JPS59213694A - Composting fermentation cell agitation control - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling stirring operation in a fermenter for composting organic waste such as municipal waste, sewage sludge, livestock waste, and agricultural waste.

Normally, such organic matter composting operations involve storing the materials (composting raw materials) for a certain period of time, and during that period, stirring at appropriate time intervals while supplying an appropriate amount of air from the floor surface, so-called cutting and turning. It is done by promoting aerobic fermentation rather than kernels and traps. Also, depending on conditions such as local weather and environment,
In some cases, the waste is stored in the open and the air supply from the floor is omitted, but in any case, in favor of composting, the turning operation is
This operation is essential for reasons such as homogenization of the material, uniformity of aeration, and substantial expansion of the aeration surface area.

On the other hand, in order to make the composting operation continuous, a function is required to move the material in a certain direction at the same time as stirring for the above-mentioned cutting and turning operation. It has equipment.

Generally, the load applied to the stirring device is proportional to the amount of material movement per unit time. That is, the load applied to the stirring device varies depending on the moisture content of the material, the height of the piled layer, the moving speed of the stirring device, etc.

By the way, composting is a process in which organic matter is decomposed by the action of bacteria, but as this reaction (fermentation) progresses, the volume of the composted material decreases. This phenomenon is the first
To explain with a diagram, the amount of composting raw material supplied to the fermenter is A, and fermentation progresses while it is being sequentially transferred toward the exit end as B, C, D, E, and F. Its volume decreases. Although the final volume of the composted product depends on the composition of the composting raw materials, it is often 14 to 14 times the original volume.

Also, depending on the charging method, there may be large variations in the height of the deposited layer at the charging section. Furthermore, the moisture content of the compost varies greatly during the fermentation process. However, despite the above-mentioned load fluctuations within the fermenter, the moving speed of the conventional stirring device has been constant or at most two speeds. As a result, the stirring device or the driving device for the moving device became too large, and because it was at a constant speed, it could not follow sudden changes in the material or changes in the height of the deposited layer, resulting in an overload condition.

The present invention overcomes the conventional method by detecting the load condition of the stirring device and its transfer device in the form of current or power and automatically increasing or decreasing the transfer speed of the stirring device within the range that the current or power allows. Eliminating the shortcomings, it absorbs material load fluctuations, ensures stable operation, prevents overload, and prevents equipment with excessive capacity, maximizing the performance and processing capacity of the stirring equipment. The object of the present invention is to provide a method for controlling stirring of a composting fermenter.

The present invention provides an agitation control method for a composting fermentation tank, in which a stirring device is moved into a fermentation tank in which composted material is deposited, and composting and fatification are performed while stirring and transferring the composted material.
Detecting the stirring power of the stirring device or the moving power of the stirring device, and comparing it with a stirring power setting value or a moving power setting value,
A method for controlling stirring of a composting fermenter, characterized in that the moving speed of the stirring device is controlled according to the deviation.

Although embodiments of the present invention will be described with reference to the drawings, the present invention should not be limited to the following embodiments.

FIG. 2 is a perspective view of a rectangular composting device equipped with a rotating paddle-type agitation transfer device, and FIG. 3 is a side view of the agitation transfer device of FIG. 2. One end of the rectangular fermenter 3 has an inlet end 1.
is provided, and an outlet end 2 is provided on the opposite side. 4 is the side wall of the fermenter. Rails 5, 5 are provided on the outside of the side wall 4, respectively, and legs 6 are provided on the rails 5. A beam 7 is spread between the legs 6, 6, so that the legs 6, 6 can run vertically on the rail 5°5 as a unit. 8 is a drive mechanism for vertically moving the legs 6. A traversing truck 9 is provided on the beam 7, and an arm 10 is fixed to the lower part of the traversing truck 9. Furthermore, a rotary paddle 12 is rotatably installed at the tip of the arm 10.

Reference numeral 13 represents a drive device for laterally moving the traversing cart 9, and reference numeral 15 represents a drive device for the rotary paddle 12.

Here, the drive device 15 of the rotary paddle 12 is the same drive motor 1.
The drive device 13 of the transverse truck 9 is driven by the same drive motor 16, and the same speed detection device (TG) 1
7. Equipped with a speed increase/decrease device (PM) 18.

In order to detect the stirring power of the stirring device when stirring and transferring the material by 120 rotations of the rotating paddle of the stirring device,
Current control device (AIC) 19 or power control device (W
IC) 20 drives the drive motor 14 of the rotary paddle 12.
Detects the operating current or operating power of the drive motor 14 and compares it with the rated current or set maximum current or rated power or set maximum power of the drive motor 14 selected as the stirring power set value, and based on the deviation, determines the moving speed of the stirring device. In order to control the traverse movement speed, a movement speed control device (SIC) 21 gives a signal to a traverse movement speed increase/decrease device (PM) 18 to control the traverse movement speed.

Further, instead of the above-mentioned control of detecting the stirring power, or in combination with this, the moving power may be detected and compared with a set value of the moving power to control the moving speed.

That is, as the moving power, the drive motor 16 of the traversing truck 9
The current or power may be detected and compared with the rated current, set maximum current or rated power, and set maximum power as the moving power set value, and the moving speed of the stirring device may be controlled based on the deviation.

Note that the current and electric power of the motor of the vertical movement drive mechanism 8 may be detected as the movement power, and the vertical movement speed may be similarly controlled.

Further, the speed of the tilting mechanism may be controlled based on the deviation based on the detected value of any of the above motors.

A schematic diagram of the operation of the embodiment of the present invention is shown in FIG.

The layer height in (a) indicates the pile height of the compost in the AA cross section of FIG. 2.

That is, the pile height is highest at the input section, decreases as fermentation progresses, and returns to about the same level at the discharge section.

Moreover, the same figure (b) shows the change of the traverse speed of the stirring device which stirs the inside of a fermentation tank, and the same figure (C) shows the operating current or operating electric power of a rotating paddle.

The horizontal axis indicates time T, which progresses from right to left.

The stirring device starts stirring from the discharge section, but since the bed height in the turning section is low, the load on the rotating paddle is small.

Therefore, the traverse speed is increased and stirring is performed until the maximum current or power is approached. In this example, the maximum speed is set in order to avoid runaway of the apparatus, so stirring is performed at the same maximum speed.

As the stirring device advances, the layer height gradually increases, so the load on the rotating paddles should not be large, and the traversing speed is gradually lowered to operate at the maximum current or power of the motor.

Although the above is an operation in a steady state, according to this method, it is also possible to cope with sudden changes in layer height, changes in water content, etc. as shown in FIG.

That is, a sudden increase in layer height or moisture content is detected by changes in current or power, and the traverse speed is reduced to deal with it.

The above has described a composting device that stirs and moves composting material while moving horizontally and vertically in a rectangular fermenter, but a composting device that stirs and moves only vertically in a rectangular fermenter,
This method can also be applied to cylindrical fermenters, etc., in which the stirring device moves in the radial and circumferential directions.

According to the present invention, since the load is grasped and stirring is performed under conditions suitable for the load, the device is not overloaded, operation management is easy, and each drive device or motor is not oversized. It is possible to provide an agitation control method for a composting fermenter that can prevent such problems, and has extremely great practical effects.

[Brief explanation of the drawing]

The drawings relate to an embodiment of the present invention; Fig. 1 is a diagram showing changes in the layer height of compost in a fermenter, Fig. 2 is a perspective view of the embodiment, and Fig. 3 is a side view of the stirring device. FIG. 4 and FIG. 5 are operation flow diagrams. 1... Inlet end, 2 Output end, 3... Fermentation tank, 4...
・Side wall, 5...Rail, 6...Legs, 7...Beam, 8
... Drive mechanism, 9... Traverse truck, 10... Arm,
12...Rotating nozzle dollar, 13...Driving device, 14...
- Drive motor, 15... Drive device, 16... Drive motor, 17... Speed detection device (TG), 18... Speed increase/decrease device (PM), 19. Current control device (AIC), 2
0: Power control device (WIC), 21: Movement speed control device (SIC). Patent applicant Ebara Corporation Ebara Electric Co., Ltd. Patent attorney 1) Twisting Takao Maruyama Figure 1 and convex

Claims (1)

[Scope of Claims] 1. A stirring control method for a composting fermentation tank, in which a stirring device is moved into a fermentation tank in which composted material is deposited, and composting is performed while stirring and transferring the composted material, comprising: the stirring device; Detecting the stirring power of or the moving power of the stirring device, and comparing it with the stirring power setting value or the moving power setting value,
A method for controlling stirring of a composting fermentation tank, characterized in that the moving speed of the stirring device is controlled according to the deviation.