JPS6116701B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vertical dehydrated sludge quantitative supply tank for storing dehydrated sludge dewatered in a dewatering device, and continuously cutting out the dehydrated sludge and supplying it to the next process. be.

In recent years, with the expansion of sewage sludge treatment facilities, the amount of sludge generated has steadily increased, and a hygienic, economical, and easy-to-maintain process or total system is required for its treatment and disposal.

In particular, when transporting dehydrated cake or dehydrated sludge to the next process such as drying, incineration, composting, or landfill disposal, temporary storage is required for work efficiency or depending on the system. In recent years, the capacity of sewage sludge treatment facilities has been gradually increasing due to the trend toward larger-scale sewage sludge treatment facilities and intensive treatment of sludge.

However, conventional storage tanks have problems such as bridging of input dehydrated cake or dehydrated sludge, difficulty in removing sludge, and adaptability to changes in sludge properties, making it impossible to increase the size of the tank.

In other words, the storage tank may have a mortar shape, a cylindrical shape,
There is a box-shaped type, and as a discharge device, a screw conveyor, a conveyor with a scraping attachment, etc. are used.

Among these, when the storage tank has a mortar shape or a cylindrical shape, when the storage amount increases, the sludge tends to cause a bridging phenomenon inside the tank, making it difficult for the dehydrated sludge to descend, so the actual storage capacity is small and , emissions are not constant. On the other hand, when the storage tank is box-shaped, there is no bridging phenomenon. However, this type of apparatus includes one in which a plurality of sets of screw conveyors are provided as a discharge device, and one in which a conveyor with the above-mentioned attachment is provided. In the former, the dewatered sludge is mixed too much by the screw conveyor, increasing stickiness and increasing the load on the equipment.In the latter, an adjustment damper is installed above the conveyor to adjust the amount of dewatered sludge falling. However, it has disadvantages such as complicated operation and poor quantitative discharge performance.

In contrast, the storage tank has a conical silo shape, and in addition to a screw conveyor installed in the discharge trough formed on the bottom, a rotor with a spring arm for sludge scraping that rotates on the bottom is used for cutting and discharging. There is an idea that by providing a system, the following effects can be produced and the above problems can be solved. That is, (a) Even if the sludge is stored for a long time, there is no problem of difficulty in discharging the sludge due to the bridging phenomenon, and even large volumes can be discharged smoothly.

(b) The sludge properties in the storage tank vary greatly depending on dewatering conditions, season, storage time, etc., but the sludge removal system that combines a conical silo's rotary cutting and discharging machine and a screw cutting conveyor is adaptable to these property changes, and the sludge It is possible to stably and quantitatively cut out the sample without any problems.

The operation of the rotary cutting and discharging machine inside the conical silo is adjusted according to the amount and properties of the sludge to be removed, so there is no convection and there is almost no dead space, so the sludge that is put in first is discharged first.

It can also be emptied almost completely.

The heavy load drive mechanism of the conical silo is equipped with a load reduction device at startup for heavy loads of stored sludge (initial load) or abnormal loads such as sludge clumping, an automatic return device to normal during operation, and several safety features. Since the equipment is systemized, the machine is self-protected and safe.

Hoconical silo equipment is durable, reliable, and easy to maintain.

F. Conical silos have high volumetric efficiency and are compact, requiring a small installation area. Also, the larger the storage capacity, the more advantageous it becomes.

The conical silo's storage and removal system is a rational discharge mechanism that effectively utilizes the properties of organic sludge and the silo effect, so there is no waste, and the power required for the rotating sludge collector and screw conveyor in the silo is small. .

On the other hand, although this type of product has the above-mentioned excellent features, depending on the properties of the dewatered sludge, the rotation of the spring arm arm may
The sludge is kneaded and becomes sticky, and when the screw conveyor discharges it, it intermittently forms large lump-like lumps, making it difficult to continuously supply a constant amount, or the screw conveyor's discharge capacity increases. Therefore, there are problems such as sludge being discharged only intermittently or intermittently (as the amount of sludge supplied to the screw conveyor becomes small).

The present invention has been made in view of the above-mentioned conventional drawbacks, and its purpose is to provide a dewatered sludge quantitative supply tank that can continuously and quantitatively supply dehydrated sludge to the next process from a storage tank with appropriate adhesiveness. There is a particular thing.

Next, the present invention will be explained with reference to the drawings which are one embodiment.

As shown in FIGS. 1 to 4, the dewatered sludge quantitative supply tank 1 according to the present invention includes a pedestal 2, a storage tank 6, a rotational speed converter 20, a dehydrated sludge raking device 29, a discharge device 38, a conveyance device 49, and an electric It is composed of a hydraulic control section 53.

The pedestal 2 has a tapered shape in which four pillars 3 each having a vertical portion 3a and an inclined portion 3b are arranged at the four corners of a square, and these are fixed to each other by beam members 4. Furthermore, a walkway 5 is provided on the girder 4.

When such a frame structure is adopted, it is possible to easily enter the truck directly under the storage tank 6, and additional equipment such as a drive mechanism, which will be described later, can be accommodated in the space formed by the inclined portion 3b, thereby saving space. be advantageous. Of course, depending on the situation, a normal rectangular pedestal may be used.

The storage tank 6 is fixed on the pedestal 2 and has a truncated conical shape with a side wall having an inclination angle θ of about 3° with respect to the vertical line.
It has a pit section 8 for discharge and a gate 9 for emergency discharge on the bottom surface. The above inclination angle is advantageous in that it can maximize the advantages of the conical shape.

Here, the pit portion 8 is formed by welding a trough 11 having a U-shaped cross section with both ends closed below a rectangular notch formed in the bottom plate 10 of the storage tank 6. 12 and outlet 13
However, an inspection port 14 is provided above the discharge port 13. Further, as indicated by Δh in the figure, the upper end of the trough 11 is slightly higher than the bottom plate 10, which prevents the separated water from flowing into the trough 11 (Figures 5 and 6).

In addition to the methods shown in FIGS. 3 and 4, the trough 11 and the screw conveyor may be provided in a manner in which the material is discharged from one direction, two directions, or three directions at the bottom.

Further, the gate 9 is provided in a rectangular notch formed in the bottom plate 10, as described above. That is, two rotary plates 16 are attached to the bottom surface of the bottom plate 10 so as to be freely rotatable by a shaft 15 and at a position slightly lower than the bottom plate 10, and these are opened and closed by a hydraulic cylinder 17 pivotally supported on the bottom surface of the bottom plate 10. This is how it was done. A sealing material is attached to the outer periphery of the rotating plate 16 to prevent foul-smelling wastewater flowing in from above the bottom plate 10 from leaking, and a discharge pipe 18 is arranged on the side of the gate 9. Figures 7 and 8).

A dehydrated sludge scraping device 29 is located at the bottom of the storage tank 6, and a manhole 19 is provided on the side wall of the storage tank 6 for carrying in and out of these devices.

The rotational speed converter 20 is formed by combining a hydraulic motor 21 and a reducer 22, and the reducer 22 is connected to the storage tank 6.
It is fixed to the lower surface of the bottom plate 10 of. This reducer 2
2 is a combination of a worm, a worm gear, a planetary gear, and a spur gear, and decelerates the rotation of a horizontal shaft 23 directly connected to a hydraulic motor 21 and transmits the rotation to a vertical reduction gear shaft 24. The reducer shaft 24 is connected to the reducer 2
2 in the vertical direction, the upper end further passes through the bottom plate 10 and reaches the inside of the storage tank 6, and a rotation speed detector 25 is attached to the lower end. The detected value by the rotational speed detector 25 is input to the electro-hydraulic control section 53. Further, the reducer shaft 24 is hollow, and a hydraulic piping pipe 26 is disposed inside the reducer shaft 24. Since this pipe 26 rotates together with the reducer shaft 24, a hydraulic rotary joint is attached to the lower end of the reducer shaft 24. 27, and is connected to the hydraulic unit in the electro-hydraulic control section 53 via this.

The rotational speed of the hydraulic motor 21 can be controlled by the electro-hydraulic control section 53 into which the detected value is input.

In addition, in the part where the reducer shaft 24 penetrates the bottom plate 10, around the notch formed in the bottom plate 10,
A weir 28 with a height ΔH is provided on the bottom surface,
This prevents sewage from flowing in from the bottom plate 10 (Figures 9 and 10).

The dewatered sludge scraping device 29 has a hollow disk shape and is fixed to the reducer shaft 24 and has a rotatable rotor 3.
0 and two crankshafts 3 provided within the rotor 30.
The spring arm 32 is attached to each end of the spring arm 1 and protrudes from the bottom surface. The crankshaft 31 is connected to the rotor 30 inside the rotor 30.
The two crankshafts 31 are connected via a shaft 33 to a hydraulic cylinder 34 pivotally supported therein, so that the two crankshafts 31 can rotate independently. Since the rotation center 31a of the crankshaft 31 is eccentric from the center of the rotor 30, the tip of the spring arm 32 and the rotor 30 are moved by the operation of the hydraulic cylinder 34.
The distance from the center can be changed. That is, the spring arm 32 extends and contracts with respect to the rotor 30. In addition, the spring arm 32
A leaf spring portion 35 at the tip of is fixed by a pin 36 so as to be replaceable. Furthermore, the hydraulic cylinder 34
The pipe 37 passes through the pipe 26 in the reducer shaft 24.

The rotor 30 is divided into three parts, as shown by the two-dot chain line in FIG. figure).

The discharge device 38 includes a screw conveyor 39 provided in the trough 11 and a cutting device 40 fixed coaxially to the discharge side end of the screw conveyor 39.
, a hydraulic motor 42 that drives the screw conveyor shaft 41 , and a tachometer 44 that measures the rotational speed of the screw conveyor shaft 41 from the end of the screw conveyor shaft 41 via a chain 43 . Here, the cutting device 40 is formed by bending a metal plate into a semicircular shape and attaching bolts 45 to both ends of the tightening band 46. A metal blade 48 is fixed to a bolt 47 of a book so that the direction of the blade 48 can be changed.
They are made into a set by facing each other. In this example,
Two sets of cutting devices 40 are provided above the discharge port 11. In addition, a hydraulic motor 42 and a tachometer 4
4 is connected to the electro-hydraulic control section 53 and is rotationally driven and inputs the speed measurement value to the electro-hydraulic control section 53, and the electro-hydraulic control section 53 controls the rotational speed of the hydraulic motor 42. It is becoming possible (Figures 5 and 6).

The conveying device 49 includes belt conveyors 50 and 51 provided below the discharge port 13 and a weighing machine 52 provided between the belt conveyor 51. Weighing machine 52
The measured values are input to the electro-hydraulic control section 53.

The electro-hydraulic control section 53 includes the rotational speed conversion section 20,
An on-site operation panel for starting and stopping the dehydrated sludge scraping device 29, discharge device 38, transport device 49, and gate 9, a hydraulic unit for driving each of the above-mentioned devices, a rotation speed detector 25, and a rotation speed meter 4.
4 and a control section that automatically controls the hydraulic unit in response to an input signal from a weighing machine 52, and is installed on the walkway 5.

Next, the operation of the dewatered sludge quantitative supply tank 1 having the above configuration will be explained.

First, dehydrated sludge treated to have a water content of 45 to 80% in the previous step is supplied into the storage tank 6 from the input port 7 by, for example, a belt conveyor 54 shown by a two-dot chain line in FIG. 1, and is stored therein.

When supplying dehydrated sludge to the next process, the belt conveyors 51 and 50, the screw conveyor 39, and the rotor 30 are sequentially operated by the electrohydraulic control unit 53.

The rotational speed of the rotor 30 is determined by the amount of dehydrated sludge stored,
The hydraulic motor 21 self-controls and changes from a set rotation speed to a maximum specified rotation speed (for example, 4.2 rpm) in accordance with the load due to changes in water content, properties, etc. The expansion and contraction of the spring arm 32 is performed by measuring the sludge load that the spring arm 32 receives, for example, by measuring the rotational speed of the rotor 30 with a rotational speed detector 25 attached to the reducer shaft 24 (measuring the amount of torque When the rotation speed is below the set lower limit, the hydraulic cylinder 34 is driven to completely retract the two spring arms 32 to reduce the load on the rotor.

Thereafter, when the rotational speed of the rotor 30 exceeds the set upper limit rotational speed, the spring arm 32 is pulled out again. In this way, in the normal operating state, the rotational speed of the rotor 30 is changed in response to load fluctuations of the dehydrated sludge, and in the abnormally high-load operating state, the spring arm 32 is repeatedly extended and contracted, and the dehydrated sludge in the storage tank 6 is Collect and discharge onto the screw conveyor 39.

The collected dewatered sludge is sent out from left to right in FIGS. 5 and 6 by the screw conveyor 39, and is further cut into pieces by the cutting device 40, and then sent from the discharge port 13 to the belt conveyor 50 and then to the belt conveyor 51. They are being carried out.

The amount of dehydrated sludge conveyed by the belt conveyor 51 is constantly measured by a weighing machine 52, and the rotation speed of the screw conveyor 39 is also measured by a rotation speed meter 44.
It is measured by. The rotational speed of the screw conveyor 39 is controlled by the hydraulic motor 42 by the electro-hydraulic control section 53 so that its discharge capacity matches the conveyance amount described above.

Note that the electro-hydraulic control unit 53 controls the spring arm 3 to match the conveyance amount and the discharge capacity.
This is also possible by controlling the rotation speed of 2.

Other methods of matching the amount of sludge filled into the discharge trough with the amount of sludge discharged include detecting the properties of dehydrated sludge (moisture, amount of dewatering aid, etc.) and changing the rotation speed using a microcomputer, for example, or predicting from empirical values. It is possible to detect the amount of discharged sludge based on control, volume of discharged sludge, height of piles, etc.

Note that the hydraulic unit in the electrohydraulic control section 53 is provided with an oil temperature detector, and when the load on the rotor 30 becomes large, the oil temperature reaches a set temperature (for example, 75°C).
If the oil temperature rises above 10°C, the spring arm 32 is retracted and the rotation of the rotor 30 is stopped, thereby lowering the oil temperature. When the oil temperature in the hydraulic tank falls below the set lower limit temperature, normal operation resumes.

In addition, the sewage generated from the dehydrated sludge in the storage tank 6 is guided to the gate 9 section by the weir 28 and the protrusion at the upper end of the trough 11 without flowing into the rotation speed conversion section 20 and the trough 11. 19, the gate 9 may be filled with sand to prevent solid components in the wastewater from coagulating inside the gate 9. The shape of the gate 9 is not limited to the examples shown in FIGS.
As with a gate 9' shown in FIG. 4, the rotating plates 16' may be sloped, and the water may be drained through a pipe 18' disposed on the side of the lowest portion of the abutting portion of the rotating plates 16'.

Furthermore, the number of cutting devices 40 is not limited to two, and the number of metal blades 48 is not limited to four,
Also, it may be a fixed type.

As is clear from the above explanation, according to the present invention, the amount of sludge conveyed by the belt conveyor, that is, the amount sent to the pit section by the moderate rotational scraping action of the spring arm, and the discharge capacity of the screw conveyor can be adjusted. We will deal with it. Therefore, the stored sludge is not mixed more than necessary due to the action of the discharger of the storage tank, and the required power is reduced to operate in an optimal state, so that no undue burden is placed on the equipment.

It is also possible to supply sludge with a desired degree of kneading.

In addition, on the contrary, it is possible to prevent the discharge capacity of the screw conveyor from being too large and the dewatered sludge supplied to the conveyor becoming discontinuous.

Therefore, for example, in the incinerator of the next step, the dehydrated sludge can be burned in a constant state, which has the effect of saving fuel.

[Brief explanation of the drawing]

Figures 1 to 3 are a front view, side view, and plan view of the dewatered sludge quantitative supply tank according to the present invention, and Figure 4 is the same as in Figure 1.
Line sectional view, Figure 5 is an enlarged view of section A in Figure 4, Figure 6
The figure is a side view of FIG. 5, FIG. 7 is an enlarged view of part B in FIG. , 11 is the 9th
- line sectional view, - line sectional view, 12th,
13 is a front view and a side view of the cutting device, and FIG. 14 is a sectional view showing another embodiment of the gate. DESCRIPTION OF SYMBOLS 1... Dehydrated sludge quantitative supply tank, 2... Frame, 6... Storage tank, 7... Inlet, 8... Pit part, 9, 9'... Gate, 10... Bottom plate, 20... Rotation speed converter, 24...
Reducer shaft, 28... Weir, 30... Rotor, 32... Spring arm, 38... Discharge device, 39... Screw conveyor, 49... Conveyance device, 52... Weighing machine,
53...Electro-hydraulic control section.

Claims (1)

[Claims] 1. A mount, a storage tank fixed on the mount, and having a dehydrated sludge input part on the top and a sludge discharge trough on the bottom, and connected to a reducer shaft that passes through the center of the bottom plate of this storage tank, and a speed converter on the bottom plate. a dewatered sludge raking device having a rotor and a spring arm that can be rotatably driven; a telescoping mechanism that extends and contracts the spring arm according to the sludge load on the spring arm; 1. A dehydrated sludge quantitative supply tank comprising: a discharge device having a screw conveyor for discharging dehydrated sludge to the outside of the storage tank; and a control section controlling the rotational speed of the spring arm or the screw conveyor.