Plunger Pump Solvent Replacement Dynamics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid feed pumps used in liquid chromatography face slow solvent replacement speeds due to stagnation areas, particularly near seals, which hinder analysis throughput.
Innovation Solution
The first plunger slides back and forth between the lower and upper limit points, while the second plunger temporarily stops near the upper limit point or moves a shorter distance, optimizing solvent flow velocity in the pressure chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If both plungers move during normal operation, then liquid feed is maintained, but solvent replacement speed is slow due to stagnation areas
Solution Approach 1:
The patent applies dynamics by making the plunger movement pattern variable based on operational phase. During solvent replacement, the second plunger is fixed while the first plunger moves actively, creating dynamic flow patterns that eliminate stagnation. During normal liquid feed, both plungers move in coordinated fashion to maintain stable flow. This dynamic adjustment of movement patterns resolves the contradiction between rapid solvent replacement and stable liquid feed.
Solution Approach 2:
The patent implements periodic action through alternating operational modes. The system periodically switches between solvent replacement mode (where only the first plunger moves) and normal liquid feed mode (where both plungers move). This periodic switching allows the system to optimize for solvent replacement speed during replacement cycles while maintaining feed stability during analysis cycles, thus resolving the contradiction.
2Loss of time
If the second plunger moves during solvent replacement, then liquid feed is maintained, but solvent replacement time increases
Solution Approach 1:
The patent extracts the second plunger from the active movement during solvent replacement phase, fixing it in place while only the first plunger moves. This extraction of the second plunger's movement function during the critical replacement phase eliminates the time loss that would occur if both plungers had to move simultaneously, thereby reducing solvent replacement time and increasing analysis throughput.
3Reliability
If plunger moves at full stroke during replacement, then replacement is thorough, but seal load increases and life decreases
Solution Approach 1:
The patent applies local quality by concentrating the replacement action primarily in the first pressure chamber where the first plunger operates, while the second plunger remains fixed. This localized approach ensures thorough replacement in the critical first chamber without subjecting the second seal to excessive movement and load. The fixed second plunger protects its seal from wear while the first plunger performs the replacement function, thus preserving seal life while maintaining replacement effectiveness.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A liquid feed pump which increases the liquid flow velocity in a stagnation area in the pressure chamber of a plunger pump, thereby improving the liquid replacement speed in the plunger pump. When the liquid in the liquid feed pump is replaced, a first plunger slides back and forth in the space between a lower limit point and an upper limit point, and the second plunger stops at least temporarily at a position near to the upper limit point or slides back and forth for a shorter distance than when the liquid feed pump usually feeds the liquid.