JP3981021B2 - Waste treatment system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a processing method and a processing system for processing waste such as food waste.
[0002]
[Prior art]
For example, in the food industry and the like, a large amount of waste having a high water content (usually 60% or more) such as decocted residue of various beverages such as vegetable scraps, leftover rice, and tea, and residual juice is generated. Moreover, in livestock farmers, a large amount of waste with a high water content such as livestock manure is generated. From these wastes, sewage or polluted water overflows and pollutes rivers, soils, etc., accumulates as sludge, or decays when left untreated to give off odors. For this reason, these waste or sewage needs to be treated promptly.
[0003]
However, when sewage discharged from this waste is discharged into a river or the like, there is a regulation such as BOD, and it is necessary to perform a purification process so that it is below the reference value. Since a large processing facility is required, there is a problem that the processing cost becomes high. There is also a method for incinerating waste, but since waste contains a large amount of water, a large energy loss is caused to evaporate the water, and the processing cost is increased as described above. It was a thing.
[0004]
Typical examples of conventional waste disposal methods are shown below.
In the first treatment method, the waste is stirred and crushed as necessary, and then the waste is dried by applying heat of combustion from the outside. In the second treatment method, waste is fermented with microorganisms in a fermenter. In the third treatment method, waste is dried in a low vacuum in a low vacuum furnace. In the fourth treatment method, the waste is compressed in a press compressor and dehydrated by the compression to form a dehydrated cake.
[0005]
And the waste processed by these processing methods is incinerated or recycled as fertilizer.
[0006]
[Problems to be solved by the invention]
However, these conventional waste disposal methods have the following problems in addition to the above-described problem of high processing costs. That is, in the first treatment method, even if a large waste is crushed, it has a non-uniform size. Therefore, when it is dried, the thermal efficiency becomes poor and the dry state becomes non-uniform. It takes time and is not suitable for recycling. In the second treatment method, it is necessary to cure the waste in the fermentor for a predetermined period, which takes time for the treatment and may cause a bad odor. In the third treatment method, the equipment cost for performing the low vacuum drying is very expensive, and the evaporated water is in the state of raw gas, so that a bad odor may be generated as described above. In the fourth treatment method, there arises a new problem that it is necessary to treat the waste liquid squeezed out by compressing the waste.
[0007]
The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a waste processing method and a processing system capable of exhibiting advantages such as being able to dry waste with high efficiency and reducing processing costs and processing time. .
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the invention according to claim 1 includes: a moisture adjusting means for adjusting the moisture of the waste by kneading the waste with a moisture adjusting material and kneading; Pellet production means for continuously producing a large number of pellets, drying means for drying the produced pellets, circulation means for returning a part of the dried pellets to the moisture adjustment means and using as a moisture adjustment material, The moisture adjustment includes a detection means for detecting the moisture content of the waste whose moisture has been adjusted, and an adjustment means for adjusting the return amount of the pellets to the moisture adjustment means according to the detection result by the detection means. means, waste as well as moisture control, and masher for crushing and kneading by kneading, in a transport mixer supplied to said mixing the waste and water adjusting material masher The detecting means is provided near the outlet of the moisture adjusting means, and the adjusting means is configured to operate a flow path switching mechanism provided on the outlet side of the drying means. Is provided in the circulation means, and is switched between a state where the dried pellets discharged from the drying means are supplied to the transport mixer of the moisture adjusting means and a state where the pellets are discharged to the discharge side. It is what.
[0009]
Therefore, according to the first aspect of the present invention, the moisture is adjusted by kneading with the moisture adjusting material, and since the pellet is dried after being manufactured into pellets, the waste is efficiently dried. Can do. Therefore, the processing cost can be reduced and the processing time can be shortened as compared with the conventional processing method. In addition, since a part of the dried pellet is circulated and used as a moisture adjusting material, it is not necessary to prepare a moisture adjusting material separately, and the processing cost can be further reduced.
[0010]
Further , according to the invention described in claim 1 , when the waste is kneaded, the waste is heated by internal friction to become moisture, and when the pellet is manufactured as a pellet, the moisture is already considerably evaporated. And sent to the drying process. Therefore, the thermal efficiency of the drying process can be further increased, the cost of the drying heat source can be saved, and the processing cost can be further reduced.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The following, the implementation form of the present invention will be described with reference to the drawings of FIGS.
[0014]
As shown in FIG. 1, the waste processing system in this embodiment is equipped with a transport mixer 11 having a screw 11a for stirring and transport. The transport mixer 11 constitutes moisture adjustment means. On the inlet side of the transport mixer 11, a waste hopper 12 for supplying waste such as food waste into the transport mixer 11, and an adjustment material for supplying a moisture adjusting material into the transport mixer 11. A hopper 13 is provided. Therefore, in the transport mixer 11, the waste from the waste hopper 12 is mixed with the moisture adjusting material from the adjusting material hopper 13, and the moisture is adjusted so as to obtain a predetermined moisture content as a whole.
[0015]
A masher 14 is disposed on the outlet side of the transport mixer 11, and waste whose moisture has been adjusted by the transport mixer 11 is supplied to the masher 14 via the transport conveyor 15. The smasher 14 constitutes a crushing means, and also constitutes a moisture adjusting means like the transport mixer 11. As shown in FIG. 4, the masher 14 includes a conveying screw 14a and a kneading blade 14b.
[0016]
In the masher 14, the moisture-adjusted waste is crushed and kneaded mainly by kneading by the blade 14b as it is conveyed by the screw 14a. For this reason, the waste and the moisture adjusting material are uniformly dispersed, and the waste in this state is conveyed toward the outlet side. The dispersion is also a result of the moisture adjustment, and therefore the moisture adjustment is also performed in the masher 14. In addition, mainly due to the kneading action by the kneading blade 14b, the waste whose moisture has been adjusted generates heat due to its internal friction, and part of the moisture is evaporated by the frictional heat, thereby reducing the moisture content. .
[0017]
On the outlet side of the masher 14, a pelleter 16 as a pellet manufacturing means is arranged in a directly connected state. Then, the crushed and kneaded waste material sent out from the masher 14 passes through the die 16a of the pelleter 16, whereby a large number of pellets are continuously produced. The pelleter 16 continuously extrudes the kneaded waste into a rod shape having a small circular cross section (diameter of about 3 to 10 mm), and the extruded waste has an appropriate length (about 5 to 20 mm) by its own weight. ) And is separated into many pellets. In this case, the waste to be supplied to the pelleter 16 is preheated by the frictional heat, and the heat generation state is maintained by internal friction in the pelleter 16. Usually, it is within a range of 50 to 80 degrees Celsius, and preferably 70 degrees Celsius or more).
[0018]
A dryer 17 made of a kiln as a drying means is disposed on the outlet side of the pelleter 16, and pellets produced by the pelleter 16 are supplied into the dryer 17 via a conveyor 18 for conveyance. The dryer 17 is provided with a heating unit 17a that is heated by a burner for heavy oil and a cooling unit 17b that is cooled by a cooling fan or the like. The pellets are dried by heating to a predetermined moisture content by passing through the heating unit 17a, and are cooled to a predetermined temperature (usually normal temperature) by passing through the cooling unit 17b. Moisture evaporated by heating is exhausted from the exhaust cylinders 17c and 17d.
[0019]
A circulation conveyor 20 and a discharge conveyor 21 are disposed on the outlet side of the dryer 17 via a flow path switching unit 19. The flow path switching device 19, the circulation conveyor 20 and the discharge conveyor 21 constitute a circulation means. When the flow path switching device 19 is switched to the circulation flow path side including the transport mixer 11 and the smasher 14, the dried pellets discharged from the dryer 17 are passed through the circulation conveyor 20 and the adjusting material hopper. 13 is circulated and supplied. When the flow path switching device 19 is switched to the discharge flow path side, pellets that are not circulated are discharged into the storage container 22 through the discharge conveyor 21 and are recycled for use as fertilizer. Therefore, a part of the manufactured pellets is supplied to the transport mixer 11 as a moisture adjusting material by the switching operation of the flow path switching device 19 and is circulated and used as the moisture adjusting material.
[0020]
As shown in FIG. 3, the processing system of this embodiment includes a control device 32 as an adjustment unit, and a moisture sensor 31 as a detection unit is connected to the input side of the control device 32, and the output side has an output side. A solenoid 33 is also connected as adjusting means for operating the flow path switching device 19. The moisture sensor 31 is provided near the outlet side of the masher 14, detects the moisture content of the crushed and kneaded waste, that is, the moisture content, and outputs the detected data to the control device 32. . The control device 32 controls the operation interval and operation time of the solenoid 33 in accordance with the detection signal from the moisture sensor 31, and adjusts the amount of pellets supplied from the dryer 17 to the adjusting material hopper 13. Thus, the moisture content of the waste in the masher 14 is adjusted to a required value by adjusting the amount of pellets.
[0021]
Next, a method for treating waste in the treatment system configured as described above will be described.
Prior to the operation of this processing system, first, waste such as food waste is introduced into the waste hopper 12, and a moisture adjusting material is introduced into the adjusting material hopper 13. In this case, when there is no pellet as a moisture adjusting material as in the first operation of this treatment system, for example, a dry product having a low water content (20% or less) such as sawdust is used. the part of the dry pellets thus produced OPERATION processing system, for use as a moisture adjusting material.
[0022]
When the operation of the processing system is started in this state, the transport mixer 11 mixes the waste from the waste hopper 12 with the moisture adjusting material from the adjusting material hopper 13 to adjust the moisture content to a predetermined moisture content. The Then, the waste after the moisture adjustment is supplied to the masher 14 and is kneaded so that the waste, the moisture adjusting material and the moisture are uniformly dispersed, and the moisture is further adjusted and further crushed. At the same time, in the smasher 14, the entire waste including the moisture adjusting material generates heat due to kneading, and a slight amount of moisture becomes steam due to the generated heat. As a result of these, for example, as shown in FIG. 4, when 1,300 kg of a water conditioning material having a moisture content of 15% is kneaded with 4,512 kg of waste having a moisture content of 67% in the first treatment process, 5,812 kg of a 55% kneaded product is obtained. The moisture content is detected by the moisture sensor 31 and output to the control device 32.
[0023]
Thereafter, the crushed and kneaded waste is supplied to the pelleter 16 while maintaining the heat generation state, and a large number of pellets that generate heat to a predetermined temperature are continuously manufactured. Then, the pellets are fed into the dryer 17 via the conveyor 18, but since the pellets generate heat at a predetermined temperature, they are naturally dried in this feeding process. Next, the pellets fed into the dryer 17 are heated and dried to a predetermined moisture content by the heating unit 17a and cooled to a predetermined temperature by the cooling unit 17b. In this case, since the waste is in the form of small pellets, the ratio of the surface area to the volume is high, and the moisture is adjusted. Therefore, the pellet drying process is performed with high efficiency without causing energy loss. As shown in FIG. 4, for example, as shown in FIG. 4, 2,760 kg of water is removed from a kneaded product having a moisture content of 55% and 5,812 kg, and 3,052 kg of dried pellets having a moisture content of 15% are produced. .
[0024]
Then, when the flow path switching device 19 is switched to the circulation flow path side based on the control by the control device 32, a part of the dried pellet circulates from the adjustment material hopper 13 into the transport mixer 11 via the circulation conveyor 20. Supplied and used as a moisture regulator. Further, when the flow path switching device 19 is switched to the discharge flow path side, pellets that are not circulated are discharged into the storage container 22 via the discharge conveyor 21 and recycled as fertilizer or the like. For example, as shown in FIG. 4, out of 3,052 kg of the dried pellets produced, 1,300 kg of pellets are used as a moisture adjusting material for the second waste treatment, and the remaining 1,752 kg of pellets are used as fertilizer. Used for recycling. For this reason, it is not necessary to prepare a moisture adjusting material separately, and the second and subsequent waste treatment can be continued while circulating and using the produced dry pellets.
[0025]
Therefore, according to this embodiment, the following effects can be obtained.
(1) In this waste processing method, the waste is kneaded with the moisture adjusting material by the transport mixer 11 and the masher 14 to adjust the moisture. Next, a number of pellets are continuously produced from the kneaded waste by the pelleter 16. Thereafter, the pellets in the production state are dried by the dryer 17. Then, a part of the dried pellets are circulated through the transport mixer 11 by the circulation conveyor 20 and used as a moisture adjusting material.
[0026]
Therefore, by kneading the moisture control material the moisture content of the waste, it is possible to reduce suitable until the water content in the drying by the drier 17, by producing it in small pellet form, the surface area to volume The ratio can be reduced. Therefore, this pellet can be uniformly dried with high efficiency. Compared with the conventional processing method, it is possible to reduce the processing cost such as the energy cost for the heat source and the processing time. In addition, since a part of the dried pellet is circulated and used as a moisture adjusting material, it is not necessary to prepare a moisture adjusting material separately, and the processing cost can be further reduced.
[0027]
(2) Further, since dry pellets having a large surface area ratio may be dried, the drying apparatus may have a simple structure such as a normal kiln, and large equipment is not required. In addition, since excess water is evaporated by drying, a sewage treatment facility or the like becomes unnecessary, and the facility cost can be reduced.
[0028]
(3) In this waste processing method, the kneading of the waste in the masher 14 is performed by kneading. Therefore, since internal frictional heat is generated during the kneading of the waste, the moisture is vaporized, and evaporation starts as soon as the waste is pushed out of the pelleter 16 as pellets. And it manufactures in the state by which the pellet was heated to predetermined temperature, it is sent to a dryer, and is naturally dried during this sending. Therefore, since a certain amount of drying is naturally performed before the drying process by the dryer 17, the energy cost of the drying process can be saved, and the processing cost can be further reduced.
[0029]
(4) Drying of the pellets, because the majority of the water is dried in the dryer 17 to be high-temperature heating with a burner or the like, Ru can suppress the generation of malodor.
[0032]
(Example of change)
In addition, this embodiment can also be changed and embodied as follows.
In each of the above embodiments, the smasher 14 is directly connected to the outlet side of the transport mixer 11 so that the waste and the moisture adjusting material are mixed, crushed and kneaded continuously.
[0034]
- drying of the pellet and this carried out by other sources of electric drying and the like.
[0039]
【The invention's effect】
As described above, as exemplified in the embodiment, in the present invention, waste can be uniformly dried with high efficiency, processing costs and processing time can be reduced, and a moisture adjusting material can be separately provided. There is no need to prepare, and an excellent effect such as the ability to further reduce the processing cost is exhibited.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating a waste treatment system according to a first embodiment.
FIG. 2 is a partial cross-sectional view showing an internal configuration of a masher.
FIG. 3 is a block circuit diagram of the processing system.
FIG. 4 is a table showing processing results.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Conveyor mixer as a moisture adjustment means, 12 ... Waste hopper, 13 ... Adjuster hopper, 14 ... Smasher and masher as moisture adjustment means, 16 ... Pelletter as pellet production means, 17 ... Drying means , 19 ... flow path switching machine, 20 ... circulation conveyor as circulation means.

Claims (1)

Moisture adjusting means for adjusting the moisture content of the waste by kneading the waste with the moisture adjusting material,
Pellet production means for continuously producing a large number of pellets from moisture-adjusted waste,
Drying means for drying the produced pellets;
Circulating means for returning a part of the dried pellets to the moisture adjusting means and using it as a moisture adjusting material;
Detection means for detecting the moisture content of the moisture-adjusted waste;
Adjusting means for adjusting the return amount of the pellets to the moisture adjusting means according to the detection result by the detecting means,
The moisture adjusting means is constituted by a masher for adjusting the moisture of the waste and crushing and kneading by kneading, and a transport mixer for mixing the waste and the moisture adjusting material and supplying the masher .
The detecting means is provided near the outlet of the moisture adjusting means, and the adjusting means is configured to operate a flow path switching mechanism provided on the outlet side of the drying means,
The flow path adjustment mechanism is provided in the circulation means, and switches between a state where the dried pellets discharged from the drying means are supplied to the transport mixer of the moisture adjustment means and a state where the pellets are discharged to the discharge side Waste treatment system characterized by being made.

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