JP7299614B2 - Fluid transfer device - Google Patents

Description

The present invention relates to a fluid transfer device that transfers a predetermined amount of fluid to a target position in a pipe by operating a pump connected to the pipe.

2. Description of the Related Art Conventionally, in various measuring devices, a fluid transfer device is used to transfer various fluids as samples to target positions in pipes. For example, the wet total organic carbon measuring apparatus described in Patent Document 1 mixes and heats a sample containing an organic carbon component with an acid solution and an oxidizing agent solution from which the carbon component has been removed in a reaction tank, Although the concentration of carbon dioxide is configured to be analyzed by an infrared gas analyzer, there are cases where mixing and heating are performed at different locations, in which case a fluid transfer device is used.

JP-A-63-173962

However, when the above heating is performed in a pipe wound around a heating element, if the mixed liquid (fluid) such as a sample is transferred to a position deviated from the target position set in the pipe, it may cause a rise. The temperature and accompanying carbon dioxide evolution cannot be carried out as intended.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluid transfer device capable of accurately transferring a predetermined amount of fluid to a target position in a pipe.

In order to solve the above problems, a fluid transfer device according to the present invention is a fluid transfer device that transfers a predetermined amount of fluid to a target position in a pipe by operating a pump connected to the pipe. a fluid detection unit provided in the pipe on the upstream side of the position and detecting the leading end and the terminal end of the fluid being transferred, a passage time from when the fluid detecting unit detects the leading end to detecting the terminal end, and the fluid detecting unit; and a control unit that stops the pump based on the positional relationship with the target position.

The control unit of the fluid transfer device may stop the pump when the time obtained by the formula "Lb×ΔT/Lf" has elapsed after the tip of the fluid being transferred is detected by the fluid detection unit, The pump may be stopped when the time determined by the formula “Lt×ΔT/Lf” has elapsed after the end of the fluid being transferred has been detected by the fluid detection unit. However, Lf is the length of the fluid in the pipe, Lb is the transfer distance between the tip of the fluid and the fluid detection part when it stops at the target position, and Lt is the length of the fluid when it stops at the target position. is the transport distance between the terminal end and the fluid sensing portion, and ΔT is the transit time.

In the above-mentioned fluid transfer device, the pipe has translucency, and the fluid detection unit has a light emitter and a light receiver arranged opposite to each other with the pipe interposed therebetween, and the light emitter outputs a predetermined amount of detection light to the light receiver. , and detect the leading end and the trailing end of the fluid being transported based on the change in the light amount of the detection light that has reached the light receiver.

In the fluid transfer device, the pipe has a first portion connected to the pump, a second portion located upstream of the first portion, and a third portion located upstream of the second portion. However, the second portion may be wound around the heating element, the target position may be in the second portion, and the fluid detection section may be provided in the third portion.

According to the present invention, it is possible to provide a fluid transfer device capable of accurately transferring a predetermined amount of fluid to a target position in a pipe.

1 is a diagram showing the main parts of a wet total organic carbon measuring device incorporating a fluid transfer device according to the present invention; FIG. 1 is a diagram showing a fluid transfer device according to a first embodiment of the present invention; FIG. FIG. 4 is a diagram showing a fluid transfer device according to a second embodiment of the present invention;

Hereinafter, embodiments of the fluid transfer device according to the present invention will be described with reference to the accompanying drawings. In addition, although an example in which it is incorporated in a wet total organic carbon measuring apparatus will be described below, the fluid transfer apparatus according to the present invention may be used by being incorporated in another apparatus.

[Wet total organic carbon measuring device]
First, the wet total organic carbon measuring device 10 will be described with reference to FIG. A wet total organic carbon measuring device 10 is an automatic measuring device for periodically measuring the concentration of total organic carbon (TOC) in a sample, and includes a sample reservoir 11 and a wash water reservoir 12. , an acid solution storage unit 13 , an oxidant solution storage unit 14 , a mixing unit 15 , a heating unit 16 , a dehumidification unit 17 , a carbon dioxide detection unit 18 and a waste liquid storage unit 19 .

The sample storage unit 11 is a tank storing water as a sample. Water expected to contain organic carbon is introduced into the sample reservoir 11 through a flow control valve (not shown).

The washing water storage unit 12 is a tank that stores washing water for washing the inner wall of the pipe through which the sample passes, the wetted part of the valve, and the inside of the mixing unit 15 . As washing water, tap water is usually used. Wash water can also be used as dilution water to dilute the sample when performing low concentration measurements. In this case, as the washing water, for example, pure water such as ion-exchanged water obtained by an ion-exchange method or RO water obtained by filtration using a reverse osmosis membrane can be used.

The acid solution reservoir 13 is a storage container that stores an acid solution for removing inorganic carbon. As the acid contained in the acid solution, inorganic acids such as sulfuric acid, hydrochloric acid and phosphoric acid can be used. The acid concentration is pre-adjusted to sufficiently lower the pH of the sample.

The oxidant solution storage unit 14 is a storage container that stores the oxidant solution. As the oxidizing agent contained in the oxidizing agent solution, for example, sodium persulfate and potassium persulfate can be used. The concentration of the oxidizing agent is adjusted in advance so that the organic carbon in the sample can be sufficiently oxidized.

Mixing section 15 is a container connected to sample reservoir 11, wash water reservoir 12, acid solution reservoir 13 and oxidant solution reservoir 14 via appropriate valves. Here, a predetermined amount of sample, a predetermined amount of acid solution stored in acid solution reservoir 13, and a predetermined amount of oxidant solution stored in oxidant solution reservoir 14 are mixed. The mixing section 15 is also connected to a heating section 16, a dehumidifying section 17, and a waste liquid storage section 19, which will be described later.

The heating unit 16 is an autoclave that includes a heating element 40, two valves 41 and 42, and a pipe 31 sealed by closing the valves 41 and 42. As shown in FIG. The heating unit 16 heats the mixed liquid (a mixture of the sample, the acid solution, and the oxidizing agent solution) confined in the pipe 31 with the heating element 40, thereby oxidizing the organic carbon in the sample and generating carbon dioxide. Let

The dehumidifying section 17 is a mist catcher that collects moisture in the sample gas sent to the carbon dioxide detecting section 18 . The sample gas contains carbon dioxide generated in the heating section 16 .

The carbon dioxide detector 18 is an infrared gas analyzer that detects the amount of carbon dioxide in the sample gas. Detecting the amount of carbon dioxide contained in the sample gas is equivalent to measuring the concentration of TOC in the sample.

The waste liquid reservoir 19 is a tank that stores the residual liquid in the mixing section 15 as waste liquid.

The wet total organic carbon measuring apparatus 10 further includes a carbon dioxide removal section 20 , a first pump 21 , a second pump 22 , a fluid detection section 50 and a control section 51 . However, the controller 51 is not shown in FIG.

The carbon dioxide removal section 20 is a carbon dioxide removal pipe that removes carbon dioxide. The carbon dioxide removal tube has soda lime as an absorbent to absorb carbon dioxide.

The first pump 21 is a tube pump (also called a squeezing pump), and has a suction operation for sucking air in a pipe (for example, the pipe 30 or the like) and a discharge operation for sending air into the pipe (for example, the pipe 30 or the like). and can be done. These two operations are performed via the carbon dioxide removal section 20 .

The second pump 22 is an electromagnetic air pump, and can perform a discharge operation of sending air into a pipe (for example, pipe 30 or the like). This operation is also performed via the carbon dioxide removal unit 20 .

The fluid detection unit 50 is composed of a light projector 50a and a light receiver 50b arranged opposite to each other across a pipe 32 connecting the mixing unit 15 and the heating unit 16 (see FIGS. 2 and 3). The light projector 50a outputs a predetermined amount of detection light toward the light receiver 50b. Further, the light receiver 50b detects the leading end and the trailing end of the liquid mixture passing between the light projector 50a and the light receiver 50b, based on the change in the amount of detection light that has reached the light receiver 50b.

The control unit 51 is composed of a microprocessor (MPU: Micro Processing Unit). The controller 51 controls at least the operation of the first pump 21 based on the detection result of the fluid detector 50 .

The wet total organic carbon measuring apparatus 10 measures the concentration of TOC in the sample according to the procedures (1) to (11) shown below, and outputs the measurement result.
(1) Through the discharge operation of the second pump 22, the zero gas is sent to each part (each pipe, the mixing part 15, the heating part 16, the dehumidification part 17, the carbon dioxide detection part 18, etc.) via the carbon dioxide removal part 20, The inside of these is replaced with zero gas.
(2) A predetermined amount of sample is sent to the mixing section 15 by the suction/discharge operation of the first pump 21 .
(3) A predetermined amount of acid solution is sent to the mixing section 15 by the suction/discharge operation of the first pump 21 .
(4) Air is introduced into the mixing section 15 via the carbon dioxide removal section 20 and the heating section 16 by the discharge operation of the first pump 21, and bubbling is performed for a predetermined time to remove inorganic carbon.
(5) A predetermined amount of oxidant solution is sent to the mixing section 15 by the suction/discharge operation of the first pump 21 .
(6) By the suction operation of the first pump 21 , all of the liquid mixture in the mixing section 15 is transferred to the target position in the pipe 31 . At this time, valves 41 and 42 are open.
(7) Close the valves 41 and 42 to seal the pipe 31 .
(8) Heating the heating element 40 to heat and pressurize the liquid mixture.
(9) Open the valves 41 and 42 to open the pipe 31 .
(10) By the discharge operation of the first pump 21 , the sample gas containing carbon dioxide in the piping 31 generated by heating is sent to the carbon dioxide detector 18 via the mixer 15 and the dehumidifier 17 .
(11) The carbon dioxide detector 18 detects the amount of carbon dioxide in the sample gas.

[Fluid transfer device (first embodiment)]
Next, referring to FIG. 2, the fluid transfer device according to the first embodiment of the present invention, which includes a first pump 21, pipes 30, 31, and 32, a fluid detector 50, and a controller 51, will be described. explain.

The pipe 30 is a first portion of the pipe that connects the first pump 21 and the mixing section 15, and has a downstream end connected to the first pump 21 and an upstream end connected to the valve 42. there is

The pipe 31 is a second portion of the pipe that connects the first pump 21 and the mixing section 15 , and has a downstream end connected to the valve 42 and an upstream end connected to the valve 41 . The piping 31 has a heated portion 33 positioned substantially in the center in the longitudinal direction wound around the heating element 40 .

The pipe 32 is a third portion of the pipe that connects the first pump 21 and the mixing section 15, and has a downstream end connected to the valve 41 and an upstream end connected to the mixing section 15. . A light projector 50 a and a light receiver 50 b that constitute a fluid detection unit 50 are provided in the middle of the pipe 32 .

The pipe 32 is made of a translucent material at least in a portion sandwiched between the light projector 50a and the light receiver 50b. Thereby, the light receiver 50b can receive the detection light output from the light projector 50a.

In this embodiment, the length of the heated portion 33 of the pipe 31 is 200 cm (100 cm + 100 cm), and the distance (transfer distance) between the upstream end of the heated portion 33 and the fluid detection section 50 is 110 cm. be. Further, in this embodiment, the transfer destination (target position M′) of the mixed liquid M is set at the center of the heated portion 33 .

Further, in this embodiment, the inner diameters of the pipes 31 and 32 are 3 mmφ. Therefore, when the amount of the liquid mixture M is 10 ml, the length of the liquid mixture M in the pipes 31 and 32 is 140 cm. In addition, the inner diameter of the pipe 30 may be 3 mmφ, or may not be 3 mmφ.

When the first pump 21 performs a suction operation, the liquid mixture M is transferred downstream through the pipe 32 . When the tip Mb of the mixture M passes between the light emitter 50a and the light receiver 50b, the amount of detection light reaching the light receiver 50b changes (decreases). The tip Mb of M is detected. The reason why the light amount of the detection light reaching the light receiver 50b is reduced is that the detection light is refracted by the liquid mixture M and does not reach the light receiver 50b.

When the first pump 21 continues to perform the suction operation, the liquid mixture M is further transferred downstream in the pipe 32 . Then, when the end Mt of the mixed liquid M passes between the light emitter 50a and the light receiver 50b, the light amount of the detection light reaching the light receiver 50b changes (increases) again. The end Mt of liquid M is detected. The reason why the light amount of the detection light reaching the light receiver 50b is increased is that the detection light is no longer refracted by the liquid mixture M.

The control unit 51 obtains the transfer speed of the mixed liquid M based on the detection result of the fluid detection unit 50 . For example, when the time from when the fluid detection unit 50 detects the tip Mb of the mixed liquid M to when it detects the end Mt, that is, when the passage time of the mixed liquid M is 5 seconds, the control unit 51 outputs "140/ 5″ calculation determines the transport speed to be 28 cm/sec.

Next, the controller 51 stops the first pump 21 based on the positional relationship between the fluid detector 50 and the target position M'. For example, the control unit 51 stops the first pump 21 when 10 seconds obtained by the calculation of "280/28" have passed since the fluid detection unit 50 detected the tip Mb of the liquid mixture M. As a result, the tip Mb of the stopped mixture M and the tip Mb' of the target position M' overlap.

In summary, Lf is the length of the mixed liquid M in the pipes 31 and 32, Lb is the transfer distance between the tip Mb' of the target position M' and the fluid detection unit 50 (50a, 50b), and ΔT is the passage time. Then, the control unit 51 detects the tip Mb of the mixed liquid M being transferred by the fluid detection unit 50 (50a, 50b) when the time obtained by the formula “Lb×ΔT/Lf” has passed. 1 pump 21 is stopped.

As described above, according to the fluid transfer device according to the present embodiment, it is possible to transfer a predetermined amount of the liquid mixture M to the target position M' with high accuracy. Even if the suction capacity of the first pump 21 changes due to temperature change or deterioration over time, the transfer accuracy does not deteriorate. Further, it is known that the tube pump does not stabilize its suction ability until the tube that has been replaced gets used to it.

[Fluid transfer device (second embodiment)]
Next, a fluid transfer device according to a second embodiment of the present invention will be described with reference to FIG. The fluid transfer device according to the present embodiment differs from that of the first embodiment in calculation by the control unit 51, but is common to the first embodiment in other respects.

That is, the control unit 51 in the second embodiment calculates the transfer speed of the liquid mixture M based on the detection result of the fluid detection unit 50. FIG. For example, when the time from when the fluid detection unit 50 detects the tip Mb of the mixed liquid M to when it detects the end Mt, that is, when the passage time of the mixed liquid M is 5 seconds, the control unit 51 outputs "140/ 5″ calculation determines the transport speed to be 28 cm/sec.

Next, the control unit 51 in the second embodiment stops the first pump 21 based on the positional relationship between the fluid detection unit 50 and the target position M'. For example, the control unit 51 stops the first pump 21 when 5 seconds obtained by the calculation of "140/28" have passed since the fluid detection unit 50 detected the end Mt of the liquid mixture M. As a result, the end Mt of the stopped liquid mixture M and the end Mt' of the target position M' overlap.

In summary, Lf is the length of the mixed liquid M in the pipes 31 and 32, Lt is the transfer distance between the end Mt' of the target position M' and the fluid detection unit 50 (50a, 50b), and ΔT is the passage time. Then, the control unit 51 in the second embodiment detects the end Mt of the mixed liquid M being transferred by the fluid detection unit 50 (50a, 50b), and the time obtained by the formula “Lt×ΔT/Lf” is The first pump 21 is stopped when the time elapses.

According to the fluid transfer device according to this embodiment, the same effects as those of the first embodiment can be obtained.

[Modification]
The configuration of the fluid transfer device according to the present invention is not limited to the configurations of the first and second embodiments. For example, the fluid transfer device according to the present invention may be used by being incorporated in a device other than the wet total organic carbon measuring device. Also, the fluid transfer device according to the present invention may be used to transfer any fluid. Fluid transfer devices according to the present invention may also be configured to detect fluid leading and trailing ends by non-optical means.

10 Wet type total organic carbon measuring device 11 Sample reservoir 12 Cleaning water reservoir 13 Acid solution reservoir 14 Oxidant solution reservoir 15 Mixing part 16 Heating part 17 Dehumidification part 18 Carbon dioxide detection part 19 Waste liquid reservoir 20 Carbon dioxide removal part 21 first pump 22 second pump 30 piping (first part)
31 piping (second part)
32 Piping (third part)
40 Heating element 41 Valve 42 Valve 50 Fluid detector 50a Light projector 50b Light receiver 51 Controller M Liquid mixture M' Target position

Claims (4)

A fluid transfer device that transfers a predetermined amount of fluid to a target position in the pipe by operating a pump connected to the pipe,
a fluid detection unit for detecting the leading edge and the trailing edge of the fluid being transferred ;
a control unit that stops the pump based on the passage time from when the fluid detection unit detects the tip to when it detects the end, and on the positional relationship between the fluid detection unit and the target position;
with
The pipe has a first portion connected to the pump, a second portion located upstream of the first portion, and a third portion located upstream of the second portion,
the second portion is wrapped around a heating element;
the target location is within the second portion;
The fluid detection section is provided in the third portion.
A fluid transfer device characterized by: Let Lf be the length of the fluid in the pipe, Lb be the transfer distance between the tip of the fluid and the fluid detection unit when stopped at the target position, and ΔT be the transit time. 3. The unit stops the pump when the time obtained by the formula "Lb×ΔT/Lf" has elapsed since the tip of the fluid being transferred was detected by the fluid detection unit. 2. The fluid transfer device according to claim 1. Let Lf be the length of the fluid in the pipe, Lt be the transfer distance between the end of the fluid and the fluid detection unit when stopped at the target position, and ΔT be the passage time. 3. The unit stops the pump when the time determined by the formula "Lt×ΔT/Lf" has elapsed after the end of the fluid being transferred was detected by the fluid detection unit. 2. The fluid transfer device according to claim 1. The pipe has translucency,
The fluid detection unit has a light emitter and a light receiver arranged opposite to each other with the pipe interposed therebetween,
The light projector outputs a predetermined amount of detection light toward the light receiver,
The fluid according to any one of claims 1 to 3, wherein the light receiver detects the leading end and the trailing end of the fluid being transported based on a change in light intensity of the detection light that has reached the fluid. transfer device.

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