JPH08166346A - Optical sludge densitometer - Google Patents

Abstract

PURPOSE: To optically measure the black sludge density which could not be measured by an optical sludge densitometer. CONSTITUTION: A part of the sludge running in a sludge transportation pipe B is sent to a sludge density measuring apparatus A via valves 2 and 9. The sludge entering the apparatus A is first brought in touch with ozone gas from an ozone-generating device 11 by an ozone contact device 4 thereby to be decolored. The decolored sludge is sent to a special pipe 7 of an optical sludge densitometer 6, where the density is measured by the sensor 6. Since the density of the sludge after decolored is measured, the density can be measured optically even when the sludge is black.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process type optical sludge concentration measuring device used in a sewage sludge treatment facility or the like.

[0002]

2. Description of the Related Art A sludge concentration meter used in a sewage sludge treatment facility is roughly classified into an ultrasonic type and an optical type according to its measuring principle. The ultrasonic method can measure high concentration (10% or more), but has a drawback that the influence of fine air bubbles contained in sludge causes a large measurement error. On the other hand, the optical method is an excellent method because the influence of air bubbles in the sludge is small.

FIG. 2 shows an example of the structure of the detection unit of the optical densitometer. In the figure, 21 is a measurement window, 22 is a fiber cable, 23 is a preamplifier box provided with a preamplifier that photoelectrically converts and amplifies light from the fiber cable, and 26 is a signal cable for outputting a signal from the preamplifier to a conversion unit. Show. A dedicated pipe is used to attach the detection unit 20. In addition, the conversion unit obtains the density signal and the like by arithmetic processing.

[0004] optical fiber cable 22, as shown in FIG. 3, the light source unit 22 ₁ for irradiating test water is constituted by a light-receiving unit 22 ₂ and 22 ₃ which are divided by the spacer 22 _4, the light source unit 22 ₁ The sludge flowing through the dedicated pipe 7 is irradiated, and the reflected light is received by the light receiving portions 22 ₂ and 22 ₃ .

[0005]

In the above-mentioned conventional optical sludge densitometer, the effect of air bubbles is extremely small, but when the sludge color becomes black, most of the projected light is absorbed by the sludge and the measurement accuracy decreases. Or, there is a problem that the measurement range is reduced.

Return sludge, even in an actual sewage treatment facility,
An optical sludge densitometer can be applied to excess sludge, concentrated sludge, etc., but when digested sludge or concentrated sludge that has advanced to an excessive degree is not measured because the sludge is black or the received light signal is small, the error increases There are many. In addition, digestive sludge and concentrated sludge with advanced corrosion contain many fine air bubbles,
A large error also occurs in the measurement with an ordinary ultrasonic sludge densitometer. There is also a model of ultrasonic sludge densitometer that applies pressure to sludge and dissolves air bubbles into the liquid to measure it (pressure-eliminating ultrasonic sludge densitometer), but the pressure-eliminating method requires large equipment and is expensive. In addition to the above, there is a drawback that continuous measurement cannot be performed because the measurement is repeated by repeatedly collecting mud, defoaming, measuring and discharging mud.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide an optical sludge concentration measuring device capable of measuring sludge concentration even with black sludge. It is in.

[0008]

In order to achieve the above object, an optical sludge concentration measuring device according to the present invention comprises a sludge decolorizing device for continuously decolorizing sludge and a concentration of the decolorized sludge for continuous decolorization. It is characterized by comprising an optical sludge concentration meter for measurement.

[0009]

[Function] When sludge is decolorized by the sludge decolorizing device, black sludge can be decolorized to a white level. Since the optical sludge densitometer measures the decolorized sludge concentration, it is possible to measure the sludge concentration of the black sludge which cannot be measured by the conventional optical sludge densitometer.

[0010]

EXAMPLE FIG. 1 shows an optical density measuring device equipped with an ozone decolorizing function for decolorizing black sludge and measuring the sludge concentration by an optical method. In the figure, A is an optical sludge concentration measuring device, B is a sludge transport pipe, 2 and 9 are valves for diverting a part of the sludge flowing in the sludge transport pipe B to the concentration measuring device A, and 4 is a valve 2
The ozone contactor for decolorizing the sludge taken in from the ozone generator 11 with ozone gas, 7 is a dedicated pipe for the optical sludge concentration meter 6 for measuring the concentration of the decolorized sludge, 12
Is a liquid level detector of the ozone contactor, 14 is a valve that is controlled by the output of the liquid level detector 13, and controls the amount of ozone discharged from the ozone contactor 4 to control the liquid level of the ozone contactor 4, and 15 is a valve 14 A pressure valve 16 connected to is a waste ozone treatment device that processes the waste ozone discharged from the pressure valve 15 and discharges it to the atmosphere. In the figure, reference numerals 3, 5, 8 and 13 denote connection pipes.

Ozone has a strong oxidizing power and has the ability to decolorize black sludge. The rate of decolorization is proportional to the amount of ozone that comes into contact with sludge, and a large amount (for example, 40 m / m ³ of sludge).
By applying 0 g of ozone, black sludge can be decolorized to a pale yellowish white level.

Further, in the optical densitometer shown as the conventional example, the color of the sludge to be measured does not have to be a pale yellowish white level, but can be sufficiently measured if it is a gray black level.

Therefore, in the ozone contactor 4, the sludge is decolorized to a gray-black level. As the optical sludge densitometer 6, the densitometer described in the conventional example is used.

As a result, it becomes possible to measure the black sludge concentration by the optical method, which could not be measured by the conventional optical sludge densitometer.

In the above embodiment, the sludge is flown through the ozone contactor 4 and decolorized with ozone gas. It is possible to use a decolorizing device that uses a method of injecting and contacting with the sludge or a method of irradiating ultraviolet rays.

[0016]

Since the present invention is configured as described above, it has the following effects.

1) Even with black sludge, the sludge concentration can be measured by an optical method.

2) The measurement range of the optical sludge concentration meter can be expanded.

3) It is possible to continuously measure black sludge containing fine bubbles, such as digested sludge and concentrated sludge that has advanced decay, and it is possible to realize appropriate monitoring and control of sludge treatment.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of an optical sludge concentration measuring apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a configuration of a detection unit of the optical sludge concentration meter.

FIG. 3 is an enlarged view of a fiber cable cross section of an optical sludge concentration meter detection unit.

[Explanation of symbols]

 A ... Optical sludge concentration measuring device B ... Sludge transport pipe 4 ... Ozone contactor 6 ... Optical sludge concentration meter 7 ... Dedicated pipe for concentration meter 11 ... Ozone generator 16 ... Waste ozone treatment device 20 ... Optical sludge concentration meter Detection part

Front Page Continuation (72) Inventor Hiroshi Noguchi 2-11-17 Osaki, Shinagawa-ku, Tokyo Incorporated company Shameidensha (72) Inventor Rie Matsui 2-1-117 Osaki, Shinagawa-ku, Tokyo Incorporated company Meidensha (72) Inventor Keiichi Tsukamoto 2-17 Osaki, Shinagawa-ku, Tokyo Inside Meidensha Co., Ltd.

Claims (1)

[Claims] 1. An optical sludge concentration measuring device comprising a sludge decolorizing device for continuously decolorizing sludge and an optical sludge densitometer for continuously measuring the concentration of the decolorized sludge.