JP3199938B2 - Leak detection device for shutoff mechanism in flow passage - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leakage detecting device for detecting leakage of a liquid in a shutoff mechanism for shutting off a handled liquid in a flow path, particularly a closed circuit flow path.

[0002]

2. Description of the Related Art In general, for example, in a dialysis apparatus shown in FIG. 7, a dialysate circulation system 10 includes a shutoff mechanism (switch) 1 for a dialysate supply system 12 and a waste liquid discharge system 14, respectively.
It is constituted by a closed circuit 18 connected via the terminals 6 and 16. In this dialysis device, the closed circuit 18
A certain amount of dialysate circulated and supplied by a circulating pump (reciprocating pump) 20 is provided with waste and water from the blood in the blood circulating system 22 which comes in contact through the dialysis membrane 24a of the dialyzer 24. (Unnecessary substances) are separated and collected, discharged as a waste liquid containing the unnecessary substances from the discharge system 14, and fresh dialysate is supplied from the dialysate supply system 12.

However, in such a dialysis fluid circulating system 10, if fluid leakage occurs in the switch 16, that is, if fluid leakage occurs in the closed circuit 18, the properties of the circulating dialysate in the closed circuit 18 change. This causes inconveniences such as excessive water removal or back filtration (dialysis fluid enters the blood). Therefore, a leak check device 26 is generally attached to such a sealed circuit 18 to apply a pressure to the closed circuit 18 in the shut-off state of the switch 16, and then check the pressure drop. It is configured to check for the above-mentioned inconvenience, that is, liquid leakage in the closed circuit 18. In the circuit 18 of this type, even if the flow rate of the reciprocating motion metering pump 20 changes, the same inconvenience as described above occurs. Therefore, the quantitativeness of the pump 20 is similarly checked. A device (not shown) can be provided.

[0004]

However, the leak check device in the above-mentioned closed circuit for circulating the dialysate has the following drawbacks.

That is, the leak check device must firstly stop the circulation of the dialysate during the check operation, during which the dialysis is temporarily stopped. For this reason, continuous leak monitoring becomes practically impossible, and has a serious difficulty in treatment safety. Further, the checking device has a drawback that the pressure sensor section is particularly expensive and complicated as a whole.

SUMMARY OF THE INVENTION An object of the present invention is to provide a leak detecting device for a shut-off mechanism in a flow passage which can continuously check for leaks of a liquid and has a versatile and relatively simple structure. .

[0007]

In order to achieve the above object, a leak detecting device for a shut-off mechanism in a flow passage according to the present invention is provided.
A shutoff mechanism for shutting off a handling liquid in the flow path, wherein the handling liquid is used as an electrolyte solution, and a shutoff portion of the shutoff mechanism is formed of an electrical insulating material; Electrodes are provided in the flow paths, and an oscillation circuit and a receiving circuit are connected and arranged to these electrodes, respectively, to constitute a leak detection unit for detecting the leak of the cutoff unit.

In this case, the receiving circuit includes a current-voltage conversion circuit section, an absolute value amplification circuit section, and an integration circuit section, and detects a leak state from the integrated voltage level of the integration circuit section in the cutoff state of the cutoff section. It can be configured as follows.

The shut-off mechanism comprises a shut-off portion of a switch, and a leakage detecting portion is connected to an oscillating circuit and a receiving circuit connected via electrodes provided in an inlet channel and an outlet channel of the switch. It can be composed of a circuit.

As an alternative, the shut-off mechanism comprises a pair of check valves in the reciprocating pump, and a leak detector for each check valve is provided with a suction-side flow path, a pump chamber and a discharge-side flow of the reciprocating pump. A receiving circuit, an oscillating circuit, and a receiving circuit are connected to each other via electrodes provided in the road section, respectively, and each of the leak detecting sections detects leakage of the shut-off section and discharges the reciprocating pump. It can also be configured to detect speed.

[0011]

According to the present invention, the leak detecting section can be constituted by an oscillating circuit and a receiving circuit respectively connected to the electrodes arranged in the upstream flow path and the downstream flow path of the electrically insulating cut-off section. Therefore, if a leak occurs in the shut-off portion, the leak state can be detected electrically, that is, immediately and continuously, by the leak detection portion via the handling liquid composed of the flowing electrolyte solution. .
The leak detecting device configured as described above can detect a leak in the pump chamber and a pump discharge speed at the same time by being appropriately mounted on various reciprocating pumps.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a leak detecting device for a shutoff mechanism in a flow passage according to the present invention will be described in detail with reference to the accompanying drawings. For convenience of description, the same components as those of the conventional structure shown in FIG. 7 are denoted by the same reference numerals, and detailed description is omitted.

First, in the leak detection device for the in-flow path shut-off mechanism of the present invention, the in-flow path shut-off mechanism includes, as described above, for example, the shut-off mechanism relating to the closed circuit 18 of the dialysate circulation system 10 in FIG. That is, it is intended for the switch 16 or various reciprocating pumps. And
As will be understood from the above description, the leak detecting device for these only detects the leak for the switch 16, while detecting both the leak in the pump chamber and the pump discharge speed for the reciprocating pump. Is what you do.

Therefore, as a first embodiment of the present invention,
FIG. 1 shows a leak detecting device according to a switch (for example, a shutoff mechanism for shutting off waste liquid in a waste liquid discharge system flow path 14) 16.
First, in the present embodiment, the handling liquid is made of an electrolyte solution, and the shutoff portion (not shown) of the switch 16 is made of an electric insulating material. Electrodes 30a and 30b are arranged in the inlet (upstream) channel portion 14a and the outlet (downstream) channel portion 14b of the switch 16, respectively. The receiving circuit 34 is connected and arranged. The oscillating circuit 32 and the receiving circuit 34 constitute a leak detecting unit 36 described later in detail. Here, the electrodes 30a and 30b are preferably made of carbon, titanium or the like whose material is strong against deterioration and excellent in stability, and the shape thereof is a ring shape having small pressure loss and excellent attachment. It is suitable. The oscillation frequency and the oscillation waveform of the signal output from the oscillation circuit 32 are preferably set in consideration of the influence of noise on the surroundings.
Set to a sine wave of 1 to 10 KHz.

In the leak detecting section 36 of the switch 16 having the above-described configuration, when the handled liquid flows in the flow path 14, it is output from the oscillation circuit 32 through the handled liquid made of the electrolytic solution. The oscillation signal c as a current value is transmitted to the receiving circuit 34 as a reception signal V as a voltage value. However, in this case, the receiving circuit 34 includes, as shown in FIG.
4a, absolute value amplifying circuit 34b and integrating circuit 34c
Therefore, as shown in FIG. 3, the reception signal V is obtained by converting an oscillation signal c as a current value into a voltage value through a current-voltage conversion circuit unit 34a and an absolute value amplification circuit unit 34b. After the conversion into the sine waveform signal V ′ and the amplified waveform signal V ″ of the absolute value.
It is configured to be converted into an integral waveform signal V as a voltage value at c. The signal V as a voltage value
The magnitude of (V ′, V ″) increases according to the magnitude of the conductivity of the electrolyte aqueous solution that is the handling liquid.

In this switch 16, when the shut-off portion operates normally and the flow path 14 is completely closed, that is, when the flow of the electrolyte aqueous solution as the handling liquid is completely cut off, the oscillation signal c Transmission is completely shut off. Accordingly, the reception signal V ₁ at the time of the interruption in the leak detection unit 36 is obtained.
As shown in FIG. 4, its size is set substantially to the voltage level V ₁ of the 0. The reception signal V ₂ in the figure, the voltage level V ₂ in the open state of the switch (Deadline unit) 16
Is shown. However, here, when the switch 16 is not completely closed even in the closed state, that is, when the handling liquid is leaking, the oscillation signal c is transmitted, albeit slightly. Thus, the received signal V ₃ at this time, the blocking reception signal V ₁ slightly larger than the voltage level (V ₁ + Δ
V). Therefore, by checking the increase voltage level ΔV in the leakage received signal V _3, it is possible to detect the leakage state of the switch 16.

As described above, according to the present invention, since the leakage of the switch (the shutoff mechanism in the flow passage) can be electrically detected, the dialysis is performed in a closed circuit for circulating the dialysate in a dialysis device, for example. The liquid leakage can be monitored continuously and easily without interrupting the dialysis operation. Therefore, the effect and safety of the dialysis treatment can be improved. Further, the device of the present invention has an advantage that it can be constructed relatively simply and inexpensively.

FIG. 5 shows, as a second embodiment of the present invention, a leak detecting device of a reciprocating motion metering pump P (for example, a water removal pump provided in a water removal system). In this embodiment, the suction-side check valve 4 that opens and closes at a predetermined cycle ΔT (see FIG. 6) in the pump chamber 50 of the reciprocating pump P.
0a and the discharge side check valve 40b, and the period ΔT (pump speed) itself is simultaneously detected.

First, also in this embodiment, the handling liquid is composed of an electrolyte solution, and the check valves 40a and 40b (cutoff portions) are made of an electrically insulating material, as in the previous embodiment. And, both check valves 40
a, 40b with respect to the upstream side and the downstream side, that is, the suction side flow path portion 18 of the reciprocating pump P.
a, 30c, and 30b are disposed in the pump chamber 50 and the discharge-side channel portion 18b, respectively.
0a, 30c, and 30b, the receiving circuit 42,
The oscillation circuit 44 and the reception circuit 46 are connected and arranged. The receiving circuit 42 and the oscillating circuit 44 constitute a leak detecting unit 48 for the check valve 40a, and the oscillating circuit 44 and the receiving circuit 46 constitute a leak detecting unit 49 for the check valve 40b.

However, the respective leak detecting sections 48 and 49 configured as described above are provided with the respective receiving circuits 42 and 46.
The received signal V corresponding to the oscillation signal c of the oscillation circuit 44 is synchronized with the operation of the reciprocating pump P, that is, the operation of the check valves 40a and 40b at the predetermined period ΔT.
a and Vb are transmitted respectively. That is, in FIG.
The voltage waveforms of these two reception signals Va and Vb are shown, respectively. Since these voltage waveforms are of the same type, only the reception signal Va on the suction side will be described below.

[0021] That is, the voltage level V _a1 relating the received signals _{Va, V a3 = (V a1} + ΔV a), V a2 , at the time of blocking respectively, leakage, shows each received voltage level at the time of release. Therefore, the leakage reception voltage level _Va3 = ( _Va1 +
By checking the increased voltage level ΔV _a at ΔV _a ), a leak condition at the check valve 40a can be detected, and alternatively, by checking the period ΔT, the pump speed can be detected. That is, the quantitativeness of the pump (the occurrence of a pump failure) can be monitored.

As described above, according to the present invention, for example, in the dialysate circulating system 10 and the water removing system shown in FIG. By installing a detection device, the circulation system 1
It is possible to continuously monitor the leakage and the quantitativeness of the dialysate or the like in the zero or water removal system without interrupting the dialysis operation. Thereby, the effect and safety of the dialysis treatment can be further improved.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and many design changes can be made without departing from the spirit of the present invention.

[0024]

As described above, the leak detection device for the shut-off mechanism in the flow passage according to the present invention comprises a shut-off mechanism for shutting off the handling liquid in the flow passage. The cut-off portion of the cut-off mechanism is made of an electrically insulating material, and electrodes are disposed in an upstream flow path and a downstream flow path near the cut-off portion, respectively, and an oscillation circuit and a reception circuit are connected to these electrodes, respectively. By arranging and configuring a leak detection unit that detects leakage of the cut-off portion, leakage at the cut-off portion can be electrically detected through a handling liquid composed of an electrolyte solution flowing due to the leak, Leakage from the cut-off portion can be easily and continuously detected without stopping the flow of the liquid handled in the flow path.

Therefore, according to the present invention, for example, in a closed circuit of the dialysis fluid circulation system in the dialysis device, it is possible to continuously monitor the leakage of the dialysis fluid without interrupting the dialysis operation. In addition, the effect and safety of the dialysis treatment can be significantly improved.

The leak detecting device according to the present invention can be applied to, for example, a reciprocating pump, and can be widely used as a quantitative monitoring means of the reciprocating pump. The effect contributing to the improvement of performance is extremely large.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a leak detection device for a shutoff mechanism in a flow passage according to the present invention.

FIG. 2 is a system diagram showing a receiving circuit of the leakage detection device shown in FIG.

3A and 3B respectively show received signals in the receiving circuit shown in FIG. 2, wherein FIG. 3A is a voltage waveform diagram of a current-voltage conversion circuit unit, FIG. 3B is a voltage waveform diagram of an absolute value amplification circuit unit,
(C) is a voltage waveform diagram of the integration circuit section.

FIG. 4 is a voltage waveform diagram showing a reception signal of the integration circuit section shown in FIG. 3 in further detail.

FIG. 5 is a schematic configuration diagram showing another embodiment of the leakage detection device of the in-flow-path shutoff mechanism according to the present invention.

6A and 6B show reception signals in the integration circuit section of the reception circuit shown in FIG. 5, respectively, wherein FIG. 6A is a voltage waveform diagram on a suction side, and FIG. 6B is a voltage waveform diagram on a discharge side.

FIG. 7 is a system diagram showing a dialysate circulation system and a blood circulation system of the dialyzer.

[Explanation of symbols]

 Reference Signs List 14 flow path 14a inlet flow path section 14b outlet flow path section 16 switch 18 closed circuit 18a suction side flow path section 18b discharge side flow path section 20 reciprocating pump 30a, 30b, 30c electrode 32 oscillation circuit 34 reception circuit 34a current -Voltage conversion circuit section 34b Absolute value amplification circuit section 34c Integrating circuit section 36 Leakage detection section 40a Suction side check valve 40b Discharge side check valve 42, 46 Receiving circuit 44 Oscillation circuit 48, 49 Leakage detection section 50 Pump room P Reciprocating motion quantitative pump

────────────────────────────────────────────────── (5) References JP-A-60-192235 (JP, A) JP-A-61-234327 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01M 3/04 G01M 3/18

Claims (4)

(57) [Claims] 1. A shutoff mechanism for shutting off a handling liquid in a flow path, wherein the handling liquid is an electrolyte solution, a shutoff portion of the shutoff mechanism is made of an electric insulating material, and an upstream side near the shutoff portion is provided. An electrode is disposed in each of the flow path and the downstream flow path, and an oscillation circuit and a reception circuit are connected and arranged to these electrodes, respectively, to constitute a leakage detection unit that detects leakage of the cutoff unit. Leak detection device of the shut-off mechanism in the flow path. 2. A receiving circuit comprising a current-voltage converting circuit, an absolute value amplifying circuit, and an integrating circuit, wherein a leakage state is detected from an integrated voltage level of the integrating circuit in a closed state of the closing section. The leak detecting device for a shut-off mechanism in a flow path according to claim 1, wherein the leak detecting device is configured as follows. 3. A shut-off mechanism comprising a shut-off portion of a switch, an oscillation circuit connected to a leak detecting portion via electrodes provided in an inlet channel and an outlet channel of the switch, and a receiving circuit. 2. The leak detecting device for a shut-off mechanism in a flow path according to claim 1, wherein said leak detecting device comprises a circuit. 4. A shut-off mechanism comprising a pair of check valves in a reciprocating motion metering pump, wherein a leak detecting unit for each check valve is provided on a suction side flow path portion, a pump chamber, and a discharge side flow channel of the reciprocating motion metering pump. A receiving circuit, an oscillating circuit, and a receiving circuit are connected to each other through electrodes provided on the respective sections, and each of the leak detecting sections detects leakage of the cut-off section, and discharge speed of the reciprocating motion metering pump. 2. The leak detecting device for a shut-off mechanism in a flow path according to claim 1, wherein the leak detecting device is configured to detect the leakage.