JP2656668B2 - Method and apparatus for reducing moisture contained in waste - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a method and an apparatus for reducing water contained in waste, and more particularly, to a method and an apparatus for reducing water contained in waste.
The combustion gas generated by burning the waste is not only used to reduce the moisture contained in the waste in the stage before the waste is crushed, but also the process of drying and crushing the waste is not performed. The present invention relates to a technique used for placing in an active gas atmosphere.

[0002]

A problem associated with previous attempts to burn wet waste is that in order to crush the waste to a particle size suitable for feed to a circulating fluidized bed combustor, the waste is reduced. The point is that it is necessary to greatly reduce the moisture contained in the water. Certain types of waste, called gobs, contain about 15% moisture and contain clay, slate,
And a mixture of other particles. Up to 15% of this mixture
If it contains some free moisture, this mixture will clog the mill that breaks the solids. However, if it contains only about 6% moisture, the gob can be crushed so that it can be burned in a furnace. Another type of waste, called sludge, contains between 60% and 70% moisture. This is usually a mixture of paper, wood and up to 70% moisture, which can clog the mill when trying to break up the solids.

[0003] In order to crush the waste without clogging the mill for crushing the waste, it is necessary to pre-dry the waste. Then, the waste itself can be used as a fuel for generating heat required for pre-drying the waste.

[0004]

However, when crushing dried waste in a crusher, sparks are generated from hard particles contained in the waste, and the waste may be burned in the crusher.

Therefore, an important object of the present invention is to provide an inert gas circulation system between a circulating fluid bed combustion boiler and a crusher so that heat generated by the combustion of wastes acts on the crusher. It is an object of the present invention to not only dry the water contained in the waste but also prevent the waste being dried from spontaneously igniting.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for reducing water contained in a waste, comprising receiving a water-containing waste in a crusher and drying it while crushing the dried waste. A method of reducing the water content of the waste by supplying to a boiler and burning, and supplying a high-temperature gas obtained by the combustion to the crusher, (a) supplied to the crusher Circulating the gas between the crusher and the separator in a state where the gas is cut off from the outside air; (b) removing granular waste contained in the circulating gas by the separator; and (c) removing the granular material removed by the separator. (D) supplying at least a part of the circulating gas to the boiler, in a state where waste and waste supplied from the crusher are shielded from outside air; The boiler burns the supplied waste with only oxygen circulated with the circulating gas, which is received by the crusher with the waste containing water, and (f) is heated by combustion and contains oxygen. The circulating gas, which has been reduced in volume and made inactive, is supplied to the crusher in a state where the circulating gas is shut off from the outside air.

Further, the apparatus for reducing the water content of the waste according to the present invention includes: (A) a crusher for receiving the water-containing waste and crushing and drying the received waste while crushing; B) a boiler that burns dry waste supplied from the crusher to obtain a high-temperature gas; (C) gas supply means for supplying the gas obtained by the boiler to the crusher; First circulating means for circulating the gas supplied to the crusher between the crusher and the separator in a state of being cut off from the outside air; and (E) at least a part of the gas circulating in the first circulating means. And (F) removing the particulate waste removed from the circulating gas by the separator and the waste obtained from the crusher, And a waste supply means for supplying to the boiler while disconnected from, (G) the boiler, the accepted crusher with waste containing water, and the with the gas first
(H) burning the waste using only the oxygen circulating in the circulation means and the second circulation means, and heating the gas supply means by heating in the boiler and reducing the oxygen content, The activated gas is supplied to the crusher in a state where the gas is shut off from the outside air.

[0008] That is, in the method and apparatus for reducing the moisture contained in the waste of the present invention, the waste containing the moisture is dried in an inert gas. There is no.

[0009]

DETAILED DESCRIPTION OF THE INVENTION Generally, moist and viscous gobs or other moist wastes are problematic in exhibiting flammability. The problem is that the waste must be crushed to a particle size suitable for combustion, and that if the moisture is too high for proper combustion, it must be evaporated. SUMMARY OF THE INVENTION The present invention provides a process for burning waste to ash, using the heat of combustion to supply incoming waste with energy and drying it.

In FIG. 1, incoming waste is collected in a bin 10 and transferred to a conveyor 11 in an enclosure 11A. The conveyor 11 delivers waste to an enclosing conduit 12 connected to an inlet fitting 13 of a roller mill 14 as a crusher. The mill 14 delivers the finely crushed waste to a conduit 15 for delivery to a cyclone 16 as a separator.
The fines of waste are collected in a cyclone 16, passed through a revolving gate 17, collected in a bin 18, and passed through an enclosure 19A as a circulating fluidized bed combustor or circulating CFB as a boiler.
Belt conveyor 19 directed to the entrance 20A of the conveyor 20
Sent by The combustion that occurs in boiler 20 produces ash, which is discharged to outlet conduit 21 and the humid air and hot gases are removed from the hot steam flowing back into the inlet bustle 24 of mill 14 from the CFB boiler. , To the cyclone 22. The fine powder separated from the high-temperature gas in the cyclone 22 is supplied to the loop seal 22A.
Is returned to the CFB boiler.

The gas, crushed waste and hot steam discharged from the mill 14 into the conduit 15 are received at the inlet 25 of the cyclone 16 and the crushed waste is passed through a conduit 27 connected to the mill 14 bustle. When the gas is recovered at the outlet 25A of the cyclone 16 by the operation of the blower 26, the gas is separated. Solids that are difficult to crush are discharged from the mill 14 at the discharge portion 14A of the rotary gate 29. The rotating gate 29 is associated with a conveyor 30 that collects the hard-to-crush waste material and delivers it to a bucket conveyor or other conveyor 31. The waste from the conveyor 31 is re-sorted by being placed on a vibrating screen device 32 which separates the combustible finely divided material from the non-combustible hard material. The pulverulent material is conveyed to
To be conveyed to the collector 33, where the hard material is discharged into a conduit 35 with the ash traveling in the outlet conduit 21 from the CFB boiler 20. This hard-to-crush material is first sorted on a roller mill,
There is no longer any valuable BTU material included.

In FIG. 1, a fine powder material and steam
It is evident that a blower 26 which draws the gas into the cyclone 16 and returns the gas via line 27 to the inlet bustle 24 of the mill 14 forms a first circulation loop.

The second circulation loop is formed of a conduit 61 branching from the middle of the conduit 27, a blower 62, and a conduit 63.
It is supplied to the boiler 20. The gas branched to the second circulation loop is heated to about 871 degrees Celsius (1600 degrees Fahrenheit) at the CFB boiler. The heated gas or vapor is withdrawn from the CFB cyclone 22 via conduit 23 and travels to a roller mill to dry the waste in mill 14.

In the system of FIG. 1, the waste from bin 10 is fed into a roller mill in a hot gas environment of about 871 degrees Celsius (1600 degrees Fahrenheit) received from outlet 23 of CFB boiler 20 (after starting with external fuel). Is crushed. Since the hot gas has an oxygen content reduced to about 6% to 8%, the hot gas environment is inert and the waste moisture is reduced to 6% or less. Since the inert gas moves in the first loop, there is no problem that spontaneous ignition occurs due to the crushing operation in the mill 14. The only way for moisture to enter the system is by the moisture that the waste carries. The moisture is evaporated and the moisture is conveyed to the cyclone 16 and then exhausted by the blower 36 from the mill circuit to the combustor circuit.

Referring now to FIG. 2, the system uses an impact mill 36 with a waste supply bin 37 for collecting a fixed amount of waste. The waste is moved by an auger 38 having a drive motor 39. The waste is moved into a supply chute 40 which opens into the impact rotor chamber.
The impact rotor chamber provides a bottom chamber for collecting hard-to-crush material. The mill 36 throws up the crushed material into the separator unit 42 so that the fine particles can be introduced into the cyclone 44 via the conduit 43. The solids are separated at this cyclone 44 from the gaseous fluid that transported the material to the cyclone 44. Material that is too large in the separator unit 42 is returned to the mill to further reduce the particle size.

Mill 36 and cyclone 44 are in a first circulation loop whereby waste is reduced by mill 36 and transferred by conduit 43 to cyclone 44 by gaseous fluid, which is returned by blower 45. The conduit 46 returns to the gaseous fluid inlet 47 of the mill 36.

The system is provided with a circulating fluid bed boiler 48 for producing hot gaseous fluid for pre-drying incoming waste. The hot gaseous fluid is heated to about 871 degrees Celsius (1600 degrees Fahrenheit) and directed to the mill inlet 47 via conduit 49. Boiler 48
Has a suction port 51 in a second loop formed by a blower 50 connected to the conduit 46 so that some of the gaseous fluid is drawn from the conduit 46 and
8 and is heated at the boiler, flows to the cyclone separator 53 to remove fine powder taken up in the boiler 48, and is returned to the combustion area of the boiler by the seal loop 54. Thus, the second loop delivers hot gaseous fluid to the mill for pre-drying in the mill to avoid clogging of the mill and create an inert atmosphere in the mill.

In either of the systems of FIGS. 1 and 2, the fuel source of the boiler is a cyclone 16 or 44, which collects the crushed particulate material and passes it through a rotary gate 17 or 55 to a bin 18 or 56. Let it pass. The bin 18 or 56 is placed on the belt conveyor 19 or 5
7 is provided at its outlet. These belt conveyors are then housed in a closed housing 19A or 58 to prevent outside air from entering the system, which must be oxygen deficient to render the system inert.

These systems recycle heat from the CFB boiler 20 or 48 to a respective mill that dries waste and breaks it down to fine particles having an average particle size that passes 50% through 700 microns. Therefore, it can operate without loss of energy.

In either system, external air only enters at bins 10 or 37 which supply waste particles to conveyor 11 or auger 38. Because oxygen is consumed in the boiler, the exhaust gas is oxygen deficient and therefore inert.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for handling waste containing gob-grade water.

FIG. 2 is a schematic diagram of another type of apparatus for handling other waste.

[Explanation of symbols]

 10, 37 bin 11A enclosure 11 conveyor 12 enclosing conduit 14, 36 mil 16, 44 cyclone 17 rotating gate 18, 56 bin 19, 57 belt conveyor 19A, 58 closed housing 20, 48 circulating fluidized bed combustor or circulating CFB 22, 53 CFB cyclone 24 Inlet bustle 26 Blower 29 Rotating gate 32, 32A Vibrating sieve 62, 50 Blower

Claims (4)

(57) [Claims] 1. A waste containing water is received by a crusher and crushed and dried, and the dried waste is supplied to a boiler to be burned, and a high-temperature gas obtained by the burning is supplied to the boiler. In the method of reducing the water content of the waste by supplying to the crusher, (a) circulating between the crusher and the separator in a state where the gas supplied to the crusher is cut off from the outside air, (B) removing the particulate waste contained in the circulating gas by the separator; and (c) blocking the particulate waste removed by the separator and the waste supplied from the crusher from outside air. (D) supplying at least a part of the circulating gas to the boiler, (e) receiving the boiler together with the waste containing water in the crusher. Burning the waste supplied using only oxygen circulating with the circulating gas, and (f) shutting off the circulating gas heated by combustion and reduced in oxygen content and rendered inactive from outside air. A method for reducing the water content of the waste, wherein the water is supplied to the crusher in a state of being crushed. 2. A crusher (14; 36) for receiving waste containing water and crushing and drying the received waste, and (B) dry waste supplied from the crusher. A boiler (20; 48) for burning a substance to obtain a high-temperature gas; (C) gas supply means (23; 49) for supplying the gas obtained by the boiler to the crusher; First circulating means (15, 26, 27; 4) for circulating the gas supplied to the crusher between the crusher and the separator (16; 44) in a state of being shielded from the outside air;
(E) second circulation means (61, 62, 63; 50, 51, 52) for extracting at least a part of the gas circulating in the first circulation means and supplying the gas to the boiler. And (F) a waste supply means for supplying the granular waste removed from the circulating gas by the separator and the waste obtained from the crusher to the boiler in a state where the waste is isolated from the outside air ( (G) the boiler is received by the crusher together with the waste containing water and the first boiler together with the gas.
(H) burning the waste using only the oxygen circulating in the circulation means and the second circulation means, and heating the gas supply means by heating in the boiler and reducing the oxygen content, An apparatus for reducing moisture contained in waste, wherein the activated gas is supplied to the crusher in a state where the gas is shut off from the outside air. 3. A take-out means (29) for taking out difficult-to-crush waste from the crusher, and a sorting means (32, 33, 35) for sorting hard-to-crush waste taken out by the take-out means. The apparatus for reducing moisture contained in waste according to claim 2, further comprising: mixing the combustible portion sorted by the sorting unit with the waste supplied by the waste supplying unit. 4. A second separator (22; 53) interposed between the boiler and the gas supply means for removing particulate waste contained in gas supplied from the boiler.
And second waste supply means (22A; 22A) for supplying the granular waste removed by the separator to the boiler.
54. The apparatus for reducing moisture contained in waste according to claim 2 or 3, further comprising: