JPH0132122B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to waste of various sizes, such as municipal waste.
Items that are mixed with solids having physical properties or items that contain solids stored in bags are transferred to an incinerator, etc. by tearing the bags and/or roughly crushing large pieces of garbage. This relates to a method of operating a dust supply device that supplies dust to the next process.

[Conventional technology]

Conventionally, for example, in incineration of municipal waste,
In both stoker furnaces and fluidized bed furnaces, in order to increase combustion efficiency, it is necessary to crush the waste to a fairly fine particle size before supplying the waste. This requires a special crusher capable of fine crushing, requiring multiple pieces of equipment and increasing equipment costs.

Recently, a two-layer fluidized bed furnace, in which the fluidized medium swirls in a vertical plane, has been developed as a type of fluidized bed furnace.According to research by the inventor and others, the smell of this type of furnace is does not need to be finely crushed;
It was found that even if the fuel is supplied only by rough destruction, the combustion efficiency can be sufficiently increased without impeding fluidization.
For example, it has been confirmed that for garbage collected from households in bags, it is sufficient to simply tear the bags, and there is no need to shred them again.

However, conventional bag tearing machines include those that use a combination of discs with multiple radial blades to tear bags by impact, and others that tear bags by shearing force, but they require a separate transfer device and remove foreign objects. If it gets caught, it may cause damage or stop the machine.
This reduced the lifespan of machines and made it difficult to operate the facility stably, necessitating changes to the method of collecting garbage.

As an invention to improve this, for example, Japanese Patent Application Laid-Open No. 57-84921 has been proposed. By adjusting the distance between the axes so that the expansion force due to the object does not exceed a predetermined limit, it is possible to eliminate the above-mentioned drawbacks of the prior art.

[Problem that the invention seeks to solve]

However, such a device still has the following problems. That is, in the above method, the distance between the axes is increased each time the enlarging force due to dust between the screws exceeds the allowable enlarging force, and as a result, when the enlarging force returns to the allowable enlarging force, the enlarging is stopped, and each time the screw is Because it is reset, the reset operation becomes frequent, which shortens the life of each part of the drive mechanism due to wear and tear.In the case of hydraulic drive, the oil temperature rises and a cooler is required, making the structure complicated. This is a problem.

The present invention solves and improves these problems, avoids frequent return movements of the screw while keeping the distance between the shafts as narrow as possible, prevents wear and tear on the drive mechanism, and improves the oil temperature in the case of hydraulic drive. The purpose of the present invention is to provide a method of operating a dust supply device that prevents the rise of the dust, eliminates the need for a cooler, and simplifies the structure.

[Means for solving problems]

The present invention is 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. rotated forward in a direction such that the sides approach each other, held parallel to each other,
And, it is equipped with two screws with opposite twisting directions, and when the expanding force that tries to spread the two screws by an object sandwiched between the two screws exceeds a predetermined value. , the operation of the dust supply device in which the two screws continue to rotate and at least one of the two screws moves in a direction to increase the distance between the shafts until it returns to a predetermined expansion force or less; In the method, a return position is determined where the distance between the shafts is minimum and the parallelism of the two screws is corrected, and a position with a certain predetermined distance is set between the return position and the position with the maximum distance between the shafts. is determined as the return start position, and detects that both ends of the screw reach the return start position while the screw increases the distance between the axes during operation of the dust supply device, and each time the detection is made at at least one end, This is a method of operating a dust supply device, characterized in that the screw is returned to the return position.

[Effect]

According to the present invention, during operation, each time the distance between the shafts increases and reaches a predetermined return start position, the screw is forcibly returned in the direction perpendicular to the axis and returned to the return position with the minimum distance between the shafts, And the parallelism is corrected. When the enlarging force increases, if the distance between the axes is slightly increased, the enlarging force immediately decreases, so the amount of increase in the distance between the axes at one time is not a large value, and the supply amount does not fluctuate. Therefore, it is not necessary to return the adjustment every time the distance between the shafts increases, but it is sufficient to return the adjustment only when there is a possibility that it will accumulate to a certain extent and affect the supply amount fluctuation. This position is determined empirically, and the return start position is determined to perform the return operation, thereby avoiding frequent return operations and preventing wear and tear on the various parts of the drive mechanism.
Prevents the temperature of hydraulic oil from rising, eliminating the need for a cooler. Furthermore, by appropriately selecting the return start position, fluctuations in the amount of supply to the furnace can be suppressed.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a municipal waste incineration facility.
The garbage stored in the pit 1 is dumped into a hopper 4 by a bucket 3 of a crane 2, and is supplied to an incinerator 6 by a dust supply device 5. Incinerator 6
, the fluidizing air supplied by the blower 7 is blown upward from the distribution plate 8 into the furnace, and the sloping wall 9
At this point, a swirling flow 10 is created in a vertical plane, and a fluid medium such as sand is made to flow along this flow to form a two-layer swirling fluidized bed. This swirling fluidized bed allows the waste to be burnt well in a short period of time without hindering its fluidization, and 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, 13 is a vibrating sieve, 14 is a conveyor for discharging lump non-combustible materials, and 15 is an elevator for collecting a fluid medium such as sand.

In the dust supply device 5, 16 is a garbage inlet;
Reference numeral 7 designates an outlet for garbage after the bag is torn, 18 designates a large incombustible material discharge port that is not allowed to enter the incinerator 6, 19 designates a return chute, and 42 designates a radiant heat shielding gate.

The structure of the dust supply device 5 is as shown in FIGS. 2 and 3. The conveyor case 20 has a garbage inlet 16.
A hopper 4 is connected through the hopper 4, and an outlet 17 for garbage is provided at one end of the lower part, and an outlet 18 for discharging lump-like non-combustible materials that are not allowed to be thrown into the incinerator 6 is provided at the other end. Inside the conveyor case 20, there are two screws that rotate in opposite directions to each other, and during normal operation, rotate in the normal direction so that their upper sides approach each other, are held parallel to each other, and are twisted in opposite directions. 21, 22
is provided. The pitch of the blades 23, 24 of the screws 21, 22 is larger near the outlet 17 than the pitch near the inlet 16.

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

As shown in FIGS. 3 and 4, the screw 21 is connected to the guide rail 3 by cylinders 28 and 29.
It is supported by moving bearings 31 and 32 that move along 0. Since the cylinders 28 and 29 are configured so that they can be displaced by the same distance as described later, the screw 21 moves parallel to the screw 22, and the distance between the shafts can be adjusted from l ₁ to It is now being held until l ₂ .

The shaft ends of the screws 21 and 22 on the motor 27 side are connected to links 33 and 3 as shown in FIGS.
4 and gears 35, 36, 37, and 38, the screw 21 continues to be driven and rotated in the opposite direction to the screw 22 even while the distance between the shafts is changing from l ₁ to l ₂ . There is.

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

FIGS. 11a to 11f explain each operation procedure. FIG. 11a shows a state in which the hydraulic pump 40 is activated and So1 a ₁ is turned on, and both cylinders 29 and 28 are moved forward. At the end of the forward movement, the return position is reached and the forward movement is stopped by the action of the limit switch, and the distance between the axes of both screws 21 and 22 becomes the shortest distance _l1 , and the parallelism of both axes is corrected.

FIG. 11b shows a normal operating state with the hydraulic pump 40 stopped and all solenoid valves turned OFF.

That is, during normal operation, the cylinders 29 and 28 are hydraulically locked, the distance between the shafts l=l ₁ is maintained, and both screws 21 and 22 are maintained parallel.

Figure 11c is the same state as Figure 11b, but
For example, an iron, a short pipe, a hammer, a shotgun,
When a small foreign object such as a small automobile part, a tire piece, a square lumber piece, etc. is caught, an excessive expansion force is generated and a high pressure is generated in the cylinders 29 and 28.
The safety valve 41 is variable, for example, about 70 to 140 kgf/cm ² , and is set to a predetermined allowable expansion force (for example, 6 TON with bearing reaction force) by adjusting the pressure. When the expansion force exceeds the allowable expansion force, the safety valve 41 opens and the cylinders 29 and 28 retreat by an equal distance, the expansion force decreases to the allowable expansion force, and the distance between the shafts is increased until the hydraulic pressure becomes equal to or less than the set pressure of the safety valve 41. expands and stops expanding when it reaches a certain value. During this time, the distance between the axes changes while the two axes remain parallel.

FIG. 11d starts the hydraulic pump 40,
The case where only the hydraulic cylinder 29 is moved forward is shown when Solb ₂ is ON. This is the movable screw 2
This is an operation to restore parallelism of 1.

In Fig. 11e, the hydraulic pump 40 is started and Sola ₁ ,
The case where only the hydraulic cylinder 28 is moved forward is shown when a ₂ is ON. This is also a movable screw 21.
This is an operation to restore the parallelism of .

FIG. 11f starts the hydraulic pump 40,
The case where Solb ₁ is ON and the hydraulic cylinders 29 and 28 are moved back in parallel is shown. This is an operation for when a large foreign object enters the system and is reversed and discharged out of the system.

The functions of crushing garbage and tearing bags by the screws 21 and 22 will be explained with reference to FIGS. 7 to 9.
FIGS. 7a and 7b show the crushing and bag-breaking action caused by compression; the garbage 39 is caught between the blades 23, 24 and the shaft, and is deformed by the compression while being pushed downward, resulting in crushing or bag-breaking. The bag is broken.

FIGS. 8a and 8b show the bag being sandwiched between the blades 23 and 24 and being crushed or torn by bending.

FIGS. 9a and 9b show that the bag is broken or broken by tearing as the pitch of the blades 23, 24 increases.

The distance between the axes is adjusted as follows. That is, in Fig. 10 a, b, and c, the distance between the shafts can vary between l ₁ and _{l 2} , but the minimum distance between the shafts l ₁ and the maximum distance between the shafts in steady state are
l ₃ and the maximum center-to-center distance l ₂ are set using a limit switch.

The position of the screw shafts at which the minimum distance between the shafts _l1 is set as the return position, and at this position, the positions of both screw shafts are determined by a limit switch or the like, and the parallelism is corrected so that they become parallel to each other.

As will be described later, the position at the maximum inter-axle distance _l3 during normal operation is also used as a return start position where a return operation for returning the screw shaft to the return position is started.

As the distance between the shafts increases, limit switches are installed at each end to detect when both ends of the screw reach the return start position (l ₃ ).
Let La, Lb.

When the distances between the screw shafts are l ₁ , l ₂ , and l ₃ , the gaps between the screw shafts are S ₁ , S ₂ , and S ₃ , respectively.For example, S ₁ = 125 mm, S ₃ = 225 mm, and S ₂ = 525 mm. It is. The screw 22 may also be moved. _S2 shall be dimensioned so that the largest amount of foreign matter to be discharged can pass through.

The expanding force generated by the dirt 39 caught between the screws 21 and 22 is detected as the oil pressure of the cylinders 28 and 29. For example, as described above, the allowable enlarging force is set as the allowable value of the enlarging force in the hydraulic circuit.

The difference between l ₃ −l ₁ is about 100 mm in the above example, but in order to reduce fluctuations in the distance between the axes, l ₃ −l ₁ is preferably set as small as possible, and may be set to about 30 mm.

The operation of the above-mentioned dust supply device will be explained according to an example shown in the sequence diagram of FIG. 12.

First, when power is supplied to the dust supply device, the hydraulic pump 40 is activated and generates hydraulic pressure. Next, when Sol a ₁ is turned on as shown in FIG. 11a, the cylinders 28 and 29 begin to move forward and the screw 21 begins to approach the screw 22. For a few seconds (for example, 5 seconds, the hydraulic cylinders 28, 29 are at l ₃ −l ₁ , e.g. 30 mm).
After operating the above (advance time), when Sol b ₂ is turned on as shown in Figure 11d, only the cylinder 29 moves forward, and after a few seconds (for example, 5 seconds), Solb ₂ is turned off and SOl is turned off as shown in Figure 11e. When a ₂ is turned on, the cylinder 29 stops, the cylinder 28 moves forward, and after a few seconds (for example, 5 seconds), Sol a ₁ and b ₁ are activated as shown in Fig. 11b.
OFF, and after several seconds (for example, 5 seconds), the hydraulic pump 40 is stopped.

The screw 2
1 moves forward in parallel, only the left end moves forward, and only the right end moves forward, but during this time, no matter where the screw 21 is initially in the inter-axis distance l ₁ to l ₃ , it returns to the return position at the farthest distance l ₁ and returns to the parallel position. The degree is corrected to maintain parallelism.

When the screws 21 and 22 are rotated in the normal direction and garbage is fed in this state, the screws 21 and 22 are
22 maintains the minimum distance l ₁ between the axes and crushes and tears the bags while maintaining parallelism.

When large debris 39 or lump-like non-combustible material enters, a force is applied to expand the distance between the shafts, but if this expanding force exceeds the allowable expanding force, the back pressure of the cylinder 29 will be applied to the safety valve 41, as shown in FIG. 11c. The cylinder 28 is also activated to move the screw 21 backward in parallel, thereby increasing the distance between the shafts. As the distance between the axes increases, the enlarging force of the dust decreases, and the movement of the screw 21 in the direction perpendicular to the axis stops at a position of a certain inter-axial distance l such that l ₃ ≧l>l ₁ where the enlarging force has decreased to the allowable enlarging force. Even when Screw 21 is opening,
Even after stopping in the direction perpendicular to the axis, the screws 21, 2
The forward rotation of No. 2 continues, and crushing, bag tearing, and transfer are performed simultaneously.

During this operation, a part of the screw 21 reaches the return start position _l3 , and when either the leftmost limit switch La or the rightmost limit switch Lb at the center distance _l3 is activated, the first
As shown in Figure 2, the pump 40 starts up again and the SOl
The translational advance of the screw 21 starting from the ON of a ₁ ,
The left end moves forward, the right end moves forward, the axis stops, and the pump stops, the distance between the axes becomes l ₁ , and the parallelism is corrected so that both axes remain parallel.

In this way, part of the screw 21 has a distance between the shafts.
When the screw 21 attempts to go beyond the position l ₃ , it returns to the return position with the shortest distance l ₁ , and the parallelism is corrected, so each time the distance between the axes increases and the expanding force returns to the allowable expanding force. , l It returns less frequently than when it does not reach ₃ , which prevents wear and tear on various parts of the drive mechanism and prevents oil temperature from rising. Moreover, since it always returns at l ₃ , if the l ₃ position is chosen as close to l ₁ as possible without the return frequency becoming excessive, the crushing action will be avoided by operating for a longer time than necessary with a longer distance between the shafts than necessary. , it is possible to prevent the bag-breaking effect from weakening, and it is also possible to prevent fluctuations in the supply amount.

Positions of the limit switches La and Lb mentioned above (l ₃ )
By adjusting the above, it is easy to make adjustments so that the return frequency is not too rapid, the period of large inter-axis distance is not too long, and the supply amount does not fluctuate too much.

If the screw 21 reaches _l3 and the expansion force still exceeds the permissible expansion force, the safety valve 43 on the outlet side of the pump 40 is opened and the pump 40 continues to operate, but for a limited time. When the detection is completed for a predetermined time or more, the rotation of the screw is stopped. Since the large foreign matter at this time is an abnormal foreign matter that should not be supplied to the furnace, the screws 21 and 22 are reversed to send the foreign matter back toward the discharge port 18, and the first
Turn on Sol b ₁ and screw 2 as shown in Figure 1 f.
1 is moved back and the distance between the shafts is opened to l ₂ as shown in FIG. Thereafter, the rotation of the screws 21 and 22 is returned to normal rotation, Sol a ₁ is turned ON as shown in FIG. 11a, the screw 21 is moved forward in translation, and returned to the return position of the shortest distance l ₁ , and the operation is continued.

Although the movement of the screw 21 in the direction perpendicular to the axis has been described above using a hydraulic cylinder, it may also be moved by an electric motor, for example, via a screw and a nut.

FIG. 13 shows the sequence at the time of stopping. This operation is also performed when the shear pin relay of the dust supply device 5 is activated and the motor 27 is stopped.

〔Effect of the invention〕

According to the present invention, the distance between the shafts of the screw is kept as narrow as possible to prevent weakening of the crushing action and bag-breaking action, while also preventing drastic fluctuations in the distance between the shafts to prevent wear and tear on various parts of the drive mechanism. It is possible to prevent the oil temperature from rising and make a cooler unnecessary, which is extremely effective in practical terms.

[Brief explanation of drawings]

The drawings relate to embodiments of the present invention, and FIG. 1 is a cross-sectional front view of a garbage incinerator, FIGS. 2 and 3 are vertical cross-sectional front views of a dust supply device, and FIG. 4 is a view taken in the direction of the arrow in FIG. Figure 5 is a cross-sectional side view of Figure 2, Figure 6 is a view at another point in time, Figures 7 to 9 are explanatory diagrams of the crushing and bag-breaking effects, and Figures 7a and b are 8A and 8B are cross-sectional views and a plan view of the screw, FIGS. 9A and b are plan views of the screw, and FIGS. 10A, B, and C are views of the screw at different stages. A cross-sectional view of the screw, FIG. 11 is a hydraulic circuit diagram, FIGS. 11a to 11f are hydraulic circuits showing operating steps, FIG. 12 is an operating sequence diagram, and FIG. 13 is a stop sequence diagram. 1... pit, 2... crane, 3... bucket, 4... hopper, 5... dust supply device, 6... incinerator, 7... blower, 8... distribution plate, 9... inclined wall, 10...Swirling flow, 11...Exhaust gas duct, 1
2... Incombustible material discharge device, 13... Vibrating sieve, 1
4... Conveyor, 15... Elevator, 16...
Inlet, 17... Outlet, 18... Outlet, 19...
Return chute, 20...Conveyor case, 21,
22... Screw, 23, 24... Feather, 2
5, 26... Bearing, 27... Motor, 28, 29
...Cylinder, 30...Guide rail, 31,3
2...Moving bearing, 33, 34...Link, 35,
36, 37, 38...gear, 39...garbage, 40
... Hydraulic pump, 41 ... Safety valve, 42 ... Radiant heat shielding gate, 43 ... Safety valve.

Claims (1)

[Claims] 1. Receive municipal waste and other items from the entrance,
It is a device that transports the material while roughly destroying it and supplies the material to the next process from the outlet.It is a device that rotates in opposite directions to each other, and in normal operation, rotates forward in a direction such that the upper sides approach each other. comprising two screws held in parallel and with opposite twisting directions;
When the expanding force that tries to spread the two screws apart due to an object caught between the screws of the book exceeds a predetermined value, the two screws continue to rotate and the two screws are In an operating method of the dust supply device, in which at least one of the two screws moves in a direction to increase the distance between the shafts until it returns to a predetermined expansion force or less, the distance between the shafts is minimized and the two screws are A return position where the parallelism is corrected is determined, and a position at a certain distance between the return position and the position of the maximum axis distance is determined as a return start position, and the screw is rotated when the screw is rotated during operation of the dust supply device. A dust supply device characterized by detecting that both ends of the screw reach the return start position while increasing the distance between them, and returning the screw to the return position each time the detection is made at at least one end. How to drive.