Method for treating water-containing waste

Abstract

To provide a method of treating a more practical method of treating a water-containing waste than heretofore.SOLUTION: A method of treating water-containing waste includes a process of arranging a storage bag 2 of the water-containing waste 1 into a heat-resistance net body 3, a process of reducing a volume of the storage bag 2, a temperature-elevating process of dewatering the volume-reduced storage bag 2 and a process of carbonizing the dewatered storage bag 2. In the process of reducing the volume of the storage bag 2 and the process of carbonizing the dewatered storage bag 2, a salt bath can be also used as a temperature-elevating medium. The process of carbonizing the dewatered storage bag 2 can be performed separately from the other processes. The storage bag 2 of the water-containing waste 1 can be conveyed by a carrier 4 having a freely closable cover.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for treating water-containing waste that can be used in underground shopping areas, busy streets, general households, medical institutions, and others where there are many restaurants.

Background Art

[0002] Conventionally, there has been a proposal for a food waste treatment device (Patent Document 1). That is, generally, food waste is treated by landfill or incineration. Since food waste contains more than 80% water and also contains organic substances that are prone to decay, when treating food waste by directly landfilling it, not only does it generate a bad smell due to nitrogen and sulfur compounds generated during the decay process, but there is also a problem of inducing the breeding of pests such as flies and mosquitoes. In addition, when directly landfilling food waste, there is a serious problem that high-concentration leachate is discharged, widely polluting the soil. For this reason, landfill facilities are recognized as one of the facilities to be avoided, making it difficult to secure sites for landfill facilities, and also because the maintenance costs are extremely high, the construction is gradually being restricted, which is a serious situation. The food waste treatment device according to this prior art is installed in each household, restaurant, etc. After inserting the generated food waste into the stirring tank and adding and stirring a microbial fermentation agent, the food waste is uniformly mixed and fermented. During the fermentation process, oxygen is sufficiently supplied, and the bad smell contained in the exhaust gas is collected by another device, so the generation of bad smell during treatment is significantly reduced, and thus it has the advantage of being extremely user-friendly. However, there was a problem that fermentation requires a certain amount of time and is not very practical.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Therefore, the present invention aims to provide a more practical method for treating water-containing waste than the prior art.

Means for Solving the Problems

[0005] To solve the above problems, the present invention takes the following technical means. (1) The method for treating water-containing waste of the present invention includes a step of disposing a storage bag for water-containing waste in a heat-resistant net body, a step of reducing the volume of the storage bag, a step of raising the temperature to dehydrate the reduced-volume storage bag, and a step of carbonizing the dehydrated storage bag. Since this method for treating water-containing waste includes a step of disposing a storage bag for water-containing waste in a heat-resistant net body, even if the storage bag undergoes thermal deformation in the step of raising the temperature to dehydrate the reduced-volume storage bag, the dehydrated water-containing waste can be held in the heat-resistant net body.

[0006] Examples of the water-containing waste include food waste, leftover food, (infectious) waste such as that from hospitals, used cloth diapers and paper diapers, and manure of pigs and chickens. It is okay if there is some mixing of waste plastics, etc. because they can be carbonized. Specifically, it is the extremely malodorous water-containing food waste in underground shopping streets and other restaurants. Usually, it is stored in a plastic bag designated by the local government office and taken to the garbage collection place from midnight to early morning. However, it smells extremely bad to people who come to work in the morning, and there is a desire to do something about it as a town.

[0007] Examples of the storage bag include a plastic bag having gas barrier properties and heat-seal fusion properties (for example, capable of storing about 20 L and about 10 kg). In addition, since it has a step of reducing the volume of the storage bag, even if a space is created between the stored items and they become bulky, volume reduction can be performed by the negative pressure action of vacuum suction, and the storage operation of new waste can be continued. And when the inside of the storage bag is vacuum-packed (further heat-sealed and fused with the inlet end being the last), it can be hygienically and cleanly stored so that odors, smells, and fungi do not escape, and the progress of the decay of the food waste inside can be suppressed and the infectivity can be inhibited.

[0008] Furthermore, since it has a temperature-raising step of dehydrating the volume-reduced storage bag, the water content rate can be reduced to improve the workability of the subsequent steps. That is, in the temperature-raising step of dehydration, the water-containing waste can be dehydrated, and in the subsequent carbonization step, the dehydrated water-containing waste can be carbonized. By separating the necessary treatment steps, the workability in both steps can be improved. In this temperature-raising step, as the temperature-raising medium, oil, tar pitch (heated to about 150 - 190°C), low-melting-point alloy / fusible alloy (melting point about 150 - 350°C), salt bath (melting point about 800°C), etc. can be used.

[0009] And since it has a step of carbonizing the dehydrated storage bag, the original water-containing waste can be easily handled throughout the process, is excellent in handling, and finally becomes a low-bulk carbide. As the temperature in the carbonization step, it is possible at about 400°C, but it is preferably about 600°C or higher and about 650°C, and it can also be set to about 800 - 900°C as a measure against dioxin.

[0010] As the carbonization atmosphere, it is in a situation of oxygen-poor or oxygen-free. For example, nitrogen gas, CO2 gas, or an inert gas can be blown in to expel oxygen (thermal decomposition without combustion). As the carbonization medium, when using dry steam of about 374°C or lower in the subcritical region (dry atmosphere), it is difficult for unpleasant odors and smoke to be generated from the organic substances in the water-containing waste. As applications of the obtained carbide, activated carbon for wastewater treatment, soil improvers for agriculture, building boards for building materials, etc. can be exemplified.

[0011] (2) A salt bath may be used as a heating medium in the step of reducing the volume of the storage bag and the step of carbonizing the dehydrated storage bag. In this way, when a salt bath is used as a heating medium in the step of reducing the volume of the storage bag and the step of carbonizing the dehydrated storage bag, not only can the water-containing waste be dehydrated by the salt bath to remove moisture, but also the subsequent carbonization process can be carried out in one go. Also, by immersing the storage bag of the water-containing waste in the heated salt bath, in the step of carbonizing the dehydrated storage bag, it is possible to obtain a carbide without burning in the absence of oxygen O2 and without generating CO2.

[0012] (3) The step of carbonizing the dehydrated storage bag may be carried out separately from other steps. In this way, if the step of carbonizing the dehydrated storage bag is carried out separately from other steps (for example, the step of reducing the volume of the storage bag), the carbonization step can be carried out at a different location and at a different time according to convenience.

[0013] (4) The storage bag of the water-containing waste may be made transportable by a carrier with an openable and closable lid. In this way, if the storage bag of the water-containing waste is made transportable by a carrier with an openable and closable lid, the treatment of the water-containing waste can be made more convenient overall.

[0014] (5) The volume reduction of the storage bag of the water-containing waste may be carried out in conjunction with the opening and closing operation of the lid of the carrier. In this way, if the volume reduction of the storage bag of the water-containing waste is carried out in conjunction with the opening and closing operation of the lid of the carrier, it is possible to reduce the volume without touching the storage bag itself, and it is not necessary to worry about getting hands dirty during use.

Advantages of the Invention

[0015] This invention has the following configuration and effects. Throughout the process, the original water-containing waste can be easily handled, is excellent in handling, and can finally be made into low-bulk carbides. Therefore, a more practical method for treating water-containing waste can be provided than before.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0017] Hereinafter, embodiments of this invention will be described. 〔Embodiment 1〕 The method for treating water-containing waste in this embodiment includes a step of disposing a storage bag for water-containing waste inside a heat-resistant net, a step of reducing the volume of the storage bag, a temperature-raising step of dehydrating the volume-reduced storage bag, and a step of carbonizing the dehydrated storage bag. As the water-containing waste, food waste and leftover rice were treated. As the storage bag, a plastic bag (accommodating about 20 L and about 10 kg) having gas barrier properties and heat-seal fusibility was used. Then, the inside of the storage bag was vacuum-packed, and the inlet end was finally heat-sealed and fused. Therefore, it can be hygienically and cleanly stocked so that odors, smells, and fungi do not escape, and the progress of the spoilage of the food waste inside can be suppressed and the infectivity can be inhibited. In the temperature-raising step, a low-melting-point alloy / easily fusible alloy (melting point of about 150 to 350 °C) was used as the temperature-raising medium. As the temperature for the carbonization step, it was treated at about 650 °C. As the atmosphere for carbonization, nitrogen gas was blown in to create an oxygen-free situation. Therefore, it did not burn but underwent pyrolysis.

[0018] In addition, a carrier with an openable and closable lid is used to make it possible to transport the storage bag for the water-containing waste. Therefore, by making it possible to transport the storage bag for the water-containing waste with a carrier having an openable and closable lid, the treatment of the water-containing waste can be made more convenient overall. Furthermore, the volume reduction of the storage bag for the water-containing waste is made to be carried out in conjunction with the opening and closing operation of the lid of the carrier. That is, by making the volume reduction of the storage bag for the water-containing waste be carried out in conjunction with the opening and closing operation of the lid of the carrier, it is possible to reduce the volume without having to touch the storage bag itself, and it is not necessary to worry about getting hands dirty during use.

[0019] Next, the usage state of the method for treating water-containing waste of this embodiment will be described. Since this method for treating water-containing waste has a step of disposing the storage bag for the water-containing waste inside a heat-resistant net body, even if the storage bag is thermally deformed in the temperature-raising step of dehydrating the volume-reduced storage bag, the dehydrated water-containing waste can be held inside the heat-resistant net body. Moreover, since it has a step of reducing the volume of the storage bag, even if there is space between the stored items and they become bulky, volume reduction can be performed by the negative pressure action of vacuum suction, and the operation of storing new waste can be continued.

[0020] Furthermore, since it has a temperature-raising step of dehydrating the volume-reduced storage bag, it is possible to reduce the moisture content and improve the workability of the subsequent steps. That is, the water-containing waste can be dehydrated in the temperature-raising step of dehydration, and the dehydrated water-containing waste can be carbonized in the subsequent carbonization step. By separating the necessary treatment steps, the workability in both steps can be improved. And since it has a step of carbonizing the dehydrated storage bag, the original water-containing waste can be easily handled throughout the entire process, is excellent in handling, and finally becomes a low-bulk carbide, which is more practical than before.

[0021] 〔Embodiment 2〕 Embodiment 2 will be described centering on the differences from the above embodiment. The step of reducing the volume of the storage bag and the step of carbonizing the dehydrated storage bag use a salt bath as the temperature-raising medium. In this way, since a salt bath is used as the temperature-raising medium in the step of reducing the volume of the storage bag and the step of carbonizing the dehydrated storage bag, not only can the water-containing waste be dehydrated by the salt bath to remove moisture, but also the subsequent carbonization process can be carried out in one continuous operation. Also, by immersing the storage bag of the water-containing waste in the heated salt bath, in the step of carbonizing the dehydrated storage bag, it is possible to obtain a carbide without burning in the absence of oxygen O2 and without generating CO2.

[0022] 〔Embodiment 3〕 Embodiment 3 will be described focusing on the differences from the above-described embodiments. The step of carbonizing the dehydrated storage bag is carried out separately from other steps. In this way, since the step of carbonizing the dehydrated storage bag is carried out separately from other steps (the step of reducing the volume of the storage bag), the carbonization step can be carried out at a different location and at a different time according to convenience.

Example

[0023] As shown in FIG. 1, a heat-resistant net body 3 was disposed (set) in a storage bag 2 (a vinyl bag having gas barrier properties) for water-containing waste (garbage) 1. The heat-resistant net body 3 containing the storage bag 2 was stored in a carrier 4 with a lid. After opening and closing the lid of the carrier 4 with a lid, the inside of the carrier 4 was evacuated so that the water-containing waste 1 would not rot. After the water-containing waste 1 was put into the storage bag 2 in the heat-resistant net body 3 in the carrier 4, it was suctioned to a negative pressure with a vacuum pump to reduce the volume and then sealed. As shown in FIG. 2, the heat-resistant net body 3 was put into a dehydrator 5 and heated. As shown in FIG. 3, the dehydrated water-containing waste 1 was supplied to a carbonization device EOCD and carbonized.

Industrial Applicability

[0024] Due to its more practical nature than before, it can be applied to the uses of various treatment methods for water-containing waste.

Explanation of Symbols

[0025] 1 Water-containing waste 2 Storage bag 3 Heat-resistant net body 4 Carrier

Claims

1. A method for treating water-containing waste, comprising the steps of disposing a storage bag (2) for water-containing waste (1) within a heat-resistant net body (3), reducing the volume of the storage bag (2), raising the temperature of the storage bag (2) with reduced volume for dehydration, and carbonizing the dehydrated storage bag (2).

2. The method for treating water-containing waste according to Claim 1, wherein a salt bath is used as a temperature-raising medium in the step of reducing the volume of the storage bag (2) and the step of carbonizing the dehydrated storage bag (2).

3. The method for treating water-containing waste according to Claim 1 or 2, wherein the step of carbonizing the dehydrated storage bag (2) is performed separately from other steps.

4. The method for treating water-containing waste according to any one of Claims 1 to 3, wherein the storage bag (2) for water-containing waste (1) can be transported by a carrier (4) with an openable and closable lid.

5. The method for treating water-containing waste according to Claim 4, wherein the volume reduction of the storage bag (1) for water-containing waste is performed in conjunction with the opening and closing operation of the lid of the carrier (4).

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