Liquid purification or separation – Processes – Liquid/liquid solvent or colloidal extraction or diffusing...
Reexamination Certificate
2002-05-31
2004-12-28
Drodge, Joseph (Department: 1723)
Liquid purification or separation
Processes
Liquid/liquid solvent or colloidal extraction or diffusing...
C137S833000, C204S450000, C204S600000, C210S511000, C422S069000, C436S178000
Reexamination Certificate
active
06835313
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an extracting method, an extracting apparatus, a separating method and a separating apparatus. The invention relates to a technique for selectively extracting an object contained in a liquid.
2. Description of the Related Art
In recent years, dioxin or the like generated from garbage incinerators and the like is recognized as serious environmental problem, and it is an important problem to measure and manage a discharge density of the dioxin. Currently, a method of measuring a density of the dioxin or the like is defined by Japanese Industrial Standards (JIS).
In the case where the dioxin or the like is measured, in order to extract the dioxin contained in water, similarly to a conventional solvent extracting method, water and an organic solvent are put into a separating funnel or the like and are shaken to be mixed, the dioxin in the water is incorporated into the organic solvent and only the organic solvent is extracted so as to be separated from the water.
However, this method requires a lot of solvent, long time and a lot of costs.
Recently, an attention is paid to &mgr;-TAS (&mgr;-Total Analysis System) which refines chemical analysis and synthesizing apparatuses and chemical analysis and synthesizing methods using a micromachine technique. The &mgr;-TAS, which is refined more finely as compared with conventional apparatuses, has the merits such that an amount of samples is small, reacting time is short and an amount of refuse is small. In the case where the &mgr;-TAS is adapted to the environment measuring field or the like, it has the merits that usage of reagent and organic solvent is small and reacting time (measuring time) is short, and further since an apparatus is small, the measurement can be made on the ground, so that the immediacy of an inspection is expected to be improved.
However, conventionally a technique for extracting a solvent using a micro fluid system to which the micromachine technique is applied has not been found.
For example, in a very narrow channel having a width of several dozen to several hundred &mgr;m, the viscosity of a liquid is dominant, and it is difficult to stir and mix liquids. For this reason, in order to incorporate the dioxin contained in the water into the organic solvent, it is inefficient to stir water and organic solvent in a channel.
In addition, it is desirable that only an organic solvent is extracted from a small amount of mixed water and organic solvent in a microarea and to separate it from the water.
SUMMARY OF THE INVENTION
Therefore, a first technical problem to be solved by the invention is to provide an extracting method, an extracting apparatus and a chip for the extracting apparatus which incorporate a substance contained in a first liquid into a second liquid efficiently in a microarea.
In addition, a second technical problem to be solved by the present invention suggests a separating method, a separating apparatus and a chip for the separating apparatus which separate a second liquid from mixed first liquid and second liquid in a microarea.
In order to solve the first technical problem, the present invention provides an extracting method which is basically characterized in that a layered first liquid and a layered second liquid come in contact with each other, and a substance in a first laminar flow of the first liquid is moved into a second laminar flow of the second liquid. More concretely, the following extracting method is provided.
The extracting method is to incorporate the substance contained in the first liquid into the second liquid so as to extract the substance. This extracting method has the first step and the second step. In the first step, the first liquid and the second liquid are transferred into a channel so as to alternately come in contact with each other respectively in not less than one or two laminar state, and the substance in the first laminar flow of the first liquid is moved to the second laminar flow of the second liquid. In the second step, the second liquid is separated from the first liquid in a lower stream side of the channel.
In the first step, the first fluid and the second fluid are allowed to flow into the channel with a very small width so as to be in the laminar state. When two or more first laminar flows and the second laminar flows exist, the first laminar flows and the second laminar flows are arranged alternately so as to come in contact with each other.
Generally the substance in the liquid diffuses voluntarily. Namely, molecules of a medium (liquid) continually collide with small matters (particles of the substance) in the medium, and the small matters move irregularly in the medium. Due to this Brownian movement, the small matters diffuse in the medium. A relative interfacial area of the liquid becomes large in the microarea (namely, a surface area becomes wider as compared with a volume), and the diffusion speed becomes abruptly high. For this reason, the particles of the substance in the first laminar flow move to the second laminar flow quickly. Namely, the particles are incorporated into the second liquid. In this case, it is preferable that the particles of the substance return with difficulty from the second laminar flow to the first laminar flow, and for example, it is preferable that the substance is easily incorporated into the second liquid easier than into the first liquid. When the substance is dioxin or the like, the first fluid can be water and the second fluid can be an organic solvent. Moreover, in order to diffuse it efficiently, it is preferable that a flow velocity of the first laminar flow is equal with a flow velocity of the second laminar flow and the flow velocities do not relatively differ.
According to the above method, the flow of the laminar flow and the particle diffusion phenomenon in the channel are used, so that the substance contained in the first liquid can be incorporated into the second liquid efficiently in the microarea.
In the first step, even if the liquids are sequentially transferred, the liquids may be stopped in the middle of the channel.
In the second step, only the second liquid is collected, so that the substance contained in the first liquid can be extracted.
Preferably at the first step, a width of one laminar flow is not more than 50 &mgr;m. When the width is not more than 50 &mgr;m, a Reynolds number becomes small, and the liquid is easily transferred in the channel in the laminar state.
The second step can collect only the second liquid in the following various forms.
Preferably, the second step includes a channel branching step. In the channel branching step, in the lower stream side of the channel, the first laminar flow is allowed to flow into a first branch channel, and the second laminar flow is allowed to flow in a second branch channel. In this case, the channels is branched for each liquid in the laminar state, so that the second liquid can be separated from the first liquid easily.
Preferably, the second step includes a charging step. In the charging step, a vicinity of an inlet of the first branch channel or the second branch channel is charged. Polarity is provided to the first liquid or the second liquid and the other liquid has no polarity by the charging step, one liquid having a polarity is activated so as to enter the charged first branch channel or second branch channel, and thus the liquids can be separated more efficiently. For example, nonpolar molecules such as petroleum ether, carbon tetrachloride, benzene, xylene, nitrobenzene and iodine can be separated from water having polarity. As for a mixed liquid composed of three or more liquids, in the case where only one liquid has polarity or where only one liquid is nonpolar, the one liquid can be separated from the other liquids.
In addition, the present invention provides the following separating method in order to solve the second technical problem.
The separating method separates a second liquid from mixed first liquid and second liquid. The separating method h
Fujii Yasuhisa
Hayamizu Shunichi
Sando Yasuhiro
Yamamoto Koji
Drodge Joseph
Minolta Co. , Ltd.
Sidley Austin Brown & Wood LLP
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