JP4744289B2 - Water quality measuring device - Google Patents

Description

  The present invention relates to a water quality measuring apparatus capable of preferably detecting the quality of water, for example, water to be measured, such as liquid to be treated contained in a reaction tank of a sewage treatment plant or a wastewater treatment facility. is there.

  When water quality is detected using a liquid mixed with bubbles, such as a liquid to be treated in a conventional sewage treatment plant, as a measurement water, a separate water collection tank is installed in front of the water quality detector, and the influence of bubbles on the measurement unit. Water removal is performed, or an air vent valve or the like is installed in a high part of the pipe to collect water into the measurement unit (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-121628 (first page, FIG. 1)

  In the conventional water quality measuring apparatus as described above, when a water collection tank is provided in front of the water quality detector to remove bubbles, periodic maintenance of the water collection tank is necessary, and an air vent valve is installed. In such a case, sampling with a lot of foreign matters, such as a sewage treatment plant, has a problem of clogging of pipes due to adhesion of mud etc. to the air vent valve, and there is a problem that stable measurement is difficult.

  The present invention has been made to solve the above-described problems of the prior art, and even if the water to be measured includes bubbles such as the liquid to be treated in the sewage treatment plant, it can be easily obtained from the sampled water to be measured. It is an object of the present invention to provide a water quality measuring device that can remove air bubbles, stably feed water to be measured from which air bubbles have been removed to a water quality detector, and reduce maintenance for a long period of time.

A water quality measuring device according to the present invention is a water quality measuring device comprising a water quality detector for detecting the quality of the water to be measured contained in the accommodating portion, and a water collection pipe communicating with the accommodating portion and the water quality detector. A branch part provided in the water sampling pipe, a bypass pipe for returning the water to be measured branched at the branch part to a position higher than the water sampling pipe, and then returning to the housing part; and the sampling in the bypass pipe A reducer interposed so that the cross-sectional area of the flow path becomes smaller in the upward direction at a position higher than the water pipe, a bypass valve interposed in the bypass pipe, and a water sampling pipe provided on the downstream side of the branch portion A pressure gauge for detecting the pressure of the water, a washing water supply unit capable of supplying washing water, and a switching means for switching the liquid to be fed to the sampling pipe to the water to be measured or the washing water, Detection result is below the specified value When divided, in which the measured water becomes as flowing is switched to the cleaning water by the switching means.

According to the present invention, the flow rate of the liquid containing bubbles flowing through the bypass pipe after the reducer is reduced by interposing the reducer so that the flow passage cross-sectional area is reduced upward in the bypass pipe acting like air bleeding. In order to remove various kinds of contaminants and bubbles from the branch of the sampling tube early, the measured water from which bubbles are removed is stably fed to the water quality detector, and the influence of the bubbles on the water quality detector is affected. Can be reduced. In addition, the piping is not clogged and maintenance can be unnecessary for a long time. Moreover, when the detection result of the pressure gauge that detects the pressure in the water sampling pipe provided downstream of the branching section falls below a predetermined value, the water to be measured is switched to wash water and allowed to flow. This makes it possible to remove dirt by automatically supplying cleaning water into the system when dirt is deposited on the piping, etc. after long-term use, enabling stable long-term water quality measurement. Become.

Embodiment 1 FIG.
FIG. 1 is a block diagram conceptually showing a main part of a water quality measuring apparatus according to Embodiment 1 of the present invention. In addition, below, this invention demonstrates the case where water quality is measured using the to-be-processed liquid accommodated in the reaction tank of the sewage treatment plant as to-be-measured water. In the figure, a container 1 consisting of a reaction tank in a sewage treatment plant contains a liquid 2 to be measured, which is agitated by an oxidizing gas such as air supplied from an aeration device (not shown). Innumerable bubbles 3 are generated. The storage unit 1 is provided with a submersible pump 5 for supplying the stored liquid 2 to be measured as water to be measured to a water quality detector 4 which is a water quality meter through a water collection pipe 6. A water sampling pipe 6 that communicates with the detector 4 is sequentially provided with a gate valve 7, a branching portion 8, and a pretreatment device 9 in the downstream direction. In the gate valve 7, the water sampling flow rate and the water sampling pressure are adjusted.

  The liquid 2 to be processed branched upward in the branching section 8 is raised to the upper part by a height h from the branching section 8 through the reducer 10 and the bypass valve 11, and then returns to the storage section 1. It is returned to the accommodating part 1 by the bypass piping 12 provided in. The reducer 10 is a known piping member in which the inner diameter of the outlet portion is continuously and smoothly narrowed down from the inlet portion. Can do. Further, the pretreatment device 9 collects water using a known macro process, and sends water permeated through pressure water to a filter (not shown) to the water quality detector 4. The pretreatment device 9 is connected to a return pipe 13 for returning surplus water to the storage unit 1. The water quality detector 4 may be, for example, a known general one, and the detailed illustration of its structure, signal processing circuit, control device, etc. is omitted. Further, the inner diameter of the pipe connected to the inlet or outlet of the reducer 10 is adapted to the inlet diameter or outlet diameter of the reducer 10.

  Next, the operation of the first embodiment configured as described above will be described. The liquid 2 to be treated in the sewage treatment plant is sampled by the submersible pump 5 from the container 1 which is a reaction tank, and sent to the water quality detector 4 through the water sampling pipe 6 and the pretreatment device 9 of the water quality detector 4. . Here, the opening degree of the gate valve 7 provided in the water sampling pipe 6 is adjusted, and the water sampling flow rate and the water sampling pressure are adjusted. A part of the liquid 2 to be processed that has passed through the gate valve 7 is directed from the branching portion 8 provided in front of the pretreatment device 9 to the reducer 10 and the bypass pipe 12 connected to the bypass valve 11, but the bypass pipe having the reducer 10. Since 12 is raised by a height h, a pressure difference is generated such that the pressure of the lower branching portion 8 is high and the pressure is lowered upward.

  For this reason, the function of the air bleeding pipe works in the bypass pipe 12 itself, and bubbles contained in the liquid to be treated 2 try to escape to the bypass pipe 12. In the case of the conventional air vent pipe, there is a problem that the pipe and valves are easily clogged in a suspension containing a lot of various kinds of impurities together with bubbles like the liquid to be treated in a sewage treatment plant. In the first embodiment, the reducer 10 is interposed so that the cross-sectional area of the flow path becomes smaller in the upward direction, so that the flow rate of the liquid containing the bubbles flowing through the bypass pipe 12 after the reducer 10 is increased, and various kinds of impurities, etc. Is removed along with the bubbles and returned to the housing portion 1, so that clogging does not occur for a long time.

  The bypass valve 11 is necessary for maintaining the flow rate of the liquid to be treated flowing through the bypass pipe 12 and the pressure of the water sampling pipe 6 which is the main pipe within a predetermined range. Thus, when the liquid 2 to be processed passes through the branching portion 8, most of the bubbles mixed in the liquid 2 to be processed pass through the reducer 10 and the bypass valve 11 to the bypass pipe 12 and return to the storage unit 1. It is. For this reason, the water to be measured is supplied to the pretreatment device 9 on the downstream side of the branching section 8 as the water to be measured with less air bubbles mixed therein, and the air bubbles that obstruct the measurement with respect to the water quality detector 4 are removed. Supplied as

  As described above, in the first embodiment, the reducer 10 and the bypass valve 11 whose inner diameter is reduced are provided in the bypass pipe 12 raised upward from the branching section 8 in front of the pretreatment device 9 which is a water sampling section. Since the air bubbles are removed with a simple structure that uses the height difference, the difference in the thickness of the pipe, and the adjustment of the opening degree of the bypass valve 11, the air quality is removed from the water quality detector 4 to be measured. Water is supplied, water sampling is prevented from being interrupted by bubbles, and water quality detection by the water quality detector 4 can be performed stably for a long time. In addition, since the air vent valve is not used, even in the water to be measured that contains a lot of contaminants such as sewage treatment plants, there is little occurrence of clogging of piping due to mud etc. adhering to the valves, and maintenance can be made unnecessary for a long time.

Embodiment 2. FIG.
FIG. 2 is a block diagram conceptually showing a main part of a water quality measuring apparatus according to Embodiment 2 of the present invention. In the figure, on the upstream side of the gate valve 7 of the water sampling pipe 6, there are a flow rate adjusting pipe 14 a branched from the water sampling pipe 6 and returned to the accommodating portion 1, and a flow rate adjusting valve 14 b interposed in the flow rate adjusting pipe 14 a. The flow rate adjusting means 14 is provided. Other configurations are the same as those of the first embodiment, and the same reference numerals denote the same or corresponding parts throughout the drawings, and thus the description thereof is omitted.
In the second embodiment, in addition to the opening degree adjustment by the gate valve 7, by adjusting the flow rate in the direction of the gate valve 7 by the flow rate adjusting valve 14b of the flow rate adjusting means 14, in addition to the effect of the first embodiment. Thus, it is possible to perform fine flow rate adjustment, pressure adjustment, and the like to the pretreatment device 9 which is a water collection unit.

Embodiment 3 FIG.
FIG. 3 is a block diagram conceptually showing the main part of a water quality measuring apparatus according to Embodiment 3 of the present invention. In the figure, a transparent member 13a is provided on the return pipe 13 from the pretreatment device 9 to the housing portion 1 so that the state of water flowing from the pretreatment device 9 to the housing portion 1, particularly the presence or absence of bubbles can be confirmed. It is configured. In addition, the transparent member 13a may be any one in which the tube itself is made of a transparent material such as plastic or glass, or in which an opaque tube is provided with a window made of a transparent material. Other configurations are the same as those of the second embodiment.
In the third embodiment, a part of the return pipe 13 near the outlet of the pretreatment device 9 is a transparent member 13a, so that in addition to the effect of the second embodiment, bubbles in the direction of the water quality detector 4 are generated. It is possible to easily confirm the presence or absence of mixing, and it is easy to confirm the removal of bubbles.

Embodiment 4 FIG.
4 is a block diagram conceptually showing the main part of a water quality measuring apparatus according to Embodiment 4 of the present invention. In the figure, a transparent member 12a similar to the transparent member 13a is provided near the outlet of the bypass valve 11 in the bypass pipe 12. Since other configurations are the same as those of the third embodiment, description thereof is omitted.
In the fourth embodiment, since a part of the bypass pipe 12 is made of the transparent member 12a, in addition to the effects of the third embodiment, the state of bubbles flowing through the bypass pipe 12 can be easily confirmed. It is possible to adjust the opening of 11 while visually checking the state of the bubbles. Note that even if only one of the transparent members 12a and 13a is provided, a corresponding effect can be expected.

Embodiment 5 FIG.
FIG. 5 is a block diagram conceptually showing a main part of a water quality measuring apparatus according to Embodiment 5 of the present invention. In the figure, the flow rate adjusting means 14 is provided with an electric valve 14c for flow rate adjustment, and a signal corresponding to the pressure of the water to be measured flowing through the water sampling pipe 6 is output to the inlet of the pretreatment device 9 of the water sampling pipe 6. And a control device 17 for controlling the motor-operated valve 14c based on a signal from the pressure gauge 16. Other configurations are the same as those in the first embodiment.
In the fifth embodiment configured as described above, the pressure gauge 16 is installed in front of the pretreatment device 9, and the opening degree of the motor operated valve 14c is controlled so that the pressure becomes constant by the control device 17, Stable water sampling is possible by adjusting the flow rate to be constant.

Embodiment 6 FIG.
FIG. 6 is a block diagram conceptually showing a main part of a water quality measuring apparatus according to Embodiment 6 of the present invention. In the figure, a water sampling section electric valve 18 is interposed in the water sampling pipe 6 between the submersible pump 5 and the gate valve 7, and further, the water sampling pipe 6 between the water sampling section electric valve 18 and the gate valve 7 is washed. A cleaning water supply pipe 21 is connected via a cleaning electric valve 20 for introducing cleaning water from the water supply unit 19. An alarm setter 22 that sets an alarm according to the output of the pressure gauge 16 and a valve switching circuit 23 that controls the water sampling section electric valve 18 and the washing electric valve 20 based on the output of the alarm setter 22 are provided. Is provided. The water sampling section motor operated valve 18, the cleaning motor operated valve 20, and the valve switching circuit 23 constitute a switching means 24. Since other configurations are the same as those of the second embodiment, description thereof is omitted.

In the sixth embodiment configured as described above, when the pressure of the water to be measured supplied to the pretreatment device 9 detected by the pressure gauge 16 falls below a predetermined value set by the alarm setting device 22 It is determined that the water collecting pipe 6 is very dirty, and the switching means 24 controls the valve switching circuit 23 so that the water collecting section electric valve 18 is “closed” and the washing electric valve 20 is “open”. Washing water is supplied from the washing water supply pipe 21 to perform water washing, and dirt such as pipes such as the water sampling pipe 6 and the bypass pipe 12, the pretreatment device 9 and the water quality detector 4 is removed.
As described above, according to the sixth embodiment, in addition to the effects of the second embodiment, when dirt is deposited on the piping or the like due to long-term use, the cleaning water is automatically supplied into the system. By supplying it, it becomes possible to remove dirt, and more stable long-term water quality measurement becomes possible.

  Note that the invention described in each of the above embodiments can be arbitrarily combined. In that case, the synergistic effect of each invention can be expected. In addition, the position of the valve may be changed as appropriate. Furthermore, although the case where the to-be-processed liquid accommodated in the reaction tank of a sewage treatment plant was measured was demonstrated to the example, as to-be-measured water, it does not specifically limit to this.

The block diagram which shows notionally the principal part of the water quality measuring device by Embodiment 1 of this invention. The block diagram which shows notionally the principal part of the water quality measuring apparatus by Embodiment 2 of this invention. The block diagram which shows notionally the principal part of the water quality measuring device by Embodiment 3 of this invention. The block diagram which shows notionally the principal part of the water quality measuring device by Embodiment 4 of this invention. The block diagram which shows notionally the principal part of the water quality measuring device by Embodiment 5 of this invention. The block diagram which shows notionally the principal part of the water quality measuring device by Embodiment 6 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Storage part (reaction tank), 2 Liquid to be processed (water to be measured), 3 Air bubbles, 4 Water quality detector, 5 Submersible pump, 6 Sampling pipe, 7 Gate valve, 8 Branching part, 9 Pretreatment device, 10 Reducer, DESCRIPTION OF SYMBOLS 11 Bypass valve, 12 Bypass piping, 12a Transparent member, 13 Return pipe, 13a Transparent member, 14 Flow rate adjustment means, 14a Flow rate adjustment tube, 14b Flow rate adjustment valve, 14c Motorized valve, 15 Flow rate adjustment valve, 15a Motorized valve, 16 Pressure 17, control device, 18 water sampling section motor valve, 19 washing water supply section, 20 washing motor valve, 21 washing water supply pipe, 22 alarm setter, 23 valve switching circuit, 24 switching means.

Claims (7)

In a water quality measurement apparatus comprising a water quality detector for detecting the quality of the water to be measured contained in the accommodation portion, and a water collection pipe communicating with the accommodation portion and the water quality detector, a branch portion provided in the water collection tube And, after raising the water to be measured branched at the branch part to a position higher than the sampling pipe, the bypass pipe returning to the housing part, and the flow path disconnection at a position higher than the sampling pipe in the bypass pipe A reducer interposed so that the area decreases in the upward direction, a bypass valve interposed in the bypass pipe, a pressure gauge for detecting the pressure in the water sampling pipe provided on the downstream side of the branch part, A cleaning water supply unit capable of supplying cleaning water, and a switching means for switching the liquid to be supplied to the sampling pipe to the water to be measured or the cleaning water, the detection result of the pressure gauge falls below a predetermined value Sometimes, the switching means Water measuring apparatus characterized by comprising the measured water as flowing is switched to the washing water.   A return pipe that pretreats the water to be measured, sends treated water to the water quality detector, and sends surplus water associated with the pretreatment to the accommodating part in a water collection pipe between the water quality detector and the branch part. The water quality measuring device according to claim 1, wherein a pretreatment device is provided.   The water quality measuring apparatus according to claim 2, wherein a transparent member is used for at least a part of the return pipe.   The water quality measuring device according to any one of claims 1 to 3, wherein a flow rate adjusting means is provided between the housing part and the branch part in the water sampling pipe.   A pressure gauge for detecting the pressure in the water sampling pipe provided on the downstream side of the branch portion is provided, and the flow rate adjusting means is controlled according to the detection result of the pressure gauge. 4. The water quality measuring device according to 4.   The water quality measuring device according to any one of claims 1 to 5, wherein air bubbles contained in the water to be measured are guided to the bypass pipe by opening control of the bypass valve.   The water quality measuring device according to any one of claims 1 to 6, wherein a transparent member is used for at least a part of the bypass pipe.

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