JPH062204U - Tube-mounted measuring instrument - Google Patents

Abstract

(57) [Abstract] [Purpose] Even if the flow rate of the test water is small, it is possible to prevent the adhesion of sludge and the like to the detection surface of the measuring instrument, and to easily remove this if any foreign matter is clogged. To provide a pipe-mounted measuring instrument that is possible. [Structure] In a short pipe 1 in which a detection unit 3 is installed, a rectifying member 9 is detachably and replaceably arranged at a position opposite to the detecting unit 3, and the rectifying member 9 narrows a fluid passage cross-sectional area between the rectifying member 9 and a detection surface 3a. The rectifying surface portion 9a for forming is formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure for preventing dirt on a detection surface of a measuring instrument mounted on a pipe such as a pipeline.

[0002]

[Prior art]

 Generally, in a sewage treatment plant, when treating sewage by the activated sludge method, it is important to properly control the sludge concentration in each process, so various measuring instruments that detect the physical quantity in the sewage Is used. For example, a scattered light type sludge densitometer as shown in FIG. 4 is used as a sludge densitometer for measuring the sludge concentration in treated water. This is to install the pipe line through which the treated water is cut, and to install it in the body of the short pipe 1 inserted by flange connection between them. The tip of the detection unit 3 inserted in the branch pipe 2 of the body of the short pipe 1 The detection surface 3a is exposed to the inner peripheral portion of the short pipe 1, and is brought into direct contact with the treated water to measure the sludge concentration. That is, the detection surface 3a is provided with a light emitting portion and a light receiving portion, and the light emitted from the light emitting portion is detected by the amount of light reflected and scattered by the sludge in the test water and incident on the light receiving portion. Is measured.

Further, in this optical sludge densitometer, optical glass is polished so that the sludge in the test water does not adhere to the detection surface 3a and interfere with the measurement.

In addition, as the sludge densitometer, there is an ultrasonic sludge densitometer exemplified in FIGS. 5 and 6. This is the attenuation of ultrasonic waves by sludge when the ultrasonic waves oscillated from the ultrasonic oscillators 4 installed at the diametrically opposite parts in the short pipe 1 are transmitted to the ultrasonic detector 5 and received by the ultrasonic receiver 5. The sludge concentration is detected by.

In addition, a cleaning nozzle 6 is installed in the short pipe 1, and cleaning water supplied from a high-pressure water pipe that comes into contact with the cleaning nozzle 6 is sprayed in two directions by the cleaning nozzle 6 to generate an ultrasonic oscillator. The surfaces of the ultrasonic wave detector 4 and the ultrasonic receiver 5 in contact with each sample water were cleaned to prevent the deterioration of the measurement accuracy due to the adhesion of sludge.

[0006] In addition to the above, as an instrument for measuring the sludge concentration, an ultrasonic type having a pressure defoaming device or an actually sampled water sample is taken out and dried for a certain period of time, and samples before and after that are taken. There is a weight measurement method that measures the sludge concentration from the difference in weight.

[0007]

[Problems to be solved by the device]

 With the sludge concentration meter, which is a conventional measuring instrument as described above, the target of measurement is treated water containing sludge, which is a sludge-like substance, so sludge adheres to the detection surface in a short period of time and the output is degraded. May interfere with measurement.

[0008] For example, in the case of an optical sludge densitometer, the detection surface is polished optical glass, so sludge does not easily adhere, but when the sludge concentration in the pipeline is high, the sludge becomes sticky due to rot and the like. When the value is high, the flow rate is low, the flow rate is low, and when these conditions are combined, dirt is likely to adhere to the detection surface.Because no cleaning device is provided, this reduces the output. In order to prevent the measurement characteristics from deteriorating, the frequency of maintenance must be increased, which requires a lot of labor.

Further, since the ultrasonic sludge densitometer is provided with the cleaning nozzle 6, when sludge adheres to the detection surfaces of the ultrasonic oscillator 4 and the receiver 5, the pipe including the short pipe 1 After draining the treated water in the line, high-pressure water is sprayed from the cleaning nozzle 6 onto the detection surfaces of the ultrasonic oscillators 4 and the receivers 5 to perform air cleaning. If the pipeline contains treated water, no cleaning effect can be expected. Therefore, there is a problem in that it is necessary to drain water from the pipeline for the cleaning work, which requires a lot of labor.

[0010] Further, the ultrasonic sludge densitometer is greatly affected by fine air bubbles in the test water due to the nature of ultrasonic waves. Therefore, when measuring the test water containing gas such as rotten sludge, an error occurs. Is inevitable. For this reason, there is also a means to measure by sampling the test water in the pressure defoaming device, but this is an intermittent measurement after a certain period of time, so it is necessary to control the sludge concentration that changes from moment to moment. Will not be suitable for. For the same reason, the above-mentioned weight measurement method is also not suitable. From this, it is expected that the optical sludge concentration meter will be equipped with a cleaning device for the detection surface. However, a cleaning device for brushes, wipers, etc. will be installed in the short pipe 1 facing the detection surface. If placed, the test water itself is sewage sludge that contains a large amount of contaminants, so that it will become entangled in the cleaning device and block the short pipe 1, so there is a problem that there is no suitable means.

In view of the above, the present invention effectively prevents sludge from adhering to the detection surface of an optical sludge densitometer or the like in response to this flow rate even when the flow rate of test water containing sludge is small. If possible, the detection surface can be easily cleaned, and if the detection surface inside the pipe is clogged with foreign substances, it will be possible to easily remove it. That is the purpose.

[0012]

[Means for Solving the Problems]

 The pipe-mounted measuring instrument of the present invention has a detection unit that exposes a detection surface inside a short pipe through which a fluid to be measured passes, and an opening formed in a portion of the short pipe facing the detection unit. The rectifying member is detachably arranged so as to be replaceable, and the rectifying member is formed with a rectifying surface portion configured to reduce a cross-sectional area of fluid passage between the rectifying member and the detection surface.

[0013]

[Action]

 With the above-described structure, the baffle surface portion destroys the plug flow state of the fluid flowing near the detection surface to cause turbulent flow, and reduces the adhesion of dirt. At the same time, the fluid flows so as to hit the detection surface strongly, and the flow velocity is washed, so that the sludge and the like are prevented from adhering to the detection surface.

[0014]

[Embodiment] An embodiment of the pipe-mounted measuring device of the present invention will be described below with reference to FIGS. 1 to 3. 1 to 3, parts corresponding to those of the embodiment shown in FIGS. 4 to 6 are given the same reference numerals, and detailed description thereof will be omitted. 1 is a partial cross-sectional side view showing an embodiment of the present invention, in which 1 is a short pipe, 2 is a branch pipe, 3 is a detection unit, and 3a is a detection surface. The short pipe 1 forms a base portion 7 which is raised in the trapezoidal cross-section as shown in the drawing near the facing portion of the central branch pipe 2. Further, the short pipe 1 is provided with a circular opening 8 at the center of the base 7. A rectifying member 9 is fitted in and attached to the opening 8. As shown in FIGS. 2 and 3, the flow regulating member 9 is formed by notching the head of a cylindrical member obliquely from both sides to form a flow regulating surface portion 9a, and a flange 10 is integrally formed on the bottom portion thereof. . Through holes 11 for bolts are drilled at predetermined positions of the flange 10. A screw hole (not shown) is formed at a predetermined position around the opening 8 in the base portion 7 of the short pipe 1.

Then, as shown in FIG. 1, the rectifying member 9 is inserted into the opening 8 of the short pipe 1, and the bolt is passed through the hole 11 to be fitted into the screw hole of the short pipe 1 to be installed. With this configuration, it is possible to perform sufficient measurement even when the inside of the short pipe 1 is sent at an extremely low flow rate. That is, the muddy water flow flowing in the short pipe 1 narrows the fluid passage cross-sectional area between the tip of the rectifying surface portion 9 a and the detecting portion 3 by the rectifying member 9 to increase the velocity of the muddy water flow flowing in that portion. . By doing so, the mud flow becomes a turbulent flow in this portion, so that the mud flow hits the detection surface 3a at a stronger flow rate and can be cleaned.

This is due to the fact that dirt hardly adheres to the detection surface 3a when the flow velocity in the short pipe 1 is approximately 1 m / sec or more, and the dirt attached at a low flow velocity is shaken lightly in water. This is due to the fact that it is possible to simply drop a water flow in a direction different from the steady flow direction to the detection surface 3a.

That is, when the sludge to be measured has a high concentration, it becomes non-Newtonian and becomes a Bingham fluid, and exhibits thixotropy whose viscosity decreases with stirring time. Therefore, the inside of the short pipe 1 has a cylindrical shape with the same diameter. In this case, the viscosity at the center of the pipe, where the flow velocity is relatively low, shows fluidity, but since the flow velocity at the pipe wall surface is low, the viscosity is high and almost no flow occurs, so-called plug flow. However, at a flow velocity of 1 m / sec or more, this plug flow state does not occur, and therefore sludge does not easily adhere. In addition, the turbulent flow state further enhances the effect of preventing the sludge from adhering.

Therefore, the inner diameter of the short pipe 1 is narrowed at the portion where the detection surface 3a is present to increase the flow velocity at this portion, and the plug flow state is destroyed to make it a turbulent flow. Sludge is less likely to adhere to the projecting surface 3a. In addition, since the detection surface 3a is a polished glass surface, the attachment of sludge is not strong. Therefore, the steady flow is washed away by the turbulent flow from different directions.

Since the rectifying member 9 can be removed and replaced freely by bolting, a plurality of rectifying members in which the height shape and the like of the rectifying surface portion 9a are appropriately formed in response to changes in the flow velocity in the short pipe 1. It is possible to perform better measurement by preparing 9 and selecting and using them.

Further, if the distance between the detection surface 3a in the short pipe 1 and the top of the rectifying surface portion 9a is narrowed, it becomes easy to be clogged by the contaminants in the sludge flow. Can be easily processed in a short time. In addition, the rectifying member 9 can be removed and the detection surface 3a can be washed through the opening 8.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0022]

[Effect of device]

 As described above in detail, according to the pipe-mounted measuring instrument of the present invention, the detection unit that exposes the detection surface is installed inside the short pipe through which the fluid to be measured is passed, and the pair of detection units in the short pipe is installed. The rectifying member is detachably and replaceably arranged in the opening formed in the facing portion, and the rectifying member is formed with the rectifying member for reducing the fluid passage cross-sectional area between the detecting member and the rectifying member. The plug flow state of the fluid flowing near the detection surface is destroyed to cause turbulence, reducing the adhesion of dirt. At the same time, the fluid flows so that it strongly hits the detection surface, and the flow velocity is washed, which has the effect of preventing the sludge from adhering to the detection surface.

Further, there is an effect that it is possible to cope with an extremely low flow rate by preparing a plurality of flow regulating members in which the shape of the flow regulating surface is changed according to the flow rate and selectively using these. Further, even if the space between the detection surface and the rectifying surface portion is blocked, the rectifying member can be easily removed, so that there is an effect that it can be easily restored in a short time. In addition, if the rectifying member is removed, there is an effect that the detection surface can be easily washed through the opening without removing the detection unit from the short pipe.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view showing an embodiment of a pipe body mounting type measuring instrument of the present invention.

FIG. 2 is a plan view showing the rectifying member in the above-mentioned embodiment taken out.

FIG. 3 is a side view of the rectifying member of the above embodiment.

FIG. 4 is a side view illustrating a conventional optical pipe-based sludge densitometer.

FIG. 5 is a side view illustrating a conventional ultrasonic sludge concentration meter.

FIG. 6 is a front view of the conventional ultrasonic sludge concentration meter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Short tube 3 ... Detection part 3a ... Detection surface 7 ... Stand part 8 ... Opening 9 ... Rectifying member 9a ... Rectifying surface part

Claims (1)

[Scope of utility model registration request] 1. In a short tube through which a fluid to be measured is passed and a detection section exposing a detection surface is installed therein, an opening formed in a portion of the short tube facing the detection section,
A tubular body mounting type measuring instrument, wherein a rectifying member is detachably arranged so as to be replaceable, and a rectifying surface portion is formed on the rectifying member so as to reduce a fluid passage cross-sectional area between the rectifying member and the detection surface.