JP2000009510A - Device and method for measuring flow rate or flow velocity of slurried liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately measure a flow rate and a flow velocity even when the flow rate of slurried liquid is small by providing a pair of electrodes at one section in a pipeline, and detecting time when the liquid surface of the slurried liquid is brought into contact with both electrodes. SOLUTION: Electrodes 2 and 3 are provided at the lower and upper ends of one section of an upright feed pipe 1. Even after an on-off valve 5 of the feed pipe 1 is closed, time when slurried liquid surface that flows in the pipe 1 toward the on-off valve 5 and is continuously collected is brought into contact with the lower electrode 2, and time when the liquid level rises successively and is brought into contact with the upper electrode 3 are sent to an operation-processing device 4 as a detection signal, and then the on-off valve 5 is opened immediately. Based on the volume of one section of the feed pipe 1 and the detection signal of the contact time of the liquid surface with the electrodes 2 and 3, the flow rate of slurried liquid is calculated. Simultaneously, based on the value of the flow rate, flow velocity is calculated. Also, the internal diameter of the feed pipe 1 or a metering tank or the installation distance of the upper and lower electrodes is determined so that detection time difference should be within nearly 1 minute to quickly perform measuring work.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a slurry-like liquid,
In particular, the present invention relates to an apparatus for measuring the flow rate or flow rate of sludge and a method for measuring the flow rate or flow rate of a slurry liquid using the apparatus.

[0002]

2. Description of the Related Art As a method of measuring and measuring a fluid flowing through a flow path such as a pipeline, the physical properties of a fluid such as an electromagnetic flowmeter and an overflow weir have conventionally been used. The method is used.

[0003] In other words, an electromagnetic flowmeter applies a magnetic field to a pipe in which a conductive fluid such as water, seawater, oil, or the like flows, in a direction perpendicular to the axial direction of the pipe, and according to Faraday's law. The flow rate in the pipeline is measured by detecting an electromotive force generated in proportion to the flow velocity in each of the axial direction of the pipeline and the vertical direction of the magnetic field. However,
Electromagnetic flowmeters themselves are very expensive, and require the flow of a conductive fluid to be measured in the pipe at all times. The fact is that the application target and application location are limited, for example, the accuracy is extremely lowered.

[0004] On the other hand, the latter overflow weir is a structure formed so as to block a flow passage and raise the level of fluid. This overflow weir is very simple for measuring a predetermined volume of fluid, but when the volume of the fluid is less than the predetermined volume, it is not possible to accurately measure the fluid and the excess overflowing from the weir is not possible. Poor accuracy of the measurement, such as the inability to measure the fluid, has been a drawback.

In particular, at present, the measurement of a slurry-like liquid, especially a slurry-like liquid having a small flow rate, cannot be handled by any of an electromagnetic flow meter and an overflow weir. This is because, when a slurry-like liquid, especially sludge containing a solid (suspended substance), is applied to these measuring instruments, dirt adheres to the inside of the measuring instrument, and clogging occurs in thin piping and filters. It depends. In addition, even if the flow of the slurry-like liquid is forced by a pump or the like, the flow of the fluid is continuously performed, for example, the flow path is blocked by the sludge component, or the narrow pipe or the filter is clogged as described above. It was difficult.

As described above, the prior art does not provide a means for accurately measuring a slurry-like liquid, and the establishment of such a measuring technique is long-awaited in the technical field.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of such a situation in the technical field,
The gist thereof is as follows: a pipeline through which the slurry-like liquid flows, an on-off valve for allowing / cutting off the flow of the slurry-like liquid connected to the pipeline, and a shaft of the pipeline in the pipeline upstream of the on-off valve. A device for measuring a flow rate or a flow rate of a slurry-like liquid including a pair of electrodes provided apart from each other in a direction, and an arithmetic processing unit connected to the pair of electrodes; and a slurry-like liquid flowing in a pipeline. A method for measuring a flow rate or a flow velocity, in which (a) a lower electrode located at the lower end of one section in a pipeline detects contact of the liquid surface of a slurry-like liquid, and the detection signal (T ₀ ) is processed. (B) detecting contact of the liquid surface of the slurry-like liquid with the upper electrode located at the upper end of the section, transmitting a detection signal (T ₁ ) to the arithmetic processing unit, and (c) ) The difference in detection signal reception time (T ₁ −
A method for measuring the flow rate or flow rate of the slurry-like liquid flowing through the pipeline, including the step of calculating the flow rate or flow rate of the slurry-like liquid flowing through the pipeline based on T ₀ ) and the volume of the one section.

That is, as a result of diligent research conducted by the present inventors, by disposing a pair of electrodes in one section in a pipeline, a viscous solid content such as a slurry-like liquid, particularly sludge, is obtained. The inventor of the present invention has found out that the fluid and the flow velocity can be measured with high accuracy even if the flow rate is small even with a small flow rate.

[0009]

FIG. 1 is a schematic view of one embodiment of a weighing device according to the present invention.

In the present invention, the measurement target is a slurry-like liquid, for example, sludge generated from a sewage treatment process such as a sewage treatment plant and a human waste treatment plant, and a wastewater treatment process such as a food factory and a chemical factory.

As shown in FIG. 1, a lower electrode 2 is provided at a lower end of one section W (hereinafter, simply referred to as a “section”) of an upright feed pipe 1, a position which is separated from the lower electrode 2 in an upstream direction, That is, the upper electrode 3 is provided at the upper end of the section W.
The electrodes 2, 3 can be fixed to the tube wall of the feed tube 1, or can be arranged to protrude / hang from a predetermined position in the feed tube 1 (away from the tube wall). Both the lower electrode 2 and the upper electrode 3 are electrically connected to the arithmetic processing unit 4, and the volume of the feed pipe 1 in the section W and the sludge A
The flow rate and flow velocity of the sludge flowing in the section W are calculated by the arithmetic processing device 4 based on the detection signals (information of the contact time) transmitted from the lower electrode 2 and the upper electrode 3 that have come into contact. The section W of the feed pipe 1 is connected to the same pipe or connected to the pipe (having an inner diameter different from the inner diameter D of the pipe).
It may be set on the measuring tank. In addition to installing the feed pipe 1 upright, a configuration in which the liquid level of sludge rises inside the feed pipe 1, for example, the feed pipe 1 can be installed at an angle.

A procedure up to the calculation of the sludge flow rate and flow rate will be described. First, the on-off valve 5 is closed automatically or manually. Even after the on-off valve 5 is closed, the time (T ₀ ) when the liquid level of the sludge A that continues to flow / remain in the feed pipe 1 toward the on-off valve 5 contacts the lower electrode 2 is a detection signal. It is transmitted to the arithmetic processing unit 4. And it is continued sludge A
The time (T ₁ ) when the liquid level of the sludge A rises and the liquid level of the sludge A comes into contact with the upper electrode 3 is transmitted to the arithmetic processing unit 4 as a detection signal. As soon as the detection signal is transmitted from the upper electrode 3 to the arithmetic processing unit 4, the on-off valve 5 is opened. Lower electrode 2
And processing unit 4 which has received the detection signal from upper electrode 3
Then, the sludge flow rate is calculated from the detected time difference (T ₁ −T ₀ ) and the volume in the pipe 1 in the section W defined by the lower electrode 2 and the upper electrode 3. At the same time, it is possible to determine the average flow velocity of the sludge in the pipeline based on the flow rate value. Note that the detection time difference (T ₁ −T ₀ ) is set so that the measurement operation can be performed quickly within approximately one minute. And the upper electrode 3 are determined.

As the electrodes constituting the lower electrode 2 and the upper electrode 3, any type can be used as long as the sludge A in the feed pipe 1 can be detected. Considering this, it is preferable to use a liquid contact electrode. Further, as a material of the electrode, a material used for a normal electrode such as stainless steel, titanium, tantalum, platinum iridium, or the like can be used.

According to one aspect of the present invention, the arithmetic processing unit 4
Is electrically connected to the on-off valve 5. That is, by adopting such a configuration, the flow rate and the flow velocity of the sludge can be automatically measured, and the interruption time of the sludge flow can be minimized.
Specifically, at the start of measurement, the on-off valve 5 is automatically closed,
Then, at the end of the measurement, that is, when the detection signal is transmitted from the upper electrode 3 to the arithmetic processing device 4, the on-off valve 5 is opened, so that a series of operations can be automated.

Further, by electrically communicating the arithmetic processing unit 4 with the recorder 6, information / numeric values input to the arithmetic processing unit 4 and information / numeric values calculated by the arithmetic processing unit 4 can be obtained.
It can be collected in the recorder 6. By analyzing the data accumulated in the recorder 6, a change in the flow rate of the sludge A is read, and the supply amount of the sludge A is measured by a flow control valve (not shown) provided further upstream of the upper electrode 3 or the like. It can be used as a judgment index when adjusting.

Hereinafter, the present invention will be described with reference to examples. However, it is needless to say that the present invention should not be limitedly interpreted based on the disclosure of the examples.

[0017]

EXAMPLE 1 A measuring tank (inner diameter of the body was 10 cm) was connected to a sludge feeding pipe so that sludge flows vertically in an upright measuring tank.
Then, a pair of electrodes (a stainless steel rod with a sharpened tip (φ5 mm)) was placed on the inner wall of the body of the measuring tank so that the distance between the lower electrode and the upper electrode was 127.5 mm. Next, the on-off valve at the lower part of the measuring tank was closed, the sludge was accumulated in the measuring tank, the liquid level was raised, and the time during which the liquid level of the sludge contacted the lower electrode and the upper electrode was measured. The on-off valve was opened when the upper electrode detected the liquid level of the sludge. In the case of the present example, the sludge liquid level was detected by the upper electrode 49.8 seconds after the lower electrode detected the liquid level of the sludge. When calculated based on this measurement result and the volume (1 l) of the same section,
The sludge flow rate in the sludge feed pipe was 20.1 cm ³ / sec.

Example 2 The sludge flow rate was measured in the same procedure and under the same conditions as in Example 1 except that the inner diameter of the body of the measuring tank was 5 cm and the distance between the lower electrode and the upper electrode was 510 mm. In the case of this example, the sludge liquid level was detected by the upper electrode 50.1 seconds after the lower electrode detected the liquid level of the sludge. When calculated based on this measurement result and the volume (1 l) of the same section, the flow rate of the sludge in the sludge feed pipe was 20.0 cm ³ / sec.

From the results of Examples 1 and 2, even if the inner diameter of the measuring tank or the separation distance of the electrodes is changed, the flow rate or flow rate of the sludge flowing through the sludge feed pipe can be measured without being substantially affected. Was confirmed.

[0020]

As described above, according to the present invention, a means for accurately measuring the flow rate and the flow rate of the slurry-like liquid, which is the intended purpose, regardless of the degree of the realization, has been realized. In addition, by measuring the flow rate and flow rate of the slurry-like liquid passing through the feed pipes for a plurality of feed pipes that constitute a system such as a sludge treatment system, the flow rate distribution and the retention status of the slurry-like liquid on the system are measured. It also has effects such as easy grasping.

[Brief description of the drawings]

FIG. 1 is a schematic view of an embodiment of a measuring device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Feeding pipe (line) 2 ... Lower electrode 3 ... Upper electrode 4 ... Arithmetic processing unit 5 ... On-off valve 6 ... Recorder A ... Sludge

Claims (8)

[Claims] An apparatus for measuring a flow rate or a flow velocity of a slurry-like liquid, comprising a pipeline through which the slurry-like liquid flows, and an opening / closing connected to the pipeline for allowing / cutting off the flow of the slurry-like liquid. A valve, a pair of electrodes provided in the pipeline on the upstream side of the on-off valve so as to be separated from each other in the axial direction of the pipeline, and an arithmetic processing unit connected to the pair of electrodes. A device for measuring the flow rate or flow rate of a slurry liquid. 2. The apparatus according to claim 1, wherein the processing unit communicates with the on-off valve. 3. The arithmetic processing unit is in communication with a recorder for recording an operation record and an operation result.
Or the apparatus according to 2. 4. The apparatus according to claim 1, wherein the slurry-like liquid is sludge. 5. A method for measuring a flow rate or a flow rate of a slurry-like liquid flowing in a pipeline, comprising the following steps: (a) using a lower electrode located at a lower end of a section in the pipeline to form a slurry. Detecting the contact of the liquid surface of the liquid, transmitting a detection signal (T ₀ ) to the arithmetic processing unit, and (b) the liquid surface of the slurry-like liquid at the upper electrode located at the upper end of one section in the pipeline. And the detection signal (T ₁ ) is transmitted to an arithmetic processing unit, and (c) the arithmetic processing unit detects a difference between the reception time of the detection signal (T ₁ −T ₀ ) and the one section. Calculating a flow rate or a flow rate of the slurry-like liquid flowing in the pipe line based on the volume of the slurry liquid. 6. The method according to claim 5, wherein the arithmetic processing unit communicates with an on-off valve provided in a pipeline downstream of the lower electrode. 7. The arithmetic processing unit is in communication with a recorder for recording an arithmetic record and an arithmetic result.
Or the method of 6. 8. The method according to claim 5, wherein the slurry-like liquid is sludge.