JPS6124910A - Incinerating disposal of raw garbage - Google Patents

Abstract

PURPOSE:To achieve a complete incineration by applying a deodorizing treatment to the liquid squeezed out of compacted raw garbage, and by supplying the recovered solid part of the raw garbage for incineration. CONSTITUTION:Pulverized raw garbage is fed to a compressive liquid remover 8 and is compressed by a press pressure of about 30kg/cm<2>, and the contained liquid is forced out of a porous cylinder as squeezed liquid along with scum. The waste liquid is diluted by three to five parts of diluter for one part of it, and is fed to an aeration tank 10. 1,000-5,000ppm of grain size adjusted fine coal (MFC) is added to one cubic meter of the dilution liquid, which is agitated for mixing by pressurized air from a blower BL. The MFC, naphtha carbon sludge and additives are then continuously fed to reaction tanks 11, 12. The liquid is then introduced into a quick solid-liquid separator tank 13 for separating into top clear liquid and sediment. The sediment is drawn by a pump 19 to a feed tank 20, from which it is recovered by a dehydrator 21 as dehydrated sludge cake containing less than 65% of moisture. The dehydrated cake is mixed with the pulverized raw garbage, and destroys vegetable cell structure of the raw garbage in a compactor 8 to enhance the incineratable component of fixed carbon.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for combustible processing of kitchen waste, and more particularly to a method for combustible processing that can completely incinerate kitchen waste, which has a low calorific value and is difficult to burn, with low fuel consumption.

Conventional technology In general, when garbage with an extremely low moisture content and kitchen waste with an extremely high moisture content are mixed and burned at the same time, the combustion of the garbage with a high calorific value is inhibited, leading to an unsuitable environment inside the incinerator. ,
Overall incineration efficiency deteriorates significantly. As a result, the consumption of heavy oil, kerosene, etc. used as combustion aids increases, and only the atmospheric temperature inside the furnace increases, resulting in significant wear and tear on the furnace walls, and the generation of toxic nitrogen oxide gas, which is a serious inconvenience. A problem has arisen.

An object of the present invention is to provide a method for combustible processing of raw kitchen waste, which has a low calorific value and is difficult to burn, so that it reaches its self-combustion limit and can be completely ashed at extremely low fuel consumption.

Summary of the Invention According to the present invention, in a method for combustible processing of raw kitchen waste, which improves the calorific value of raw kitchen waste by compressing and dehydrating the raw kitchen waste at a pressure of 50 kg/cIrL" or more, The solid content of the diluted solution is 100% of the solid content of the diluted pulverized coal, which has been diluted with 6 to 5 times the weight of dilution water and whose particle size is adjusted so that the particle size of 9 mesh to 500 mesh is in the range of 85 to 95 weight is. Add and mix 60 to 200 parts by weight per part by weight, and if necessary, coagulation aids such as naphtha carbon and oil carbon, isoelectric point setting agents such as iron salts, sulfuric acid, sodium hypochlorite, and polyaluminum chloride, and caustic soda. , solid-liquid separation is performed continuously by adding a neutralizing agent such as milk of lime and a flocculation agent such as a polymer flocculant, and then the settled flocs are dehydrated and the collected carbon-containing cake is added to the raw kitchen waste. A method for combustible processing of raw food waste is provided, which is characterized by mixing and compacting.

Structure of the Invention In the present invention, raw kitchen waste is compressed and dehydrated at a pressure of 60 Yu/α2 or more to increase its calorific value and make it combustible.

An important feature of the present invention is that the squeezed juice discharged from the above-mentioned compression dehydration should be subjected to a coagulation sedimentation treatment using particle size-adjusted pulverized coal (hereinafter abbreviated as NFC), and the resulting carbon-containing cake should be subjected to a compression dehydration treatment. The purpose is to mix it with raw kitchen waste and perform combustible treatment through compression dehydration.

That is, the squeezed juice is diluted with 6 to 5 times the weight of dilution water, MFC is added and mixed, and coagulation and sedimentation treatment is performed.

The particle size of this NFC is adjusted so that the particle size of 9 mesh to 500 mesh is in the range of 85 to 95 weight coefficient, and is made of pulverized coal such as low carbonization coal, brown coal, lignite, and grass coal. . By using pulverized coal whose particle size has been adjusted in this way, coagulation and sedimentation separation of squeezed juice can be carried out quickly and effectively.

In the present invention, NFC is used in an amount of 60 to 200 parts by weight per 100 parts by weight of solid content of squeezed juice.

If the amount is less than this range, the desired effect will not be achieved during coagulation and sedimentation separation, and if the amount is used in a large amount, the processing efficiency of juice will be reduced.

In the coagulation sedimentation separation, the above NFC is mixed into a diluted squeezed juice and stirred, then the mixture is left to stand and separated into a supernatant liquid and a carbon-containing solid content, and this carbon-containing solid content is filtered and dehydrated. Do it by doing this.

1 According to the present invention, the solid content contained in squeezed juice can be sufficiently coagulated and sedimented simply by using the above-mentioned NFC as a coagulation-sedimentation agent, but if necessary, a coagulation aid such as naphtha carbon or oil carbon fat, Isoelectric point setting agents such as iron salts, sodium sulfate, sodium hypochlorite, and polyaluminum chloride, and neutralizing agents such as caustic soda and milk of lime may be appropriately blended.

In general, the solid content contained in the compressed dewatered liquid from raw kitchen waste exists in a stable sol state that is extremely evenly blended with water as a dispersion medium. This cannot be done easily. Therefore, according to the present invention, by using pulverized coal having a predetermined particle size distribution as a flocculating and settling agent, sedimentation and separation of solid content can be carried out extremely easily.

In addition, compressed dewatered liquid from raw kitchen waste has an EOD of 30,000
~160,000ppm, C0I) 20,000~
50,000Pp”s and 5540.000~50,
000 ppm, and is a foul-smelling, concentrated waste liquid containing amino acid-based putrefactive organic matter, but the advantage is that the above-mentioned coagulation and sedimentation treatment using pulverized coal oxidizes and decomposes the putrefactive components, making the waste liquid odorless. is also achieved.

In the present invention, the carbon-containing cake obtained by the above-described coagulation and sedimentation treatment is further mixed with raw kitchen waste, and subjected to compression dehydration treatment to make it combustible.

That is, the raw kitchen waste has a moisture content of 75% by weight or more,
When this is dehydrated using a pressure of 30 kg/crn'' or more, the water content is usually dehydrated to about 65 to 60% by weight.

In this case, the calorific value of the raw kitchen waste is 387 Kca17 ust, so if compression treatment is performed without using a carbon-containing cake, the lower calorific value will be approximately 1.000 Kca17 kgtmt even if the moisture content reaches a maximum of 60%. (The heat of vaporization of water is calculated as approximately 9.7 Kcal/mol).

Since the moisture content of the carbon-containing cake obtained by coagulation-sedimentation separation is around 60%, the NFC is 4.000%.
When pulverized coal with a calorific value of rca17 kg is used in the same amount as the solid content in the squeezed liquid, its lower calorific value is approximately 1,
It is 200 Kcal/J. However, since this carbon-containing cake has a moisture content of about 30 inches after being air-dried for several days, its lower calorific value is about 2.800 rcal/yu, which far exceeds its self-combustion limit. Therefore, it can be used as a combustion aid for the compressed kitchen waste. For reference, FIG. 1 shows the relationship between the moisture content of the carbon-containing cake and the combustion temperature.

In addition, the combustion temperature t and the solid content lower heating value (absolutely dry average) H
l (The relationship with Kcal/kg is expressed by the following formula.

In the formula, P represents the water content (X1>).

For example, 15 tons of ordinary garbage (2,000Kcal/
kgwtt (60%HtO)> and raw kitchen waste 1st (387
, 5Kcal/kgwat (75% HtO)) will be described.

In this case, in order to maintain combustion at 800℃, 1,3
33 Kcal/kgwt O calorific value is required (ignition 420, I Kcal/kgwgt, gas sensible heat increase 845.3 WAIwgt, furnace body dissipated heat 616 Kca
l/kgvutt).

Therefore, the amount of heavy oil consumed for combustion is (1655 - Toa Postal Service Σ)/6 U Oo = 23.31
/l, wat (heavy oil has a calorific value of 6000 fC ginmel).

On the other hand, using a pressure of 30 kg/cm2 or more, 1
When kitchen waste is compressed and dehydrated at 5 torb, the water content is reduced to about 60% or less, and the weight of the kitchen waste is about %.

Therefore, garbage and compressed kitchen waste (lower calorific value is 1.
The lower calorific value of the mixture with OQ Q Kcal/kg is 1.662KC → 勺. 800 yen of this mixed pulp
To maintain combustion at a temperature of °C, 1,59 ozy/
kgwtt of heat is required. Since the ignition heat in this case is 503.3 Kt:vi/kg and the calorific value of the mixed waste is 1,662 Kcal/Jψat, auxiliary combustion by heavy oil is almost unnecessary.

Furthermore, according to the present invention, a carbon-containing cake (moisture content: 30
The lower heating value of 2,800%
Kt″αl/kgwtt, and if this is mixed with raw kitchen waste before compression treatment (20% by weight based on the solid content of raw kitchen waste) and compression treatment is performed, the lower calorific value of the compressed kitchen waste is i, 5
Q Q lLa1/Jvugt. Therefore, the lower calorific value of the waste mixed with garbage increases to 17501 Lal/kg. It will be understood that the combustion of this mixed waste can be carried out extremely stably without using heavy oil or kerosene.

The amount of carbon-containing cake used from the flocculation treatment varies depending on the carbon quality of the MFC used in the treatment, but it is usually in the range of 10 to 100% by weight, especially 20% by weight, based on the solid content of raw kitchen waste.
A preferable range is from 50% by weight. If the amount is smaller than this, no increase in calorific value will be brought about, and if the amount is used in a large amount, the processing efficiency of raw food waste will be reduced.

Furthermore, FIG. 2 is a diagram showing the relationship between heavy oil consumption by type of incinerator and lower calorific value of the garbage to be incinerated in high-temperature incineration (combustion exhaust gas temperature 900° C.).

In Figure 2, curve A is a model without air preheating (semi-mechanical furnace), curve B is a model that uses 200°C preheated air (mechanical furnace), and curve C is a model that uses 600°C preheated air (jet type furnace). ) is shown.

According to this figure 2, in a model that uses preheated air at 200°C, the dust calorific value is approximately 1,600, αl/Q.
At g, the theoretical heavy oil consumption is 0, that is, at the self-combustion limit.

Furthermore, in the case of an incinerator using 600° C. preheated air, it will be understood that the self-combustion limit, which does not require heavy oil, is reached by compression treatment alone.

Therefore, by the combustible treatment of the present invention, the calorific value of raw kitchen waste is increased to be close to that of miscellaneous garbage, making it possible to stabilize the combustibility of the incinerator without using heavy oil or the like.

PREFERRED EMBODIMENTS OF THE INVENTION The combustible disposal method of the present invention will be explained below based on specific examples shown in the accompanying drawings.

In FIG. 6, which shows a flowchart of the combustible disposal method of the present invention, the collected garbage is distributed by a crane 1 to a garbage pit 2 and a kitchen garbage pit 6, and the garbage is supplied to an incinerator 22 by a greifhar.

Raw kitchen waste is disassembled from a hopper 4 by a crusher 5, and metals are collected by a magnetic separator 6 and stored on a metal recovery surface 7. The crushed raw kitchen waste from which metals have been removed is conveyed by a conveyor and supplied to a compression dehydrator 8, where it is processed at approximately 30 kg.
It is compressed with a press pressure of "g/cx" and the contained water is squeezed out as juice from the porous cylinder along with the scum.

The weight of the dehydrated compressed kitchen waste and the weight of the squeezed sewage are approximately the same. The extracted dirty juice is as described above, both BCD and COD are 70,
Since it contains foul-smelling organic substances exceeding 000 ppm k, it is received in the sewage pit 9, diluted 6 to 5 times, and sent to the aeration tank 10, and the diluted liquid has an MFC of 1.00 per cubic meter.
0pP to 5. Add in the range of QOQP 7m and use Prower B.
After mixing and stirring with a pressure of L, NFC and naphtha carbon sludge (EDEXe
C agent) and auxiliary agent are placed in their respective suspension tanks or dilution tanks (i.
4, 15, 16, 17° 18) are added sequentially and automatically, and flowed into the rapid solid-liquid separation tank 13, where they are rapidly and accurately separated into purified supernatant water and coagulated sediment. The supernatant water becomes colorless, transparent and odorless treated water and is recycled and used as dilution water in the aeration tank 10, and the surplus water is used as effluent water below the regulatory standard value. 1
The sediment Sr from No. 6 is sent to the supply tank 20 via the sludge extraction pump 19.
The carbon-containing sludge dehydrated cake with a moisture content of 65% or less is collected by the NFC cell 7 precoat continuous dehydrator 21. This dehydrated cake can also be used as a fertilizer, but it can be fed and mixed with the crushed raw kitchen waste as described above, and the compressor 8 can easily destroy the plant cell structure in the waste and increase the combustible component of fixed carbon.

Effect of the invention 4 Generally, the amount of heavy oil consumed in the incineration of urban garbage is 100 to 150 tons per ton of incineration, but according to the method for combustible disposal of kitchen waste according to the present invention, only a small amount of heavy oil (
Complete combustion is possible by using only 10 tons (154/l), and the energy saving effect is enormous.

Further, in the present invention, the waste liquid discharged from the compression treatment of raw food waste is treated to be odorless, and the recovered solid content is used for combustible treatment of raw food waste, so that the treatment process can be carried out extremely rationally.

・Furthermore, according to the combustible treatment method of the present invention, it is possible to adjust the extremely high-temperature combustion of vinyl chloride contained in miscellaneous garbage, which has been rapidly increasing in recent years, to an appropriate combustion temperature, and as a result, the maintenance of the furnace body becomes easier. This makes it possible to reduce the generation of harmful gases such as nitrogen oxides.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the relationship between the moisture content of a coal-containing cake and combustion temperature, and Figure 2 is a diagram showing the relationship between heavy oil consumption by incinerator model and lower calorific value of waste to be incinerated in high-temperature incineration. FIG. 3 shows a flowchart of the combustible disposal method of the present invention. Reference number 2 is a garbage pit, 6 is a kitchen waste pit, 4 is a hopper, 5 is a crusher, 6 is a magnetic separator, 8 is a compression dehydrator, 9 is a sewage pit, 11 and 12 are reaction tanks, 13
21 is a solid-liquid separation tank, 21 is a dehydrator, and 22 is an incinerator.

Claims (3)

[Claims] (1) In a method for combustible processing of raw kitchen waste in which the calorific value is increased by compressing the raw kitchen waste at a pressure of 30 kg/cm^2 or more and dehydrating it, the squeezed juice discharged in the compression process is Dilute with dilution water, 9 mesh to 50
Pulverized coal whose particle size is adjusted to be in the range of 85 to 95% by weight of 0 mesh particle size is added to the diluted liquid with a solid content of 1
Add and mix 30 to 200 parts by weight per 00 parts by weight, and if necessary, coagulation aids such as naphtha carbon and oil carbon, isoelectric point setting agents such as iron salts, sulfuric acid, sodium hypochlorite, and polyaluminum chloride. Solid-liquid separation is performed continuously by adding a neutralizing agent such as caustic soda or milk of lime, and a floc strengthening agent such as a polymer flocculant, and then the settled flocs are dehydrated and the collected carbon-containing cake is added to the raw kitchen waste. A method for combustible disposal of raw kitchen waste, which is characterized by mixing and compressing raw kitchen waste. (2) The combustible treatment method according to claim 1, wherein the moisture content of raw kitchen waste is 75% by weight or more, and the moisture content is compressed to 60% by weight or less. (3) The carbon-containing cake is added at a rate of 10 to 1 per solid content of raw kitchen waste.
The combustible treatment method according to claim 1 or 2, wherein the combustible treatment method is mixed with raw kitchen waste in a proportion of 0.00% by weight.