阅读说明：本技术 多模式色谱溶剂管理系统及其控制方法 (Multi-mode chromatography solvent management system and control method thereof ) 是由 杨三东 封娇 王丰琳 于德秀 唐涛 李彤 于 2020-07-20 设计创作，主要内容包括：本发明公开了一种多模式色谱溶剂管理系统及其控制方法,包括至少两个泵头,每个所述泵头均对应一个切换阀,所述切换阀至少有两个流体进口和两个流体出口,所述泵头进口、出口分别通过流体管路,与对应的所述切换阀连通,并在所述流体管路上分别串接有压力变送器和单向阀；所述切换阀还与溶剂瓶连通；每个所述切换阀的流体出口均通过流体管路汇集至一处总出口；本发明结构合理、简单,通过监控流路中压力的变化,进而改变切换阀与泵头的工作状态实现多泵头同步工作下完成纳升梯度输液,流量准确、精度高；还可以调整为多泵头顺序输液,实现微升或毫升流量下连续输液,压力稳定且流体脉动小。(The invention discloses a multi-mode chromatography solvent management system and a control method thereof, wherein the multi-mode chromatography solvent management system comprises at least two pump heads, each pump head corresponds to a switching valve, the switching valve is provided with at least two fluid inlets and two fluid outlets, the inlet and the outlet of each pump head are respectively communicated with the corresponding switching valve through fluid pipelines, and the fluid pipelines are respectively connected with a pressure transmitter and a one-way valve in series; the switching valve is also communicated with a solvent bottle; the fluid outlet of each switching valve is converged to a main outlet through a fluid pipeline; the invention has reasonable and simple structure, changes the working state of the switching valve and the pump heads by monitoring the pressure change in the flow path so as to complete nano-liter gradient transfusion under the synchronous work of the multiple pump heads, and has accurate flow and high precision; the infusion pump can also be adjusted to multi-pump head sequential infusion, realizes continuous infusion under microliter or milliliter flow, and has stable pressure and small fluid pulsation.)

1. A multimodal chromatography solvent management system comprising at least two fluid transport units;

the fluid delivery unit includes: the device comprises a pump head (7), a pressure transmitter (8), a switching valve (9), a solvent bottle (11) and a one-way valve (12);

the pump head (7) is respectively provided with a solvent inlet (702) and a solvent outlet (701); the switching valve (9) is a multi-channel switching valve, and is provided with at least two fluid inlets and two fluid outlets which are respectively a first fluid inlet, a second fluid inlet, a first fluid outlet and a second fluid outlet;

the solvent outlet (701) is communicated with the first fluid inlet of the switching valve (9) through a fluid pipeline, and the pressure transmitter (8) is connected in series on the fluid pipeline;

the solvent inlet (702) is communicated with the first fluid outlet of the switching valve (9) through a fluid pipeline, and the one-way valve (12) is connected in series on the fluid pipeline; the second fluid inlet of the switching valve (9) is communicated with the solvent bottle (11);

a second fluid outlet of the switching valve (9) is set as a fluid outlet of the fluid delivery unit; the fluid outlets of the fluid delivery units are each connected to a fluid mixer (10) by a fluid line.

2. The management system according to claim 1, wherein the check valve (12) is a ball seat type check valve, and a direction in which the fluid can pass through the check valve (12) is from the first fluid outlet end to the solvent inlet (702) end.

3. The management system according to claim 1, wherein the switching valve (9) is a six-way valve, and is composed of a stator and a rotor, the surface of the stator is provided with 6 interfaces along the circumferential direction, the rotor is internally provided with 3 channels, and outlets at two ends of the channels respectively correspond to the interfaces of the surface of the stator.

4. The management system of claim 3, wherein the switching valve surface interfaces are numbered sequentially to form ports 1-6, port 1 is the first fluid inlet, port 4 is the second fluid inlet, port 5 is the first fluid outlet, port 2 is the second fluid outlet, and ports 3 and 6 are provided with plugs.

5. The management system of claim 3, wherein one end of the rotor is connected to a rotating mechanism, the rotating mechanism is a speed reducer and a motor, or the rotating mechanism is a servo motor.

6. A control method based on a multimode chromatography solvent management system is characterized by comprising the following specific steps:

s1, adjusting the switching valve to a state that the second fluid inlet is communicated with the first fluid outlet and the first fluid inlet is not communicated with the second fluid outlet, starting the pump head to enter a liquid suction stage, and allowing the solvent in the solvent bottle to sequentially pass through the switching valve and the one-way valve under the action of negative pressure to enter the cavity of the pump head;

s2, after the fluid suction phase of the pump head is finished, adjusting the switching valve to a state where the second fluid inlet is not communicated with the first fluid outlet, and the first fluid inlet is communicated with the second fluid outlet, and the pump head enters a fluid infusion phase; the solvent in the cavity of the pump head flows out sequentially through the pressure transmitter and the switching valve under the positive pressure; the pressure measurement in the fluid pipeline is displayed by a pressure transmitter, and information is fed back to a control circuit, the power of a pump head is adjusted by the control circuit, and the pressure in a flow path is stabilized;

and S3, after the pump head infusion stage is finished, repeating the steps S1-S2 until the infusion task is finished.

7. The control method according to claim 6, wherein all the fluid delivery units in the management system perform the steps of S1-S3 at the same time, and each step is performed at the same time.

8. The control method according to claim 6, wherein the fluid delivery unit sequentially performs the steps of S1-S2; and when the last fluid delivery unit executing the infusion task in the system finishes the infusion task, the first fluid delivery unit executing the infusion task executes the infusion task again to form an infusion cycle consisting of all the fluid delivery units until the infusion task is finished.

9. The control method according to claim 8, wherein in the execution sequence of the fluid delivery units, the execution cycles of any two adjacent fluid delivery units have an overlapping interval, namely, the fluid delivery unit which executes infusion later completes the imbibing stage before the infusion of the pump head of the previous fluid delivery unit is stopped and enters the infusion stage, but the corresponding infusion flow path is not opened, and the pump head forms pre-compression on the fluid in the cavity; the control circuit controls the compression state of the pump head, so that the fluid pressure generated by the rear infusion pump head is consistent with the infusion pressure of the pump head of the first infusion fluid conveying unit; when the infusion stage of the first infusion fluid delivery unit is finished, the control circuit adjusts the corresponding switching valve to close the infusion flow path of the first infusion fluid delivery unit and open the infusion flow path of the second infusion fluid delivery unit.

Technical Field

The invention relates to a solvent conveying system, in particular to a multi-mode chromatography solvent management system and a control method thereof.

Background

In recent years, high performance liquid chromatography has played an increasingly important role in drug analysis, food analysis, analysis of harmful substances in the environment, and biomacromolecule analysis in the biochemical field. The infusion pump is one of the core components of the high performance liquid chromatograph, and the application range and performance parameters of the infusion pump are continuously changed along with the development of chromatographic technology. For example, the transfusion flow index undergoes the development change from milliliter grade to micro-upgrade or nano-upgrade, the maximum pressure resistance of the system is gradually increased from 40MPa to 60MPa, and the maximum pressure resistance can exceed 130MPa at present. With the continuous expansion of the application field, the specificity of the instrument is gradually enhanced, and parameters such as the flow range are gradually differentiated. At present, chromatographs have been developed into various product series, for example, preparative liquid chromatography using a flow rate of several tens milliliters to several hundreds milliliters per minute, analytical liquid chromatography using several tens microliters to several milliliters per minute, nanoliter liquid chromatography using several hundreds nanoliters to several microliters per minute, and the like.

A nano-liter liquid chromatography infusion pump is an extremely high precision infusion system that tends to use a high precision motor to directly drive the plunger in motion with much higher precision than conventional cam drives (CN 105822521B). Other physical phenomena that are not mechanically driven can also be used (CN1207568C) due to the small flow of nanoliters. Patent CN108445120B discloses a binary gradient solvent delivery system, which utilizes a single switching valve device and 2 injection infusion pump heads to realize 2 kinds of imbibition and gradient infusion to mobile phase, avoiding the influence of one-way valve on infusion process under low flow. However, the main disadvantage of the injection type nano-liter pump is that the pump chamber volume is limited, and only a single analysis can be performed at a nano-liter flow rate, so the range of use is limited.

For users who have requirements for both nano-scale and milli-scale flow rates, it is often necessary to purchase two sets of chromatography systems with different flow ranges, which increases the purchase, use and maintenance costs of the instrument. Therefore, how to expand the flow range of the chromatographic infusion pump on the premise of ensuring the infusion precision is one of the problems to be solved for developing the liquid chromatographic system.

Disclosure of Invention

In view of the above, the present invention provides a multi-mode chromatography solvent management system and a control method thereof, which can solve the above problems.

For this purpose, the present invention is implemented by the following technical means.

A multi-modal chromatography solvent management system comprising at least two fluid transport units;

the fluid delivery unit includes: the device comprises a pump head, a pressure transmitter, a switching valve, a solvent bottle and a one-way valve;

the pump head is respectively provided with a solvent inlet and a solvent outlet; the switching valve is a multi-channel switching valve, and at least comprises two fluid inlets and two fluid outlets which are respectively a first fluid inlet, a second fluid inlet, a first fluid outlet and a second fluid outlet;

the solvent outlet is communicated with the first fluid inlet of the switching valve through a fluid pipeline, and the pressure transmitter is connected to the fluid pipeline in series;

the solvent inlet is communicated with the first fluid outlet of the switching valve through a fluid pipeline, and the one-way valve is connected to the fluid pipeline in series; the second fluid inlet of the switching valve is communicated with the solvent bottle;

the second fluid outlet of the switching valve is set as the fluid outlet of the fluid conveying unit; the fluid outlets of the fluid delivery units are connected to the fluid mixer through fluid lines.

Further, the check valve is a ball seat type check valve in which a fluid can pass from the first fluid outlet end to the solvent inlet end.

Further, the switching valve is a six-way valve and comprises a stator and a rotor, 6 interfaces are arranged on the surface of the stator along the circumferential direction, 3 channels are arranged inside the rotor, and outlets at two ends of each channel respectively correspond to the interfaces on the surface of the stator.

Furthermore, the surface interfaces of the switching valve are sequentially numbered to form a port 1-6, the port 1 is the first fluid inlet, the port 4 is the second fluid inlet, the port 5 is the first fluid outlet, the port 2 is the second fluid outlet, and the ports 3 and 6 are provided with the plug.

Furthermore, one end of the rotor is connected with a rotating mechanism, and the rotating mechanism is a speed reducer and a motor, or the rotating mechanism is a servo motor.

On the other hand, the invention provides a control method based on a multi-mode chromatography solvent management system, which comprises the following specific steps:

s1, adjusting the switching valve to a state that the second fluid inlet is communicated with the first fluid outlet and the first fluid inlet is not communicated with the second fluid outlet, starting the pump head to enter a liquid suction stage, and allowing the solvent in the solvent bottle to sequentially pass through the switching valve and the one-way valve under the action of negative pressure to enter the cavity of the pump head;

s2, after the fluid suction phase of the pump head is finished, adjusting the switching valve to a state where the second fluid inlet is not communicated with the first fluid outlet, and the first fluid inlet is communicated with the second fluid outlet, and the pump head enters a fluid infusion phase; the solvent in the cavity of the pump head flows out sequentially through the pressure transmitter and the switching valve under the positive pressure; the pressure measurement in the fluid pipeline is displayed by a pressure transmitter, and information is fed back to a control circuit, the power of a pump head is adjusted by the control circuit, and the pressure in a flow path is stabilized;

and S3, after the pump head infusion stage is finished, repeating the steps S1-S2 until the infusion task is finished.

Further, all the fluid delivery units in the management system perform the steps of S1-S3 at the same time, and the execution time of each step is the same.

Further, the fluid delivery unit sequentially performs the steps of S1-S2; and when the last fluid delivery unit executing the infusion task in the system finishes the infusion task, the first fluid delivery unit executing the infusion task executes the infusion task again to form an infusion cycle consisting of all the fluid delivery units until the infusion task is finished.

Furthermore, in the execution sequence of the fluid delivery units, the execution cycles of any two adjacent fluid delivery units have an overlapping interval, namely, the fluid delivery unit which executes infusion later completes the imbibing stage before the infusion of the pump head of the previous fluid delivery unit is stopped, and enters the infusion stage, but does not open the corresponding infusion flow path, and the pump head forms pre-compression on the fluid in the cavity; the control circuit controls the compression state of the pump head, so that the fluid pressure generated by the rear infusion pump head is consistent with the infusion pressure of the pump head of the first infusion fluid conveying unit; when the infusion stage of the first infusion fluid delivery unit is finished, the control circuit adjusts the corresponding switching valve to close the infusion flow path of the first infusion fluid delivery unit and open the infusion flow path of the second infusion fluid delivery unit.

The invention has the following advantages:

the invention can not only carry out stable transfusion in a nano-liter grade gradient transfusion mode, but also utilize a circuit to control and increase the number of working pump heads or the working sequence of the pump heads without changing the connection of the structure and a flow path, thereby converting the continuous stable transfusion into continuous stable transfusion under microliter flow or milliliter flow; the one-way valve in the system only plays a role in auxiliary sealing in a non-infusion state, and does not undertake a main sealing task in the infusion process, so that the stability and the accuracy of the flow of the system are improved; the system has simple structure and stable work, is suitable for popularization and application in the field, and has wide market and application prospect.

Drawings

FIG. 1 is a schematic view of a liquid-absorbing state in a first embodiment of the present invention;

FIG. 2 is a schematic view illustrating an infusion state according to an embodiment of the present invention;

FIG. 3 is a diagram illustrating an operating state according to a second embodiment of the present invention;

fig. 4 is a schematic diagram of another operating state in the second embodiment of the present invention.

In the figure:

1-1 port; no. 2-2; no. 3-3; no. 4-4; no. 5-5; no. 6-6; 7-pump head; 8-a pressure transmitter; 9-a switching valve; 10-a fluid mixer; 11-solvent bottle; 12-a one-way valve; 701-solvent outlet; 702-solvent inlet.

Detailed Description

It should be noted that, in the description of the present invention, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.