CARBONIZATION/OIL RECOVERY TREATMENT FURNACE

Abstract

There is provided a carbonization/oil recovery processing furnace which can be manufactured at a relatively low cost and has less deterioration due to corrosion in association with operation, and can also be maintained and managed at low cost. The carbonization/oil recovery processing furnace is constituted so as to process discarded materials including plastic waste by carbonization and oil recovery with the use of superheated steam which is supplied from the outside, and the carbonization/oil recovery processing furnace is constituted of iron-made external structures and stainless steel-made internal structures which can be separated from the external structures.

Claims

1. A carbonization/oil recovery processing furnace which processes discarded materials including plastic waste by carbonization and oil recovery with the use of superheated steam which is supplied from the outside, the carbonization/oil recovery processing furnace comprising: an iron-made external structure and a stainless steel-made internal structure which can be separated from the external structure.

2. The carbonization/oil recovery processing furnace according to claim 1, wherein the internal structure is fitted to the inside of the external structure so as to be put in and taken out.

3. The carbonization/oil recovery processing furnace according to claim 1, wherein the internal structure is constituted of furnace linings which are divided into a plurality and the plurality of furnace linings are fixed to an inner surface of the external structure so as not to be in contact with each other at a normal temperature.

4. The carbonization/oil recovery processing furnace according to any one of claim 1 including a furnace main body, an upper portion of which is open and a lid which closes an upper opening of the furnace main body, wherein at least the furnace main body is constituted of the external structure and the internal structure.

5. The carbonization/oil recovery processing furnace according to any one of claim 2 including a furnace main body, an upper portion of which is open and a lid which closes an upper opening of the furnace main body, wherein at least the furnace main body is constituted of the external structure and the internal structure.

6. The carbonization/oil recovery processing furnace according to any one of claim 3 including a furnace main body, an upper portion of which is open and a lid which closes an upper opening of the furnace main body, wherein at least the furnace main body is constituted of the external structure and the internal structure.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0012] FIG. 1 is a longitudinal sectional view of a carbonization/oil recovery processing furnace according to a preferred embodiment of the present invention.

[0013] FIG. 2 is a view which shows a state that an internal structure of a furnace main body of the carbonization/oil recovery processing furnace is replaced.

[0014] FIG. 3 is a view which shows a state that an internal structure of a lid of the carbonization/oil recovery processing furnace is replaced.

[0015] FIG. 4 is a longitudinal sectional view of a carbonization/oil recovery processing furnace according to a different preferred embodiment of the present invention.

[0016] FIG. 5(a) is a view which shows a normal temperature state of furnace linings of the carbonization/oil recovery processing furnace, and (b) is a view which shows a state thereof during operation.

[0017] FIG. 6 is a view which shows a state that the furnace linings as the internal structure of the furnace main body of the carbonization/oil recovery processing furnace are replaced.

[0018] FIG. 7 is a view which shows a state that the furnace linings as the internal structure of the lid of the carbonization/oil recovery processing furnace are replaced.

MODE OF CARRYING OUT THE INVENTION

[0019] Hereinafter, a description will be given of a preferred embodiment of the present invention with reference to drawings.

[0020] FIG. 1 is a longitudinal sectional view of a carbonization/oil recovery processing furnace according to a preferred embodiment of the present invention. The carbonization/oil recovery processing furnace 1A is constituted of a furnace main body 2, an upper portion of which is open, and a lid 3 which closes an upper opening of the furnace main body 2. The furnace main body 2 is constituted of an iron-made external structure 4 and a stainless steel-made internal structure 5 which is fitted to the inside of the external structure 4. The internal structure 5 is pulled upward, by which the internal structure 5 can be separated from the external structure 4. The lid 3 is constituted of an iron-made external structure 6 and a stainless steel-made internal structure 7 which overlap each other. The external structure 6 and the internal structure 7 of the lid 3 can also be separated from each other.

[0021] A collar-like portion 2a which protrudes outwardly is formed at an upper end of the furnace main body 2. The collar-like portion 2a is joined with an outer peripheral portion of the lid 3 by using a joining unit 8 such as a bolt, by which the furnace main body 2 is made integral with the lid 3. Thereby, a furnace space 9 which is surrounded by the furnace main body 2 and the lid 3 is kept in a hermetic state.

[0022] The lid 3 is provided with a hot water/steam supplying port 10. The hot water/steam supplying port 10 is connected to a superheated steam supplying unit set outside (not shown) and superheated steam from the superheated steam supplying unit is supplied from the hot water/steam supplying port 10 to the furnace space 9. It is noted that the furnace main body 2 or the lid 3 is provided with an exhaust port (not shown) for discharging air of the furnace space 9 on supplying the superheated steam.

[0023] A description will be given of a method for processing discarded materials by the carbonization/oil recovery processing furnace 1A.

[0024] The lid 3 is removed and discarded materials X are fed into the furnace space 9. Then, the lid 3 is attached to the furnace main body 2 to supply superheated steam to the furnace space 9. A temperature of the superheated steam is about 300° C. to 600° C. When the furnace space 9 is filled with the superheated steam, the furnace space 9 is kept in an oxygen-free state. In the oxygen-free state, the discarded materials X are brought into contact with the superheated steam at a high temperature, by which organic waste is subjected to carbonization and also plastic-derived waste is subjected to oil recovery. Carbonized substances and oils generated from the carbonization/oil recovery processing are collected and recycled.

[0025] Where the discarded materials X contain plastic-derived waste, a corrosive gas such as a chlorine gas, a hydrogen chloride gas, etc., is generated from the plastic-derived waste. The internal structures 5, 7 which are exposed to a corrosive gas are made of stainless steel and stainless steel is relatively high in resistance to a corrosive gas and, therefore, the internal structures 5, 7 are less likely to undergo corrosion. The external structures 4, 6 are covered with the internal structures 5, 7 and kept in an oxygen-free state and, therefore, do not undergo corrosion even when a corrosive gas is present in the furnace space 9.

[0026] However, corrosion advances in the stainless steel-made internal structures 5, 7 when they are operated for a long time. When corrosion advances to a certain extent, the internal structures 5, 7 are replaced. The furnace main body 2 of the carbonization/oil recovery processing furnace 1A is constituted so that the internal structure 5 is fitted to the inside of the external structure 4. Thus, as shown in FIG. 2, the internal structure 5 is pulled upward in relation to the external structure 4, by which the internal structure 5 can be replaced easily. Further, as shown in FIG. 3, in the case of the lid 3, the internal structure 7 is removed from the external structure 6, by which the internal structure 7 can be easily replaced.

[0027] In the carbonization/oil recovery processing furnace 1A, the furnace main body 2 and the lid 3 both have a two-layer structure. The external structures 4, 6 are made of iron which is relatively low in cost, while the internal structures 5, 7 are made of stainless steel which is relatively high in resistance to a corrosive gas. The external structures 4, 6 are made of iron and can be manufactured at a relatively low cost, and the internal structures 5, 7 are made of stainless steel, by which it is possible to suppress corrosion by a corrosive gas in association with operation. Where corrosion advances to a certain extent in the internal structures 5, 7 due to long-term operation, only the internal structures 5, 7 are replaced. As described so far, since it is only necessary to replace a part of the carbonization/oil recovery processing furnace instead of manufacturing a new carbonization/oil recovery processing furnace, the carbonization/oil recovery processing furnace 1A can be maintained and managed at low cost.

[0028] FIG. 4 is a longitudinal sectional view of a carbonization/oil recovery processing furnace according to a different preferred embodiment of the present invention. In the carbonization/oil recovery processing furnace 1B, internal structures 5, 7 are constituted of plate-like furnace linings 11 which are divided into a plurality. The furnace linings 11 are made of stainless steel.

[0029] As shown in FIG. 5(a), the furnace linings 11 are each fixed to inner surfaces of the external structures 4, 6 so as not to be in contact with each other at a normal temperature. Stainless steel is larger in thermal expansion coefficient than iron and, therefore, when a temperature is elevated during operation, as shown in FIG. 5(b), an end surface portion of each of the furnace linings 11 is kept in contact with each other. Therefore, the external structures 4, 6 are not exposed to a corrosive gas, by which the external structures 4, 6 are prevented from corrosion.

[0030] The plate-like furnace linings 11 which are divided into a plurality may be each constituted as follows. There is provided a port portion through which a support member different in height of attachment to the external structures 4, 6 penetrates, the port portion is inserted into the support member, an end surface of each of the plate-like furnace linings is in contact with an upper portion and a lower portion thereof alternately only by a difference in height so that each of the adjacent furnace linings 11 is not equal in height, and the furnace linings are attached by means of welding, etc., via the support member. In this case, even on expansion of each of the furnace linings due to thermal expansion, an end portion of each of the furnace linings 11 overlaps each other to cover the external structures 4, 6 and the end surfaces thereof come into contact with each other to the extent necessary. Therefore, it is possible to easily arrange the furnace linings, with expansion coefficient taken into consideration.

[0031] As with the previously described carbonization/oil recovery processing furnace 1A, the carbonization/oil recovery processing furnace 1B also processes discarded materials X by carbonization and oil recovery. When corrosion advances to a certain extent in the internal structures 5, 7, the internal structures 5, 7 are replaced. As shown in FIG. 6 and FIG. 7, the internal structures 5, 7 are replaced by replacing the furnace linings 11. In this case as well, since it is only necessary to replace apart of the carbonization/oil recovery processing furnace instead of manufacturing a new carbonization/oil recovery processing furnace, the carbonization/oil recovery processing furnace 1B can be maintained and managed at low cost.

[0032] Each of the carbonization/oil recovery processing furnaces 1A, 1B according to the above-described preferred embodiments is constituted of the furnace main body 2 and the lid 3 and designed so that discarded materials X are fed into the furnace space 9 from above. However, they may be fed into the furnace space 9 from the lateral side thereof. Further, if discarded materials can be put into the furnace space and taken out therefrom, the furnace may be constituted so as to be free of the lid.

DESCRIPTION OF SYMBOLS

[0033] 1A, 1B: Carbonization/oil recovery processing furnace

[0034] 2: Furnace main body

[0035] 3: Lid

[0036] 4, 6: External structure

[0037] 5, 7: Internal structure

[0038] 11: Furnace linings

[0039] X: Discarded materials