JP2007040684A - Treatment method of high-moisture content livestock feces - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustion treatment method of high-moisture content livestock feces, which can provide high transportability within a device in addition to smell suppressing effect, coupled with dispersibility and combustion property of a firework fuel of wooden carbide and semi-carbide. <P>SOLUTION: The high-moisture content livestock feces is mixed/dispersed with a wooden carbide or semi-carbide in a weight ratio of 90/10 to 60/40, and the resulting mixture is dried/burnt. By mixing the high-moisture content livestock feces with the wooden carbide or semi-carbide in the weight ratio, the apparent viscosity of the mixture is raised, and a swelled body of semi-solid state to extremely high viscosity state is obtained. Accordingly, the transportability up to supply to the following drying/burning process is enhanced. Since the wooden carbide or semi-carbide has a low content of silica component, compared with chaff smoked charcoal, generation of clinker or the like in a combustion furnace can be preferably suppressed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for burning and processing viscous animal droppings having a high water content such as pig droppings. In addition, the high water content livestock feces in this invention shows the livestock feces with a moisture content of 70% or more.

  Until now, various methods for treating livestock manure such as swine manure with relatively high water content have been proposed. For example, a method of converting livestock feces into organic fertilizer or directly reducing them to farmland, a method of fermenting livestock feces, and the like can be mentioned. However, each of these methods has problems. For example, in the method of converting to organic fertilizer or directly returning to farmland, the treatment of livestock excrement that increases year by year is not in time. In addition, in the fertilizer conversion method, nitric acid and nitrite nitrogen in the soil are difficult to be absorbed by the soil, so that the contamination can easily spread to groundwater and spread over a wide area. In addition, the methane fermentation method is suitable for the production of combustible gas, but since an aqueous liquid residue itself remains, a secondary treatment for completely removing it is required.

  Apart from this, when the livestock excrement is burned and treated, secondary treatment is not required as in the methane fermentation method, which is an excellent treatment method. However, since the viscous animal manure forms a single continuous phase as it is, it is necessary to devise a method to increase the surface area as much as possible in order to complete combustion when supplying it into the combustion furnace. In a state where the surface area is small, there is a concern that harmful gases such as dioxin may be generated due to incomplete combustion or uneven combustion, and that the combustion itself may not be stably maintained. In addition, since viscous livestock feces having a high water content are in a liquid state, securing transportability can be said to be a major technical issue when being supplied to a combustion furnace.

  In the combustion treatment of livestock excrement, it is necessary to supply livestock excrement as fuel to the combustion furnace with the surface area dispersed as much as possible. For example, there is a method of supplying livestock feces as droplets to a combustion furnace. For that purpose, for example, it is generally considered to use a spray nozzle. However, there is a high possibility that solid matter such as pebbles as well as wood fragments such as wood fragments and firewood will be mixed in the viscous animal manure, and the combustion process may become unstable due to the blockage of the spray nozzle tip hole. There are still many points that need to be improved. A pretreatment for removing the solid matter by filtration in advance may be performed. However, it is not an advantageous method because the filtration time becomes longer and maintenance such as periodic replacement of the odorous furnace material is required.

  Then, as a method of burning in a state where the surface area of livestock feces as fuel is made as large as possible, there is a method described in Patent Document 1, for example. In Patent Document 1, carbon such as rice husk charcoal or charcoal is mixed at a weight ratio of 1: 1 using a screw conveyor into animal manure containing about 80% of moisture, and dried via a passage for drying. A method of performing incineration in a combustion furnace after the process is described. Since husk husk charcoal and charcoal are mixed in the livestock manure, the surface of the livestock manure after drying the mixture can be burned as much as possible, and the combustion efficiency is improved.

JP 48-59678 A

  In Patent Document 1, rice husk charcoal is mixed with livestock droppings at a weight ratio of 1: 1, so that when processing a large amount of livestock droppings, the same amount of rice husk is required. However, because the production of rice husks has a large seasonal variation factor, it is not necessarily an optimal combination for carbons to be mixed in order to constantly treat livestock droppings regardless of the season. Furthermore, when the rice husk charcoal is burned at a high temperature, the silicic acid, which is the main component of ash, remains as a lump and clinker is generated in the combustion furnace, causing problems that prevent stable combustion.

  In addition, in the case where livestock excrement such as pig excrement is burned and processed, as described above, it is important to ensure transportability for transporting livestock excrement close to liquid to the combustion furnace. 1, there is no suggestion about the transportability of the mixture after mixing carbons such as rice husk charcoal and charcoal into livestock dung, depending on the mixing ratio of livestock dung and carbons such as rice husk charcoal and charcoal The transportability of livestock manure to the combustion furnace has not been studied.

  Therefore, the present invention relates to a method for burning and treating viscous water manure with high water content such as pig manure, and has high transportability in the apparatus, and a large amount of animal manure is treated in a furnace while suppressing the generation of clinker as much as possible. It is an object of the present invention to provide a method capable of performing a stable combustion process in the inside.

  The method for treating high water content animal manure of the present invention that achieves the above object is to mix animal waste manure with high water content and wood-based carbide or semi-carbide at a weight ratio of 90/10 to 60/40 and to dry it. It is characterized by burning.

  In one preferred embodiment of the present invention, the wood-based carbide is low-grade charcoal.

  As one of the preferable embodiments of the present invention, in the method for treating high water content livestock feces, the weight ratio between the high water content livestock feces and the wood-based carbide or semi-carbide is 90/10 to 65/35. A more preferred weight ratio is 90/10 to 70/30.

  According to the method for treating livestock excrement of high water content of the present invention, for example, wood-based carbide or semi-carbide is obtained by carbonizing or semi-carbonizing wood-based materials such as thinned wood, wood chips, wood pieces, sawdust, etc. Therefore, livestock excrement having a high water content can be treated simultaneously with waste that has been treated as waste, such as thinned wood, wood chips, wood chips, and sawdust.

  When carbonized or semi-carbonized wood-based materials such as thinned wood, wood chips, wood chips, sawdust, etc. are used as combustion aids, low-quality carbides are preferred. Due to the blending effect of the combustion aid, the combustion of the livestock feces adhering to and carried on the surface of the combustion aid is further promoted, and the livestock feces can be completely burned. Such low-quality carbides are prepared by selecting the ratio of oxygen required for carbonization or semi-carbonization and the mixing method when carbonizing thinned wood, wood chips, wood pieces, sawdust, etc. be able to.

  By mixing livestock manure and wood-based carbide or semi-carbide, high water content livestock manure adheres to and supported on the surface of wood-based carbide or semi-carbide and is transported to the combustion furnace. According to the method for treating rate dung, since the dung and woody carbide or semi-carbide are mixed at a weight ratio of 90/10 to 60/40, the apparent viscosity of the mixture increases, resulting in a semi-solid. Or a very high-viscosity wet body, the transportability from mixing to drying to supply to the combustion furnace is improved. In addition, the mixing ratio of livestock manure and wood-based carbide or semi-carbide is preferably 90/10 to 65/35 by weight, considering the processing of large amounts of pig manure and further transportability, combustibility, etc. Preferably, it is 90/10 to 70/30.

  Here, it is preferable to disperse or crush the lump of the mixture in the process of mixing and drying with livestock dung and woody carbide or semi-carbide. Due to the dispersion and crushing of the mixture, the surface area of the mixture conveyed to the combustion furnace increases, and the mixture can be completely burned. In addition, the dispersion and crushing of the mixture makes it easy for the air supplied to the combustion furnace to enter the gaps of the mixture, so that stable combustion conditions can be ensured, and excess air with respect to the theoretical air volume can be secured. The ratio can be suppressed appropriately, and the heat balance and operating cost of the combustion apparatus can also be reduced.

According to the processing method of the high water content livestock feces of the present invention, the following effects are obtained.
(1) Wood-based carbides or semi-carbides such as, for example, completely carbonized or semi-carbonized wood-based materials such as thinned wood, wood chips, wood chips, sawdust, etc. are themselves flammable. Since it is used as a certain combustion aid, livestock excrement can be burned very easily.
(2) Live water excrement and wood-based carbide or semi-carbide are mixed at a weight ratio of 90/10 to 60/40, so that the viscosity of the mixture increases, resulting in a semi-solid or extremely high-viscosity wet body It has good transportability until it is supplied to the drying / combustion process.
(3) Compared to the case of livestock dung alone, combustible wood-based carbide or semi-carbide is preferably dispersed in the mixture, so that the surface area of livestock dung can be burned as much as possible, The energy efficiency of the combustion process is improved.
(4) Since the wood-based carbide or semi-carbide is mixed with the high water content animal droppings, the odor of the animal droppings can be suppressed.
(5) Since wood-based carbide or semi-carbide is used, air easily enters the gaps of the mixture, and stable combustion conditions can be ensured.
(6) Because wood-based carbides or semi-carbides are mixed with livestock dung, it is preferable to avoid dangers such as abnormal combustion and explosion that are likely to occur when only wood-based carbides or semi-carbides are burned. it can.

  Hereinafter, the processing method of the high water content livestock feces in embodiment of this invention is demonstrated. In the present embodiment, the processing method will be described taking pig dung as an example of high water content animal dung. In general, swine manure has a higher water content than chicken manure or cow dung and has a water content of about 70 to 90% by weight. Moreover, in the case of a piglet, the moisture content is further high and has a moisture of 90% or more. The processing method of the high water content livestock excrement in the present embodiment includes a step of mixing and dispersing a wood-based carbide or semi-carbide into the high water content livestock feces and pulverizing as necessary, and combustion for burning the wet mixture while drying it. Process. Below, each process is demonstrated in detail.

(1) Mixing / dispersing step First, wood-based carbide or semi-carbide is mixed with pig feces at a ratio of 85/15 to 70/30 as a preferred weight ratio. As a mixing method, various conventionally known methods can be applied. Typical examples include a mixing device with a stirring blade, a rotating blade, various mixers having a shearing action, and various Japanese machines (kneaders). By mixing pork manure and wood-based carbide or semi-carbide at a preferred weight ratio of 85/15 to 70/30, the viscosity of the mixture increases, resulting in a semi-solid or extremely high-viscosity wet body Thus, in order to perform the drying / combustion described later, the operability when transporting through the apparatus is improved.

  As the wood-based carbide or semi-carbide, low-grade carbide obtained by carbonizing or semi-carbonizing thinned wood, wood chips, wood pieces, sawdust, etc., which has been conventionally treated as waste, is optimally used. Such carbide has good combustion characteristics in the combustion process described later, and makes it possible to completely burn pig dung while maintaining stable combustion. In this sense, in this mixing / dispersing step, it is also preferable to perform crushing / crushing while mixing, if necessary. The low-grade charcoal that is easily crushed in the above sense can be said to be a preferable auxiliary combustion material from the viewpoints of dispersibility, combustibility, and odor control.

(2) Drying / combustion step Next, the mixture is transported to the drying / combustion step in order to remove, dry and burn the water present in the mixture of livestock droppings and combustion aids. A conventionally known apparatus can be used as the drying apparatus for the mixture in the present embodiment. In this drying process, water contained in the mixture is removed to some extent in order to improve the combustion efficiency in the combustion process described later, and the mixture is semi-dried or dried.

  When the degree of drying progresses above a certain level, it often becomes a lump. Therefore, the surface area of the mixture can be increased by further dispersing / pulverizing operations to further reduce the mass of the mixture. As a device for dispersing and pulverizing such a mixture, a conventionally known device can be used.

  Through the above operations, the dispersed and pulverized semi-dried or dried mixture is supplied to the combustion furnace to be burned. Examples of the incinerator used at this time include a fluidized bed type, a stoker type, a rotary kiln type, a tornado type combustion furnace, and the like. In the process from drying to combustion, in the same apparatus, for example, drying or semi-drying may be performed in the former stage and combustion may be performed in the latter stage, and different types of furnaces may be used for the drying apparatus and the combustion apparatus. It is also possible to apply.

  In the incineration step in the present embodiment, it is desirable to burn the mixture at a high temperature of 800 ° C. or higher so as not to generate harmful substances such as dioxins. Usually, wood-based carbides, which are solid combustion aids, are used, and there is a potential danger such as dust explosion in the process of being introduced into the combustion furnace at a certain limit temperature or higher. Because it is mixed with feces, even if it is dried after mixing and the moisture content is reduced, it contains the pork feces-derived material, so the flammability is preferably moderated, and the risk of abnormal combustion and explosion etc. It can be easily avoided.

  The mixture eventually becomes gas and ash by combustion. Since the ash contains components such as phosphorus useful as a fertilizer, it can be used effectively. In the present embodiment, pig feces and wood-based carbide are mixed at a preferred weight ratio of 80/20 to 70/30, so that a large amount of ash discharged after incineration is produced.

  As described above, according to the preferred embodiment of the present invention, the swine feces and the wood-based carbide are mixed at a weight ratio of 80/20 to 70/30. It becomes a solid or extremely high-viscosity wet body, and the transportability in the apparatus becomes high. Moreover, since the ratio of the pig droppings to mix is high, a large amount of pig droppings can be processed. Furthermore, the wood-based carbide or semi-carbide used in the present invention has a low silica content, such as rice husk and charcoal, in a high-temperature combustion furnace. It is a material, and pig feces can be burned stably and continuously for a long time.

  In addition, according to the present embodiment, in the case of a low-grade charcoal, especially as a wood-based carbide or semi-carbide, when the mixture is dried and burned, the combustion characteristics are also excellent, so that the swine manure is more stable. And complete combustion is possible.

  In addition, the heat generated in the combustion process in the present embodiment may be used for reducing the moisture content of feces with high water content, or for pre-drying or drying a mixture with a wood-based carbide or semi-carbide. I can do it.

Below, the example which processed pig feces with the experimental rotary kiln type combustion apparatus is shown.
First, 67 parts of pig feces (water content 88%) subjected to solid-liquid separation and 33 parts of low quality charcoal were mixed while partially pulverizing the charcoal. This mixture was fed into a rotary kiln at a speed of 50 g / min. In the former stage of the rotary kiln whose inner wall was heated to 550 ° C., the water in the mixture was evaporated, and in the latter stage, it was completely burned at an oven temperature of 830 ° C. via an ignition burner.

  INDUSTRIAL APPLICABILITY According to the present invention, the transportability in the apparatus is high, and it is possible to treat livestock excrement having a high water content, which is useful. Further, the ash generated by the combustion treatment can be used as a fertilizer, and can be suitably used as a method for treating livestock excreta that does not discharge harmful substances and can effectively use the product.

  Further, the heat generated in the combustion process in the present embodiment can be used for dehydration / drying of agricultural and forestry products and culture of microorganisms. Since the gas temperature in the vicinity of the combustion furnace outlet is 800 ° C. or higher, for example, this heat can be applied to a plurality of drying apparatuses having different purposes in multiple stages according to the temperature drop stage. For example, since a heat source of 400 ° C. to 600 ° C. is suitable for drying wood and the like, a high-temperature gas just emitted from the combustion furnace can be used via a pipe. It can also be used for drying agricultural crop residues that require heat at 550C to 500 ° C and for culturing microorganisms such as algae that require heat of 100 ° C or lower.

Claims (1)

  A method for treating high water content livestock feces, comprising mixing livestock feces with high water content and wood-based carbide or semi-carbide at a weight ratio of 90/10 to 60/40, and drying and burning the mixture.