Separator

Abstract

A separator separates a first from a second phase of a liquid in a tubular container. The separator has a float made of elastic material having a circumferential sealing edge and at least one ballast fastened to the underside of the float. The density of the ballast is greater than the density of the float and the density of the entire separator lies in a value range between the density of the first phase and the density of the second phase of the liquid. In order to securely prevent penetration of parts of the second phase of the liquid into the region above the separator within the tubular container, when the separator moves into the sealing position and is positioned there, the sealing edge of the float is formed at a predetermined distance greater than zero above the center of gravity of the entire separator.

Claims

1. A separator (100) for separating a first phase from a second phase of a liquid under centrifugal force in a tubular container (200), comprising: a float (110) made of elastic material having a circumferential sealing edge (112) which rests against an inner side of the tubular container in a sealing manner (200) when the separator is in a sealing position (220); and at least one ballast (120) fastened to an underside of the float (110) wherein a density of a material of the ballast (120) is greater than a density of a material of the float (110), wherein a density of the separator (100) lies in a value range between a density of the first phase and a density of the second phase of the liquid, thereby causing the center of gravity (SG) of the separator to assume a position at a phase boundary between the first phase and second phase of the liquid during centrifugation; and wherein the sealing edge (112) of the float (110) is formed at a distance (d) greater than zero above the center of gravity (SG) of the separator (100), wherein the float is disk-shaped with a downwardly extending bulge forming a buoyancy body, and wherein the ballast comprises a plurality of circumferentially spaced fingers extending downwardly from an underside of the float, each of the finger having an upper end connected to the float and a free lower end.

2. The separator (100) according to claim 1, wherein the liquid is blood, the first phase is blood serum and the second phase is cruor.

3. The separator (100) according to claim 1, wherein the distance (d) is between 0.05 mm and 4 mm.

4. The separator (100) according to claim 1, wherein the distance (d) is between 1 mm and 3 mm.

5. The separator (100) according to claim 1, wherein the sealing edge (112) extends horizontally in the circumferential direction (R).

6. The separator (100) according to claim 1, wherein the sealing edge (112) extends wave-shaped in the circumferential direction (R) with formation of wave crests (117) and wave troughs (118) and wherein the distance (d) in this case is measured from a deepest wave trough (118) to the center of gravity (SG) of the separator (100).

7. The separator (100) according to claim 1, wherein the float (110) has a spherical deformation.

8. A tubular container, comprising the separator according to claim 1, wherein the separator is detachably clamped in an initial position and wherein the separator is configured to move from the initial position into a sealing position and to rotate by 90° when subjected to a centrifugal force.

9. The separator (100) according to claim 1, wherein the fingers are inwardly curved whereby the upper ends of the fingers are further apart from one another than their lower ends.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGS. 1a and 1b show a separator having disk-shaped float according to a first embodiment.

(2) FIG. 2 shows the separator according to FIGS. 1a and 1b in a tubular container.

(3) FIG. 3 shows an enlarged detail illustration of FIG. 2.

(4) FIG. 4 shows a separator according to a second embodiment.

(5) FIG. 5 shows a separator according to a third embodiment.

(6) FIG. 6 shows a separator according to a fourth embodiment.

(7) FIG. 7 shows a separator according to a fifth embodiment.

DETAILED DESCRIPTION

(8) The invention is described in detail in the following with reference to said figures in the form of exemplary embodiments. The same technical elements are designated by the same reference numerals in all figures.

(9) FIGS. 1a and 1b shows a separator 100 according to a first embodiment in a perspective view and in a side view. Its float 110 is generally disk-shaped, but it is spherically deformed. Therefore, the circumferential edge 112 is formed wave-shaped with wave troughs 118 and wave crests 117 when viewed from the side. Ballast bodies 120 stick out in the shape of fingers 124 downward from the underside of the disk-shaped float 110 in each case in the region of the wave troughs 118. Material accumulations on the upper side of the disk-shaped float are preferably designed from the material of the float in the region of the wave crests 117; these accumulations act as additional buoyancy bodies 113. In the embodiment shown in FIGS. 1a and 1b, the fingers 124 and the buoyancy bodies 113 are respectively arranged alternately distributed at a circumferential angular distance of φ=90° at the periphery of the disk-shaped float.

(10) FIG. 2 shows the separator according to FIGS. 1a and 1b in the interior of the tubular container 200. In the delivery state the separator is located in its initial position 210. It is then propped up against the inner side of the tubular container 200 on the one side with the free ends of the fingers 124 and on the other side with the free ends of the buoyancy bodies 113. The free ends of the buoyancy bodies 113 are therefore preferably rounded in accordance with the inner radius of the tubular container 200. In the initial position 210, blood flowing into the tubular container can flow around the separator 100, so that the blood can also reach deeper volume regions of the tubular container.

(11) Under the action of a force, in particular the centrifugal force, the separator 100 is detached from its initial position 210 and moves into a sealing position 220. At the same time it turns by 90°. The separator 100 deforms back into its starting state only when it is no longer under the action of the centrifugal force. Its sealing edge 112, in the sealing position 220 in the circumferential direction R, rests everywhere against the inner side of the tubular container 200 in a sealing manner and in this way, separates the two phases of the liquid or the blood effectively from each other.

(12) FIG. 3 shows an enlarged detail from FIG. 2. Specifically, FIG. 3 shows the separator 100 in the sealing position within the tubular container 200. The reference characters S1 designates the center of gravity of the float 110; reference characters S2 designates the center of gravity of the ballast 120. The center of gravity of the entire separator 100 is designated by the reference character SG.

(13) FIG. 3 shows the vertical container 200 having liquid located therein after centrifugation. The liquid, for example, blood, has separated into two phases due to the centrifugation. The density of the first phase, for example, blood serum S, is less than the density of the second phase, for example, cruor K. The first phase having the lower density therefore floats on the second heavier phase after centrifugation. This is shown in FIG. 3. There, the lighter blood serum floats on the heavier cruor.

(14) The density of the entire separator 100 lies in a value range between the density of the first phase and the density of the second phase of the liquid or of the blood. Therefore, in the sealing position shown, the separator 100 in FIG. 3 is automatically positioned so that its entire center of gravity SG lies exactly at the phase boundary between the first and the second phase of the liquid.

(15) As explained above, the sealing edge 112 of the separator or the float 110 has a predetermined distance d to the center of gravity SG of the entire separator. This distance d, also called security distance, should not be chosen, as explained above, on the one hand, too large, but on the other hand, also not too small. If it is chosen too small, there is a risk that the first phase of the liquid above the separator is contaminated by portions of the second phase K, while the separator 100 moves into the sealing position. On the other hand, when it is chosen too large, too much of the first phase of the liquid will be lost; this is the residual amount RM at the first phase of the liquid which accumulates between the sealing edge 112 of the separator in the sealing position and the phase boundary. This residual amount RM is no longer available for the medical analysis of the first phase of the liquid. This distance d lies, for example, within a range of 0.05 mm to 4 mm, preferably between 1 mm to 3 mm. The distance d is basically always measured from the lower edge of the sealing edge 112 to the phase boundary. In the wave-shaped sealing edge, as shown in FIG. 3, it is measured from the deepest wave trough 118 of the sealing edge up to the center of gravity SG of the entire separator, respectively up to the phase boundary.

(16) It is important that the technical teaching of the invention just described applies to any separator. It applies in particular not only to the separator according to the first embodiment of the invention, as shown in FIGS. 1 to 3.

(17) Further possible separators are shown in the following FIGS. 4 to 7; these are briefly described in the following; however, as stated, the technical teaching of the invention is not limited to these embodiments of the separator.

(18) FIG. 4 shows the separator 100 according to a second embodiment in a perspective view and in a cross-sectional representation. The separator 100 consists of a float 110 and a ballast 120. The float 110 is designed disk-shaped having a bulge as a buoyancy body 113 in its center and having a circumferential sealing edge 112. The ballast 120 is designed in the form of a plurality of fingers 124 which extend away from the underside of the disk-shaped float 110. The fingers 124 are arranged distributed on the edge of the ballast.

(19) FIG. 5 shows the separator 100 in a spherical configuration (3rd embodiment). It consists of the elastic float 110 having the sealing edge 112 that is circular in top view. This does not stand in the way of the sealing edge 112 being formed wave-shaped in the side view of FIG. 5. Reference numeral 118 designates a wave trough of the sealing edge 112. The distance d is measured from this wave trough downward to the center of gravity of the separator.

(20) A ballast 120 is fastened to the underside of the float 110. The float 110 is locally narrowed according to FIG. 5. It is designed as a membrane 116 in the region of the narrowing 114. The membrane is designed wave-shaped with wave crests and wave troughs. Regardless thereof or alternatively, the membrane 116 could also be formed of elastic material. The formation of the membrane in wave shape and/or of elastic material is required to enable a spring action of the membrane. The membrane acts as a tension spring, whereby the float and the ballast are moved a bit closer to each other. The separator is widened as a result, in particular the float, with the result that, in the sealing position, the sealing edge presses with a sufficiently large pressure against the inner side of the container in order to effectively delimit the two phases of the liquid from each other.

(21) The float 110 has a local flattening 119″ or bead on its upper side facing away from the ballast 120. The float does not rest against the inner side of the container in a sealing manner in the initial position in the region of the flattening, and thus enables a local flow around the separator with the liquid flowing into the container.

(22) FIG. 6 shows the spherical separator 100 in a fourth embodiment. This embodiment substantially differs only in the shape of the membrane 116 and in the design of the surface of the float from the embodiment according to FIG. 5.

(23) The wave crests and the wave troughs of the membrane 116 are also annular, but here they are designed oval. The upper side of the float 110 has an elevation 119′ instead of the flattening. The flattening and the elevation equally cause residues of the liquid, in particular, blood residues, being unable to accumulate in their surroundings, which residues cannot escape between the separator and the wall of the container.

(24) FIG. 7 shows the separator 100 in a fifth cup-shaped design. Apart from its outer (cup) shape, this separator substantially differs from the separator according to FIGS. 5 and 6 only in the circumferential sealing edge 112. The sealing edge 112 is not wave-shaped here, but designed to extend straight horizontally.

LIST OF REFERENCE NUMERALS

(25) 100 separator

(26) 110 float

(27) 112 sealing edge

(28) 113 buoyancy body/material bulge

(29) 116 membrane

(30) 117 wave crest

(31) 118 wave trough

(32) 119′ elevation

(33) 119″ flattening/bead

(34) 120 ballast

(35) 124 fingers

(36) 200 container

(37) 210 initial position

(38) 220 sealing position

(39) d distance

(40) K cruor, general second phase of the liquid

(41) R circumferential direction

(42) S blood serum, generally first phase of the liquid

(43) S1 center of gravity of the float

(44) S2 center of gravity of the ballast

(45) SG center of gravity of the entire separator

(46) RM residual amount

(47) φ circumferential angular distance