JP2001289780A - Densitometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To substantially prevent interruption of concentration measurement information and to facilitate control and maintenance against contamination of a densitometer, by allowing easy and quick replacement of only the part which is hindering measurement due to contamination. SOLUTION: In the densitometer, having a detection end provided with a transmission part or a light-emitting part for emitting measurement waves such as visible rays, near infrared rays, infrared rays, ultrasonic waves, microwaves, or laser beams and a reception part or the light-receiving part of the measurement waves and measuring a pollutant concentration in liquid/gas, a contact member having a liquid/gas contact face ant allowing transmission of the measurement waves is installed removably, in at least a part of the surface of the detection end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a densitometer for measuring the concentration of a pollutant in a liquid or a gas,
Contaminated parts can be replaced quickly and easily,
The present invention relates to a concentration meter which is easy to maintain and is suitable for measuring the concentration of sludge.

[0002]

2. Description of the Related Art Information on the concentration of sludge generated from sewage, human waste or industrial wastewater treatment equipment or the concentration of pollutants suspended in gas is used to manage the operation of liquid and gas treatment equipment containing these pollutants. It is necessary information for. If the measurement signal of the concentration of the pollutant deviates from the true value, an erroneous control signal will be sent to the processing equipment, making it difficult to perform a correct operation. Therefore, it is desired that a densitometer for measuring the concentration of a pollutant is always kept in a normal measurement state.

Conventionally, for example, in a sludge densitometer using laser light, a light emitting part for generating laser light and a light receiving part for receiving the light are built in a transparent glass tube to constitute a detection end. The glass tube at the detection end forms a liquid contact surface with the sludge to be measured, but if the surface of the glass tube is contaminated with sludge, the detection end portion is appropriately lifted from the sludge to remove the adhering matter. And clean the surface. For example, cleaning with a soap solution or ultrasonic cleaning is performed, and physical removal and removal are performed using a brush.

[0004]

In the above-described methods for cleaning and cleaning the detection end, especially when the contamination is remarkable, the glass tube is strongly rubbed with a brush or the like in order to finish the operation in a short time. Work must be done. For this reason, fine scratches may be formed on the surface of the glass tube, and when such scratches occur, contaminants easily adhere to the scratched portions, and the cleaning interval is shortened. During the cleaning, the measurement signal from the densitometer is cut off, so that it cannot be used for controlling the processing equipment, and it becomes difficult to appropriately operate the processing equipment. Further, if the cleaning interval is lengthened, the contamination of the surface of the glass tube proceeds, so that a correct concentration measurement signal is not output as described above, and it becomes difficult to properly operate the processing apparatus.

For such cleaning, a method may be considered in which the contaminated concentration meter itself is replaced, and the contaminated portion of the removed densitometer is sufficiently washed for a long time so as not to be damaged. However, in this method, a spare densitometer must be prepared for replacement, and the equipment cost increases when there are many places where the densitometer is installed. Although a method of replacing only the contaminated portion is also conceivable, the conventional densitometer does not have a structure that can easily replace the glass tube and the like, and the glass tube itself is not so inexpensive.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to make it possible to easily and promptly replace only a portion that hinders measurement due to contamination, thereby substantially preventing the interruption of concentration measurement information. In addition, the purpose of the present invention is to facilitate the management and maintenance of concentration meter contamination.

Another object of the present invention is to solve the above-mentioned problems and to desirably prevent the detection end portion from being contaminated with a simple and inexpensive structure.
It is an object of the present invention to provide a densitometer capable of measuring the concentration of a pollutant stably over a long period of time by at least greatly extending the time until the contamination.

[0008]

In order to solve the above-mentioned problems, a densitometer according to the present invention comprises a transmitting part or a light-emitting part of a measuring wave such as visible light, near-infrared ray, infrared ray, ultrasonic wave, microwave and laser light. A concentration meter for measuring the concentration of a pollutant in a liquid or a gas, comprising a detection end provided with a unit and a reception unit or a light reception unit, wherein at least a part of the detection end has a liquid contact surface Alternatively, a contact member which forms an air contact surface and is capable of transmitting the measurement wave is detachably mounted.

The contact member to be attached to the detection end can be made of a rigid body, for example, a transparent glass body, but it can conform to the outer shape of the detection end. Preferably, it is made of a flexible member, for example, a soft contact lens-like member.

Preferably, the contact member is in close contact with the surface of the detection end over substantially the entire inner surface of the contact member. If you do this,
Foreign matter enters between the contact member and the surface of the detection end,
This can prevent the measurement from being hindered.

When the concentration meter measures the concentration of particles in a liquid or a gas, at least the outer surface of the contact member has a charge of the same polarity as the particles to be measured. Is preferred.

The outer surface of the contact member having the same polarity charge has, for example, the same polarity charge when the particle to be measured in the liquid or gas to be measured has a negative charge. As the layer, for example, a layer made of aluminum oxide, copper oxide, magnesium oxide, zinc oxide, or a layer containing these, which exhibits a negative charge in water, is provided by coating or the like. When the particle to be measured has a positive charge, a layer having a charge of the same polarity as the layer, for example, a layer made of silicic acid, titanium oxide, zirconium oxide, or a layer containing these, showing a positive charge in water. Is provided by coating or the like.

Further, the outer surface of the contact member may be formed of a photocatalyst-containing layer. Typically, titanium oxide can be used as the photocatalyst. Since titanium oxide is generally available in the form of fine particles, the titanium oxide fine particles are mixed in a solution containing a suitable binder, the solution is coated on a predetermined surface of the contact member, and dried (as necessary). By heating and drying), a desired photocatalyst-containing layer can be formed.

In this embodiment, it is possible to use the measurement light itself from the light emitting part for exciting the photocatalytic activity of the photocatalyst containing layer. However, a light source for exciting the photocatalytic activity can be separately provided. When the measurement light by the light emitting unit is composed of laser light or visible light, the light having a wavelength component effective for exciting the photocatalytic activity is used for the excitation.
Therefore, when laser light is used, it is preferable to set the light to a wavelength containing a wavelength component particularly effective for photocatalytic activity excitation, and when using visible light, an ultraviolet wavelength component particularly effective for photocatalytic activity excitation is set. It is preferable to set the light to include.

When the measurement light itself is used as the excitation light, the measurement light is applied to the photocatalyst-containing layer from the inside of the detection end, and the measurement light is also used for the original concentration measurement. Since it must be used, it is preferable to form the layer as thin as possible so that this layer can transmit a sufficient amount of measurement light.

Such a densitometer of the present invention is particularly useful as a sludge densitometer. Of course, it can also be used as a concentration meter for measuring the concentration of pollutants in gas, for example, a concentration meter for measuring the concentration of particles in exhaust gas.

In the densitometer according to the present invention as described above, on the surface of the detection end, for example, on the surface of the glass tube forming the detection end, the detection end is basically made of a separate member. A contact member is mounted. The contact member is
Since the liquid-contacting surface or the air-contacting surface is formed and formed on a member that can transmit the measurement wave, the predetermined concentration measurement performance can be maintained without any problem even when the contact member is mounted. Since the contact member is detachably mounted, when the surface of the contact member becomes more contaminated, only the contact member can be replaced. By replacing the contaminated contact member, the measurement state of the densitometer is completely returned to the normal measurement state. That is, in the present invention, the portion that hinders the concentration measurement due to contamination is constituted by a contact member,
Depending on the extent of the contamination, only that part will be replaced easily and quickly. Therefore, there is no need for a spare densitometer or a spare expensive glass tube, etc., and it is possible to replace only the contact member in a very short time, so that the concentration measurement information that may hinder the operation of the processing equipment can be blocked. Does not occur. In addition, management and maintenance of the concentration meter itself with respect to contamination can be performed very easily.

Further, in the present invention, a contamination preventing function can be added to the surface of the contact member as needed.

For example, if a coating layer having the same polarity as the particles to be measured is provided on the outer surface of the contact member, the particles to be measured in the liquid or gas to be measured and the coating layer are mutually charged by the same polarity. They will repel each other. Since this repulsive force acts in a direction to separate the particles to be measured from the coating layer, the particles to be measured are prevented from adhering to the surface of the coating layer, and the surface of the coating layer of the contact member is prevented from being contaminated.
Alternatively, the particles to be measured hardly adhere to the surface of the coating layer, and the progress of contamination on the surface of the coating layer is greatly delayed. As a result, long-term stable operation of the processing equipment using the density measurement signal from the densitometer becomes possible.

If a photocatalyst, for example, a layer containing titanium oxide is provided on the outer surface of the contact member, the photocatalytic activity can be excited by the irradiation light. Due to the photocatalytic activity of the titanium oxide, organic substances and the like in the liquid or gas in contact with this layer are decomposed, and the surface of the contact member is kept in a state in which contaminants are extremely difficult to adhere. As a result, the contamination of the contact member is prevented, and the concentration of the pollutant can be stably and accurately measured over a long period of time.

Further, by using the measurement light itself to excite the photocatalytic activity of the photocatalyst-containing layer, there is no need to separately provide a special light irradiation means, and it has an extremely simple structure and is inexpensive.
Desired performance can be exhibited.

Further, when a coating layer having the same polarity of charge as the above-mentioned particles to be measured is provided, particularly, the particles to be measured are particles having a positive charge, and the coating layer is formed of a titanium oxide-containing layer. In this case, in addition to the above-mentioned repulsive action due to the charge of the same polarity, the action due to the photocatalytic activity of titanium oxide is also obtained, and the organic substances in the liquid or gas in contact with this layer are decomposed, and the surface of the detection end becomes Contaminants are kept in a state where they are less likely to adhere, and contamination is more reliably prevented.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 and FIG.
1 shows a densitometer according to an embodiment of the present invention, particularly one in which the present invention is applied to a sludge densitometer. FIG.
In the figure, 1 indicates the entire sludge concentration meter. A sensor main body 4 is attached to one end of the light emission / reception control unit 2 via a cap nut 3, and a cable 5 connected to another control device is connected to the other end. O-rings 6, 7, and 8 are appropriately provided on the sensor main body 4 in order to ensure a sealing property with respect to a site where the sensor main body 4 is mounted, for example, internal sludge in a sludge feed pipe (not shown). Is provided.

At the tip of the sensor body 4, a detection end 9a,
9b is protruded. As shown in FIG. 2, one detection end 9 a includes a transmission unit or a light-emitting unit 10 for measuring waves inside, and the transmission unit or the light-emitting unit 10 is cylindrically formed from the surroundings, for example, made of quartz glass. Is covered with a glass tube 11. The other detecting end 9b includes a receiving unit or a light receiving unit 12 for receiving or receiving a measurement wave from the transmitting unit or the light emitting unit 10 therein.
Is similarly covered with a glass tube 13 from the periphery. As a measurement wave for concentration measurement emitted from the transmitting unit or the light emitting unit 10, a visible light, a near infrared ray, an infrared ray, an ultrasonic wave, a microwave, a laser beam, or the like having a predetermined wavelength and a predetermined intensity is used. When the measurement wave is the measurement light, it is guided to the light emitting end by, for example, an optical fiber.

Contact members 14a, 14a and 1b are formed on the surfaces of the glass tubes 11, 13 at least at positions corresponding to the measurement wave transmitting portions to form a liquid contact surface or an air contact surface and transmit a measurement wave.
4b is detachably mounted. Contact member 14
a and 14b can be composed of a contact lens-like hemispherical member 21 as shown in FIG. 3, for example.
It is made of a member which is flexible and can be adhered to substantially the entire inner surface of the member along the surface of the glass tubes 11 and 13.

The contact members 14a and 14b are fixedly held on the surfaces of the glass tubes 11 and 13 of the detection ends 9a and 9b. If the contact members 14a and 14b can be held only by the close contact as described above, a special fixing member is required. It is not necessary to provide it. However, in order to more reliably prevent the falling-off during use, it is preferable to provide the fixing members 15a and 15b as shown in FIG. In the present embodiment, rubber bands that can be easily attached and detached are used as the fixing members 15a and 15b.

In such a densitometer 1, the detection end 9
Since the contact members 14a and 14b are detachably provided at the measurement wave transmitting portions on the surfaces of the a and 9b, the surfaces of the contact members 14a and 14b (that is, the liquid contact surface and the air contact surface) are contaminated. In the case, the contact member 14
Only a and b can be replaced easily and very quickly. The exchange completely eliminates the obstacle to the measurement of the concentration of pollutants. Since the replacement can be performed in a very short time, there is no interruption of the concentration measurement signal for a long time that affects the operation of the processing equipment, and the smooth and stable operation and management of the processing equipment can be continued. . In addition, since the replacement operation is extremely simple, the concentration meter 1
Management and maintenance can be performed very easily.

Further, by forming the contact members 14a, 14b from members having flexibility, the contact members 14a, 14b can be brought into close contact with the surfaces of the glass tubes 11, 13 over their entire inner surfaces, and a gap is provided between them. And the situation in which a foreign substance intrudes can be avoided. Therefore, the desired concentration measurement performance is reliably ensured.

The contact member as described above can be further provided with a contamination preventing function on its surface.
For example, as shown in FIG. 4, a coating layer 3 having the same polarity of charge as the particles 32 to be measured is formed on the outer surface of the contact member 31.
If 3 is provided, the adhesion of the measured particles 32 to the surface of the coating layer 33 can be prevented or suppressed by the repulsive force between the charges having the same polarity.

Further, as shown in FIG.
If the photocatalyst containing layer 42 is provided on the outer surface of
The photocatalytic activity can be expressed in the photocatalyst containing layer 42 by using the measurement light from the photocatalyst, and the adhesion of contaminants to the surface of the photocatalyst containing layer 42 can be prevented or suppressed by the decomposition action of organic substances and the like by the photocatalytic activity. can do.

Further, when the particles to be measured have a positive charge, if the photocatalyst-containing layer 42 is formed of a titanium oxide-containing layer, the effect of preventing the adhesion of contaminants based on the photocatalytic activity will be described with reference to FIG. As described above, a repulsive action due to the charge of the same polarity is obtained, and the contamination is more reliably prevented.

Although each of the above embodiments mainly describes a sludge concentration meter, the present invention can also be applied to a concentration meter used for measuring the concentration of pollutants in gas.

[0033]

As described above, according to the densitometer according to the present invention, the detachable contact member is attached to the measurement wave transmitting portion of the detection end, and the concentration member can be easily and quickly adjusted according to the degree of contamination. In addition, since only the contact member can be replaced very easily, the predetermined operation of the processing equipment using the concentration measurement information can be smoothly continued without substantially interrupting the concentration measurement information. In addition, management and maintenance for contamination of the densitometer itself can be easily performed.

Further, since the contact member is formed as a small member separate from the glass tube or the like at the detection end, it is easy to carry out processing and processing for adding a contamination prevention function to the contact member itself. it can. If the outer surface of the contact member has a charge of the same polarity as the particles to be measured, the repelling force between the charges of the same polarity can enhance the pollution prevention performance, and if a photocatalyst containing layer is provided, the organic substance due to its photocatalytic activity can be obtained. And the like, the pollution prevention performance can be enhanced. Therefore, in addition to facilitating the replacement of the contact member, the replacement cycle can be greatly extended. As a result, predetermined appropriate operation and management of the processing equipment using the measurement signal from the densitometer can be stably performed over a long period of time.

[Brief description of the drawings]

FIG. 1 is a plan view of a densitometer according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a detection end of the densitometer of FIG.

FIG. 3 is an enlarged perspective view showing an example of a contact member used for the densitometer of FIG.

FIG. 4 is a cross-sectional view of a tip of a detection end of a densitometer according to another embodiment of the present invention.

FIG. 5 is a sectional view of a tip end of a detection end of a densitometer according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Densitometer 2 Light receiving / emitting control part 3 Cap nut 4 Sensor main body part 5 Cable 6, 7, 8 O-ring 9a, 9b Detection end 10 Transmitting part or light emitting part 11, 13 Glass tube 12 Receiving part or light receiving part 14a, 14b Contact Member 15a, 15b Fixing member 21 Contact lens-like contact member 31, 41 Contact member 32 Particle to be measured 33 Coating layer having the same polarity charge as the particle to be measured 42 Photocatalyst containing layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G047 EA20 GA09 2G057 AA01 AB01 AB02 AB03 AB04 AB06 AC01 AC03 BA10 BB02 CB01 DB06 DB08 DC01 JA20 2G059 AA01 BB01 BB06 EE01 EE07 GG01 HH01 HH02 JJ17 NN07 PP10

Claims (8)

[Claims] A detection end provided with a transmitting part or a light emitting part and a receiving part or a light receiving part of a measuring wave such as visible light, near infrared ray, infrared ray, ultrasonic wave, microwave, laser light, etc. A concentration meter for measuring the concentration of a contaminant therein, wherein a contact member capable of forming a liquid contact surface or an air contact surface on at least a part of the surface of the detection end and transmitting the measurement wave is detachably attached. A densitometer characterized by being attached. 2. The densitometer according to claim 1, wherein said contact member comprises a flexible member. 3. The densitometer according to claim 1, wherein the contact member is in close contact with the surface of the detection end over substantially the entire inner surface of the contact member. 4. A concentration meter for measuring the concentration of particles in a liquid or gas, wherein at least the outer surface of the contact member has a charge of the same polarity as the particles to be measured. Densitometer according to any of the above. 5. The densitometer according to claim 1, wherein an outer surface of the contact member is formed of a photocatalyst-containing layer. 6. A photocatalyst comprising titanium oxide.
Densitometer. 7. The densitometer according to claim 5, wherein the measurement light itself from a light emitting section is used as excitation light for photocatalytic activity of the photocatalyst containing layer. 8. A sludge concentration meter comprising a sludge concentration meter.
The densitometer according to any one of the above.