include naphthalene-based fluidizing agents such as Mighty 2000WH (trade name, manufactured by Kao Corporation), melamine-based fluidizing agents such as Melment F-10 (trade name, manufactured by Showa Denko KK), and the like. Polycarboxylic acid fluidizers such as Darex Super 100pH (trade name, manufactured by Grace Chemicals Co., Ltd.), antibacterial agents such as silver, copper and zinc, deodorizers such as ammonium chloride and zinc chloride, zeolite, apatite, etc. Adsorbents, strength improvers such as carbon fibers having a length of 1 mm to 5 cm, basalt fibers, rock wool, and metal aluminum.
When mix | blending an arbitrary component with a mixture, it is preferable to determine the compounding quantity of an arbitrary component in the range of 5-10 mass%, for example.

From the viewpoint of moldability, water may be blended as appropriate for the purpose of adjusting the fluidity of the mixture, etc., but when the organic sludge is blended at a suitable blending ratio, It is not necessary to add water.
Moreover, when there is much water | moisture content, it is preferable to contain crushed materials, such as glass, roof tile, fly ash, clinker ash, for example. In particular, by blending crushed tiles, excess moisture can be absorbed, the fluidity of the blend can be adjusted, and the moldability can be improved.
When glass is used, preferably, a high-melting glass particulate filler having a melting temperature of 900 ° C. or higher is more preferable. By using particles of high melting point glass, moisture adjustment is possible while maintaining pores formed in the fired porous ceramic body. High melting point glass and fly ash can also be used as a strength improver.

The particle diameter of the high melting point glass or tile particles is preferably 0.1 to 5 mm. If the particle diameter is less than 0.1 mm, the formation of pores in the porous ceramic fired body may be insufficient. If the pores are not sufficiently formed, the removal performance of unnecessary substances contained in the gas and the durability of the porous ceramic fired body may be deteriorated.
If the particle diameter is more than 5 mm, moldability may be deteriorated, or the metal fitting at the extrusion port may be damaged during molding.

  Moreover, clinker ash and fly ash are discharged from a thermal power plant and are preferable from the viewpoint of effective utilization of waste.

  The content of the high melting point glass, tile particles, fly ash and clinker ash in the mixture may be appropriately selected according to the intended fluidity of the composition without departing from the purpose of the present invention. 3-40 mass parts is preferable with respect to a total of 100 mass parts of raw materials other than glass and roof tiles, and 10-30 mass parts is more preferable.

The mixing apparatus used for a mixing process is not specifically limited, A well-known mixing apparatus can be used.
Examples of the mixing apparatus include a kneader such as a mix muller (manufactured by Toshin Kogyo Co., Ltd.), a kneader (manufactured by Moriyama Co., Ltd.), a mixer (manufactured by Nippon Ceramics Co., Ltd.), and the like.

The forming step is a step of forming the mixture obtained in the mixing step into an arbitrary shape.
A known molding method can be used as the molding method, and can be determined in consideration of the properties of the mixture and the desired shape of the molded body. As a specific molding method, a molding machine is used to perform extrusion molding to obtain a molded body such as a plate, granule, or columnar shape including pellets, etc., and a mixture is filled into a mold of any shape and molded. Examples thereof include a method of obtaining a body, a method of extruding, stretching or rolling a mixture, and then cutting it into an arbitrary size.
Examples of the molding machine include a vacuum clay molding machine, a flat plate press molding machine, and a flat plate extrusion molding machine. Among these, a vacuum clay molding machine is preferable.

The moisture content of the mixture before firing is preferably more than 1% by mass, more preferably 5% by mass or more, further preferably 10% by mass or more, and particularly preferably 20% by mass or more. . If the water content of the mixture is below the lower limit, it may be difficult for unnecessary substances to enter the porous ceramic fired body obtained.
On the other hand, the moisture content of the mixture before firing is preferably 45% by mass or less, and more preferably 30% by mass or less. If the water content of the mixture exceeds the upper limit, moldability may be impaired.

The firing step is a step of firing the molded body (firing operation) and firing clay and the like to obtain a porous ceramic fired body.
As described above, it is preferable to fire the molded body without drying. A porous ceramic fired body obtained by firing without mixing after mixing raw materials has a higher performance of removing unnecessary substances. Moreover, when not drying, the productivity of a porous ceramic fired body can also be improved.

  In the case of drying the molded body, the molded body may be naturally dried, or may be dried by treating in a hot air drying oven at 50 to 220 ° C. for an arbitrary time. It is good also considering the moisture content of a molded object as 1 mass% or less by drying.

The firing operation is not particularly limited, and a known method can be used. Examples thereof include a method of firing at an arbitrary temperature using a continuous sintering furnace such as a roller hearth kiln or a batch sintering furnace such as a shuttle kiln. Among these, it is preferable to use a continuous sintering furnace for the firing operation from the viewpoint of productivity.
The firing temperature (maximum temperature reached) can be determined according to the properties of the mixture, and is, for example, 850 ° C to 1200 ° C. If it is more than the said lower limit, most organic substances in organic sludge will volatilize and it will reduce weight. If it exceeds the above upper limit value, vitrification of the entire structure of the ceramic fired body proceeds and the pores may be blocked.
A porous ceramic fired body having pores in the micrometer order and pores in the nanometer order can be obtained by the above manufacturing method.

  When it is desired to form a granular material after the firing step, it may have a crushing step of crushing the porous ceramic fired body into an arbitrary size as necessary. In the crushing step, the porous ceramic fired body obtained in the firing step is crushed and ground with a hammer mill, biaxial rotary crushing, jet mill, ball mill, edge runner mill, etc., to obtain a porous ceramic fired body granular material be able to. The obtained granular material is sieved to an arbitrary particle size as necessary.

  Clay or slag used as a raw material when producing a porous ceramic fired body contains a metal oxide or the like, and this metal oxide functions as an acidic component or a basic component in the fired body. The acidic component of the porous ceramic fired body can adsorb a basic substance, and the basic component of the porous ceramic fired body can adsorb an acidic substance.

[Water supply means]
In the case where the gas purification unit includes a porous ceramic fired body, it is preferable to further include water supply means for supplying water to the porous ceramic fired body. When water is supplied to the porous ceramic fired body, components in the gas easily come into contact with basic components, acidic components, etc. of the porous ceramic fired body, and it becomes easy to remove unnecessary substances in the gas.
Examples of the water supply means include spray nozzles, jet nozzles, perforated pipes and plate-like objects. In the case of a pipe or plate having a hole, it is preferably arranged above the porous ceramic fired body.
When the gas purification unit includes water supply means, the water that has passed through the porous ceramic fired body may be supplied again to the water supply means using a pump or the like.
As will be described later, the water supplied by the water supply means may include at least one selected from the group consisting of acidic substances, basic substances, and surfactants.

<Other configurations>
In the waste treatment apparatus, a suction fan or a blower fan for flowing gas into the waste treatment apparatus may be installed. Moreover, a demister that captures mist in the gas may be installed.
Various instruments such as a thermometer and a densitometer may be installed without departing from the object of the present invention.

(Waste treatment method)
The waste treatment method using the waste treatment apparatus 1 includes a heating step and a gas purification step.

The heating step is a step of heating and carbonizing the organic waste containing moisture.
Although the heating temperature in a heating process can be made into arbitrary temperature, 100 degreeC or more is preferable. When the heating temperature is less than 100 ° C., it takes time to reduce the volume of sludge and the like, resulting in low productivity. The heating temperature is preferably 250 ° C. or higher. If heating temperature is 250 degreeC or more, the organic waste containing a water | moisture content can be carbonized easily.

The heating temperature is preferably 1500 ° C. or lower, and more preferably 950 ° C. or lower. When the heating temperature exceeds the upper limit, the degree of volume reduction does not change compared to the amount of energy used for the heat treatment, which is disadvantageous in terms of cost.
Moreover, if it is 950 degrees C or less, the carbide | carbonized_material obtained by carbonizing the organic waste containing a water | moisture content can be easily used as a fuel. Organic waste containing water such as sludge heat-treated at 950 ° C. or less has a large calorific value and can be preferably used as a fuel.
Further, the carbide obtained by heat treatment at a low temperature has a larger calorific value than the carbide heat-treated at a high temperature, and more specifically, the heating temperature is more preferably 600 ° C. or less.
Usually, the odor becomes stronger as the heating temperature becomes lower. This is because if heating is performed at a high temperature, unnecessary substances contained in the gas discharged from the heating section are also thermally decomposed to reduce the amount of unnecessary substances in the gas, but if the heating temperature is lowered, the heat of unnecessary substances is reduced. Since the amount of decomposition decreases, unnecessary substances contained in the gas increase. However, in the waste treatment apparatus of the present invention, discharge of unnecessary substances can be suppressed even when organic waste is heated at a low temperature of 600 ° C. or lower.
Moreover, it is preferable that the atmosphere inside a heating part at the time of a heating is a reducing atmosphere. Furthermore, since the organic waste can be easily pyrolyzed, it is preferable to set the atmosphere so that the limit oxygen concentration, which is the oxygen concentration necessary for the combustible to continue to burn, does not substantially exceed.

  The gas purification step is a step of performing at least one of spraying water on the gas generated in the heating step by the spraying means and passing the gas generated in the heating step through the porous ceramic fired body of the adsorption means.

When water-soluble components are included in the gas generated in the heating process as dust, malodorous substances and harmful substances, the dust can be trapped in water mainly by spraying water on the gas. In addition, water-soluble components among harmful substances can be dissolved in water.
When water is injected into the gas, it is preferable that the gas is sprayed randomly and at high speed in various directions from two or more locations in the gas. When water is injected in this manner, the chance of contact of water with dust and water-soluble components in the gas can be increased. Therefore, the removal performance of dust and a water-soluble component becomes high.

The water to be sprayed may contain at least one selected from the group consisting of acidic substances, basic substances, and surfactants. When acidic substances, basic substances, and surfactants are added to water, in addition to dust and water-soluble components, water-insoluble and sparingly soluble basic substances, acidic substances, oil-based components, and neutral components Etc. can be removed.
As the acidic substance, the basic substance, and the surfactant, the same substances as those supported on the porous ceramic fired body can be used.
Moreover, you may add the fragrance | flavor for masking, a chelating agent, an antibacterial agent, a catalyst, etc. to water in the range which does not deviate from the objective of this invention.

  The temperature at the time of water spraying may be arbitrarily set in consideration of the temperature of the gas to be purified, the solubility of the components contained in the gas, the vapor pressure, and the like.

  When the gas generated in the heating process is passed through the porous ceramic fired body, unnecessary substances are physically adsorbed on the surface of the porous ceramic fired body and removed. In addition, the basic component in the gas is mainly ionically adsorbed and removed by the acidic component in the porous ceramic fired body, and the basic component in the porous ceramic fired body is mainly used in the gas. Acidic components are ionized and removed.

When purifying the gas with the porous ceramic fired body, it is preferable to supply water to the porous ceramic fired body because the removal rate of unnecessary substances increases.
Moreover, it is preferable to contain at least one selected from the group consisting of an acidic substance, a basic substance, and a surfactant in the water supplied to the porous ceramic fired body. As the acidic substance, the basic substance, and the surfactant, the same substances as those supported on the porous ceramic fired body can be used.
When the acidic substance or the like is included in the water supplied to the porous ceramic fired body, unnecessary substances can be further removed without supporting the acidic substance or the like on the porous ceramic fired body. If the acidic substance and the like are passed along with water in the porous ceramic fired body having a large surface area, the chance of contact between each component in the gas and the acidic substance increases, and a new acidic component or the like becomes porous ceramic. Since it is supplied into the fired body, it is considered that the removal performance of unnecessary substances is improved.

  When two adsorbing means are provided, one adsorbing means supplies water containing an acidic substance to the porous ceramic fired body to mainly remove basic substances in the gas. Water containing the substance may be supplied to the fired porous ceramic body to remove mainly the acidic substance in the gas.

(Function and effect)
In the waste treatment apparatus, unnecessary substances in the gas generated when the organic waste is heated by the heating unit are removed by at least one of spraying water and adsorption by the porous ceramic fired body. Therefore, unnecessary substances can be sufficiently removed at low cost.
Moreover, the carbide | carbonized_material which carbonized the organic waste by the waste processing apparatus of this invention can be utilized for a fuel, a deodorizing agent, a soil improvement material, etc., and a waste can be used as a useful thing.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated more concretely, this invention is not limited to a following example.

(Manufacture example 1) Manufacture of a porous ceramic fired body 20 mass parts of roof tiles are added to 50 mass parts of slag, 25 mass parts of organic sludge, and 25 mass parts of clay (total 100 mass parts). Using Shinto Kogyo Co., Ltd.) to obtain a plastic mixture (mixing step).
Next, the mixture was extruded into a cylindrical shape having a diameter of 1.5 cm using a vacuum kneader and then cut into a length of 3 cm to obtain a cylindrical shaped body (water content: 15% by mass). The molded body was subsequently fired in a continuous sintering furnace without using a drying step under firing conditions of a firing temperature of 1050 ° C. and a residence time of 7 minutes at the firing temperature (firing step). As the continuous sintering furnace, a roller hearth kiln (effective length of the sintering furnace: total length 15 m, the sintering furnace was divided into zones 1 to 10 each having a length of 1.5 m) was used. The fired porous ceramic body obtained by firing was a mixture of granular materials and lumps having a long diameter of about 3 cm to 10 cm with fine cracks.
The obtained porous ceramic fired bodies were pulverized with a hammer mill. Next, using a sieve, it was sieved to a size of more than 5 mm and 10 mm or less to obtain a granular material of a fired porous ceramic body. The resulting porous ceramic fired body was confirmed to have micrometer-order pores and nanometer-order pores. In particular, those having a pore diameter of 1 to 30 μm and 200 to 500 nm were often observed. In addition, the apparent density of the fired porous ceramic body was 0.7 g / ml, the saturated water content was 43% by mass, and communication between pores was also confirmed.

<Raw materials>
In addition, the raw material of the porous ceramic fired body used in the above production example is specifically as follows.

[Organic sludge]
As the organic sludge, the activated sludge discharged from the wastewater treatment facility by the activated sludge method of the dyeing factory (Komatsu Seiren Co., Ltd.) through the coagulation / dehydration process was used. The activated sludge had an organic content (based on solid content) of 83% by mass and a water content of 85% by mass.

[clay]
As the clay, Sakaime clay (Gifu Prefecture) was used.

[Slag]
Cast iron slag was used as a foaming agent. The cast iron slag _is a ductile iron slag _{SiO 2, Al 2 O 3,} CaO, Fe 2 O 3, FeO, MgO, MnO, K 2 O, the Na ₂ O as main components.

[tile]
After being used as a roof tile for a house, the one with a particle diameter of 0.1 mm to 1.2 mm obtained by pulverizing the discarded one was used.

<Measurement and confirmation of physical properties>
The physical property values of the porous ceramic fired body were measured by the following methods.

[Check hole diameter]
Confirmation of the micrometer-order pores and nanometer-order pores of the porous ceramic fired body was observed at 30 to 10,000 times using an electron microscope (SEMEDX Type H type, manufactured by Hitachi Science Systems).

[Apparent density]
When the porous ceramic fired body is granular, dry soil mass (g) measured by the three-phase distribution / volumetric weight (actual volume method) in “Soil Standard Analysis / Measurement Method” (Hakutosha) ) To obtain the apparent density (provisional specific gravity, g / ml).
Moreover, when the granular material of the porous ceramic fired body was larger than the measurement container, the sample was cut into a rectangular parallelepiped, and the external dimensions of the sample were measured with calipers to determine the volume. The cut sample was completely dried, the mass was measured with an electronic balance (mass dried), and the apparent density was calculated by the following equation (2).
Apparent density (g / cm ³ ) = [absolute dry mass (g)] / [volume (cm ³ )] (2)

[Saturated water content]
The porous ceramic fired body was immersed in water for 60 minutes, taken out from water, immediately measured for mass (saturated moisture content mass), and the saturated moisture content was determined by the following formula (3). The saturation moisture content was measured for the number of samples (N) = 10, and the average value was obtained.
Saturated moisture content (mass%) = [(saturated moisture content mass−absolute dry mass) / absolute dry mass] × 100 (3)

[Check for communication between pores]
The presence or absence of communication between pores in the porous ceramic fired body was confirmed by immersing the obtained porous ceramic fired body in water, sufficiently absorbing water, cutting or crushing, and observing the cross section. When moisture was evenly distributed and retained in the porous ceramic fired body, it was determined that the pores were in communication with each other. When moisture did not spread inside the porous ceramic fired body, it was determined that the individual pores or pores were independent, and the pores were not in communication or inadequate communication.

Example 1
As shown in FIG. 1, the waste treatment apparatus 1 according to the first embodiment includes a heating unit 10 that uses a rotary kiln, a first purification unit 20, a second purification unit 30, and a third purification unit 40. It was supposed to be.

  The first purification means 20 is such that the spray nozzle 22 is attached to the side surface 21 a of the tank 21. Moreover, in the 1st purification | cleaning means 20, the circulation pump 23 and the piping 24 which circulate the water collected at the bottom part of the tank 21 and supply it again to the spray nozzle 22 were provided. Moreover, the discharge pipe 25 which discharges the water collected in the lower part of the tank 21 was attached.

The 2nd purification means 30 shall be provided with the tank 31 provided with the porous ceramic sintered body layer 32 of one layer. The tank 31 was connected to the upper part of the tank 21. The porous ceramic fired body layer 32 is configured by filling the mesh-like container with the granular material of the porous ceramic fired body obtained in Production Example 1 with a thickness of about 2.5 cm, and is perpendicular to the gas flow. Arranged to be. In addition, a spray nozzle 33 that sprays water on the upper surface of the porous ceramic fired body layer 32 is provided inside the tank 31. A non-woven fabric demister 34 that captures and removes mist is disposed above the spray nozzle 33. Was provided.
Further, in the second purification means 30, a circulation pump 35 and a pipe 36 that circulate the water accumulated at the bottom of the tank 31 and supply the water to the spray nozzle 33 again are provided.

In the third purification means 40, the spray nozzles 42a, 42b, and 42c are attached to the tank 41. The spray nozzle 42 a was attached to the side surface 41 a of the tank 41, and the spray nozzles 42 b and 42 c were attached to the upper surface 41 b of the tank 41. The spray nozzle 42b sprays water directly below, and the spray nozzle 42c sprays water diagonally below.
A non-woven fabric demister 44 that captures and removes mist is provided above the spray nozzle 42c. Moreover, in the 3rd purification means 40, the discharge pipe 43 which discharges a part of water collected in the lower part of the tank 21 was attached. In addition, a circulation pump 45 and a pipe 46 that circulate a part of the water accumulated at the bottom of the tank 41 and supply the spray nozzles 42a and 42b again are provided.
Further, the third purification means 40 includes a chemical tank 47 and a pipe 48 and a pump 49 for supplying the chemical liquid put in the chemical liquid tank 47 to the spray nozzle 42c.

  Further, the upper part of the heating unit 10 and the upper part of the tank 21 were connected by a pipe 51, the upper part of the tank 31 and the upper part of the tank 41 were connected by a pipe 52, and the pipe 53 was attached to the upper part of the tank 41. A blower fan 64 a is attached to the pipe 51, a blower fan 64 b is attached to the pipe 52, and an exhaust fan 64 c is attached to the pipe 53.

In the waste treatment apparatus 1 of this example, the sludge is heated by the heating unit 10, and the gas discharged from the heating unit 10 is purified by the first purification unit 20, the second purification unit 30, and the third purification unit 40. .
Specifically, the sludge was heat-treated at 450 to 500 ° C. by the heating unit 10. The heating unit 10 is heated in a state where the combustible material (sludge) does not substantially exceed the limit oxygen concentration that is an oxygen concentration necessary for continuing combustion, and the organic matter in the sludge is thermally decomposed. The sludge was carbonized by the heat treatment. The obtained carbide had a lower calorific value of 23000 kJ / kg (5350 kcal / kg) (analysis method: JIS M8814) and had a calorific value sufficient for use as a fuel.
Next, the gas discharged from the heating unit 10 was introduced into the tank 21 through the pipe 51 using the blower fan 64a at a gas supply rate of 3 m ³ / min.
Next, tap water supplied from the water supply pipe 24 a was sprayed on the gas inside the tank 21 in a full circle spray pattern using the spray nozzle 22. A part of the water accumulated at the bottom of the tank 21 was sprayed again into the tank 21 from the spray nozzle 22 using the circulation pump 23 and the pipe 24, and the remaining water was discarded through the discharge pipe 25. Thereby, in the 1st purification | cleaning means 20, the dust and water-soluble component which were mainly contained in gas were removed.

Next, the gas discharged from the upper part of the tank 21 was introduced into the tank 31 and passed through the porous ceramic fired body layer 32. At that time, the water accumulated at the bottom of the tank 21 and the tap water supplied from the water supply pipe 36 a are supplied to the spray nozzle 33 using the circulation pump 35 and the pipe 36, and the porous ceramic fired body layer is supplied from the spray nozzle 33. 32 was sprayed with tap water.
The gas that passed through the porous ceramic fired body layer 32 was passed through the demister 34 to capture the mist, and then introduced into the upper portion of the tank 41 through the pipe 52 using the blower fan 64b.

Next, tap water supplied from the water supply pipe 46a was sprayed onto the gas introduced into the tank 41 in a full circle spray pattern using the spray nozzles 42a and 42b. Further, the chemical solution stored in the chemical solution tank 47 was supplied to the spray nozzle 42c via the pipe 48 and the pump 49, and the chemical solution was sprayed in a full circle spray pattern using the spray nozzle 42c. The chemical solution was water to which zinc chloride, ammonium chloride and a surfactant were added.
Further, using the circulation pump 45 and the pipe 46, a part of the water accumulated at the bottom of the tank 41 was returned to the spray nozzles 42 a and 42 b, and the remaining water was discarded through the discharge pipe 43.
The gas that passed through the tank 41 was passed through the demister 44 to capture the mist, and then discharged to the outside of the tank 41 through the pipe 52 using the exhaust fan 64c.

The deodorizing performance of malodorous substances and the like in Example 1 was evaluated by the following method.
That is, the concentrations of propionic acid, normal butyric acid, normal valeric acid, isovaleric acid, and sulfur oxide (all of which are malodorous substances) contained in the gas were measured according to Environmental Agency Notification No. 9 of 1972. . The measurement results are shown in Table 1.
In addition, the tester conducted a sensory test on the odor of the gas. The evaluation results are shown in Table 1.
The gas sampling locations were the pipe 51, the pipe 52, and the pipe 53.

As shown in Table 1, in the waste treatment apparatus 1, malodorous substances contained in the gas discharged from the heating unit could be sufficiently removed by the gas purification unit.
Moreover, in Example 1, when a little fragrance | flavor was added to the chemical | medical solution tank 47, the unpleasant bad odor was not felt at all and the good fragrance of the fragrance | flavor was felt.

DESCRIPTION OF SYMBOLS 1 Waste disposal apparatus 10 Heating part 20 1st purification | cleaning means 21 Tank 22 Spray nozzle 23 Circulation pump 24 Piping 25 Discharge pipe 30 2nd purification means 31 Tank 32 Porous ceramic sintered body layer 33 Spray nozzle 34 Demister 35 Circulation pump 36 Piping 40 third purifying means 41 tank 42a, 42b, 42c spray nozzle 43 discharge pipe 44 demister 45 circulating pump 46 pipe 47 chemical tank 48 pipe 49 pump 51, 52, 53 pipe 64a, 64b blower fan 64c exhaust fan

Claims (5)

A heating unit that heats organic waste containing moisture, and a gas purification unit that purifies gas discharged from the heating unit,
The waste treatment apparatus, wherein the gas purification unit includes at least one of spraying means for spraying water on the gas and adsorption means made of a fired porous ceramic body for purifying the gas.   The waste treatment apparatus according to claim 1, wherein the gas purification unit includes both the spraying unit and the adsorbing unit, and the adsorbing unit is disposed downstream of the spraying unit.   The waste processing apparatus according to claim 1 or 2, wherein the porous ceramic fired body is obtained by firing a raw material for a porous ceramic fired body and then firing without drying.   The waste processing apparatus according to any one of claims 1 to 3, wherein the porous ceramic fired body is a granular material.   The waste treatment apparatus according to any one of claims 1 to 4, wherein the water supplied by the spraying means includes at least one selected from the group consisting of an acidic substance, a basic substance, and a surfactant.

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