Modular Metering Pump for Liquid Chromatography
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Solution Overview
Problem
Conventional metering pumps in liquid chromatography systems face challenges with bubble purging during priming, sample volume precision, and difficult maintenance, leading to system downtime and inefficiencies in high-pressure operations.
Innovation Solution
A modular metering pump design featuring a pump housing, drive nut, anti-rotation guide pin, lead screw, and pusher element, with a stepper motor and gearbox for precise control, and a separable pod head for easy maintenance and replacement, allowing for high-pressure operation and improved precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional metering pumps are used, then basic metering function is provided, but sample volume precision and high-pressure operation capability are insufficient
Solution Approach 1:
The pump is divided into modular components including a pump head assembly, drive mechanism, and control system. This segmentation allows for optimized design of each component for high-pressure operation while maintaining precise metering capabilities through the lead screw and drive nut mechanism.
Solution Approach 2:
The pump employs a dynamic drive mechanism with a lead screw and drive nut that converts rotational motion to precise linear motion of the plunger. This dynamic system enables accurate sample volume delivery while withstanding high pressures through the robust mechanical connection between the drive nut and plunger.
2Reliability
If the pump components are integrated for high-pressure operation, then reliability is improved, but maintenance and servicing become difficult
Solution Approach 1:
The pump head assembly is designed as a separate, removable module that can be easily detached from the drive mechanism. This segmentation allows maintenance personnel to access and service the plunger, seals, and pump chamber without disassembling the entire pump, thereby maintaining high-pressure reliability while significantly improving ease of repair.
3Measurement precision
If precise sample metering is achieved through complex mechanisms, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The complex precision metering mechanism is extracted into a dedicated pump head assembly that is pre-calibrated and functions as a complete unit. This extraction allows the precision mechanism to be optimized independently while the rest of the system remains relatively simple, reducing overall device complexity while maintaining high measurement precision.
4Reliability
If maintenance requires full disassembly for component replacement, then reliability is maintained, but loss of time increases
Solution Approach 1:
The pump head assembly is designed as a self-contained module that can be quickly removed and replaced without disassembling the drive mechanism or control system. This segmentation allows maintenance personnel to replace worn components or entire pump heads in minutes rather than hours, dramatically reducing downtime while maintaining component integrity through proper modular design.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The modular design enables efficient high-pressure metering with improved precision, reduced downtime, and easier maintenance, addressing the limitations of conventional pumps by allowing for precise sample volume control and quick reconfiguration for different operating conditions.
Implementation Method 1
The lead screw has a threaded outer surface in engagement with the threaded bore of the drive nut. A rotation of the lead screw imparts an axial translation to the drive nut, pusher element and plunger.
Implementation Method 2
The cartridge housing may have an axial cavity with a spring disposed therein. The spring is configured to apply an axial force to the plunger.
Implementation Method 3
The sensor may be an optical sensor having an optical emitter and an optical detector configured to receive light emitted along an optical path from the optical emitter, wherein the optical detector generates a signal responsive to an interruption of the optical path by the anti-rotation guide pin.
Data Source
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AI summary
Described is a metering pump that may be used to meter volumes of sample in a chromatography system. The metering pump has a modular configuration that allows for separation of a head pod from a drive assembly for easy serviceability. The head pod includes a pump head (36), cartridge housing (38), seal wash housing (40) and plunger (42). The drive assembly can be implemented in an inline drive configuration. Alternatively, the drive assembly can be implemented in an offset drive configuration in which a stepper motor (60) is displaced laterally from other drive assembly components but is coupled through a belt (110) and pulley system (102).