JPS606688B2 - Liquid dilution method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid dilution method and device for diluting various liquid samples for the purpose of reducing the impact on the human body, especially when analyzing liquids with strong radioactivity or harmful liquids. It is.

Conventionally, when diluting a liquid by automatic means without manual intervention, the method of measuring the liquid to be diluted using a flow meter, etc., and mixing the measured diluent into the liquid to be diluted, or using two metering pumps. A method of mixing both liquids is known.

In this type of conventional liquid dilution method, the dilution ratio is 2
Although it is possible to change the steepness up to 1 to 1, it is impossible to change the dilution ratio as drastically as 10 to 1. Nowadays, when handling liquid samples containing radioactivity, etc., it is desired that the dilution ratio can be changed significantly depending on the strength of the radioactivity, etc.

Therefore, the inventor of the present invention has developed a liquid dilution method and device that can satisfy the above-mentioned demands.As a result of various studies,
A plurality of two-liquid liquid feeding means and a mixing means each consisting of a two-liquid metering pump or the like are provided, and the liquid to be diluted is sequentially delivered to one liquid supply side of each two-liquid liquid feeding means in series in multiple stages via the mixing means. By supplying the diluted liquid in parallel to the other liquid supply side of each of the two-liquid feeding means and controlling the number of driving stages of each of the two-liquid feeding means, the final drive stage of the two-liquid feeding It has been found that the dilution ratio of the liquid to be diluted obtained from the means and the mixing means can be significantly changed.

Accordingly, a general object of the present invention is to provide a method and apparatus for diluting a liquid that can significantly change the dilution ratio of the liquid by combining two liquid feeding and mixing means in multiple stages.

The main object of the present invention is to provide a plurality of combinations of two-liquid liquid feeding means and a plurality of mixing means, and supply the liquid to be diluted to one supply side of the first two-liquid liquid feeding means, and pass the liquid to the next two liquid feeding means through the mixing means. The diluted liquid is supplied to one supply side of the two-liquid feeding means in a stepwise manner, and the diluted liquid is simultaneously and parallelly fed to the other supply side of each two-liquid feeding means, so that the number of uses of the two-liquid feeding means is controlled. An object of the present invention is to provide a liquid dilution method characterized in that the dilution ratio can be made variable by selection.

In the liquid dilution method described above, a discharge pipe is led out for each two-liquid liquid feeding means and mixing means, and these are passed through the drain pipe, and a branch pipe is led out from a part of the discharge pipe, and this is connected to the following two liquid dilution methods. It is preferable to construct the system so that a part of the diluted liquid is sequentially mixed and diluted by passing a tube through one supply side of the liquid feeding means.

Further, by fixing the discharge capacity of one of the two-liquid feeding means and making the discharge capacity of the other variable, the dilution ratio can be arbitrarily set.

When carrying out the above method, a plurality of two-liquid feeding means and a plurality of mixing means are each provided, and the liquid to be diluted pipe is connected to one of the two-liquid feeding parts, and the diluted liquid piping is connected to the other liquid feeding part. The liquid pipes are conveyed, and both liquid sending parts of these two-liquid liquid sending means are connected to the mixing means, and the discharge pipe led out from the mixing means is connected to the drain pipe, and a branch pipe is led out from a part of the discharge pipe. This is then passed step by step through each one of the liquid sending parts of the two-liquid liquid feeding means, and a reservoir is provided in a part of the discharge pipe, and a sample collection tube is led out from each reservoir. This can be achieved by providing and configuring a controller that selectively drives and controls.

In this case, a two-lot type positive displacement pump or a two-lot type reciprocating metering pump can be suitably used as the two-liquid feeding means.

Further, a reservoir may be provided in each part of the discharge tube, and a sample collection tube may be led out from each reservoir to enable sampling of the diluted liquid at each dilution ratio. Furthermore, the matching means can be constructed by matching a pressure valve and a static mixer. Next, the liquid dilution method according to the present invention will be described in detail below in relation to the apparatus for implementing this method. FIG. 1 is a system diagram showing an example of an apparatus for carrying out the method of the present invention, in which reference numeral 10 denotes a diluent storage tank;
Warehouse 2 is a diluted liquid storage tank, 14a, 14b...14M
Two lotus-type positive displacement pumps are shown as liquid feeding means.

In addition, these two lotus type positive displacement pumps 14a, 14b...14
n may be one that operates the two pump chambers 18, 20 at the same time using a common motor-driven rotation mechanism 16 as a drive source, and the structures of the pump chambers 18, 20 are not particularly limited. In this embodiment, the piping 24 led out from the diluent storage tank 10 via the outlet valve 22 is fitted into one pump chamber 18 of the first double-displacement pump 14a. Further, the piping 28 led out from the diluent storage tank 12 via the outlet valve 26 is connected to the first two-lot type positive displacement pump 14.
A lotus is applied to the other pump chamber 20 of a. In this way,
The liquid to be diluted and the liquid to be diluted in the pump chambers 18 and 2 of the pump 14a are discharged by the pump action in the pump chambers 18 and 20, and then join the discharge pipe 30a to serve as a mixing means. The mixture is diluted via a pressurizing valve 32 and a static mixer 34. Note that the discharge pipe 30a is connected to a drain pipe 36. In this case, the discharge pipe 30a is connected to a drain pipe 36.
A branch pipe 38a is led out from a part of a, and this branch pipe 38
a is conveyed to one pump chamber 18 of the second two-select displacement pump 14b. Further, the other pump chamber 20 of the second two-lot type positive displacement pump 14b is connected to the diluent storage tank 1.
The piping 28 derived from 2 and the lotus are suitable. The liquid discharged from each pump chamber 18, 20 of the second two-way displacement pump 14b connected and arranged in this manner is also discharged from the discharge pipe 30b in the same manner as in the first two-way displacement pump 14a. and is mixed and diluted via a pressurizing valve 32 and a static mixer 34. The discharge pipe 30b is connected to a drain pipe 36. Further, a branch pipe 38b is led out from a part of the discharge pipe 30b, and is connected to the third two-lotus positive displacement pump 14c in the same manner as described above. As mentioned above, the liquid to be diluted is supplied to the first two-select positive displacement pump 14.
a, the second two-lot type positive displacement pump 14b, ...... The diluted liquid is sequentially supplied in multiple stages to the second two-lot type positive displacement pump 14n, and the diluent is supplied to each two-lot type positive displacement pump 14a, 14b・
... 14n in parallel at the same Z time. In addition, each of the two lotus-type positive displacement pumps 14a, 14b...
. . 14n, each motor drive rotation mechanism 16 is configured to be provided with a controller 40 as appropriate to centralize the control system and to be able to control each one individually. Further, reservoirs 42a, 42b...42n are provided as appropriate in a part of the discharge pipes 30a, 30b...30n led out from each of the two lotus-type passenger Z displacement pumps 14a, 14b...14n. Sample collection tubes 44a, 44b...44n are led out from these reservoirs 42a, 42b...42n, respectively, and these tubes correspond to each sample receiver 48 provided collectively in the sink 46 of the sample collection room. Each sample is then piped through a sampling valve 50. Note that these reservoirs 42a, 42b...
- 42n is provided as a damper in each of the discharge pipes 30a, 30b, . Therefore, the capacity of these reservoirs 42a, 42b...42n is
One stroke at most is sufficient. Next, the operation of the liquid diluting device configured as described above will be explained.

The liquid to be diluted and the diluted liquid are supplied by the first two lotus type positive displacement pump 14.
The liquid is sent through a, and mixed and diluted through a pressurizing valve 32 and a static mixer 34. In this case, the double lotus displacement pump 14a fixes the discharge amount of one pump chamber 18 or 20, and changes the mixing ratio of the other pump chamber 20 or 18 as appropriate by variable adjustment of the stroke length. It is preferable to configure it so that it can be set. In this way, a part of the liquid mixed and diluted at a predetermined ratio via the first two-select positive displacement pump 14a is transferred to the branch pipe 38a.
is supplied to the second double-displacement pump 14b, and the remainder is discharged via the Doreso piping 36. Also"
A portion of the diluent liquid led out to the Doreso piping 36 is stored in the IJ reservoir 42a, and can be sampled via the sample collection tube 44a. Second double lotus positive displacement pump 1
4b as well, it is possible to further mix and dilute the mixture at a predetermined ratio in the same way as the first double-displacement pump 14a described above. Thereafter, in the same manner, stepwise dilution of the liquid can be achieved using the third and subsequent double-displacement pumps 14a. Therefore, in this embodiment, if the pump discharge capacity of the liquid to be diluted is set as acc'min and the pump discharge capacity of the diluted liquid is set as bcc'min, then the following equation holds true.

a-b; ax '1' (
(where x is the dilution magnification) Therefore, based on the above formula '1), the dilution magnification on the pump discharge side for each stage is as shown in the following formula.

Dilution ratio a+b in the first pump -...【4} an In addition, if the pump discharge capacity of the liquid to be diluted is fixed at acc/min, and the pump discharge capacity of the diluted liquid is made variable for each stage, the pump discharge side of each stage will be The dilution ratio can be arbitrarily selected, and it goes without saying that the dilution ratio for each stage can be varied in various ways.

Therefore, for example, the pump discharge capacity of the liquid to be diluted should be set to 5cc'm.
in, and the pump discharge capacity of the diluted liquid is 10 cc/min.
The dilution ratio on the pump discharge side for each stage when four double-lotus positive displacement pumps are used is as shown in the above ■ to [4}
Based on the formula:

In this way, according to the present invention, dilution of the liquid can be achieved at a desired dilution ratio by using an arbitrary number of the first to n-th two lotus positive displacement pumps. In this case, the mixing means corresponding to each double-displacement pump is provided with a pressure valve (back pressure valve) 32 whose pressure is set lower than the pump discharge pressure and higher than the outlet pressure of the drain pipe 36, so that The liquid to be diluted does not flow into the side of the two-lot positive displacement pump via the branch pipe 38.Furthermore, in the present invention, each discharge pipe 30' of each two-lot positive displacement pump 4 is Since the reservoir 42 is provided also as a damper, there is no particular problem even if the phase of the pump at each stage is affected. FIG. 2 shows another embodiment of the apparatus for carrying out the method of the present invention.

In other words, "In this example," as a two-liquid feeding means,
Two lotus type reciprocating metering pumps 4a and 14b are used. In this case, the pistons 52 and 54, which are compatible with the cylinders constituting the pair of pump chambers 8a and 20a, can be controlled by a common motor drive rotation mechanism 16, respectively. Moreover, the discharge capacity in each pump chamber 18a, 20a can be made variable by appropriately changing the stroke length of the piston hubs 2, 54. Furthermore, each pump chamber turtle 8
8. Corresponding to 2Qa, a suction check valve 66 and a discharge check valve 58 are provided on the supply side and discharge side of the liquid to be diluted and the diluted liquid, respectively. Dilution of the liquid can be achieved in exactly the same way as in the example shown.

As is clear from the embodiments described above, according to the present invention,
It has a simple configuration, high accuracy, and allows the dilution ratio to be changed significantly.

In particular, the dilution ratio can be arbitrarily set by varying the discharge capacity ratio of each two-liquid feeding means or by selecting the number of two-liquid feeding means to be used. In this case, it is preferable to keep the discharge capacity ratio of each two-liquid feeding means constant and to vary only the number of units used, since this allows the control system to have a simple configuration. In addition, as the two-liquid feeding means, the aforementioned reciprocating metering pump and the vane-type rotary pump as a positive displacement pump are suitable, but ``other methods include controlling the solenoid valve with a single-touch actuated tandem-type piston device. Automatic measuring devices such as measuring bottles can also be used.

Although the preferred embodiments of the present invention have been described above, it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[Brief Description of the Drawings] Figure 1 is a general system diagram of an apparatus for carrying out the liquid dilution method according to the present invention; Figure 2 is an apparatus showing an embodiment in which a reciprocating metering pump is used as a liquid feeding pump. This is a system diagram of the main parts. 10... Diluted liquid storage tank, 2... Diluted liquid storage tank, corner 4... Two lotus type positive displacement pump, 16... Moyu Drive rotation mechanism, turtle 8, 28...Pump chamber "22.
... Outlet valve 18a, 20a ... Reciprocating metering pump, 24 ... Piping, 26 ... Outlet valve, 28.
... Piping, 30 ... Discharge pipe, 32 ... Pressure valve 34 ... Static mixer, 36 ... Drain pipe, 38 ... Branch pipe, 40 ... Re-controller ~ 4
2...Reservoir, turtle 4...Sample collection tube, 46...
...Sink, 48...Sample receiver, 50...Sample collection valve L 52, 54...Piston 56...
・...Suction check valve, 58...Discharge check valve. FIG.
．． IFIG. 2

Claims (1)

[Scope of Claims] 1. A plurality of two-liquid feeding means and a plurality of mixing means are provided, and the liquid to be diluted is supplied to one supply side of the first two-liquid feeding means, and the next liquid is fed through the mixing means. The diluent is supplied to one supply side of the two-liquid liquid feeding means in a stepwise manner, and the diluted liquid is simultaneously and parallelly fed to the other supply side of each two-liquid liquid feeding means, and the number of times the two-liquid liquid feeding means is used is A liquid dilution method characterized by making the dilution ratio variable by selecting. 2. Lead out a discharge pipe for each two-liquid liquid feeding means and mixing means, connect these to the drain pipe, lead out a branch pipe from a part of the discharge pipe, and connect it to one of the next two-liquid liquid feeding means. 2. The liquid dilution method according to claim 1, which comprises sequentially mixing and diluting a portion of the mixed diluent by communicating with the supply side of the liquid diluent. 3. The liquid dilution method according to claim 1 or 2, wherein the discharge capacity of one of the two liquid feeding means is fixed and the discharge capacity of the other is variable. 4 A plurality of two-liquid feeding means and a plurality of mixing means are each provided, one of the liquid feeding parts of the two-liquid feeding means is connected to the diluent liquid piping, and the other liquid feeding part is connected to the diluted liquid piping. Both liquid feeding parts of the liquid feeding means are connected to the mixing means, and a discharge pipe led out from the mixing means is connected to the drain pipe, and a branch pipe is led out from a part of the discharge pipe to sequentially feed two liquids. Control that communicates with the liquid feeding section of each one of the means in stages, provides a reservoir in a part of the discharge pipe, leads out a sample collection tube from each reservoir, and selectively drives and controls the two-liquid liquid feeding means. A liquid diluting device characterized by being provided with a container. 5. The liquid diluting device according to claim 4, wherein the two-liquid feeding means comprises a double-displacement pump. 6. The liquid diluting device according to claim 4, wherein the two-liquid feeding means comprises a dual reciprocating metering pump. 7. The liquid according to claim 5 or 6, wherein a reservoir is provided in each part of the discharge pipe, and a sample collection tube is led out from each reservoir, so that the diluted liquid can be collected at each dilution ratio. dilution device. 8. The liquid diluting device according to any one of claims 4 to 7, wherein the mixing means includes a pressure valve and a static mixer.