JPS58205554A - Sludge concentrating device - Google Patents

Abstract

PURPOSE:To maintain the concn. of sludge in concd. liquid approximately constant at all times, by measuring the concn. of sludge in the concd. liquid formed under various disturbing factors exactly and controlling the operating conditions for a decanter type centrifugal concentrator. CONSTITUTION:A decanter type centrifugal concentrator 1, a means L1 for detecting the rate of feed liquid, a means C1 for detecting the concn. of sludge in feed liquid, a means L2 for detecting the amt. of the formed clean liquid, a means C2 for detecting the concn. of sludge in the formed clean liquid, and a means L3 for detecting the amt. of the formed concd. liquid are provided. The concn. of sludge in the formed concd. liquid is calculated in accordance with the detection signals obtained with the above-described detection means, in an operator, and further, the concn. of sludge in the concd. liquid is controlled in accordance with the results of the calculation, in a controller. In other words, the concn. of sludge in the concd. liquid discharged from the concentrator 1 is known easily and exactly, and the concn. of the concd. sludge is maintained as uniformly as possible by the control operation, whereby the load in the sludge disposal stage is made uniform and the process balance is improved additionally.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a decanter-type centrifugal wetting device that can maintain the sludge concentration in a concentrated solution as uniform as possible.

Gravity separation methods, pressurized flotation methods, centrifugal force separation methods, etc. are known as sludge a-condensation methods, and the appropriate method is selected depending on the circumstances of each treatment system.-7
)S, In many cases, it is difficult to obtain the four-fold effect as designed at a fixed point. The sludge concentration of surplus sludge produced by activated sludge generators fluctuates depending on the properties of the treated water and seasonal changes, which disrupts the sludge treatment process or wastewater treatment process. From this point of view, it is necessary to control the sludge concentration process, which corresponds to the starting point of the process, and to keep the sludge concentration of the a-condensate discharged from this process as uniform as possible, thereby reducing load fluctuations in subsequent processes. Various attempts are being considered to reduce this.

In order to maintain a uniform sludge concentration in the concentrate, first
It is a prerequisite to adopt a concentration method that can be easily controlled, and among the above-mentioned methods, the centrifugal separation method satisfies this condition. In other words, in the centrifugal force separation method, it is possible to control the separation efficiency by adjusting the centrifugal force, but especially when using a decanter type centrifugal a-clamping machine, it is possible to control the solid content by adjusting the differential speed between the bowl and the screw conveyor. That is, the sludge transport speed is controlled in the chamber, and if the sludge transport speed increases, the sludge liquid will be thin, and if the sludge transport speed decreases, the sludge will be thick. Because it has the characteristic that t becomes ], it is not affected only by structural factors, but by adjusting operating conditions
The degree of sludge a in the liquid can be controlled to open the fibers.

Therefore, in meeting the above requirements, it can be said that the use of a decanter-type centrifugal concentrator is extremely effective, but even if a decanter-type centrifugal ms machine is actually used, If it is not possible to measure the sludge concentration, it will not be possible to determine whether the control accuracy is good or bad, and it will not be possible to make corrections to the control operation, making it impossible to maintain a uniform sludge concentration in the concentrated liquid over a long period of time. Therefore, it was considered to measure the sludge concentration in the concentrated liquid, but since the concentration is generally as high as 3 to 5, it is either impossible to measure with conventional measuring instruments, or the measurement accuracy is low. If you want to obtain high-precision measurement results, you will need to install expensive equipment, which will increase the equipment cost. method and ultrasonic measurement method are known, but the former method cannot be used for the above purpose because it targets low J sludge, and the latter method cannot detect air bubbles in the sludge. Expensive pressurized defoaming equipment is required to extinguish the foam, which increases the economic burden.
- There is no guarantee that high #R degree measurement force 5 will always be performed. From this point of view, JP-A-56-44) 452
In No. 1, a rotating device is installed in the thickening tank, and the sludge concentration is estimated from the rotational torque of the rotor in the device. Methods for estimating concentration have been proposed. However, these methods essentially measure the concentration from the viscosity of the concentrated liquid, and the relationship between the two cannot always be said to remain constant under the presence of various disturbance factors such as the shape of the concentration tank and the temperature environment. Therefore, it cannot be a highly advanced method.

The present invention has been made with such prior attention in mind, and the sludge concentration of the shrinkage liquid can be accurately measured even under various disturbance factors, and based on this, the operating conditions of the decanter type centrifugal AA machine can be adjusted. By controlling the concentrated l1Ii liquid sludge 2!1
It is an object of the present invention to provide a sludge filtration device that can maintain a substantially constant level of sludge at all times. The sludge return device of the present invention that can effectively achieve the above object includes an il + decanter type remote concentration S machine, (2) supply liquid level detection means, and (3) supply liquid sludge a degree detection means. , 14) Produced clear liquid sludge detection means, 15: Produced clear liquid sludge concentration detection means, i6
(7) a calculating means for calculating the sludge a degree of the produced concentrated liquid based on the detection signals obtained by the respective detecting means; (8) based on the calculation results; 5. According to the apparatus of the present invention, direct detection of sludge concentration can be carried out by supplying a low concentration of sludge. Since it targets liquids and clear liquids, extremely highly accurate values can be obtained. Therefore, the concentrated liquid sludge concentration calculated from these detected concentration values and each detected liquid volume value is extremely accurate.
Since it activates the i-liquid sludge concentration control means,
The sludge concentration in the concentrated liquid is maintained as uniform as possible, and the load on each subsequent treatment process is approximately unified, resulting in the balance and efficiency of the treatment process, which has a tremendous effect on the industry.

The configuration and effects of the present invention will be explained below based on examples, but the main points of the present invention are that the objects for direct detection of sludge concentration are limited to the feed liquid and the clarified liquid, and that each component is organically communicated. However, there are no particular restrictions on the configuration of individual devices or means.

FIG. 1 is an explanatory diagram showing the entire structure of the apparatus of the present invention. A decanter type centrifugal compressor 1 is composed of a box 2, a rotating pow/L/8, and a screw conveyor 4. Bowl 3 is Soita M2
At the same time, the screw conveyor 4 and Bob/L
The rotational speed difference of /8 is obtained by reducing the speed difference between the rotational speed transmitted from motor M2 and the rotational speed transmitted from motor M1 using speed reducer S. The feed liquid introduced into the screw conveyor 4 is separated into clear liquid and sludge (7 types) by centrifugal force in the bowl A/8, but the sludge is transferred according to the difference in rotational speed between the bowl 3 and the screw conveyor 4. The speed is obtained, and the solid content separation efficiency is determined by the size of the speed difference.
In other words, the sludge concentration M rate changes. Therefore, the feed liquid introduced into the air conditioning section of the screw conveyor 4 as shown by the arrow undergoes separation between the bowl 3 and the screw conveyor 40, and the clarification surface is separated from the left side of Poku A/3 as shown by A. The concentrated liquid is conveyed to the right side by the action of the screw conveyor 4, and is finally discharged as shown by B, and the concentrated liquid is transferred to the box 2, respectively.
After exiting, it is ejected in the direction shown by the arrow. Since the decanter slow-speed MuaM1 machine shown in the same figure is shown conceptually, Makizo can freely change the design of the Pou Y1 screw bearing, supply liquid introduction mechanism, drive mechanism, etc. The point is that the introduced feed liquid can be subjected to centrifugal separation to separate a clear liquid and a concentrated liquid, and that the ms peak can be controlled, and if successful, it can be used for confession. The difference in the rotational speed between the bowl 8 and the screw conveyor 40 can be changed freely, such as motors Ml and M2 of the Okamant-Kuma stage variable speed type, and the motors M1 and M2 of the Okamant-Kuma stage variable speed type, etc. In the figure, the motor M1
This shows a continuously variable speed type. Each of the feed, fresh liquid, and IM condensate lines has 1ilffL1. L21
L3 and densitometer 1. C2 is provided, and the supply liquid amount is 1. Clear liquid liquid volume 2゜concentrated liquid volume〆3 (unit: normal / h3
/hr), and feed liquid sludge concentration q1. The clarified liquid sludge a degree q2 (unit: usually g/m3) is detected respectively. Regarding the concentration q3 of the cat liquid sludge, as mentioned above, it is not a direct target of construction. Although common equipment is used for the flow meter and concentration meter, an electromagnetic flow meter and a scattered light transmission type turbidity meter are typically preferred. The above j1 to 13 and ql, '12 are respectively introduced into the computing unit and expressed as follows: γ1 is the specific gravity of the feed liquid, r2 is the specific gravity of the fresh liquid, r3
is the specific gravity of the concentrated liquid) K Therefore, the force for determining 93 51 Based on sewage or human waste (If the target is sludge, r1'=:r2':, γ3=, 1 can be set, so the above [11 The expression is (non-conduct).

/3 and neck (), so q3 can be easily determined.If this (13) is higher than the target value, the sludge concentration of the concentrate is high, so the motor M1 should be adjusted by the controller. Control is performed to reduce the sludge concentration of the concentrated liquid by widening the speed difference and increasing the solid content conveyance speed, and on the other hand, if 93 is lower than the target value, control is performed in the opposite direction.
Improve 3. If this value is set to -, it is easy to maintain r3 near the target concentration, and the load on the sludge treatment process can be made uniform.

Since the present invention is configured as described above, it is possible to easily and accurately know the sludge concentration of the concentrated liquid discharged from a decanter-type centrifugal thickener, and to concentrate it by performing control operations. It is also possible to maintain the sludge concentration as uniform as possible, and the load in the sludge treatment process has been made uniform, making it possible to further improve the process balance.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the overall concept of the present invention. 3...bowl , 4-screw conveyor Applicant: Kobe Steel, Ltd.

Claims (1)

[Claims] il + decanter type concentrator, liquid volume detection means for the feed liquid, produced clarified liquid, and produced concentrated rice liquor, each sludge concentration detection means for the supplied liquid and produced clarified liquid, and a detection unit from each of the above-mentioned detection means. A sludge concentration method comprising: a calculation means for calculating the sludge concentration in the concentrated liquid produced based on the above No. 1, and a control means for controlling the sludge concentration in the concentrated liquid based on a signal from the calculation means. Device.