JP2960309B2 - Sludge treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sludge treatment apparatus for performing sludge treatment by centrifugal dehydration.

[0002]

2. Description of the Related Art Conventionally, various techniques for sludge treatment have been provided by solid-liquid separation treatment employing a centrifugal dehydration method. In order to promote the solid-liquid separation treatment, for example, an inorganic flocculant and an amphoteric polymer are used. Used by mixing with raw sludge.

It is necessary to monitor and supervise the inflow (mixing amount) of these inorganic flocculants and amphoteric polymers into the raw sludge to a certain value. PH is measured in a tank or a sludge supply line up to a centrifugal dehydrator, and the inflow amount of the inorganic flocculant is arbitrarily adjusted according to the measurement result.

[0004] As the inorganic coagulant, for example, P
Aluminum oxide (PAC) with H of 4.5 to 5.0 (1500
It is known that a good solid-liquid separation state can be obtained by the use of ２０００2000 ppm).

On the other hand, for the amphoteric polymer, proportional injection corresponding to this concentration is performed by arbitrarily determining the inflow amount to the raw sludge or measuring the TS concentration of the raw sludge.

[0006] For the amphoteric polymer, when the inflow concentration proportional control of 0.7% with respect to the concentration TS of the raw sludge is performed, if the separation state is not good due to a change in the sludge properties, the separation liquid is used. The generated bubbles become black.

[0007]

However, in the conventional sludge treatment method as described above, the pH of the raw sludge is directly measured by a PH meter immersed in the raw sludge in the sludge tank. There is a problem that the PH sensor is easily soiled and correct PH measurement cannot be performed.

Further, with respect to the amphoteric polymer, unevenness of the raw sludge concentration, contamination of the concentration sensor due to the direct measurement of the raw sludge concentration, and occurrence of measurement errors associated therewith cannot be avoided. Since the injection amount (inflow amount) is dependent on human perception, the optimum amount of injection cannot be performed, and as a result, the sludge separation result becomes non-uniform.

Further, even if the injection rate of the amphoteric polymer is controlled to be constant, there is a problem that it is impossible to cope with fluctuations in sludge properties.

The present invention has been made in order to solve the above-mentioned conventional problems. According to the change in sludge properties, the solid-liquid separation of raw sludge is carried out by the optimal injection of an inorganic flocculant and an amphoteric polymer. It is intended to obtain a sludge treatment device that can be controlled satisfactorily.

[0011]

SUMMARY OF THE INVENTION A sludge treatment apparatus according to the present invention is a centrifugal machine that mixes an inorganic coagulant and an amphoteric polymer with raw sludge, performs solid-liquid separation by centrifugal dehydration, and generates a separated liquid and a dewatered cake. Dehydrator, provided with a PH meter for measuring the PH value of the separated liquid discharged from the centrifugal dehydrator, and a chromaticity meter for measuring the color of the foam of the separated liquid discharged from the centrifugal dehydrator According to the results of measurement by the chromaticity meter and the PH meter, the separated liquid monitoring control means optimally controls the supply amounts of the inorganic flocculant and the amphoteric polymer to be mixed into the raw sludge.

[0012]

The sludge treatment apparatus according to the present invention monitors the color of the foam of the separated liquid discharged from the centrifugal dehydrator with a chromaticity meter, and if the color of the foam is black, it indicates that the separated liquid has deteriorated. By judging, increasing the mixed amount of the amphoteric polymer to make the color of the foam white, while monitoring the PH of the separated solution,
The amount of the inorganic coagulant mixed is controlled so that the PH value falls within about 5.

This makes it possible to efficiently carry out the centrifugal dewatering of the raw sludge and to avoid the contamination of the chromaticity sensor and the sensor of the PH meter itself and the occurrence of measurement errors due to this.

[0014]

【Example】

Embodiment 1 FIG. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a sludge tank in which raw sludge is stored.
This is a pump that is sent to the outside through

Reference numeral 4 denotes a centrifugal dewatering machine that receives the raw sludge sent out by the pump 2 and separates and removes a dewatered cake and a separated liquid of the raw sludge that has been dewatered by centrifugation by high-speed rotation.

Reference numeral 5 denotes an inorganic coagulant tank containing an inorganic coagulant, 6 a pump for sending the inorganic coagulant from the inorganic coagulant tank 5 to the pipe 3 and mixing it with raw sludge, and 7 a inorganic pump. This is a controller for controlling the delivery amount of the coagulant 5.

Reference numeral 8 denotes an amphoteric polymer tank containing the amphoteric polymer, 9 denotes a pump for sending the amphoteric polymer from the amphoteric polymer tank 8 to the pipe 3 and mix it with the raw sludge, and 10 denotes a delivery amount of the amphoteric polymer. Is a controller that controls

Reference numeral 11 denotes a pipe for discharging the separated liquid discharged from the centrifugal dehydrator 4. The pipe 11 is connected to a bypass pipe 12 for bypassing a part of the separated liquid. Is connected to a separation liquid monitoring / control device 15 provided with a PH meter 13 and a chromaticity meter 14 and a pump 16. In addition, 17 is a discharge passage of the dehydrated cake.

The pH meter 13 measures the pH of the separated liquid.
The colorimeter 14 measures the color of the bubbles generated in the separated liquid, and enables these measured data to be supplied from the separated liquid monitoring and control device 15 to the controllers 7 and 10. .

Next, the operation will be described. First, the pump 2 is driven to feed the raw sludge contained in the sludge tank 1 into the centrifugal dehydrator 4 rotating at high speed through the pipe 3.

At this time, the inorganic coagulant tank 5
The inorganic flocculant inside the pipe 3 is fed into the pipe 3 by the pump 6 and mixed with the raw sludge in the pipe 3, and the amphoteric polymer in the amphoteric polymer tank 8 is fed into the pipe 3 by the pump 9. Mixed into the raw sludge.

For this reason, in the centrifugal dehydrator 4, a liquid material obtained by mixing an inorganic flocculant and an amphoteric polymer into raw sludge is separated into a solid and a liquid by a centrifugal action by high-speed rotation. The dewatered cake is discharged from the centrifugal dehydrator 4 through the discharge passage 17 as appropriate, and is subjected to a process such as disposal, and the liquid separated liquid is subjected to necessary water purification treatment or the like, and is disposed or collected.

At this time, a part of the separated liquid is
Is supplied to the separated liquid monitoring and control device 15 via the bypass pipe 12 by the PH meter 13 attached thereto.
The pH value of the separated solution was measured, and the
As a result, the chromaticity of the bubble of the separated liquid passing through the bypass pipe 12 is measured.

In these measurements, since the sensors of the PH meter 13 and the chromaticity meter 14 are not exposed to the raw sludge, the PH value and the chromaticity of the foam can be detected with high accuracy.

In this case, in the two-liquid centrifugal dehydration using an amphoteric polymer and an inorganic flocculant, the state of the separated liquid is improved by using aluminum oxide (2000 ppm) having a pH of 5.0. The chromaticity value BC (BC100 → white, BC0 → black) of the foam generated in the above is 50 to 60.
By setting the degree, the state of the separated liquid is improved similarly to the above.

For this reason, in the present invention, the separated liquid monitoring and control device 15 operates the controller 6 so that the PH value measured by the PH meter 13 becomes 5.0, and the inorganic flocculant tank by the pump 6 is operated. Optimum control of the amount of the inorganic coagulant delivered from Step 5.

On the other hand, with respect to the amphoteric polymer,
When the chromaticity value BC measured by 4 is 60 or more, it is determined that the mixing amount of the amphoteric polymer so far is excessive, and the separated liquid monitoring and controlling device 15 operates the controller 10 to
The amount of the amphoteric polymer delivered from the amphoteric polymer tank 8 by the pump 9 is reduced.

When the chromaticity value BC is 50 to 60, the mixed amount of the amphoteric polymer is determined to be within the proper range, and the amount of the amphoteric polymer delivered by the pump 9 is maintained as it is. Conversely, when the chromaticity value BC is 50 or less, it is determined that the amount of the amphoteric polymer mixed is insufficient because the foam is cloudy, and the amount of the amphoteric polymer delivered by the pump 9 is reduced. increase.

In this way, in response to the change in the sludge properties, that is, the state of the separated liquid after separation of the dewatered cake (BC
Value), the state of the separated liquid can be optimally controlled, the contamination of the sensor of the PH meter itself can be avoided, the treatment state of the raw sludge can be maintained in a good condition, and the treatment efficiency is greatly improved as compared with the past. Can be improved.

[0030]

As described above, according to the present invention, a centrifugal dehydrator for mixing a raw sludge with an inorganic coagulant and an amphoteric polymer, performing solid-liquid separation by centrifugal dehydration, and forming a separated liquid and a dewatered cake. And a PH meter for measuring the PH value of the separated liquid discharged from the centrifugal dehydrator, and a chromaticity meter for measuring the color of the foam of the separated liquid discharged from the centrifugal dehydrator, According to the results of measurement by the chromaticity meter and the PH meter, the separation liquid monitoring and control means is configured to optimally control the supply amounts of the inorganic flocculant and the amphoteric polymer to be mixed into the raw sludge. The solid-liquid separation of raw sludge can be controlled well by the optimal injection of inorganic coagulant and amphoteric polymer, and the amount of inorganic coagulant injected can be optimized by preventing contamination of PH sensor etc. Can control There is an effect that things can be obtained.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a sludge treatment apparatus according to one embodiment of the present invention.

[Explanation of symbols]

 4 Centrifugal dehydrator 13 PH meter 14 Chromaticity meter 15 Separation liquid monitoring and control device (Separation liquid monitoring and control means)

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C02F 11/00-11/20 B04B 1/00-15/12 B01D 21/01

Claims (1)

(57) [Claims] 1. A centrifugal dehydrator for mixing a raw sludge with an inorganic flocculant and an amphoteric polymer and performing solid-liquid separation by centrifugal dehydration to produce a separated liquid and a dewatered cake; A PH meter for measuring the PH value of the separated liquid, a chromaticity meter for measuring the color of the foam of the separated liquid discharged from the centrifugal dehydrator, and, according to each measurement result by the chromaticity meter and the PH meter, A sludge treatment apparatus comprising: a separated liquid monitoring control means for optimally controlling the supply amounts of an inorganic flocculant and an amphoteric polymer to be mixed into raw sludge.