JP2015071450A - Liquid feeding device for small capacity liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of feeding small capacity liquid with constant flow without a drive mechanism and without a pulsating flow.SOLUTION: A method comprises the steps of: pressing one or a plurality of inner containers at constant pressure in an outer container having sealing performance; and discharging liquid in the one or the plurality of inner containers to the outside of the outer container through one or a plurality of conduits penetrating from the inner container to the outer container.

Description

  The present invention relates to a small volume liquid feeding device.

Many liquid feeding devices are used, but the flow rate range is wide, the liquid feeding principles are wide-ranging, and even an overview is not easy. However, since the present invention focuses on a small capacity, no pulsating flow, no driving mechanism, and a constant flow rate, from this point of view, the problems of the prior art will be briefly cited.
As a liquid feeding method of the non-drive mechanism, a method using gravity or air pressure can be considered. When gravity is used, the difference between the liquid level of the liquid to be supplied and the pressure difference between the discharge ports is used. However, there is a problem that the flow rate decreases when the liquid level decreases with the liquid supply.
A method of pressurizing a container containing a liquid to be fed with air is also used. In that case, it is necessary to secure the pressure resistance of the container and to take safety measures. In addition, if the pressure of the air to be pressurized fluctuates, the discharge flow rate fluctuates, so it can be said that the needs for emphasizing constant flow rate cannot be met as it is.

  There is a method of pushing the piston of the syringe barrel from the viewpoint of realizing a non-pulsating flow excluding the condition of the non-driving mechanism. If the speed at which the piston is pressed is constant, non-pulsating constant flow rate liquid feeding is possible. However, for that purpose, the precise mechanical accuracy of the drive mechanism is required.

  In many cases, in a liquid delivery device having a mechanical drive unit, a pulsating flow is generated, which adversely affects measurement in the analytical chemistry field. In addition, the gravity-based liquid delivery device has the disadvantages that the flow rate decreases as the liquid level decreases and the discharge pressure is small. Furthermore, the liquid feeding device that pushes the piston of the syringe barrel has a problem that a precise drive mechanism is required.

  One or more inner containers in a sealed outer container are pressurized with a pressurized medium at a constant pressure, and one or more through one or more conduits that penetrate the outer container from the inner container. When the liquid in the plurality of inner containers is discharged to the outside of the outer container, a constant flow rate liquid feeding device that does not have a pulsating flow and does not require a driving mechanism can be realized, and the problem can be solved. The inner container does not need to have a sealing property, but when the inner container has a variable volume, it can be sealed to prevent contact with the pressurized medium.

When the inside of the outer container having airtightness is pressurized, in the case of the inner container having no airtightness, the liquid in the inner container is also pressurized. When the conduit is immersed therein, the liquid in the inner container is discharged from the conduit at the same pressure. On the other hand, when the inner container has sealing properties and volume variability, the volume of the inner container decreases, and the liquid inside is discharged to the outside through a conduit.
The inner container can reduce the contamination from the inside of the outer container by isolating the liquid to be sent from the pressurized medium, and if multiple inner containers are installed, the liquid can be fed simultaneously while preventing mutual contamination. It becomes possible. In addition, since it is not necessary to consider pressure resistance for the inner container that is not sealed, it is possible to select a material that is highly compatible with the liquid to be fed.
Furthermore, if a pressure adjusting mechanism is added to the outer container, the pressure applied to the liquid to be delivered becomes constant, so that pulsating flow can be prevented and the stability of the discharge flow rate is increased.
Further, if the inner container is sealed, contact between the pressurized medium and the liquid to be fed can be prevented, so that the probability of contamination is further reduced.

As the outer container, a resin or glass wide-mouth bottle with a pressure-resistant and sealed lid is used, a hole for allowing the conduit to pass through the lid, a hole for introducing a pressurized medium, and pressure adjustment Make a hole to connect the vessel. Each hole is fitted with a joint that provides a tight seal.
The inner container can be of any shape and material as long as it can be installed in the outer container. If not sealed, it is necessary that the conduit can be immersed in the liquid. When sealing, the necessity of immersion of a conduit changes with shapes and installation methods. When the entire inner container is filled with liquid or when the conduit is attached downward, it is not necessary to insert the conduit into the inner container and immerse it.
Further, there is no particular limitation on the method for realizing volume variability. It can be a syringe or a flexible container. The material of the syringe can be made of glass or resin. The material of the flexible container can be vinyl chloride or low density polyethylene, and is not limited.
The pressurizing medium can be air or water. When air is used, it is supplied inside the outer container with an air pump. And the pressure inside an outer side container is kept constant by a pressure regulator. When employing water, it is necessary to seal the inner container in order to prevent contact with the liquid to be delivered. The water pressure is adjusted with a pressure regulator.
Although there is no restriction | limiting in the system of a pressure regulator, In the simple thing, the system of interrupting | blocking a flexible flow path with a spring is also possible. That is, when the pressure of the pressurizing medium becomes larger than the shut-off pressure by the spring, the flow path is opened and an excessive pressurizing medium is discharged to the outside. If the pressure decreases, the pressure of the pressurized medium increases because the flow path of the blocking portion is narrowed or blocked. This keeps the pressure within a certain range.
In addition, when the pressure resistance performance of the pump that supplies the pressurized medium is low, there is an outflow from the pump, and the above-described pressure adjustment mechanism can be dispensed with.

Example 1 As an outer container, a cylindrical glass bottle having a diameter of 9 cm and a height of 18 cm was adopted. The lid was made of resin, connected to a glass bottle with a screw, and provided with a sealing property by sandwiching a sealing material. Further, a protective film for preventing impact was wound around the outside of the glass bottle. The lid was drilled with a conduit, a pressurizing tube, and a pressure adjusting hole. In order to give each hole a sealing property, a through connector for a panel was used.
A resin wide-mouth bottle was adopted as the inner container, and a hole for a conduit was made in the lid. The through hole connector for the panel was used for the seal of the hole. The conduit is a PFA tube (inner diameter: 2 mm, outer diameter: 3 mm) and has a length that reaches from the vicinity of the bottom surface of the inner container to the outside through the inner container lid and the outer container lid. The end portion can be connected to a liquid feeding purpose system such as an external device.
The pressurization was carried out by using an air pump to send air into the outer container with a PFA tube (inner diameter 2 mm, outer diameter 3 mm). As the pressure regulator, a bleed-type commercial product was used.

  Method of using Example 1: The liquid to be fed was placed inside the inner container, the lid with the conduit was tightened, it was placed inside the outer container, and the outer container lid was tightened and sealed. The air pump was activated and air was sent to the outer container. After that, when the pressure was set with the pressure regulator, the pressure inside the outer container increased, the pressure inside the inner container that was not sealed up also increased, and the discharge of the liquid-sending target was started. The flow rate can be adjusted by changing the air flow rate or changing the pressure with a pressure regulator. Liquid feeding was possible at a constant flow rate until the liquid in the inner container was almost empty.

  Example 2: A syringe barrel was adopted as the inner container. The configuration and usage are the same as in Example 1, but when the pressure inside the outer container increased, the syringe barrel piston was pushed in and liquid feeding was started. When the syringe barrel was adopted, it was easy to prevent contamination, and it was easy to set a plurality of syringe barrels. In this case, the conduit was connected to the outlet of each syringe barrel.

  Example 3: A low density polyethylene container was used as the inner container. The lid of the inner container was sealed. Other components and the usage method are the same as those in the first embodiment.

It is Example 1 of this invention. It is Example 2 of this invention.

DESCRIPTION OF SYMBOLS 1 Outer container 2 Outer container lid 3 Inner container 4 Conduit 5 Pressurization medium inlet 6 Pressure regulator

Claims (4)

  One or more inner containers in a sealed outer container are pressurized and through one or more conduits that penetrate the outer container from the inner container. A liquid delivery device that discharges liquid to the outside of the outer container.   The liquid feeding device according to claim 1, wherein the inner container is sealable and has volume variability.   The liquid feeding device according to claim 1 or 2, wherein air or water is supplied into the outer container as a pressurizing method.   The liquid feeding device according to claim 1, claim 2, or claim 3 having a mechanism for adjusting the pressure of air or water in the outer container.

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