JPS59173625A - Refuse feeding device - Google Patents

Abstract

PURPOSE:To release automatically the bridge by the signal received from a bridge detecting circuit located between two transferring screws, in a refuse feeding device in which the urban refuse is fed from an entrance, and the refuse is supplied after being transferred as the refuse is coarsely broken down. CONSTITUTION:Two screws 21, 22 are provided in a conveyer case 20 of a refuse feeding device, those screws are rotated respectively in inverse direction, rotated forwardly in the manner that the upper side of the screws are brought closer to each other, and kept under relatively parallel location, also screws are formed to be twisted respectively in inverse direction. One screw 22 is directly rotated with a motor supported at its normal position with respect to the conveyer case 20. The screw 21 is supported with a movable bearing, formed in such a structure that the shaft distance for the screw 22 is made adjustable within l1-l2. At the detection of forming of a bridge between the screw 21 and 22 in normal operation, the shaft distance is extended, then the origin for forming of the bridge such as a plate-shaped matter 39 and the like is dropped down, thereby, the bridge is broken.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for handling materials such as municipal waste, which is a mixture of solid materials with various sizes and physical characteristics, and materials containing solid materials contained in bags, by breaking the bags. This relates to a feeding device that transports bagged and/or large-sized waste while roughly crushing it and supplies it to the next process such as an incinerator.

Conventionally, for example, in the incineration treatment of municipal waste, it has been necessary to crush the waste into fine particles beforehand, whether in a stoker furnace or a fluidized bed furnace, in order to increase the combustion efficiency. For this purpose, a special crusher capable of fine crushing is required, making the equipment complex and increasing the equipment cost. A type fluidized bed furnace has been developed, but according to the research of the inventor and others, in this type of furnace, there is no need to finely crush the waste, and even if the waste is supplied only with coarse crushing, fluidization will be inhibited. It was found that the combustion efficiency could be sufficiently increased without any problems.

For example, it has been confirmed that for garbage collected from households in bags, it is sufficient to tear the bags, and there is no need to shred them again.

However, conventional bag-breaking machines use a combination of disks with multiple radial blades to break bags by impact, or break bags by shearing force, but they require a separate transfer device. If foreign matter gets caught in the machine, it may cause damage or stoppage of the machine, which shortens the life of the machine and makes it difficult to operate the facility stably, necessitating a change in the way garbage is collected.

In order to improve this, for example, Japanese Patent Application No. 55-1615
According to 98, by providing two parallel and oppositely threaded screws and adjusting the distance between their axes so that the expansion force caused by the sandwiched object does not exceed a predetermined limit,
It is possible to eliminate the above-mentioned drawbacks of the conventional ones.

However, the form of municipal waste is miscellaneous, and the reality is that we do not know what is going into it, and large pieces of board-like or box-like objects may be mixed in with it. When these plate-like objects ride on the two screw blades in a bridging manner, this plate-like object becomes a nucleus, and the debris on the top forms a bridge (a bridging phenomenon), and the transport function of the feeding device is There was a drawback that the phenomenon of inhibition occurred.

The present invention eliminates the above-mentioned drawbacks of the conventional method, and when bridging (arching) occurs, the arching is automatically canceled within a very short period of time without interfering with furnace operation, making unmanned operation possible. The purpose of this invention is to provide a dust supply device that provides

The present invention accepts handled items such as municipal waste from the entrance,
It is a device that transports the treated material while roughly destroying it and supplies it to the next process from the outlet.It rotates in opposite directions, and during normal operation, rotates in a direction such that the upper sides approach each other (hereinafter referred to as "correct"). It is equipped with two screws that are held parallel to each other and have opposite twisting directions, and the two screws are mutually rotating. , in a feeding device for an incinerator in which at least one screw moves and the distance between the axes of the two screws can be changed, the temperature of the freeboard in the furnace or the temperature of the exhaust gas at the furnace outlet is lower than a predetermined value. A bridge detection section is provided to detect that the oxygen concentration in the exhaust gas has decreased or that the oxygen concentration in the exhaust gas has exceeded a predetermined value. This feeding device is characterized by being equipped with a bulge release mechanism that moves to a predetermined position so as to expand the distance between the shafts and release the bridge.

If the embodiment of the present invention is explained using the drawings, FIG.
This is an example of a municipal waste incineration facility, in which waste stored in a pit 1 is dumped into a hopper 4 by a packet 3 of a crane 2, and is supplied to an incinerator 6 by a feeding device 5. In the incinerator 6, fluidizing air supplied by a blower 7 is ejected upward into the furnace from a dispersion plate 8, hits an inclined wall 9, and becomes a swirling flow 10 in a vertical plane, causing a fluidizing medium such as sand to flow along the swirling flow 10. A two-layer swirling fluidized bed is formed. This swirling fluidized bed allows waste to burn well in a short period of time without hindering fluidization.
High combustion efficiency can be obtained even if fine crushing is not performed in advance.

11 is a combustion exhaust gas duct, °12 is a non-combustible material discharge device, 1
3 is a vibrating sieve, 14 is a conveyor for discharging lumpy incombustibles,
15 is an elevator for collecting fluidized media such as sand.

In the feeding device 5, 16 is an inlet for garbage, 17 is an outlet for garbage after the bags are torn, 18 is an outlet for large non-combustible materials that are not allowed to enter the incinerator 6, and 19 is a return chute.

The feeding device 5 is driven by a motor, but the detected temperature of the thermometer T1 that detects the temperature inside the freeboard or the thermometer T2 that detects the exhaust gas temperature of the duct at the incinerator outlet falls below a predetermined value. Either that or that the oxygen concentration in the exhaust gas detected by the oxygen concentration meter T3 that detects the oxygen concentration in the exhaust gas exceeds a predetermined value is determined by a signal from the bridge detector T4 having a detection mechanism. The bridge release mechanism T5 is activated to release the bridge.

As shown in FIGS. 2 and 3, the structure of the feeding device 5 is such that a hopper 4 is connected to the conveyor case 20 via a waste port 16, a waste outlet 17 is provided at one end of the lower part, and a waste outlet 17 is provided at the other end of the conveyor case 20. is provided with an outlet 18 for discharging lump-like incombustible materials that are not allowed to be introduced into the incinerator 6. Inside the conveyor case 20 are two screws that rotate in opposite directions, rotate in the normal direction so that their upper sides approach each other during normal operation, are held parallel to each other, and are twisted in opposite directions. 2J and 22 are provided. Vanes 23.24 of screw 21.22
The pitch 6 near the exit 17 is larger than the pitch near the entrance 16.

One screw 22 is supported by bearings 25, 26 at a fixed position relative to the conveyor case 20, and is directly rotated by a motor 27. Screw 2 during normal operation
2 rotates in a normal counterclockwise direction when viewed from the motor 27 side, and the screw 21 rotates in a normal clockwise direction.

The screw 21 is supported by a cylinder 28.29 on a displacement bearing 31.32 which moves along a force idle rail 30, as shown in FIGS. 3 and 4. Since the shillings 28 and 29 are configured to be displaced by equal distances as described below, the screw 21 moves parallel to the screw 22, and the center distance adjustment is 1.
It is designed to be carried out from 1 to 12.

The shaft ends of the screws 21 and 22 on the motor 27 side are connected to links 33, 34 and gears 35.34, as shown in FIGS. 5 and 6.
According to 36.37.38, the distance between the shafts is 1 from '11.
2, the screw 21 continues to be driven and rotated in the opposite direction to the screw 22. The functions of crushing garbage and tearing bags by the screws 21 and 22 will be explained with reference to Figures 7 to 9.

Figure 7 (a) (+)) shows the crushing and bag-breaking effect due to compression, and the garbage 39 is caught and caught in the opening between the blades 23 and 24 and the shaft, and is deformed due to compression while being pushed downward. , shredding or bag breaking is performed.

FIG. 8 shows a state in which the bag is crushed or torn by bending the bag between the blades 23 and 24.

FIG. 9 shows that the increasing pitch of the vanes 23, 24 results in crushing or breaking the bag by tearing.

However, the reality is that municipal waste comes in a variety of forms, and it is difficult to predict what will enter it (sometimes large pieces of board-like or box-like material may be mixed in). When these plate-like objects are placed on top of the two screw blades in a bridging manner, this plate-like object becomes a core, and the debris on the top forms a bridge (a bridging phenomenon), and the transport of the feeding device. A phenomenon in which functions are inhibited may occur.

When these phenomena occur, the waste supply to the furnace is interrupted, i.e. the fuel supply is interrupted, so the furnace and fluidized medium (
(sand) temperature decreases, and auxiliary fuel oil is required.

Therefore, in order to achieve stable and energy-saving operation of the furnace, when the above bridging phenomenon occurs, arching must be automatically canceled within a very short period of time without interfering with furnace operation, and the transport function of the feeder can be restored normally. An important issue is getting back to work.

Therefore, in the fuel supply device of the present invention, first, the state of at least one of the temperature of the exhaust gas, the temperature at the freeboard, or the oxygen concentration in the exhaust gas is detected to understand the state of occurrence of bridging. In other words, as mentioned above, when a bridge occurs in some of the two screws, the supply of waste to the incinerator is stopped, so the combustion reaction in the incinerator decreases, and the oxygen concentration in the exhaust gas increases accordingly. If the oxygen concentration in the exhaust gas is measured, it can be determined that a bridge has occurred when the oxygen concentration becomes larger than a preset oxygen concentration.

Note that since the carbon dioxide concentration in the heat exhaust gas decreases, the occurrence of a bridge can also be detected using a carbon dioxide concentration meter for the same reason.

In addition, as the supply of garbage is interrupted due to the occurrence of bridges,
The temperature of the exhaust gas from the incinerator naturally decreases, and for example, if you measure the temperature of the exhaust gas at the exhaust gas outlet of the incinerator, or measure the temperature in the upper space of the incinerator, you can find out that the temperature decreases. This allows you to know that a bridge has occurred. In this way, the present invention first detects the occurrence of a bridge, and then automatically performs the operation to release the bridge. The feeding device of the present invention releases the bridge from the bridge detection section.

After receiving a signal indicating that a bridge has occurred, the distance between the axes is moved as shown in FIGS. 10(a) and (1)). That is, assuming that the minimum distance between the shafts is 11'% and the maximum distance between the shafts is 12, transportation is carried out at the minimum distance between the shafts of 11 as shown in FIG. 10 (,) during normal operation.

In this state, the dust 39 on the plate-shaped object is removed from the screw 21゜2.
If the blade crosses the blade 2 in a bridge-like manner, the transport function will be inhibited, but as shown in FIG. 1
By expanding to an arbitrary position between 1 and 12, the bridge of the debris 39 of the plate loses its support and falls into the opening of the two screws. When the plate-like object 39 that forms the core of the arching falls, the debris on top of it also follows and falls. Plates and pond garbage are shown in Figure 10 (b).
When the state shown in is reached, the transport function is restored by returning the movable screw 21 to its original position, and the plate-like objects and other debris are caught between the screws 21 and 22, compressed, and destroyed. , the bag-breaking effect is also restored.

Moreover, this opening operation takes about 1 minute and does not interfere with the operation of the furnace at all.

Note that even during this operation, the two screws continue to rotate in the normal direction.

FIG. 11 shows an example of a hydraulic circuit for adjusting the distance between the shafts as described above.

FIGS. 11-a-f explain each operation procedure. In step 11-a, the hydraulic pump 40 is activated, Sol a is turned ON, and both cylinders 29 and 28 are moved forward. The movable screw moves in parallel.

In FIG. 11-b, the hydraulic pump 40 is stopped;
All solenoid valves are in the OFF state, indicating the state during normal operation.

That is, during normal operation, the cylinders 29 and 28 are hydraulically locked and the center distance 1=11 is maintained.

Fig. 11-C shows the same condition as Fig. 11-b, but if a small foreign object such as an iron, short pipe, hammer, cannonball, small automobile parts, tire fragment, or square lumber fragment is bitten, the produces an excessive expansion force, causing cylinder 2
9. Generates high pressure at 28. The safety valve 41 is, for example, 70-
It is variable to about 140 kgf/cm2, and by adjusting the pressure, a predetermined allowable expansion force (for example, 6TO due to bearing reaction force)
Set it to N). When the expansion force exceeds the allowable expansion force, the safety valve 41 opens and the two cylinders 28 move back by an equal distance, decreasing to the allowable expansion force and increasing the distance between the shafts until the hydraulic pressure becomes equal to or less than the set pressure of the safety valve 41. , the expansion stops when the value becomes .

FIG. 11-d starts the hydraulic pump 40 and
]2ON', only the hydraulic cylinder 29 is moved forward. 'This is an operation for restoring the parallelism of the movable screw 21.'

FIG. 11-e starts the hydraulic pump 40 and 5ola1
, a2 ON to move only the hydraulic cylinder 28 forward. This is also an operation for restoring the parallelism of the movable screw 21.

Figure 11-f starts the hydraulic pump 40, 5o11)
, ON, and the hydraulic cylinders 29 and 28 are retracted in parallel. This is an operation for when a large foreign object comes in and is reversed and discharged out of the system.

By combining some of the above operations, the automatic bridge cancellation operation can be performed automatically.

The operation of FIG. 11-ctdte is described in Japanese Patent Application No.
This is for automatically returning the movable screw position and restoring parallelism in -3233. Further, in this example, each operation is performed by a hydraulic mechanism, but an electric motor or other method may also be used. FIG. 12 shows an example of a bridge release sequence. When the bridging phenomenon occurs, the waste (that is, fuel) cannot be supplied into the furnace (or the amount supplied decreases), so the temperature of the exhaust gas exiting the furnace 1 drops rapidly. In addition, the oxygen concentration in the exhaust gas from the furnace rises rapidly.

During normal operation, the furnace output temperature is 850 to 900'C.
The furnace is operated at an oxygen concentration of about 6 to 9% in the exiting waste. Therefore, the setting values for the bridge release sequence operation are, for example, the furnace exit exhaust gas temperature 800 and the oxygen concentration in the 'C1 furnace' exhaust gas 15% (both settings are variable), and one (or both 7j) is set to each setting. When the value is reached, the sequence of FIG. 12 is activated. The procedure for canceling the bridge will be explained with reference to FIG.

When the temperature or oxygen concentration reaches a predetermined value, a signal indicating a minor failure is issued to notify the operator that the bridge release sequence will be activated, and the hydraulic pump 40
5oi1), perform f ON (backward operation), and after a few seconds (for example, 25 seconds...this time is the time for the hydraulic cylinder to retreat through the shaft opening distance of approximately 300+n+n, and the setting value is variable)SolblOFF. (Backward stop) So
After a few seconds (for example, 25 seconds + α = 30 seconds...this time is enough time for the hydraulic cylinder to return to the distance between the shafts of 11 and the distance between the shafts of 1
1 (movement stops at stopper) Sofa,
OFF (Forward stop) Hydraulic pump turns OFF. During this period, the operating time is about 1 minute, and there is no problem with the operation of the furnace. Through these operations, if the temperature of the exhaust gas at the furnace outlet and the oxygen concentration in the exhaust gas at the furnace outlet return to their original values, the minor failure signal will stop and normal operation will continue, but the condition will not return to normal even after, for example, two minutes have passed. In this case, a serious malfunction warning will be issued. At this time, the operator monitors the inside of the furnace and expands the movable screw even further to a maximum distance of 12.
...approximately 600mm) Try to remove the bridge or stop the furnace operation.

Note that this is an abnormal situation, and in most cases it will be canceled by the automatic sequence described above.

Further, although this sequence has been described as an example in which each operation is performed using a timer, a limit switch may be provided instead of the timer.

In addition, in the present invention, the bridge detection section may be equipped with M number of sensors such as a thermometer and an oxygen concentration πL as described in the embodiment, or whether one thermometer or oxygen concentration meter is It is also possible to provide only a sensor and detect the occurrence of a bridge based on its signal.

According to the present invention, even if bridging occurs due to foreign matter covering the screw, it is possible to detect this, eliminate the bridging in a short period of time, and provide a feed device that does not interfere with furnace operation. Above all, it is possible to achieve a very large effect.

[Brief explanation of the drawing]

The drawings relate to embodiments of the present invention, and FIG. 1 is a cross-sectional front view of a waste incinerator, FIGS. 2 and 3 are a vertical cross-sectional front view and a plan view of a feeding device, and FIG. 4 is a cross-sectional front view of a waste incinerator. Fig. 5 is a cross-sectional side view taken along II-II in Fig. 2, Fig. 6 is a view at another point in time, and Figs. 7 to 9 are illustrations of the crushing and bag-breaking effects. Figures 7(,) and (b) are cross-sectional views and plan views of the screw, Figures 8 (a) and (b) are cross-sectional views and plan views of the screw, and Figures 9 (a) and (b). is a plan view of the screw, Figures 10 (11) and (1)) are cross-sectional views of the screw in different processes, Figure 11 is a hydraulic circuit diagram, and Figures 11 (a') to f) show the operating process. The hydraulic circuit shown in FIG. 12 is an operation sequence diagram. 1. Pit, 2. Crane, 3. Packet, 4.
・Hopper, 5. Dust supply device, 6. Incinerator, ? ... Blower, 8. Dispersion plate, 9. Inclined wall, 10. Swirl flow,
11...Exhaust gas duct, 12...Incombustible material discharge device, 13
・・Vibrating sieve, 14・・Conveyor, 15・・Elevator, 16・・Inlet, 17・・Exit, 18・・Discharge port, 1
9. Return chute, 20. Conveyor case, 21.
22...Screw, 23.24...Blade, 25.26
・・Bearing, 27・・Motor, 28.29・・Cylinder,
30... Guide rail, 31, 32... Moving bearing, 33
．． 34...Link, 3513G437138...Gear,
39... Garbage, 40... Hydraulic pump, 41... Safety valve. Patent applicant: Ebara Corporation Patent attorney Sen 1) Neji

Claims (1)

[Scope of Claims] 1. A device that receives materials such as municipal waste from an inlet, transports them while roughly destroying them, and supplies the materials to the next process from an outlet, which rotate in opposite directions. During normal operation, the upper sides are rotated in a direction that approaches each other (hereinafter referred to as forward rotation, and the opposite is referred to as reverse rotation), and are held parallel to each other and rotate in opposite twisting directions. An incinerator equipped with two screws, in which at least one screw can move and the opening of the two screws can be changed while the two screws are mutually rotating. In the feeding system, the temperature of the free board in the furnace or the temperature of the furnace outlet [J
A bridge detection section is provided to detect that the temperature of the gas held in the exhaust gas has fallen below a predetermined value, or that the oxygen concentration in the exhaust gas has exceeded a predetermined value, and the movable section is provided with a bridge detection section that detects when the temperature of the gas held in the exhaust gas has fallen below a predetermined value, or when the oxygen concentration in the exhaust gas has exceeded a predetermined value. A feeding device comprising a bridge release mechanism that moves the screw to a predetermined position so as to expand the distance between the axes between the two screws and release the bridge. 2. The bridge release mechanism. 2. The feeding device according to claim 1, wherein the feeding device is a mechanism for expanding the interaxial distance between the two screws to a predetermined value and then returning them to the original position.