HOMOGENEOUS FLUID COMPOSITION BY CONTROLLING A PRIMARY PISTON OF A PISTON PUMP SYSTEM

Abstract

Fluid supply system (150) for providing a fluid to a fluid consumer (30), wherein the fluid supply system (150) comprises a feed device (25) for supplying the fluid composed of several fluidic components (A to D), a primary piston pump (111) to which fluid to be pumped can be supplied by means of the feed device (25) and which has a primary piston (115) arranged reciprocally in a primary piston chamber (117) for conveying the fluid, and a control device (70) for controlling the primary piston (115) such that, independently of a fluidic component (118) arranged downstream of the primary piston (115), a suction characteristic of the primary piston (115) can be adjusted depending on the composition of the fluid from the several fluidic components (A to D) such that a fluid with a homogeneous composition is supplied to the fluid consumer (30) within a respective time window.

Description

TECHNICAL BACKGROUND

[0001] The present invention relates to a fluid supply system and a method for supplying a fluid to a fluid consumer, as well as a sample separation device.

[0002] In HPLC, a liquid (mobile phase) is typically moved through a stationary phase (e.g., in a chromatographic column) at a very precisely controlled flow rate (for example, in the range of microliters to milliliters per minute) and at high pressure (typically 20 to 1000 bar and above, currently up to 2000 bar), at which the compressibility of the liquid may be noticeable, in order to separate individual components of a sample liquid introduced into the mobile phase. Such an HPLC system is known, for example, from EP 0,309,596 B1 of the same applicant, Agilent Technologies, Inc.

[0003] The pump, which conveys the mobile phase at high pressure, may have a reciprocating piston in a piston chamber, which displaces the fluid. During pump operation, achieving the most homogeneous solvent composition possible can be advantageous for a precisely executed chromatographic separation process.

[0004] WO 2013 / 013717 of the same applicant, Agilent Technologies, Inc., discloses a fluid supply system for metering two or more liquids in controlled ratios and for supplying a resulting mixture. The fluid supply system comprises a plurality of solvent supply lines, each fluidically connected to a fluid source for providing a respective fluid, and a pump unit having a reciprocating element for drawing in liquid supplied at an inlet of the pump unit and for supplying the pressurized fluid at an outlet of the pump unit. The pump unit is designed to receive liquids from selected solvent supply lines and to supply a pressurized mixture of the fluids at its outlet.Furthermore, a proportioning valve is provided between the solvent supply lines and the inlet of the pump unit. This valve is designed to modulate the solvent composition by sequentially coupling selected solvent supply lines to the inlet of the pump unit. A longitudinal mixing unit is used to mix longitudinally adjacent sections of fluids in order to change their flow order.

[0005] DE 10 2012 200 218 of the same applicant, Agilent Technologies, Inc., discloses a method for metering two or more liquids in controlled proportions in a liquid supply system and for delivering a resulting mixture, wherein the liquid supply system comprises a plurality of solvent supply lines, each of which is fluidically connected to a reservoir containing a liquid, a proportioning valve which is interposed between the solvent supply lines and an inlet of a pump unit, wherein the proportioning valve is configured to modulate a solvent composition by sequentially coupling selected of the solvent supply lines to the inlet of the pump unit, wherein the pump unit is configured to receive liquids from the selected solvent supply lines and to deliver a mixture of the liquids at its outlet.The method comprises: drawing a first liquid into the pumping unit via a first solvent supply line; determining one or more switching points for switching between different solvent supply lines, wherein the switching points are determined in such a way that at the switching points the liquid supplied to the pumping unit is within a predefined pressure range; switching from the first solvent supply line to a second solvent supply line at one of the switching points; drawing a second liquid into the pumping unit via the second solvent supply line. REVELATION

[0006] It is an object of the invention to provide a homogeneous and precise fluidic composition for a fluid consumer. This object is achieved by means of the independent claims. Further embodiments are shown in the dependent claims.

[0007] According to an exemplary embodiment of the present invention, a fluid supply system is provided for supplying a fluid (i.e., a liquid and / or a gas, optionally comprising solid particles, for example, a mobile phase of a chromatographic sample separation device) to a fluid consumer (in particular, a fluidic system, such as a fluidic component, which is to be supplied with fluid for its intended operation), wherein the fluid supply system includes a feed device for supplying the fluid consisting of several (i.e.,a fluid composed of at least two fluidic components (for example, different solvents, in particular water and at least one organic solvent such as acetonitrile), a primary piston pump to which fluid to be pumped (in particular in the form of successive fluid packets) can be supplied by means of the supply device and which has a primary piston arranged reciprocally (i.e. move back and forth) for pumping the fluid in a primary piston chamber, and a control device (which may, for example, be designed as one or more processors or as part of a processor) for controlling the primary piston such that, regardless of a fluidic component arranged downstream of the primary piston, a suction characteristic (i.e.a behavior of the primary piston during the intake of fluid from the supply device, in particular a course of the intake velocity over time or as a function of the volume already drawn in) of the primary piston as a function of the composition of the fluid from the several fluidic components is adjustable in such a way that (in particular in successive strokes of the primary piston pump and the secondary piston pump) the fluid consumer is supplied with a fluid that is at least within a respective time window essentially homogeneous in composition.

[0008] According to another exemplary embodiment of the invention, a sample separation device is provided for separating a fluidic sample located in a mobile phase into fractions, wherein the sample separation device has a fluid supply system with the features described above for providing the mobile phase as the fluid to a fluid consumer, and the fluid consumer designed as a sample separation device (in particular downstream of a secondary piston pump if a two-piston pump system with a secondary piston pump arranged downstream of the primary piston pump is present) for separating the different fractions of the sample located in the mobile phase.

[0009] According to yet another exemplary embodiment, a method for supplying a fluid to a fluid consumer is provided, wherein the fluid, composed of several fluidic components, is supplied to a primary piston pump, which has a primary piston that reciprocates to pump the fluid in a primary piston chamber, and the primary piston is controlled in such a way that, independently of a fluidic component arranged downstream of the primary piston (in particular a secondary piston of a secondary piston pump downstream of the primary piston pump), a suction characteristic of the primary piston is adjusted depending on the composition of the fluid from the several fluidic components such that (in particular in successive strokes) a fluid with a substantially homogeneous composition is supplied to the fluid consumer, at least within a respective time window.

[0010] Within the scope of this patent application, the term "homogeneously composed fluid" can be understood to mean, in particular, that different fluidic sections or segments in a fluid line at an outlet of the secondary piston pump have a uniform, and especially segregation-free, composition of the various fluidic components. In a homogeneous configuration, the individual sections should not exhibit spatially separated areas of unmixed or segregated fluidic components. Those skilled in the art of fluid supply systems will understand that even in a homogeneously composed fluid, minor variations in composition can occur, for example, caused by switching artifacts of proportioning valves, which can lead to minute ridges in a still essentially homogeneous fluid profile.

[0011] Within the scope of this patent application, the term "homogeneous at least within a given time window" can be understood to mean, in particular, that the provided fluid is essentially free from density fluctuations or demixing phenomena, but can certainly be deliberately modified with regard to its composition over longer periods. An example of this is the use of the fluid composed of the several fluidic components as a mobile phase for passing through a chromatographic gradient mode in a chromatographic sample separation instrument.After the fluidic composition of the homogeneous fluid has remained constant within a time window assigned to a fluid section flowing through the fluid supply system, the relative contributions of the fluidic components can then be changed to supply the fluid receiver, designed as a sample separation device, with a solvent composition that remains essentially homogeneous and free from demixing phenomena, but is successively varied in subsequent time windows. Alternatively, the homogeneous fluid can also be used as a mobile phase for an isocratic sample separation mode, in which no solvent gradient with a time-varying solvent composition is required.

[0012] Within the scope of this patent application, "controlling an intake characteristic of the primary piston, independently of the fluidic component, to provide a homogeneously composed fluid" can be understood, in particular, to mean that, according to an exemplary embodiment, the primary piston is controlled alone and without regard to a separate and isolated movement of the fluidic component arranged downstream of it (for example, a secondary piston) with the premise of generating a homogeneously composed fluid. Intuitively, the control of the fluidic component (for example, the secondary piston) can thus not contribute to generating a homogeneously composed fluid, but instead fulfill a different fluidic control task (for example, providing a constant flow rate).

[0013] According to an exemplary embodiment, in a fluid supply system (for example, based on two piston pumps arranged in series), the movement pattern of a primary piston of a primary piston pump can be specifically adapted such that the fluid supplied to a fluid consumer has a constant composition over at least a certain time window (for example, over several movement cycles or strokes of the piston in the piston chamber), and in particular is a mixture of several fluidic components that is as homogeneous as possible (without pronounced spatial and / or temporal inhomogeneities). A corresponding control logic for controlling the movement of the primary piston can, for example, dynamically process a sequence of fluid packets arranged one after the other in such a way that a stable mixture is obtained at the fluid consumer.According to the invention, this can be achieved by simply or exclusively controlling the primary piston to avoid inhomogeneities, without affecting the freedom of a downstream fluidic component (for example, the secondary piston) to supply the fluid to the fluid consumer, for example, according to a desired quantity-time characteristic (in particular with a constant flow rate). By functionally decoupling the control of the primary piston to provide a spatially and temporally stable mixture of the fluidic components to form a homogeneous fluid, on the one hand, and the control of the fluidic component (for example, the secondary piston) to fulfill quantitative requirements of the fluid consumer, a simple and effective piston operation can be achieved from a control engineering perspective.Although, according to an exemplary embodiment, the control of the primary piston alone and without a contribution from the fluidic component (for example, the secondary piston) can aim to achieve the most stable possible mixture of the fluidic components, the control device can nevertheless coordinate or synchronize the movement of the primary piston and the fluidic component (for example, the secondary piston) so that the homogeneous fluid provided by the primary piston can be conveyed by the fluidic component (for example, the secondary piston) with desired flow rates and / or pressure properties, etc., into the fluidic system connected downstream of the secondary piston pump with the fluid consumer.

[0014] Further details of the fluid supply system, the sample separation device and the process are described below.

[0015] According to a preferred embodiment, the fluid supply system can further comprise a secondary piston pump to which fluid to be pumped can be supplied by means of the primary piston pump. The secondary piston, as the fluidic component, has a secondary piston arranged reciprocally in a secondary piston chamber for conveying the fluid. The control device can be configured to control the primary piston such that, independently of the secondary piston, the intake characteristic of the primary piston can be adjusted depending on the composition of the fluid from the several fluidic components, ensuring that the fluid consumer is supplied with a homogeneously composed fluid within a given time window.Using only the primary piston to achieve a homogeneous mixture can be particularly advantageous in a series two-piston pump, as the secondary piston can then be dedicated to fulfilling other fluidic tasks, such as maintaining a constant flow rate. According to an alternative embodiment, a parallel-head pump can also be provided.

[0016] According to one embodiment, the control device for the secondary piston can be configured such that the fluid is supplied at one outlet of the secondary piston pump with a predetermined flow rate profile, particularly a constant flow rate. For example, providing a constant flow rate over time can be highly desirable for chromatographic separation tasks in order to achieve high detection accuracy in analytical separation processes. Meeting these requirements can be the task of controlling the secondary piston, which, given the functionality of the primary piston, does not need to take into account undesirable inhomogeneities in the supplied fluid that are suppressed by the primary piston. Preferably, the primary piston does not contribute to maintaining a constant flow rate, and the secondary piston does not contribute to forming a stable fluidic mixture.

[0017] According to one embodiment, the control device for controlling the primary and secondary pistons can be configured such that, in a first operating mode, the primary piston chamber is filled with fluid from the supply device, while the secondary piston chamber, which is fluidically decoupled from the primary piston chamber in the first operating mode, delivers fluid to the fluid consumer. In a second operating mode, during which the primary piston chamber is fluidically coupled to the secondary piston chamber, fluid is transferred from the primary piston chamber to the secondary piston chamber, and fluid is delivered from the primary piston chamber to the fluid consumer. The first operating mode can occupy a longer proportion of the time in a duty cycle of the fluid supply system than the second operating mode.In the first operating mode, the secondary piston pump delivers fluid, previously pumped into the secondary piston chamber by the primary piston pump, to an outlet of the secondary piston pump and from there to the fluid consumer. Simultaneously, the primary piston retracts within the primary piston chamber according to a movement profile defined by the control unit, thereby filling it with fresh fluid from the supply unit (priming process). This movement of the primary piston is designed to ensure a homogeneous fluid composition. As the secondary piston pump approaches a (particularly near) empty state, the two piston chambers can be fluidically interconnected, so that the now fluid-filled primary piston chamber subsequently fills the empty secondary piston chamber with fresh fluid and simultaneously supplies fluid to a fluidic path downstream of the secondary piston pump.In the first operating mode, the primary piston performs a suction motion to draw fluid from the feed device. The secondary piston performs an ejection motion to expel fluid into a connected fluidic system (for example, a fluid pickup, which may be located in a chromatographic separation path). In the second operating mode, fluid is transferred from the primary piston chamber to the secondary piston chamber. During this transfer, a fluid flow into the fluidic system located downstream of the secondary piston pump may be maintained, but this is not mandatory.

[0018] According to one embodiment, the control device can be configured to actuate the primary piston in the first operating mode to provide a homogeneously composed fluid, and in the second operating mode to actuate the fluid at an outlet of the secondary piston pump, in particular with an increased (especially an increased average) movement speed of the primary piston compared to the first operating mode. Specifically, only during the first operating mode, in which the primary piston pump is fluidically decoupled from the secondary piston pump, can the primary piston alone adjust the homogeneity of the fluidic mixture.In the second operating state, which should preferably be set as short as possible and in which correct and controlled proportioning is not strictly necessary, the primary piston pump serves to supply flow to a fluidic system (for example, a chromatographic separation path) downstream of the secondary piston pump and to refill the previously (at least partially) emptied secondary piston pump. To keep this second operating state, which may not provide correct and controlled proportioning at least temporarily, short, the piston movement in the second operating state can be accelerated or set faster compared to the first operating state.

[0019] According to one embodiment, the control device can be configured to at least temporarily halt or stop the primary piston in the first operating mode for a specific period. By bringing the primary piston to a standstill in the primary piston chamber during the first operating state, particularly during an initial phase of the first operating state, the mixing behavior of the fluid composed of the several fluidic components can be influenced.

[0020] According to one embodiment, the control device can be configured to vary the speed of the primary piston in the primary piston chamber in the first operating mode, particularly a constant speed for certain sections. Specifically, the combination of temporarily stopping the primary piston in an initial phase of the first operating state with a subsequent adjustment to a predetermined (and in particular, constant) piston speed in the remaining final phase of the first operating state can be used to adjust the homogeneous fluidic properties of the composite fluid.More generally, both the timing of the onset of piston movement in the primary piston pump after a temporary standstill of the primary piston and the steepness of the piston movement trajectory (i.e., the particularly constant piston velocity) after the onset of movement of the primary piston can be used as degrees of freedom or design parameters to achieve homogeneous mixing of the fluidic components of the fluid.

[0021] According to one embodiment, the primary piston can remain stationary during the first operating mode in an initial section and move uniformly backwards at a constant speed from a predetermined start time, while the secondary piston can move uniformly forwards at a preferably constant speed throughout the entire first operating state.

[0022] According to one embodiment, the fluid supply system can include a fluidic valve between the primary and secondary piston pumps. The fluidic valve can be switched by means of a control device to decouple the primary and secondary piston pumps fluidically in the first operating mode and to couple them fluidically in the second operating mode. The control device can thus act on the fluidic valve in a fluidic connecting line between the two piston pumps in such a way that it can selectively enable or prevent fluid flow from the upstream primary piston pump to the downstream secondary piston pump. The fluidic valve can interrupt the fluid flow in the first operating mode and allow it in the second. Alternatively, a check valve can also be implemented.

[0023] According to one embodiment, the control device for controlling the intake characteristics of the primary piston can be designed taking into account at least one operating parameter indicative of a current operating state of the fluid supply system, and in particular taking into account a combination of several such operating parameters. The fluidic conditions in a fluid supply system, especially when implemented in a sample separation device such as a chromatography sample separation device, are extremely complex. In some cases, the fluidic conditions are so complex that artifact-free control is no longer possible due to the predictability of the system behavior.This applies, for example, to the operation of piston pumps at very high pressures (1200 bar and above), where effects such as the compressibility of liquids or the influence of system elasticity must be considered, or to piston pump operation where turbulent fluid flows occur. Precise prediction of system behavior also becomes difficult when complex chemical and physical interactions and mixing effects between different solvent components must be taken into account. However, even in such cases, phenomenologically or empirically determined disturbances can be identified through an analysis of system behavior. Furthermore, it has proven possible in such cases to suppress or eliminate identified artifacts by specifically influencing the system (according to exemplary embodiments, by adjusting the movement profile of the primary piston).According to the described configuration, the presence of a specific value of an operating parameter (in particular, the current composition of the fluid from the several fluidic components) and the resulting threat of inhomogeneity can be addressed by adjusting or readjusting the movement profile of the primary piston during its intake phase. The suppression of undesirable inhomogeneities in a solvent composition is particularly precise if a corresponding target movement profile of the primary piston is identified for an entire set of operating parameters (for example, the stroke length of one or both piston pumps in combination with a proportional composition of the fluidic components) and then imposed on the primary piston during operation.

[0024] According to one embodiment, the at least one operating parameter can be selected from a group consisting of a stroke volume (i.e., a volume of displaced fluid when a respective piston of a respective piston pump moves between top dead center and bottom dead center) of at least one of the piston pumps, a total flow rate (i.e.,Fluid volume delivered per time interval or fluid mass delivered per time interval) of the fluid downstream of the secondary piston pump, substances of the combined fluidic components (for example, the type (e.g., organic or inorganic, polar or nonpolar) and / or the material (e.g., water or acetonitrile) and / or their physical and / or chemical properties (e.g., density, mixing behavior) of the individual solvent components used to mix a particular mobile phase), relative proportions (e.g., percentage mass or volume contributions) of the combined fluidic components, and a gradient steepness (i.e., the rate at which a percentage proportion of one solvent component in the composite fluid is increased and another is decreased) of a change in the relative proportions of the combined fluidic components of the fluid.Empirical studies have shown that the aforementioned operating parameters in particular can have a significant influence on undesirable demixing phenomena and other inhomogeneity effects, and thus, with appropriate adjustment of the corresponding values, can lead to a homogeneous fluid composition.

[0025] According to one embodiment, the control unit can be configured to apply a combination of several operating parameters to a predefined characteristic map as the basis for controlling the intake characteristics. This map, depending on the current values ​​of the combined operating parameters, defines a movement profile for the primary piston. Such a characteristic map can, for example, be stored in a database as a parameter set or implemented as a lookup table. For a given set of selected operating parameters, a corresponding target movement profile for the primary piston can be extracted from the characteristic map, with which a homogeneous fluid composition can be achieved, at least within the predefined time window.Visually, the characteristic map can be understood as a multidimensional elevation profile. A desired behavior of the fluid supply system with regard to the homogeneity of the supplied fluid can be achieved if the fluid supply system, and in particular the movement profile of the primary piston with respect to its intake characteristics, moves along troughs on the elevation profile. If the intake characteristics of the primary piston intuitively follow corresponding "sweet spots," i.e., a sequence of advantageous system states, along the characteristic map, this empirically leads to the desired homogeneous fluid composition. The intake process, derived from the characteristic map, is preferably independent of the transfer phase in which the mixture is pumped further.

[0026] According to one embodiment, the characteristic map can be empirically determined, modeled, projected, and / or preconfigured. With an empirical determination of the characteristic map, the fluid supply system can be operated for different sets of operating parameters, and a specific intake characteristic of the primary piston can be determined for each set, resulting in a homogeneous fluid composition for that particular set of operating parameters. This empirical determination of the characteristic map can be carried out, for example, at the factory or before the initial commissioning of the fluid supply system.During the actual operation of the fluid supply system, i.e., when supplying the fluid to the fluid consumer, the current presence of a specific set of operating parameters can be detected. By comparing this with the characteristic map, the target intake characteristic of the primary piston can be derived, allowing the primary piston to be controlled accordingly. When modeling the fluid supply system, its behavior can be theoretically analyzed using model assumptions, and the corresponding characteristic map can be derived from this analysis. A projection of a characteristic map onto a future operating scenario can be performed based on a historical characteristic map and / or historical system behavior.It is also possible to preconfigure a characteristic map for a specific type of fluid supply system and then execute it accordingly during the operation of such a fluid supply system.

[0027] According to one embodiment, the characteristic map can be generated by supplying fluid to the primary and secondary piston pumps for sets of different values ​​of the operating parameters (particularly during a characteristic map calibration prior to supplying fluid to the fluid consumer), determining a target movement profile of the primary piston for each set of different values ​​of operating parameters, which fulfills a predefined homogeneity criterion for the homogeneity of the fluid downstream of the secondary piston pump, and storing the target movement profile fulfilling the homogeneity criterion as part of the characteristic map for each set of different values ​​of operating parameters. Such a characteristic map calibration can be carried out, in particular, before the initial commissioning of a fluid supply system, for example, at the factory.A target motion profile of the primary piston, which then forms part of the generated characteristic map, is understood to be a trajectory of the primary piston within the primary piston chamber that achieves a substantially homogeneous fluid composition. The aforementioned homogeneity criterion can be the criterion that the fluid is homogeneous or represents a stable mixture within a certain tolerance range.

[0028] According to one embodiment, the generated characteristic curve can be used for a class of fluid supply systems or sample separation devices. Intuitively, such a characteristic curve can be inherited or used jointly for a class of devices. This eliminates the need for separate calibration of each individual sample separation device.

[0029] According to one embodiment, a specific entry in the generated characteristic map can be modified if it is recognized that the modified entry improves the homogeneity of the fluid composition. A found entry in the characteristic map can thus be optimized by selecting or overwriting it with better conditions in terms of the homogeneity criterion.

[0030] According to one embodiment, the supply device can comprise a plurality of supply lines, each fluidically coupled to a fluid component source for providing a respective fluidic component, and a proportioning valve arranged between the supply lines and the primary piston pump. The proportioning valve can be controlled by the control device to modulate the composition of the fluid from packages of fluidic components upstream of the primary piston pump by sequentially coupling selected supply lines to the primary piston pump. With such a proportioning valve, a sequence of serial packages of separate fluidic components can be supplied to the primary piston pump. Optionally, a mixing device can be provided for mixing the packages between the proportioning valve and one of the piston pumps.The separated or premixed packets then reach the primary piston pump, which, using the specified suction characteristics, processes the sequence of fluid packets into a homogeneous fluid.

[0031] According to one embodiment, the control device for controlling the primary piston can be designed such that its movement profile in the primary piston chamber corresponds to a predetermined intake flow rate threshold, which in turn corresponds to a minimum delivery velocity of the primary piston pump. Such an intake flow rate threshold can be used as a design parameter for adjusting the intake characteristics of the primary piston.

[0032] According to one embodiment, the control device for controlling the intake characteristics of the primary piston can be designed such that it promotes mixing of the multiple fluidic components and / or inhibits separation of these components. Such a tendency toward separation can arise, for example, from differing densities and / or different chemical properties of different fluidic components. Optionally, in addition to appropriately controlling the intake characteristics of the primary piston, such separation tendencies can be suppressed by at least one further measure.Examples of such measures include implementing an active mixer in the primary piston chamber, supplying the fluidic components to the primary piston chamber under a turbulence-inducing flow geometry, providing a mixer upstream of the primary piston pump, and separating and subsequently merging partial flows of the fluidic components upstream of the primary piston pump.

[0033] According to one embodiment, the fluid pumping system, consisting of two piston pumps, can function as a high-pressure pump for pumping mobile phase to a separation unit of the sample separation device for separating different fractions of a fluidic sample contained in the mobile phase. Such a high-pressure pump delivers mobile phase (in particular, a solvent composition) from one or more liquid containers to a sample separation unit, such as a chromatographic column. The delivered mobile phase is then mixed with the fluidic sample at an injector device.

[0034] According to one embodiment, the sample separation device can be designed as a chromatographic separation device, in particular as a chromatographic separation column. In chromatographic separation, the chromatographic separation column can be provided with an adsorption medium. The fluidic sample can be retained on this medium and only subsequently released fractionally in the presence of a specific solvent composition, thus achieving the separation of the sample into its fractions.

[0035] The sample separation instrument can be a microfluidic instrument, a life science instrument, a liquid chromatograph, an HPLC (high-performance liquid chromatograph), an UHPLC system, an SFC (supercritical liquid chromatograph), a gas chromatograph, an electrophoresis instrument, and / or a gel electrophoresis instrument. However, many other applications are possible.

[0036] The pumping system can, for example, be set up to transport the mobile phase through the system at high pressure, for example several hundred bar up to 1000 bar and more.

[0037] The sample separation device may include a sample injector for introducing the sample into the fluidic separation path. Such a sample injector may have an injection needle that can be coupled to a seat within a corresponding fluid path. The needle can be extended from this seat to receive the sample, and after the needle is reinserted into the seat, the sample is located in a fluid path that can be switched into the separation path of the system, for example by switching a valve, thus introducing the sample into the fluidic separation path.

[0038] The sample separation device may include a fraction collector for collecting the separated components. Such a fraction collector can, for example, direct the different components into separate liquid containers. Alternatively, the analyzed sample can be discharged into a waste container.

[0039] Preferably, the sample separation device can include a detector for detecting the separated components. Such a detector can generate a signal that can be observed and / or recorded, and which is indicative of the presence and quantity of the sample components in the fluid flowing through the system. BRIEF DESCRIPTION OF THE FIGURES

[0040] Other objectives and many of the accompanying advantages of exemplary embodiments of the present invention will become readily apparent and more readily understood with reference to the following more detailed description of exemplary embodiments in conjunction with the accompanying drawings. Features that are essentially or functionally the same or similar are designated with the same reference numerals.

[0041] Fig. Figure 1 shows an HPLC system according to an exemplary embodiment of the invention.

[0042] Fig. Figure 2 shows a fluid supply system for providing a fluid to a fluid consumer according to an exemplary embodiment of the invention.

[0043] Fig. 3 and Fig. Figure 4 shows diagrams in which piston chamber volumes of two piston pumps of a fluid supply system for providing a fluid to a fluid consumer according to an exemplary embodiment of the invention are shown.

[0044] Fig. Figure 5 shows a diagram that depicts, as a function of time, a course of a signal indicative of a conventional fluid composition, showing switching artifacts and demixing artifacts, wherein the demixing artifacts can be suppressed with a fluid supply system according to an exemplary embodiment of the invention.

[0045] The representation in the drawing is schematic.

[0046] Before describing exemplary embodiments with reference to the figures, some basic considerations will be summarized on the basis of which exemplary embodiments of the invention have been derived.

[0047] According to an exemplary embodiment, to achieve homogeneity of a fluid supplied by a fluid supply system, at least one parameter indicative of the suction characteristics of a primary piston of a primary piston pump of a two-piston pump system, in particular a suction flow threshold, can be set depending on one or more operating parameters, especially piston stroke and / or fluid composition. This allows the creation of a multi-channel pump that precisely proportions a fluid.

[0048] In the field of liquid separation, for example in HPLC, quaternary pumps are used. These pumps typically consist of a single high-pressure pumping channel equipped at the inlet with a fast and precise solvent selection valve (proportioning valve). This valve is connected to a set of two or more (typically four) reservoirs or bottles containing different solvents. The solvent selection valve alternately connects the pumping channel inlet to each of the solvent bottles, determining the intake window for each solvent. This ensures accurate proportioning of the solvent mixture.

[0049] Such a quaternary pump is configured to deliver the fluid against a substantial pressure required to force it through a separation medium in a sample separation apparatus. Furthermore, it is designed to mix multiple solvents, achieving a precise and stable composition according to a programmed time- or volume-based profile. A uniform and homogeneous composition is to be delivered, even when individual solvents are added in serial batches. Additionally, a programmed change in composition should reach the pump outlet rapidly, with minimal propagation delay, so that the fluid volume downstream of the valve is as small as possible.

[0050] However, this set of requirements is inherently contradictory. Thorough mixing in a small volume requires a homogeneous mixture, whereas the solvents are supplied to the high-pressure pump in divided or separate packages.

[0051] During the intake phase of the pump cycle (i.e., when solvents are drawn into the primary piston chamber), the gradient valve (multiplexer) connects the pump inlet to the multiple solvents in an alternating serial manner.

[0052] The serially drawn-in solvent packets are to be mixed before the liquid leaves the primary piston chamber. However, both a suction mixer and a flow pattern within the primary piston chamber exhibit flow-dependent dynamic behavior, which, with intelligent control of the primary piston, can promote mixing under optimal conditions. The movement of the primary piston can be controlled to enable uniform aspiration, proportioning, and delivery of fluid.

[0053] According to an exemplary embodiment, the primary piston is controlled, independently of the current flow conditions or the movement of the secondary piston (which supplies the solvent to the connected fluidic system), to complete a suction cycle to achieve the best possible precision in the fluid composition. This operating mode can essentially proceed by driving the primary piston according to a dynamically adaptable motion pattern to achieve optimal performance over a flow range or for a given instantaneous set of operating conditions. The operating condition or conditions that are incorporated into this control logic can include a stroke volume, an overall flow rate, a solvent combination, a solvent proportion, a gradient steepness, etc.Corresponding target patterns for respective parameter combinations of the operating conditions for the movement of the primary piston can be preconfigured, projected, modeled or empirically determined.

[0054] Traditionally, the intake characteristic of the primary piston can be stretched over the largest possible period, which is obtained as a result of a one-dimensional optimization with regard to the proportioning precision from one stroke to another.

[0055] According to an exemplary embodiment, multidimensional optimization is possible not only to provide precise proportioning but also to achieve optimal mixing of solvent packages, thereby improving homogeneity when a changed composition is delivered across pump strokes.

[0056] One approach, according to an exemplary embodiment, can activate the suction operation just in time (just-in-time). For example, a fixed suction flow rate threshold can be implemented, i.e., a minimum permissible suction flow rate (achievable, for example, by delaying the solvent suction or by causing a piston movement pause as needed after or during suction).

[0057] According to an exemplary embodiment, it is also possible to adjust the intake threshold value depending on the stroke volume. The stroke volume depends on the flow rate and can even depend on the pressure. The stroke volume can also depend on the gradient slope.

[0058] According to another exemplary embodiment, it is also possible for the intake threshold to depend on a composition, i.e., the proportions of individual solvents in the mixture. The intake flow rate can essentially be adjusted to achieve the best possible performance over the entire composition range, or under specific or instantaneous conditions. The optimal intake threshold may also depend on a previous historical composition.

[0059] According to an exemplary embodiment, the intake threshold can depend on the solvents used. In this regard, the solvent behavior can have an influence. The mixing dynamics and the thermal behavior of the solvents can also be taken into account. Furthermore, differences in density and viscosity between different solvent packages can be considered. Volume changes during a mixing process can also be factored in.

[0060] Fig. Figure 1 shows the basic structure of an HPLC system. 10 , such as for liquid chromatography. A fluid pumping system 20 , which uses solvents from a feeding device 25 supplied, drives a mobile phase through a sample separation device 30 (such as a chromatographic column) that contains a stationary phase. An optional degasser. 27can degas the solvents before they enter the fluid pumping system 20 be supplied. A sample delivery unit 40 is between the fluid pump system 20 and the sample separation device 30 arranged to introduce a sample liquid into the fluidic separation path. The stationary phase of the sample separation device 30 It is designed to separate components of the sample. A detector, see flow cell. 50 The device detects separated components of the sample, and a fractionation unit can be provided to dispense these components into designated containers. Unneeded liquids can be collected in a drain container. 60 will be issued.

[0061] While a fluid path exists between the fluid pumping system 20 and the sample separation device 30Typically under high pressure, the sample liquid is first introduced under normal pressure into a section separate from the liquid path, a so-called sample loop, the sample delivery unit. 40 The sample liquid is then introduced into the high-pressure liquid path. During the introduction of the sample liquid, initially at normal pressure, into the high-pressure liquid path, the contents of the sample loop are pressurized to the system pressure of the HPLC sample separation instrument. 10 brought a control device 70 controls the individual components 20 , 25 , 27 , 30 , 40 , 50 , 60 of the sample separation device 10 .

[0062] As in Fig. As shown schematically in section 1, the fluid pumping system can be 20from an upstream primary piston pump 111 and a secondary piston pump located downstream of it 112 be educated.

[0063] Fig. 2 shows a fluid supply system 150 to supply a fluid to a in Fig. 2 fluid consumers not shown (for example, the sample separation device) 30 according to Fig. 1) according to an exemplary embodiment of the invention.

[0064] The feeding device 25 has four supply lines 104 until 107 on, each of which is fluidically connected to one of four fluid component sources 100 until 103 A proportioning valve is used to provide a respective fluidic component A to D. 108 is between the supply lines 104 until 107 and an entrance 189 the primary piston pump 111arranged. The proportioning valve 108 is by means of the control unit 70 for modulating the composition of the fluid from packages of fluidic components A to D upstream of the primary piston pump 111 by sequentially coupling selected of the supply lines 104 until 107 with the primary piston pump 111 controllable. This means that the control device 70 the proportioning valve 108 (especially according to a multiplexer scheme) such that sequences of fluid packets of components A, B, C and D are successively passed through a fluid line 109 , through an inlet valve 113 and through the entrance 189 the primary piston pump 111 flow.

[0065] The primary piston pump 111 (see also reference mark “ I “), which is via the feeding device 25The fluid to be pumped can be supplied in packets, and has a primary piston chamber for conveying the fluid. 117 reciprocally arranged primary piston 115 up. The primary piston 115 as well as one between the primary piston pump 111 and a secondary piston pump 112 (see also reference mark “ II “) switched fluid valve 114 for selectively enabling or preventing fluid communication between the two piston pumps 111 , 112 are also by means of the control unit 70 controllable. The secondary piston pump 112 is by means of the primary piston pump 111 Pumped fluid can be supplied if the fluid valve 114 is in a corresponding switching state. The secondary piston pump 112 features a secondary piston chamber for conveying the fluid 120 reciprocally arranged secondary pistons 118on, which also uses the control device 70 is controllable and is located at its outlet 180 Fluid ready.

[0066] Sensor devices 162 , 164 and 166 are in associated fluid lines 109 , 187 and 121 Implemented, they capture an associated sensor parameter (in particular a flow rate and / or pressure of the flowing fluid) and supply the sensor values ​​to the control unit. 70 The control unit 70 The control unit can control the components it controls, taking these sensor values ​​into account. Furthermore, the control unit can 70 in a database 172 They access stored data to fulfill their tax obligations. For example, the database can be used to... 172A characteristic map, described in more detail below, may also be stored, which provides a corresponding control logic, particularly for the primary piston, for a set of specific operating parameters. 115 provides for.

[0067] The control unit 70 It is used to control the primary piston. 115 such that – regardless of whether the secondary piston is controlled 118 – an intake characteristic of the primary piston 115 depending on the composition of the fluid from the several fluidic components A to D, it can be adjusted such that in different strokes of the primary piston pump 111 and the secondary piston pump 112 the fluid consumer 30At least temporarily, namely within the respective time and associated target fluid window, a homogeneously composed fluid is provided; that is, a fluid in which the individual fluidic components A to D are mixed together to form a uniform fluid composition, without any significant density fluctuations in the fluid. The target composition of the fluid can change over time (so that a different time window is set with each change), for example, when controlled by the control device. 70 a different solvent composition is requested (for example, an increase in component B while simultaneously decreasing component A) (for example, to run through a chromatographic gradient mode).

[0068] Controlling the primary piston 115 This occurs independently of the secondary piston. 118 , than the control logic of the primary piston 115The system alone is responsible for creating a homogeneous fluid composition, or is adapted to this. Nevertheless, the control unit coordinates and synchronizes this process. 70 the primary piston 115 and the secondary piston 118 temporally, as referring to Fig. 3 and Fig. 4 can be detected. Temporal synchronization is therefore necessary because both pistons must be synchronized within a specific time period. 115 , 118 are fluidically coupled. In other time periods, however, in which both pistons 115 , 118 Since they are fluidically decoupled from each other, the pistons can 115 , 118 They are controlled separately and independently of each other, with the proviso that at the next switching point to the fluidically coupled state, the pistons 115 , 118 are located in a position suitable for subsequent fluidic coupling. The control unit 70 controls the secondary piston118 at times such that at one exit 180 the secondary piston pump 112 The fluid is supplied at a constant flow rate (i.e., volume of fluid per unit time). In other words, the controlled movement of the primary piston occurs. 115 (except during a transfer phase) solely to generate a homogeneous fluid composition, whereas the controlled movement of the secondary piston 118 (except during a transfer phase) supplying the downstream side of the outlet 180 The connected fluidic system operates at a constant flow rate. Therefore, it can be said that (except during the transfer phase) the control is provided by the control unit. 70 the movement of the primary piston 115 and the secondary piston 118 Temporally coordinated or synchronized, but functionally decoupled.

[0069] The control unit 70It serves to control the intake characteristics of the primary piston. 115 taking into account a combination of factors relevant to the current operating state of the fluid supply system 150 Indicative operating parameters. Examples of such operating parameters that are incorporated into the control logic for controlling, in particular, the primary piston. 115 The stroke volumes (which may be the same or different) of the piston pumps can be included. 111 , 112 , a total fluid flow rate downstream of the secondary piston pump 112 , substances of the combined fluidic components A to D, relative proportions of the combined fluidic components A to D, and a gradient steepness of a change in the relative proportions of the combined fluidic components A to D of the fluid. Advantageously, the control device applies 70 as a basis for controlling the intake characteristics of the primary piston 115the combination of current values ​​from several of the operating parameters to a predefined value stored in the database 172 stored characteristic map which, depending on the current values ​​of the combined operating parameters, defines a movement profile for the primary piston 115 in the primary piston chamber 120 specifies that, at least within the respective time window, the fluid consumer 30 Each fluid can be provided with a homogeneous composition.

[0070] To determine this characteristic curve, the following can be done before the fluid supply system is commissioned for the first time. 150 A corresponding calibration must be carried out, in which various values ​​of the aforementioned operating parameters are tested and an empirical movement profile of the primary piston is determined. 115 is determined, with which an artifact-free homogeneous supply of fluid is possible under the given operating conditions.

[0071] Fig. Figure 3 shows a diagram 300 , in which the pistons 115 , 118 limited piston chamber volumes V of the two piston pumps 111 , 112 of the fluid supply system 150 to supply a fluid to a fluid consumer 30 shown according to an exemplary embodiment of the invention. The diagram 300 has an abscissa 302 , along which an operating time t is plotted. Along a coordinate 304 is a volume V in the respective piston chamber 117 , 120 depicted. Fig. Figure 3 shows the movement profiles of the primary piston. 115 (reference mark) I ) and the secondary piston 118 (reference mark) II ). For the primary piston 115Two different possible movement profiles are shown, indicated by a dashed and a dash-dotted line, respectively. The following discussion focuses primarily on the control logic corresponding to the dashed line.

[0072] According to the example of Fig. 3 is the control unit 70 to control the primary piston 115 and the secondary piston 118 is designed in such a way that in a first operating mode 310 the primary piston chamber 117 by means of a temporary backward movement of the primary piston 115 with fluid from the feed device 25 is filled while in the first operating mode 310 from the primary piston chamber 117 fluidically decoupled secondary piston chamber 120 Fluid by means of a forward movement of the secondary piston 118 to the fluid consumer 30 promotes. In a second operating mode320 , during which the primary piston chamber 117 with the secondary piston chamber 120 It is fluidically coupled, by means of a forward movement of the primary piston. 115 and a simultaneous backward movement of the secondary piston 118 Fluid from the primary piston chamber 117 into the secondary piston chamber 120 transferred and fluid to the fluid consumer 30 promoted. The fluidic valve 114 is via the control unit 70 switched to enter the first operating state 310 the primary piston pump 111 from the secondary piston pump 112 to decouple fluidically and in the second operating state 320 the primary piston pump 111 with the secondary piston pump 112 to couple fluidically.

[0073] In the first operating mode 310 The primary piston will be 115to provide a homogeneously composed fluid. In the second operating mode 320 The primary piston will be 115 to supply the fluid at the outlet 180 the secondary piston pump 112 with a different operating mode compared to the first 310 increased movement speed of the primary piston 115 targeted. Fig. But 3 also shows that the control unit 70 the primary piston 115 in the first operating mode 310 temporarily, namely in an initial temporal phase 312 of the depicted duty cycle, stops. The control unit 70 can in the first operating mode 310 one in a final section 314 The primary piston's speed, while variable, remains constant during the depicted duty cycle. 115 in the primary piston chamber 117adjust. In contrast, the secondary piston moves. 118 throughout the entire first operating mode 310 at a uniform speed in the secondary piston chamber 120 , in order to maintain a constant flow rate at the outlet 180 to ensure the fluids provided. The time periods of the initial section. 312 and the final section 314 as well as the magnitude of the velocity in the final section 314 are design parameters for controlling the primary piston 115 with an associated motion profile to dynamically adjust the homogeneity of the supplied fluid depending on the current fluid composition.

[0074] In the second operating mode 320 Both pistons move 115 , 118 with a consistently constant speed, which, compared to the first operating mode 310The risk is increased. The transfer phase should be carried out as quickly as possible.

[0075] Fig. 4 shows a diagram 400 , in which the pistons 115 , 118 limited piston chamber volumes of the two piston pumps 111 , 112 of the fluid supply system 150 to supply a fluid to a fluid consumer 30 shown according to another exemplary embodiment of the invention.

[0076] Unlike Fig. 3 is according to Fig. 4 within the first operating mode 310 a further refined control of the movement of the primary piston 115 This is implemented in terms of control technology by placing a control signal between the initial section in the first duty cycle. 312 and the final section 314 two intermediate sections 402 , 404 are inserted, in which the primary piston 115 is moved particularly quickly (intermediate section)402 ) or comes to a standstill again in the meantime (intermediate section) 404 ). In a subsequent second duty cycle, within the associated first operating mode 310 a different control of the primary piston compared to the preceding first duty cycle 115 chosen, in which the initial section 312 the primary piston 115 is moved uniformly and in the final section 314 the primary piston 115 is stationary. Thus, the control of the primary piston can change in successive duty cycles. 115 differentiate.

[0077] Fig. 5 shows a diagram 500 , which depends on time t (compare abscissa) 302 ) a course of a signal S indicative of a fluid composition (compare ordinate) 502 ) represents switching artifacts 504 and demixing artifacts 506 shows, whereby the demixing artifacts 506with a fluid supply system 150 are suppressible according to an exemplary embodiment of the invention.

[0078] Fig. Figure 5 thus shows the time dependence of a signal obtained with a mixed fluid, which exhibits small and inconsequential relatively high-frequency switching artifacts. 504 exhibits characteristics resulting from the switching of the proportioning valve 108 originate from. Demolition artifacts are often significantly more disturbing. 506 These can occur, for example, every fifteen piston strokes. They often manifest as an alternating pattern of strong overshoots. 508 and subsequent (especially essentially uniform-surface) sub-oscillations 510 Without wishing to be bound to a specific theory, the inventors present here suggest that these demixing artifacts 506These arise from undesired demixing processes and inhomogeneities between fluidic components of a mixed fluid. This is illustrated by exemplary embodiments of the invention through appropriate control of the primary piston. 115 such demixing artifacts 506 suppresses or eliminates unwanted separation by promoting precise mixing of the fluidic components and inhibiting unwanted separation.

[0079] It should be noted that the term "have" does not exclude other elements and that "a" does not exclude a plurality. Elements described in connection with different embodiments may also be combined. It should also be noted that reference numerals in the claims should not be interpreted as limiting the scope of protection of the claims. QUOTES INCLUDED IN THE DESCRIPTION

[0080] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0081] EP 0309596 B1

[0002] WO 2013 / 013717

[0004] DE 102012200218

[0005]

Claims

[1] Fluid supply system ( 150 ) to supply a fluid to a fluid consumer ( 30 ), wherein the fluid supply system ( 150 ) shows: a feeding device ( 25 ) for supplying the fluid composed of several fluidic components (A to D); a primary piston pump ( 111 ), which is supplied by means of the feeding device ( 25 ) fluid to be pumped can be supplied and the one for pumping the fluid in a primary piston chamber ( 117 ) reciprocally arranged primary piston ( 115 ) exhibits; and a control unit ( 70 ) to control the primary piston ( 115 ) such that regardless of a downstream of the primary piston ( 115 ) arranged fluidic component ( 118 ) an intake characteristic of the primary piston ( 115) depending on the composition of the fluid from the several fluidic components (A to D) is adjustable in such a way that the fluid consumer ( 30 ) a homogeneously composed fluid is provided within a given time window. [2] Fluid supply system ( 150 ) according to claim 1, where the fluid supply system ( 150 ) furthermore a secondary piston pump ( 112 ) exhibits, which is operated by means of the primary piston pump ( 111 ) fluid to be pumped can be supplied and one of them is for pumping the fluid into a secondary piston chamber ( 120 ) reciprocally arranged secondary piston ( 118 ) as the fluidic component; where the control unit ( 70 ) to control the primary piston ( 115 ) is set up in such a way that, regardless of the secondary piston ( 118 ) an intake characteristic of the primary piston ( 115) depending on the composition of the fluid from the several fluidic components (A to D) is adjustable in such a way that the fluid consumer ( 30 ) a homogeneously composed fluid is provided within a given time window. [3] Fluid supply system ( 150 ) according to claim 2, wherein the control device ( 70 ) to control the secondary piston ( 118 ) is designed in such a way that at an outlet ( 180 ) the secondary piston pump ( 112 ) the fluid is provided with a predetermined flow rate profile, in particular with a constant flow rate. [4] Fluid supply system ( 150 ) according to claim 2 or 3, wherein the control device ( 70 ) to control the primary piston ( 115 ) and the secondary piston ( 118 ) is trained in such a way that: in a first operating mode ( 310 ) the primary piston chamber ( 117) with fluid from the feed device ( 25 ) is filled while in the first operating mode ( 310 ) from the primary piston chamber ( 117 ) fluidically decoupled secondary piston chamber ( 120 ) Fluid to the fluid consumer ( 30 ) promotes; in a second operating mode ( 320 ), during which the primary piston chamber ( 117 ) with the secondary piston chamber ( 120 ) is fluidically coupled, fluid from the primary piston chamber ( 117 ) into the secondary piston chamber ( 120 ) is transferred and at the same time fluid is still being transferred from the primary piston chamber ( 117 ) to the fluid pickup ( 30 ) is promoted. [5] Fluid supply system ( 150 ) according to claim 4, wherein the control device ( 70 ) is designed to form the primary piston ( 115 ) in the first operating mode ( 310 ) to provide a homogeneously composed fluid. [6] Fluid supply system ( 150 ) according to claim 4 or 5, wherein the control device ( 70 ) is designed to form the primary piston ( 115 ) in the first operating mode ( 310 ) to at least temporarily stop. [7] Fluid supply system ( 150 ) according to one of claims 4 to 6, wherein the control device ( 70 ) is trained in the first operating mode ( 310 ) a, in particular sectionally constant, velocity of the primary piston ( 115 ) in the primary piston chamber ( 117 ) to vary. [8] Fluid supply system ( 150 ) according to any one of claims 1 to 7, wherein the control device ( 70 ) to control the intake characteristics of the primary piston ( 115 ) taking into account at least one factor relevant to a current operating state of the fluid supply system ( 150) indicative operating parameters, especially taking into account a combination of several operating parameters. [9] Fluid supply system ( 150 ) according to claim 8, wherein the at least one operating parameter is selected from a group consisting of a stroke volume of at least one of the piston pumps ( 111 , 112 ), a total fluid flow rate downstream of the secondary piston pump ( 112 ), ingredients or constituents of the fluidic components (A to D), physical and / or chemical properties of the fluidic components (A to D), relative proportions of the fluidic components to be combined (A to D), and a gradient steepness, i.e. a rate of change of relative proportions of the combined fluidic components (A to D) of the fluid. [10] Fluid supply system ( 150 ) according to claim 8 or 9, wherein the control device ( 70) is designed to apply a combination of several operating parameters to a predefined map as a basis for controlling the intake characteristics, which, depending on the current values ​​of the combined operating parameters, creates a movement profile ( I ) for the primary piston ( 115 ) specifies. [11] Fluid supply system ( 150 ) according to claim 10, wherein the characteristic map is empirically determined, modeled, projected or preconfigured. [12] Fluid supply system ( 150 ) according to any one of claims 1 to 11, further comprising at least one of the following features: the feeding device ( 25 ) has a plurality of supply lines ( 104 until 107 ), each of which is fluidic with a fluid component source ( 100 until 103 ) to provide a respective fluidic component (A to D) is fluidically coupled, and a proportioning valve ( 108) that between the supply lines ( 104 until 107 ) and the primary piston pump ( 111 ) is arranged, wherein the proportioning valve ( 108 ) by means of the control unit ( 70 ) for modulating the composition of the fluid from packages of fluidic components (A to D) upstream of the primary piston pump ( 111 ) by sequentially coupling selected of the supply lines ( 104 until 107 ) with the primary piston pump ( 111 ) is controllable; the control unit ( 70 ) is used to control the primary piston ( 115 ) designed in such a way that its movement profile ( I ) in the primary piston chamber ( 117 ) in accordance with a predetermined intake flow rate threshold, which results in a minimum delivery velocity of the primary piston pump ( 111 ) corresponds; the controlled intake characteristic of the primary piston (115 ) is designed in such a way that it promotes the mixing of the several fluidic components (A to D) and / or inhibits the separation of the several fluidic components (A to D). [13] Sample separation device ( 10 ) for separating a fluidic sample in a mobile phase into fractions, wherein the sample separation device ( 10 ) shows: a fluid supply system ( 150 ) according to any one of claims 1 to 12 for providing the mobile phase as the fluid to a fluid consumer ( 30 ); and the fluid pickup designed as a sample separation device ( 30 ) to separate the different fractions of the sample in the mobile phase. [14] Sample separation device ( 10 ) according to claim 13, further comprising at least one of the following features: the sample separation device ( 30) is designed as a chromatographic separation device, in particular as a chromatographic separation column; the sample separation device ( 10 ) is configured to analyze at least one physical, chemical and / or biological parameter of at least one fraction of the fluidic sample; the sample separation device ( 10 ) has at least one of the following components: a chemical, biological and / or pharmaceutical analysis instrument, a liquid chromatography instrument and an HPLC instrument; the piston pumps ( 111 , 112 ) are configured to drive the mobile phase with high pressure; the piston pumps ( 111 , 112 ) are configured to drive the mobile phase with a pressure of at least 100 bar, in particular at least 500 bar, and further in particular at least 1000 bar; the sample separation device ( 10) is configured as a microfluidic device; the sample separation device ( 10 ) is configured as a nanofluidic device; the sample separation device ( 10 ) has an injector device ( 40 ) to introduce the fluidic sample into the fluidic path between the piston pumps ( 111 , 112 ) and the sample separation device ( 30 ) on; the sample separation device ( 10 ) has a detector ( 50 ) to detect the separated factions; the sample separation device ( 10 ) features a sample fractionator ( 60 ) to divide the separate factions. [15] Method for supplying a fluid to a fluid consumer ( 30 ), wherein the procedure exhibits: Supplying the fluid composed of several fluidic components (A to D) to a primary piston pump ( 111), which are used to pump the fluid into a primary piston chamber ( 117 ) reciprocating primary piston ( 115 ) exhibits; Control of the primary piston ( 115 ) such that regardless of a downstream of the primary piston ( 115 ) arranged fluidic component ( 118 ) an intake characteristic of the primary piston ( 115 ) depending on the composition of the fluid from the several fluidic components (A to D) is adjusted such that the fluid consumer ( 30 ) a homogeneously composed fluid is provided. [16] Method according to claim 15, further comprising supplying the by means of the primary piston pump ( 111 ) pumped fluids to a secondary piston pump ( 112 ), which are used to pump the fluid into a secondary piston chamber ( 120 ) reciprocating secondary piston ( 118 ) as the fluidic component. [17] Method according to claim 15 or 16, wherein controlling the intake characteristic of the primary piston ( 115 ) is carried out based on at least one operating parameter indicative of a current fluidic operating state, in particular taking into account a combination of several operating parameters. [18] Method according to one of claims 15 to 17, wherein a combination of current values ​​of several of the operating parameters is applied to a predetermined map as the basis for controlling the intake characteristics, which, depending on the current values ​​of the combined operating parameters, produces a movement profile ( I ) for the primary piston ( 115 ) specifies. [19] Method according to claim 18, wherein the characteristic map is generated by performing a characteristic map calibration prior to supplying fluid to the fluid consumer ( 30 ): the primary piston pump ( 111) and the secondary piston pump ( 112 ) using parameter sets with different values ​​of the operating parameters; fluid is supplied; for each set of different values ​​of operating parameters a target movement profile ( I ) of the primary piston ( 115 ) is determined, with which a given homogeneity criterion for the homogeneity of the fluid downstream of the secondary piston pump ( 112 ) is fulfilled; and for each set of different values ​​of operating parameters, the target motion profile that fulfills the homogeneity criterion ( I ) is stored as part of the characteristic map. [20] Method according to claim 19, further comprising at least one of the following features: The generated characteristic map is used for a class of sample separation devices ( 10) used; a respective entry in the generated characteristic map is changed if it is recognized that the changed entry improves the homogeneity of the fluid composition.

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