Quaternary gradient pump system

Abstract

The utility model discloses a quaternary gradient pump system, which relates to the technical field of liquid chromatography and comprises a solvent bottle, a mixer, a piston pump and a controller. A mobile phase containing a sample is stored in the solvent bottle, and a sample outlet pipe of the solvent bottle is connected with a corresponding sample inlet of the mixer to provide the mobile phase for the mixer; the mixer mixes the mobile phases to obtain a mixed mobile phase, and a sample outlet of the mixer is connected with an inlet pipeline of the piston pump to provide the mixed mobile phase for the piston pump; the piston pump comprises two opposite pump cavities, a common piston rod and a driving device; two ends of the common piston rod are respectively positioned in the two pump cavities and are driven by the driving device to reciprocate at a constant speed, so that the piston pump pumps a mixed mobile phase at a constant speed; and the driving device is electrically connected with the controller, receives the flow control command and controls the speed of the reciprocating motion. According to the system, the precision, stability, consistency and low pulsatility of the pumping flow are improved, so that the repeatability and reliability of an analysis result are ensured.

Description

Technical Field

[0001] This utility model relates to the field of liquid chromatography analysis technology, and more specifically to a quaternary gradient pump system for liquid chromatography analysis. Background Technology

[0002] High-performance liquid chromatography (HPLC) is a laboratory instrument used to separate, identify, and quantify the components in a mixture. It is widely used in fields such as chemistry, biochemistry, pharmaceuticals, and environmental monitoring.

[0003] The basic principle of liquid chromatography (LC) is based on the distribution of different components in a sample between the stationary and mobile phases. Driven by the mobile phase, different components in the sample are separated according to their different affinities with the stationary phase. After separation, the components are detected by a detector, and data is output, ultimately forming a chromatogram to achieve the analysis of the sample components. The mobile phase can be a single solvent or a mixture of multiple solvents. In LC, the mobile phase acts as a sample carrier, propelling the sample through the chromatographic column, allowing the sample to interact with the stationary phase and achieve separation. To meet the experimental needs of multi-sample analysis, binary or quaternary gradient pump systems are typically used to simultaneously control the mixed input of different samples. Furthermore, to ensure the reproducibility and reliability of the analytical results, as well as better separation effects, the flow rate of the mobile phase should remain stable and consistent. Therefore, higher requirements are placed on the flow control accuracy, stability, and low pulsation of the LC mobile phase pumping system. However, existing gradient pump systems typically operate by alternating between two or more piston pumps. Gradient pump systems have many components and pipelines, are complex to manufacture, have high manufacturing costs, and require long cleaning times for each experiment. Furthermore, they require synchronous control of the piston movement in the piston pump to achieve a stable pumping flow rate. When there is a deviation in the synchronous control, or when there is a delay or deviation in the control due to play between the drive unit and the piston, pulsating pumping is likely to occur, resulting in poor stability of the pumping flow rate.

[0004] Therefore, how to improve the stability and consistency of the pumping flow rate of a gradient pump system is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the present invention provides a quaternary gradient pump system, which controls the mixing ratio of sample mobile phases in different solvent bottles through a mixer, and improves the output stability of the piston pump through an improved dual-chamber shared piston rod, thereby improving the pumping flow stability and consistency of the gradient pump system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This utility model discloses a quaternary gradient pump system, including: a solvent bottle, a mixer, a piston pump, and a controller;

[0008] The solvent bottle stores the mobile phase containing the sample, and the sample outlet tube of the solvent bottle is connected to the corresponding inlet of the mixer to provide the mobile phase to the mixer;

[0009] The mixer mixes the mobile phase to obtain a mixed mobile phase. The outlet of the mixer is connected to the inlet pipe of the piston pump to provide the mixed mobile phase to the piston pump.

[0010] The piston pump includes two opposing pump chambers, a common piston rod, and a drive device; the two ends of the common piston rod are located in the two pump chambers respectively, and reciprocate at a constant speed under the drive device, so that the piston pump pumps the mixed mobile phase at a constant speed; the drive device is electrically connected to the controller, receives flow control commands, and controls the speed of the reciprocating motion.

[0011] Furthermore, the mixer is also provided with a flushing inlet, which is connected to a flushing solution bottle pipeline. The flushing inlet is provided with a flushing solenoid valve, which is electrically connected to the controller and receives the switch signal from the controller to provide flushing solution to the mixer and the piston pump.

[0012] Furthermore, the mixer's inlet includes a first inlet, a second inlet, a third inlet, and a fourth inlet; each inlet is equipped with a solenoid valve; the solenoid valve is electrically connected to the controller, receives pulse signals from the controller, and intermittently switches on and off according to the pulse signals to allow the mobile phase to enter the mixer for mixing, thereby obtaining the mixed mobile phase.

[0013] Furthermore, the solvent bottle includes a first solvent bottle, a second solvent bottle, a third solvent bottle, and a fourth solvent bottle corresponding to the first injection port, the second injection port, the third injection port, and the fourth injection port; the top of the solvent bottles is connected by a connecting pipe to ensure that the gas pressure in each solvent bottle is equal.

[0014] Furthermore, it also includes a bidirectional air pump, which is connected to the connecting pipeline; the bidirectional air pump is electrically connected to the controller, and when it receives a degassing command, it evacuates the solvent bottle to allow the dissolved air in the mobile phase inside the solvent bottle to escape under low pressure, and when it receives a pressurization command, it pressurizes the solvent bottle to provide an initial flow pressure for the mobile phase inside the solvent bottle.

[0015] Furthermore, the common piston rod includes a first column and a second column, wherein the cross-sectional area of ​​the first column is twice the cross-sectional area of ​​the second column.

[0016] Furthermore, the pump chamber and the common piston rod are slidably connected by a sealing ring. The pump chamber includes a first pump chamber and a second pump chamber. The first column is slidably connected to the first pump chamber, and the second column is slidably connected to the second pump chamber. There are gaps between the first column and the cavity of the first pump chamber, and between the second column and the cavity of the second pump chamber, so that the mixed mobile phase can flow freely in the cavity.

[0017] Furthermore, a channel is provided between the first pump chamber and the second pump chamber, and a one-way valve is provided in the channel to allow the mixed flow phase pumped out of the first pump chamber to flow unidirectionally into the second pump chamber.

[0018] Furthermore, the inlet of the piston pump is located on the side of the first pump chamber, and the inlet is equipped with an inlet valve;

[0019] The outlet of the piston pump is located on the second pump chamber side, and the outlet is equipped with an outlet valve;

[0020] The inlet valve is electrically connected to the drive device. When the drive device controls the first column to enter the first pump chamber, the inlet valve is closed; when the drive device controls the first column to be withdrawn from the first pump chamber, the inlet valve is opened.

[0021] Furthermore, the outlet valve has a mixed mobile phase outlet and a waste liquid outlet. The mixed mobile phase outlet is connected to the inlet of the chromatographic column of the liquid chromatograph, and the waste liquid outlet is connected to the pipeline of the waste liquid collection device. The outlet valve is electrically connected to the controller, and controls the opening and closing of the mixed mobile phase outlet and the waste liquid outlet according to the command issued by the controller.

[0022] Furthermore, the function of each component is explained using the general procedure of a liquid chromatography analysis experiment. The general procedure is as follows:

[0023] Different mobile phases containing samples are placed into different solvent bottles. The solvent bottle caps are equipped with sample outlet tubes and connecting pipe interfaces. After tightening the caps, the bottles are sealed to the mixer and connecting pipes. One end of the sample outlet tube is located at the bottom of the solvent bottle. The rinsing solution bottle is filled with rinsing solution and connected to the mixer rinsing inlet via tubing.

[0024] The controller sends a degassing command, and the bidirectional pump draws air to degas the mobile phase in each solvent bottle. After the set degassing time is reached, the controller sends a pressurization command, and the bidirectional pump pumps the helium stored in the gas storage bottle into the solvent bottle to pressurize each solvent bottle and ensure that the mobile phase in the solvent bottle can flow out of the solvent bottle during the experiment. Each solvent bottle has the same height and the same gas pressure inside the bottle, thereby ensuring that the mobile phase pressure at the sample inlet of the mixer is the same. Combined with the pulse control command, the mixing ratio of the mobile phase of each sample is precisely controlled.

[0025] The controller simultaneously sends an open command to the flushing solenoid valve, a start command to the piston pump drive unit, and a command to the piston pump outlet valve to close the mixed mobile phase outlet and open the waste liquid outlet to perform the cleaning operation; after cleaning is completed, the flushing solenoid valve is closed, the piston pump is stopped, the waste liquid outlet is closed, and the mixed mobile phase outlet is opened.

[0026] The controller sends different pulse signals to different solenoid valves according to the set mixing ratio. The solenoid valve opens at the upper edge of each pulse and automatically closes at the lower edge, thereby controlling the opening time of the solenoid valve pulse and thus controlling the mixing ratio of different mobile phases to ensure accurate gradient elution in the experiment.

[0027] As can be seen from the above technical solution, compared with the prior art, this utility model discloses a quaternary gradient pump system. By connecting multiple solvent bottles through connecting pipes, the gas pressure in each bottle can be made as equal as possible, thereby reducing the impact of pressure differences on the uniformity of mobile phase delivery. Combined with solenoid valves and pulse signals, it can achieve efficient mixing of different mobile phases, thus obtaining accurate gradient elution in liquid chromatography analysis. The removal of dissolved air by a bidirectional gas pump reduces the generation of bubbles in the gradient pump system, improving the accuracy of flow control. Precise flow control is achieved by accurately adjusting the reciprocating speed of the piston pump to meet different experimental requirements. The dual-chamber structure with a shared piston rod and the combination of channels and one-way valves ensure the stability and low pulsation of the mixed mobile phase pump flow rate. This system improves the accuracy, stability, consistency, and low pulsation of the pump flow rate, thereby ensuring the repeatability and reliability of analytical results. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of the present utility model.

[0030] Figure 2 A schematic diagram of the mixer structure provided for an embodiment of this utility model.

[0031] Figure 3 A schematic cross-sectional view of the piston pump provided in an embodiment of this utility model.

[0032] In the diagram, 1 is the mixer; 2 is the piston pump; 11 is the first injection port; 12 is the second injection port; 13 is the third injection port; 14 is the fourth injection port; 15 is the flushing injection port; 21 is the first column; 22 is the second column; 23 is the first pump chamber; 24 is the second pump chamber; 25 is the channel; 26 is the one-way valve; 27 is the inlet; 28 is the outlet; and 29 is the connection part. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] This utility model discloses a quaternary gradient pump system, such as Figure 1 As shown, it includes: solvent bottle, mixer 1, piston pump 2, and controller;

[0035] The solvent bottle stores the mobile phase containing the sample, and the outlet tube of the solvent bottle is connected to the corresponding inlet of the mixer 1 to provide the mobile phase to the mixer 1;

[0036] Mixer 1 mixes the mobile phase to obtain a mixed mobile phase. The outlet of mixer 1 is connected to the inlet pipe of piston pump 2 to provide the mixed mobile phase to piston pump 2.

[0037] The piston pump 2 includes two opposing pump chambers, a common piston rod, and a drive device; the two ends of the common piston rod are located in the two pump chambers respectively, and reciprocate at a constant speed under the drive of the drive device, so that the piston pump 2 pumps the mixed mobile phase at a constant speed; the drive device is electrically connected to the controller, receives the flow control command, and controls the speed of the reciprocating motion.

[0038] In a specific embodiment, such as Figure 2 As shown, the mixer 1 is also provided with a flushing inlet 15, which is connected to the flushing solution bottle pipeline. The flushing inlet 15 is provided with a flushing solenoid valve, which is electrically connected to the controller and receives the switch signal from the controller to provide flushing solution to the mixer 1 and the piston pump 2.

[0039] Furthermore, the sample inlets of the mixer 1 include: a first sample inlet 11, a second sample inlet 12, a third sample inlet 13 and a fourth sample inlet 14; each sample inlet is equipped with a solenoid valve; the solenoid valve is electrically connected to the controller, receives the pulse signal sent by the controller, and switches intermittently according to the pulse signal to allow the mobile phase to enter the mixer 1 for mixing, thereby obtaining a mixed mobile phase.

[0040] In one specific embodiment, the solvent bottle includes a first solvent bottle, a second solvent bottle, a third solvent bottle, and a fourth solvent bottle corresponding to the first inlet 11, the second inlet 12, the third inlet 13, and the fourth inlet 14; the top of the solvent bottles is connected by a connecting pipe to make the gas pressure in each solvent bottle equal.

[0041] In one specific embodiment, the system further includes a bidirectional air pump connected to a connecting pipeline; the bidirectional air pump is electrically connected to a controller, and upon receiving a degassing command, it evacuates the solvent bottle to allow dissolved air in the mobile phase inside the solvent bottle to escape under low pressure; upon receiving a pressurization command, it pressurizes the solvent bottle to provide initial flow pressure for the mobile phase inside the solvent bottle.

[0042] In a specific embodiment, such as Figure 3 As shown, the common piston rod includes a first column 21 and a second column 22, the cross-sectional area of ​​the first column 21 being twice the cross-sectional area of ​​the second column 22. A connecting part 29 is provided between the first column 21 and the second column 22, and the connecting part 29 is fixedly connected to the driving device, so that the common piston rod reciprocates at a uniform speed under the drive of the driving device, which includes a linear motor and a drive controller.

[0043] Furthermore, the pump chamber and the common piston rod are slidably connected by a sealing ring. The pump chamber includes a first pump chamber 23 and a second pump chamber 24. The first column 21 is slidably connected to the first pump chamber 23, and the second column 22 is slidably connected to the second pump chamber 24. The cross-sectional area of ​​the first column 21 is smaller than the cavity cross-sectional area of ​​the first pump chamber 23, so that there are gaps between the first column 21 and the cavity of the first pump chamber 23, and between the second column 22 and the cavity of the second pump chamber 24, so that the mixed mobile phase can flow freely in the cavity.

[0044] Furthermore, a channel 25 is provided between the first pump chamber 23 and the second pump chamber 24, and a one-way valve 26 is provided in the channel 25 to allow the mixed flow phase pumped out of the first pump chamber 23 to flow into the second pump chamber 24 in one direction.

[0045] Furthermore, the inlet 27 of the piston pump 2 is located on the first pump chamber side, and the inlet 27 is equipped with an inlet valve; the outlet 28 of the piston pump 2 is located on the second pump chamber side, and the outlet 28 is equipped with an outlet valve.

[0046] The inlet valve is electrically connected to the drive device. When the drive device controls the first column 21 to enter the first pump chamber 23, the inlet valve is closed; when the drive device controls the first column 21 to be withdrawn from the first pump chamber 23, the inlet valve is opened.

[0047] Specifically, the drive controller controls the linear motor to move at a constant speed, driving the common piston rod to move towards the first pump chamber 23. At this time, the inlet valve is closed, and the one-way valve 26 is in the open state (e.g., Figure 3As shown, the one-way valve disc is a ball located between the limiting seal ring and the support structure (the spring between the valve disc and the support structure is not shown). The flowing phase in the first pump chamber 23 flows into the second pump chamber 24. Since the cross-sectional area of ​​the first column 21 is twice the cross-sectional area of ​​the second column 22, the reduction in volume of the first pump chamber 23 is twice the increase in volume of the second pump chamber 24. Half of the flowing phase flowing out of the first pump chamber 23 is temporarily stored in the second pump chamber 24, and the other half is pumped out of the piston pump 2.

[0048] The drive controller controls the linear motor to move at a constant speed, driving the common piston rod to move towards the second pump chamber 24, and simultaneously sends an opening command to the inlet valve. At this time, the one-way valve 26 is in the closed state, and the mobile phase enters the first pump chamber 23 through the inlet 27; the second column 22 squeezes and pumps the mobile phase in the second pump chamber 24 out.

[0049] During the reciprocating motion, the actual pumping speed of the piston pump 2 is half of the product of the cross-sectional area of ​​the first column 21 and the uniform motion speed, and the product of the cross-sectional area of ​​the second column 22 and the uniform motion speed. The two are equal in size. Since the volume changes of the first pump chamber 23 and the second pump chamber 24 are completely synchronized, the pumping flow rate of the piston pump 2 during the uniform reciprocating motion can be ensured to be stable and consistent.

[0050] In one specific embodiment, the outlet valve has a mixed mobile phase outlet and a waste liquid outlet. The mixed mobile phase outlet is connected to the inlet of the chromatographic column of the liquid chromatograph, and the waste liquid outlet is connected to the pipeline of a waste liquid collection device. The outlet valve is electrically connected to a controller, which controls the opening and closing of the mixed mobile phase outlet and the waste liquid outlet according to commands issued by the controller. A damper can also be installed after the mixed mobile phase outlet to further reduce the pumping pulsation of the gradient pump system.

[0051] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0052] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A quaternary gradient pump system, characterized in that, include: Solvent bottle, mixer (1), piston pump (2), controller; The solvent bottle stores the mobile phase containing the sample, and the outlet tube of the solvent bottle is connected to the corresponding inlet of the mixer (1) to provide the mobile phase to the mixer (1); The mixer (1) mixes the mobile phase to obtain a mixed mobile phase. The outlet of the mixer (1) is connected to the inlet pipe of the piston pump (2) to provide the mixed mobile phase to the piston pump (2). The piston pump (2) includes two opposing pump chambers, a common piston rod, and a drive device; The two ends of the common piston rod are located in the two pump chambers respectively. Under the drive of the drive device, it reciprocates at a constant speed, so that the piston pump (2) pumps the mixed flow phase at a constant speed. The drive device is electrically connected to the controller, receives the flow control command, and controls the speed of the reciprocating motion.

2. The quaternary gradient pump system according to claim 1, characterized in that, The mixer (1) is also provided with a flushing inlet (15), which is connected to the flushing liquid bottle pipeline. The flushing inlet (15) is provided with a flushing solenoid valve, which is electrically connected to the controller and receives the switch signal from the controller to provide flushing liquid to the mixer (1) and the piston pump (2).

3. The quaternary gradient pump system according to claim 1, characterized in that, The mixer (1) has the following inlets: a first inlet (11), a second inlet (12), a third inlet (13), and a fourth inlet (14); each inlet is equipped with a solenoid valve; the solenoid valve is electrically connected to the controller, receives the pulse signal sent by the controller, and switches intermittently according to the pulse signal to allow the mobile phase to enter the mixer (1) for mixing, thereby obtaining the mixed mobile phase.

4. A quaternary gradient pump system according to claim 3, characterized in that, The solvent bottles include a first solvent bottle, a second solvent bottle, a third solvent bottle, and a fourth solvent bottle corresponding to the first inlet (11), the second inlet (12), the third inlet (13), and the fourth inlet (14); the tops of the solvent bottles are connected by a connecting pipe to make the gas pressure in each solvent bottle equal.

5. A quaternary gradient pump system according to claim 4, characterized in that, It also includes a bidirectional air pump, which is connected to the connecting pipeline; the bidirectional air pump is electrically connected to the controller, and when it receives a degassing command, it evacuates the solvent bottle to allow the dissolved air in the mobile phase inside the solvent bottle to escape under low pressure, and when it receives a pressurization command, it pressurizes the solvent bottle to provide an initial flow pressure for the mobile phase inside the solvent bottle.

6. A quaternary gradient pump system according to claim 1, characterized in that, The common piston rod includes a first column (21) and a second column (22), wherein the cross-sectional area of ​​the first column (21) is twice the cross-sectional area of ​​the second column (22).

7. A quaternary gradient pump system according to claim 6, characterized in that, The pump chamber and the common piston rod are slidably connected by a sealing ring. The pump chamber includes a first pump chamber (23) and a second pump chamber (24). The first column (21) is slidably connected to the first pump chamber (23), and the second column (22) is slidably connected to the second pump chamber (24). There are gaps between the cavity of the first column (21) and the cavity of the first pump chamber (23), and between the cavity of the second column (22) and the cavity of the second pump chamber (24), so that the mixed mobile phase can flow freely in the cavity.

8. A quaternary gradient pump system according to claim 7, characterized in that, A channel (25) is provided between the first pump chamber (23) and the second pump chamber (24), and a one-way valve (26) is provided in the channel (25) so that the mixed flow phase pumped out by the first pump chamber (23) flows into the second pump chamber (24) in one direction.

9. A quaternary gradient pump system according to claim 7, characterized in that, The inlet (27) of the piston pump (2) is located on the first pump chamber side, and the inlet (27) is provided with an inlet valve; The outlet (28) of the piston pump (2) is located on the second pump chamber side, and the outlet (28) is provided with an outlet valve; The inlet valve is electrically connected to the drive device. When the drive device controls the first column (21) to enter the first pump chamber (23), the inlet valve is closed; when the drive device controls the first column (21) to be withdrawn from the first pump chamber (23), the inlet valve is opened.

10. A quaternary gradient pump system according to claim 9, characterized in that, The outlet valve has a mixed mobile phase outlet and a waste liquid outlet. The mixed mobile phase outlet is connected to the inlet of the chromatographic column of the liquid chromatograph, and the waste liquid outlet is connected to the pipeline of the waste liquid collection device. The outlet valve is electrically connected to the controller and controls the opening and closing of the mixed mobile phase outlet and the waste liquid outlet according to the command issued by the controller.

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