GB2611768A

GB2611768A - Device for fluid loading

Info

Publication number: GB2611768A
Application number: GB2114632.9A
Authority: GB
Inventors: Lukhaub Waldemar
Original assignee: Stratec SE
Current assignee: Stratec SE
Priority date: 2021-10-13
Filing date: 2021-10-13
Publication date: 2023-04-19
Also published as: GB202114632D0

Abstract

Disclosed is a pump which is fluidly linked to a fluid container, the fluid container being arranged to be higher than the pump, where there is at least one end of the fluid pathway between the pump and the fluid container which is open and higher than the fluid container, such that fluid flows from the fluid container to the pump under gravity and gas which is expelled from the fluid as it flows can flow to the open end, preventing air from entering the pump. There may be an interface between the fluid container and the pump for attaching the fluid container to the fluid pathway. The fluid may be a liquid, or a liquid mixed with a solid or a gas.

Description

DEVICE FOR FLUID LOADING

DESCRIPTION

Field of the Invention

[0001] The invention relates to a device for fluid loading.

Brief description of the related art

[0002] Automated analyser systems for use in clinical diagnostics and life sciences are produced by a number of companies. For example, STRATEC'13' SE, Birkenfeld, Germany, produces a number of devices for specimen handling and detection for use in automated analyser systems and other laboratory instrumentation [0003] STRATEC'' designs and manufactures automated analytical systems in the field of in vitro diagnostics (IVD), which use a number of individual instrument components to process diagnostic assays. A pressure difference may exist between the different instrument components due to a hydrostatic effect. Depending on the used fluids, the pressure difference may cause a forming of bubbles in a piping system, which can have a negative effect on dispensing the intended amount of a fluid [0004] Devices known from the prior art have usually the pumps placed above a storage of fluids. For receiving a short dispensing line between the equipment components and the pump, the pump is usually position above a reservoir for storage of a fluid and in vicinity of the equipment component.

[0005] Disadvantages of available solutions from the prior art relate to the already mentioned pressure difference between the pump, located on top, and the tank, located at the bottom, due to the hydrostatic effect. Depending on the fluid and the proportion of dissolved gases, bubbles may form in the piping system. These bubbles have a negative effect on the accuracy of the appropriate dosing of the fluid quantity. This effect is particularly strong at low volumes.

[0006] In systems comprising a closed fluid circulation, the line system must be flushed and vented after replacing a liquid container. A further disadvantage is that replacing and flushing can be quite time-consuming or require elaborate procedures. In addition, system fluid is wasted with each flush. Another disadvantage is that liquids can outgas more, especially at high altitudes, so there is more bubbling.

[0007] Thus, there is a need to provide a device for avoiding the occurrence of air bubbles in automated analyzer systems.

Object of the Invention [0008] It is therefore the object of this invention to provide a device and a method for avoiding air bubbles in line systems caused by outgassing of liquids.

Summary of the Invention

[0009] The present invention provides a device for handling liquids, comprising a fluid container which is arranged at a higher level than a pump, wherein a fluid connection between the fluid container and the pump is open at one end, wherein said end is arranged at a higher level than the fluid container, so that the fluid flows to the pump by gravity and trapped air bubbles rise in the open fluid connection to the open end.

[0010] It is intended that the fluid container can be a storage for a fluid [0011] An interface can be arranged in the fluid connection between fluid container and pump in another embodiment of the invention for attaching the container for instance.

[0012] Another aspect of the invention provides a junction which is arranged between fluid container, pump, and open end.

[0013] It is further envisaged that a fluid reservoir can be arranged between junction and pump.

[0014] The device may further comprise a sensor that is arranged between junction and open end.

[0015] In another aspect of the present invention, the pump is self-blocking.

[0016] The pump can be a peristaltic pump.

[0017] The device may further comprise a valve.

[0018] According to the present invention, a fluid is a liquid, or a mixture of a liquid with gas or solids.

[0019] Another object of the invention refers to an automated analyser system comprising a device as described above for providing fluids.

[0020] Still other aspects, features, and advantages of the present invention are readily apparent from the following detailed description, simply by illustrating preferable embodiments and implementations. The present invention is also capable of other and different embodiments and its several details can be modified in various obvious respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention.

Summary of the Figures

[0021] The invention will be described based on figures. It will be understood that the embodiments and aspects of the invention described in the figures are only examples and do not limit the protective scope of the claims in any way. The invention is defined by the claims and their equivalents. It will be understood that features of one aspect or embodiment of the invention can be combined with a feature of a different aspect or aspects of other embodiments of the invention, in which: [0022] FIG. I shows exemplary arrangement according to the present invention.

Detailed Description of the Invention and the Figures [0023] The technical problem is solved by the independent claims. The dependent claims cover further specific embodiments of the invention.

[0024] The present invention solves the above problems by arranging a container as a fluid reservoir above a pump and connecting the line between the container and the pump as a so called "open system". The fluid flows to the pump by gravity and trapped air bubbles can rise in the (open) fluid connection system and thus do not enter the pump. The air bubbles will thus not have an influence on the system and consequently on the pump accuracy.

[0025] A fluid within the meaning of the present invention, refers to a liquid, or a mixture of a liquid with a gas, a solid or other material. To avoid air bubbles in a piping system according to the present invention, the container is located above the pump within the meaning that the container has a higher position in relation to the pump, so that any negative pressure will be avoided, and the fluid does not outgas The goal for a device according to the presented invention is to have always pressure in the fluid connection between container and pump so that no outgassing of the fluid will occur. To eliminate possible air bubbles in the system, trapped air bubbles can rise in the open fluid connection and thus will not enter the pump [0026] An exemplary arrangement of the present invention is shown in FIG. I. A container 5 serves as a storage for a fluid and is connected by a fluid connection 7 with pump 11. The fluid connection 7 is a conduit which may be a hose or a pipe, depending on the system. The pump 11 controls the fluid flow and provides a permanent approximately continuous fluid transport. In the simplest case, a self-blocking pump II e.g. peristaltic pump is used. An interface 25 may be used for attaching a container to the fluid connection 7. Alternatively, an optional valve can be integrated into the system to prevent leaking fluids even in the event of a pump failure.

[0027] There is a junction 27 between container 5 and pump 11. The fluid connection 7a is open and the open end 23 is clearly located above within the meaning of being arranged at a higher point in relation to the container 5. This allows the fluid Ito flow out of the container 5 at any time, and the fluid level 15 in the fluid connection 7a will level off at the same level as the fluid level in the container 5, according to the law of communicating tubes. At least one sensor 13 in a suitable location can be used in an embodiment according to the present disclosure to monitor the fluid 1 resources.

[0028] In principle, the fluid connection 7b coming from the container 5 to the pump 11 should have a continuous gradient so that the fluid 1 can flow undisturbed. In particular, at the junction 27, the fluid connection 7a must be as vertical as possible so that gas bubbles can rise undisturbed. A fluid reservoir 9 can be arranged below junction 27 but before pump 11 for facilitating the change of a container 5 due to the additional fluid which is stored in reservoir 9. [0029] A larger cross-section/diameter of the fluid connection 7c (hose or pipe) between the junction 27 and pump 11 facilitates the rising of gas bubbles (arrow 21) in the open system compared to fluid connections with a smaller cross-section/diameter. The disadvantage of the larger cross-section of the fluid connection 7c is the increased dead volume, which is in the fluid connection 7c, however, an increased dead volume can also be used as a "reserve" for fluid to carry out a replacement of the container 5 without intempting the system. Basically, the diameter of 7c may be the largest, wherein the diameter of the fluid connection 7b is greater than the diameter of fluid connection 7a. Such a configuration of the using different diameters for fluid connections 7 a, b, c may be advantageous but is not compulsory.

[0030] Arrow 17 in FIG. 1 shows the height difference between fluid level 15 in container 5 and pump 11. Arrow 19 indicates the part of the fluid connection 7 where only fluid 1 is flowing in the fluid connection 7.

[0031] The advantages of a device according to the present invention can be summarized as follows: - a bubble-free conveying and dispensing of fluids; - more accurate dispensing possible, - device is independent from the altitude (>2000m above sea level); - a reduced effort for purging the system; 5 - minimized losses when flushing in the system; - even after longer downtimes, the entire system does not have to be flushed to remove any air bubbles that may have formed. The cross-section of the hose to the environment is very small (e.g. approx. 1 mm) to minimize surfaces which are in contact with air for reducing or avoiding a possible alteration of fluids; - in particular advantageous for small volumes with low throughputs; - process monitoring by the standard optical sensors possible, dispensing of fluids is only possible if the optical sensor does not detect any air bubbles; - with a suitable dimensioning of the fluid connections, the contents of the piping system can be used as a "reserve" until an empty container is replaced by a full container; - depending on the design, the system fluid can even be processed permanently under exclusion of air, e.g. if the reservoir is made of an elastic material, as in the case of an infusion bag; - the container can be replaced at any time.

[0032] The foregoing description of the preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiment was chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents. The entirety of each of the aforementioned documents is incorporated by reference herein.

Reference Numerals 1 fluid container 7a, b, c fluid connection 9 fluid reservoir Ii pump 13 sensor fluid level 17 height difference fluid level 19 flow direction fluid 21 direction rising bubbles 23 open end fluid connection interface 27 junction

Claims

CLAIMSA device for handling liquids, comprising a fluid container which is arranged at a higher level than a pump, wherein a fluid connection between the fluid container and the pump is open at one end, wherein said end is arranged at a higher level than the fluid container, so that the fluid flows to the pump by gravity and trapped air bubbles rise in the open fluid connection to the open end The device of claim I, wherein the fluid container is a storage for a fluid The device of claim 1 or 2, wherein an interface is arranged in the fluid connection between fluid container and pump for attaching container.The device of any one of claims I to 3, wherein a junction is arranged between fluid container, pump, and open end.5. The device of claim 4, wherein a fluid reservoir is arranged between junction and pump.6. The device of claim 4 or 5, wherein a sensor is arranged between junction and open end.7. The device of any one of claims Ito 6, wherein the pump is self-blocking.8. The device of claim 7, wherein the pump is a peristaltic pump.The device of any one of claims I to 8, wherein a fluid isal quid, or a mixture of a liquid with a gas or a solid.The device according to any one of claims 1 to 9, further comprising a valve 11 An automated analyser system comprising a device according to any one of claims 1 to 10 for providing fluids.