JPH0510200B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an endless belt-shaped first rotating filter cloth that forms a first gravity dewatering section for a material to be treated from a supply device, and the A second rotary filter cloth forming a second gravity dewatering section for the processed material from the movable filter cloth is provided so as to be freely rotatable and driven, and
The gravity dewatering section is provided with a thickness adjustment roller for adjusting the thickness of the workpiece sent therefrom, a first sensor detecting the amount of the workpiece on the workpiece supply side of the first gravity dewatering section, and the first sensor. A second sensor is provided to detect the amount of material to be processed near the upper side of the thickness adjustment roller of the gravity dewatering section, and based on information from the first and second sensors, the amount detected by the second sensor is less than a setting. In order to maintain the amount detected by the first sensor within a set range, the amount of material to be processed supplied from the supply device is adjusted, and when the amount detected by the second sensor exceeds the set value, the amount of material to be processed from the supply device is adjusted. The present invention relates to a dewatering apparatus that is provided with an automatic control device that reduces the supply amount of the processed material to a set amount, and that is provided with a forced dewatering section for the processed material from the second gravity dewatering section.

[Conventional technology]

Conventionally, in the above-mentioned dehydration apparatus, if the thickness of the processed material supplied from the first gravity dehydration section to the second gravity dehydration section is controlled, the dewatering ability of the entire apparatus can be sufficiently enhanced, and the processing material can be We did not provide a structure for monitoring and controlling the amount of sludge in the second gravity dewatering section because we believed that there would be no problems such as leakage from the edges of the filter cloth (we are unable to provide any literature).

[Problem that the invention seeks to solve]

However, in actual operation, when the properties of the material to be processed change drastically, the amount of material to be processed sent out from the second gravity dewatering section decreases drastically, and the dehydration processing capacity decreases. The workpieces are sent out from the gravity dewatering section over the thickness adjustment rolls, resulting in problems such as poor dewatering in the forced dewatering section and leakage of the workpieces from the edges of the filter cloth.

An object of the present invention is to ensure that good processing is performed in the forced dewatering section even if the properties of the processed material change widely.

[Means for solving problems]

The characteristic configuration of the present invention includes a third sensor that detects the amount of the processed material on the processed material supply side of the second gravity dewatering section, and a third sensor that detects the amount of the processed material near the upper side of the thickness adjustment roller of the second gravity dewatering section. A fourth sensor is provided, and a speed governor is provided to change the speed of the first rotary filter cloth forming the first gravity dewatering section, and based on information from the third and fourth sensors, the amount detected by the fourth sensor is is less than the setting, the speed governor is automatically operated to maintain the amount detected by the third sensor within the setting range, and when the amount detected by the fourth sensor exceeds the setting, the speed of the first rotating filter cloth is increased. The present invention includes a speed governor control device that automatically operates the speed governor to reduce the speed to a set speed, and its effects are as follows.

[Effect]

In other words, if the properties of the material to be processed are such that the dewatering efficiency in the first gravity dewatering section is low, but the dewatering efficiency is greatly increased when the material is supplied to the second gravity dewatering section by impact, the dewatering efficiency will be greatly increased. There is a risk that the thickness of the material to be processed sent out from the double-gravity dewatering section becomes abnormally small, resulting in only a small amount being dehydrated in the forced dewatering section considering its processing capacity, but such an inconvenient phenomenon This is detected as a decrease in the detection amount by the third sensor, and the speed of the first rotary filter cloth is increased by automatic operation of the speed governor, thereby reliably preventing a decrease in throughput.

In addition, if the properties of the workpiece are such that the dewatering efficiency in the first gravity dewatering section is high but the dewatering efficiency in the second gravity dewatering section is low, it is necessary to remove water from the second gravity dewatering section by climbing over the thickness adjusting roller. If the material to be treated is sent out in a state where the material is unbalanced, the thickness of the material may be uneven in the forced dewatering section, resulting in insufficient dewatering, or the material may be over-supplied, causing the material to be removed from the edge of the filter cloth. However, such an inconvenient phenomenon is detected as an increase in the detection amount by the third and fourth sensors, and is reliably prevented by reducing the speed of the first rotating filter cloth by automatic operation of the speed governor. is prevented.

Then, when the speed of the first rotary filter cloth is controlled based on the detection information from the second gravity dewatering section, this first
In the first gravity dewatering section equipped with a filter cloth, the supply amount from the supply device side is controlled so that the thickness of the processed material becomes an appropriate value under the controlled speed state of the first rotary filter cloth. It is also possible to avoid excess or deficiency in the amount of treatment in the 1-gravity dewatering section. This makes it possible to make the entire gravity dewatering process respond well to large changes in the dehydration properties of the material to be treated, while keeping the amount of material to be treated, which is ultimately sent to the subsequent treatment system, in a stable state.

〔Effect of the invention〕

As a result, in a device that has multiple gravity dewatering sections in the first stage and second stage, the processing state in the gravity dehydration section on the front stage side is changed based on the detection result of the object to be processed in the latter stage. According to the present invention,
Compared to conventional dewatering equipment that only has a single gravity dewatering unit, and even those that have multiple stages of gravity dewatering units, they either do not control the processing state at all or control each stage independently. This provides the following advantages:

In other words, if the material to be processed remains in the supply device for the material to be processed before being supplied to the gravity dewatering section,
Since it is difficult to grasp the dehydration properties of the processed material, it is necessary to first supply the processed material from the supply device to the gravity dehydration section and then control the supply amount based on its dehydration properties. . At this time, if there is only one stage of gravity dehydration section, then in a dehydration device that controls the supply amount from the supply device in the previous process, the nature of the material to be treated stored in the supply device will be affected. It is difficult to perform accurate control unless the properties of the processed material actually introduced into the gravity dewatering section remain unchanged. In addition, in dewatering equipment that controls the rotating speed of the filter cloth in the gravity dewatering section itself into which the material to be processed is input, the amount of material to be processed after passing through the gravity dewatering section is not stable, and the subsequent There is a disadvantage that it is difficult to perform post-work such as forced dehydration treatment. Compared to such a structure, the present invention, which is configured as described above with multiple stages of gravity dewatering sections, can avoid such inconveniences.

In other words, the amount of material to be processed sent out from the second gravity dewatering section can be stabilized by controlling the rotating speed of the first filter cloth of the first gravity dewatering section, regardless of changes in the dehydration properties of the material. I can do it. In the first gravity dewatering section, the first
Since the amount of material to be processed is controlled based on the detection results in the first gravity dewatering section while taking into account the change in the speed of the filter cloth in the gravity dewatering section, the amount of material to be processed is controlled as a result. An appropriate amount of the material to be treated is supplied to the first gravity dewatering section in a state that also corresponds to changes in the filter cloth speed. Therefore, even if there is a large change in the dehydration properties of the material to be treated, the amount of the material to be finally sent out can be kept stable, and
This has the advantage that the dehydration ability of the entire device can be fully enhanced.

In addition, even if the gravity dewatering section is equipped with multiple stages, the processing state is not controlled at all, or each stage is controlled independently, resulting in a large change in the dehydration properties of the processed material. This is advantageous in that a corresponding dewatering process and a process in which the amount of processed material sent out from the final gravity dewatering section can be maintained stably can be performed.

〔Example〕

Next, examples will be shown.

As shown in FIG. 1, a rotary mixer 3 is provided to mix the material to be treated supplied from the first storage tank 1 and the flocculant supplied from the second storage tank 2. First gravity dewatering section for processed materials
A first rotary filter cloth 4 in the form of an endless belt forming an endless strip A ₁ is provided so as to be freely rotatable, and an endless filter cloth 4 forming a second gravity dewatering section A ₂ in which the first rotary filter cloth 4 flows to the processed material A belt-shaped second rotary filter cloth 6 is provided, and in cooperation with the second rotary filter cloth 6, a constrictive pressure dewatering zone B gradually compresses the cake, a shear dewatering zone C consisting of a meandering path, and a high pressure forced dewatering section B having a dewatering zone D;
The endless belt-shaped third rotary filter cloth 7 forming C and D,
The first and second gravity dewatering sections are installed so that they can be driven and rotated freely, and the first and second gravity dewatering sections
A dewatering device is constructed in which the cake is sent from A ₁ and A ₂ to forced dewatering sections B, C, and D, where it is continuously dehydrated, and the dehydrated cake is collected by a scraper 8 onto a conveyor 9. Note that 10a, 10b, and 10c are containers for collecting wastewater obtained in the dehydration process.

In the high-pressure dewatering zone D, a large number of rolls 12a and 12b, for example 17 rolls, are arranged close together, and the cake between the second and third rotating filter cloths 6 and 7 is squeezed by the roll 12b and its cooperation. The rotary belt 14 is arranged so as to contact only the lower third rotary filter cloth 7 over almost the entire width, and is wound around all the rolls 12a and 12b, for example, eight belts. The filter cloths 6 and 7 are wound around many rolls 12b so that water from the outside of the filter cloths 6 and 7, that is, from the cake, can easily flow down from the rotary belt 14.

Rolls 15a and 15b that separately drive the second and third rotary filter cloths 6 and 7, and a roll 15c that drives the rotary belt 14 are interlocked and connected to the motor _M1 by a single winding transmission device 17. along with those rolls 1
5a to 15c are arranged near the lower side of the high-pressure dehydration zone D, so that the cake clamping pressure by the second rotary filter cloth 6 increases as the lower side of the rolls 12a increases, and the lower side of the rolls 12b The third rotary filter cloth 7 is configured so that the cake clamping pressure exerted by the rotary belt 14 increases as the filter cloth 7 moves toward the side, thereby improving the cake dewatering efficiency. A dedicated motor for the roll 15d that drives the first moving filter cloth 4
_M2 are interlocked and connected, and two tensioning rolls 16a, 16b are connected to the second rotating filter cloth 6, two tensioning rolls 16c, 16d are connected to the third rotating filter cloth 7, and One tensioning roll 16e for the moving belt 14
is attached.

A thickness adjusting roller 11a that adjusts the thickness of the cake sent to the first gravity dewatering section _A1 and then to the second gravity dewatering section _A2 , and the second gravity dewatering section _A2 ,
Thickness adjusting rollers 11b for adjusting the thickness of the cake sent to the forced dewatering sections B, C, and D are each provided so as to be able to rise freely against the downward biasing force of a spring or the like.

The first gravity dewatering section A ₁ is equipped with a first sensor 18 that detects whether the amount of the material to be processed is within a set range, larger or smaller than the set range based on the level detection of the material to be processed. A second sensor 19 is provided on the processing material supply side and detects whether the amount of processing material is less than a setting or more than a setting based on the level detection of the processing material.
It is located near the upper side of 1a.

An automatic control device 20 is provided to operate the control valves V ₁ and V ₂ for the amount of material to be supplied and the amount of flocculant supplied based on information from the first and second sensors 18 and 19,
The second sensor 19 is configured to automatically adjust the supply amount of the processed material in order to maintain the amount detected by the first sensor 18 within the set range when the amount detected by the second sensor 19 is less than the setting. When the detected amount exceeds a set value, the amount of supplied material to be processed is reduced to a set amount (including zero), and
The thickness of the cake supplied from the first gravity dehydration section _A1 to the second gravity dehydration section _A2 is made constant.

The second gravity dewatering section _A2 is equipped with a third sensor 21 that detects whether the amount of the material to be processed is within a set range, or more or less than that based on the level detection of the material to be processed. A fourth sensor 22 is located on the side where the material to be processed is supplied from A ₁ and detects whether the amount of the material to be processed is less than the setting or more than the setting based on the level detection of the material to be processed;
It is located near the upper side of the thickness adjustment roller 11b.

A speed governor control device 24 is provided that automatically operates the speed governor 23 of the first rotary filter cloth 4 based on information from the third and fourth sensors 21 and 22.
The speed governor 23 is configured to automatically operate in order to maintain the detected amount by the third sensor 21 within the set range when the detected amount by the third sensor 21 is less than the set value, and
When the amount detected by the fourth sensor 22 exceeds a setting, the speed governor 23 is configured to be automatically operated to reduce the speed of the first rotary filter cloth 4 to the set speed (including stopping). , the thickness of the cake supplied from the second gravity dehydration section _A2 to the forced dehydration sections B, C, and D is made constant.

[Another example]

Next, another example will be shown.

The configuration for supplying the processed material to the first gravity dewatering section _A1 in a manner that allows the supply amount to be adjusted can be modified as appropriate, and these components are collectively referred to as a supply device S. Further, in order to adjust the supply amount, appropriate means can be used, such as changing the amount in an analog manner or changing the amount by intermittent supply.

The dehydration form of the forced dehydration sections B, C, and D can be changed as appropriate, such as one type or a suitable combination of multiple types.

The speed governor 23 for the first rotating filter cloth 4 can be of a type that changes the speed in an analog manner, a type that changes the speed by repeatedly stopping and stopping the drive, or any other suitable type.

The object of dehydration treatment and the purpose of treatment may be any.

[Brief explanation of drawings]

The drawings are schematic illustrations of embodiments of the invention. 4...First rotating filter cloth, 6...Second rotating filter cloth, 11
a, 11b...thickness adjustment roller, 18...first sensor,
19...Second sensor, 20...Automatic control device, 21
...Third sensor, 22...Fourth sensor, 23... Speed governor, 24... Speed governor control device, A ₁ ... First gravity dehydration section, A ₂ ... Second gravity dehydration section, B, C, D... Forced dehydration Department, S...supply device.

Claims (1)

[Claims] 1. An endless strip-shaped first rotary filter cloth 4 forming a first gravity dewatering section _A1 for the processed material from the supply device S;
Further, second rotary filter cloths ₆ forming a second gravity dewatering section A2 for the processed material from the first rotary filter cloth 4 are provided so as to be rotatable and driven, respectively. Thickness adjusting rollers 11a, 1 are provided in the dewatering sections _A1 , _A2 to adjust the thickness of the processed material sent therefrom.
1b, which detects the amount of material to be processed on the material supply side of the first gravity dewatering section _A1 , and a sensor 18 near the upper side of the thickness adjusting roller 11a of the first gravity dewatering section _A1 . A second sensor 19 for detecting the amount of material to be processed is provided, and based on information from the first and second sensors 18 and 19, when the amount detected by the second sensor 19 is less than a setting, the amount detected by the first sensor 18 is determined. In order to maintain the detected amount within a set range, the amount of the processed material supplied from the supply device S is adjusted, and the second sensor 19
When the detected amount exceeds the setting, the supply device S
The dewatering apparatus is provided with an automatic control device 20 that reduces the amount of material to be processed from the second gravity dewatering section _A2 to a set amount, and is provided with forced dewatering sections B, C, and D for the material to be processed from the second gravity dewatering section A2. , a third sensor 21 for detecting the amount of material to be processed on the material supply side of the second gravity dehydration section _A2 , and the second gravity dehydration section
A speed regulating device 23 that is provided with a fourth sensor 22 that detects the amount of material to be processed near the upper side of the thickness adjustment roller 11b of _A2 , and that changes the speed of the first rotary filter cloth 4;
and based on the information from the third and fourth sensors 21 and 22, when the amount detected by the fourth sensor 22 is less than the setting, the third sensor 21
In order to maintain the detected amount by the fourth sensor 22 within a set range, the speed governor 23 is automatically operated, and when the detected amount by the fourth sensor 22 exceeds the set value, the first
A dewatering device provided with a speed governor control device 24 that automatically operates the speed governor 23 to reduce the speed of the rotary filter cloth 4 to a set speed.