Non-pulsating Pump Stroke Adjustment for Line Pressure Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing non-pulsating pumps face challenges in maintaining constant flow rates due to pulsations caused by changes in line pressure, leading to reduced precision in pulsation detection and suppression.
Innovation Solution
A non-pulsating pump design incorporating a drive mechanism with a cam mechanism and crossheads, along with a stroke adjustment mechanism that adjusts the effective stroke length of the plunger based on pressure differences to ensure the inner pressure of the pump chamber matches the line pressure, thereby maintaining a constant flow rate and suppressing pulsations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pressure sensor or flow rate sensor is provided on the common line with an air release valve to detect and suppress pulsation, then pulsation detection capability is improved, but pulsation suppression precision deteriorates due to gradual curved line shape of pulsation waveform reducing detection precision
Solution Approach 1:
The patent applies preliminary action by adjusting the stroke length of the plunger before discharge occurs to prevent pulsation. The control unit calculates the required stroke length adjustment based on detected line pressure and discharge flow rate, then adjusts the stroke length in advance during the compression step so that the inner pressure of the pump chamber reaches the line pressure exactly at the discharge step starting point angle, preventing premature discharge and pulsation generation
Solution Approach 2:
The patent implements feedback control by continuously detecting line pressure and discharge flow rate, calculating the necessary stroke length adjustment, and adjusting the plunger stroke length accordingly. The control unit uses a feedback loop where the detected pulsation conditions are fed back to modify the stroke length, creating a closed-loop control system that dynamically suppresses pulsation
2Manufacturing precision
If the inner pressure of the pump chamber is increased to match line pressure before discharge, then discharge timing control is improved, but device complexity increases due to additional stroke adjustment mechanism
Solution Approach 1:
The patent applies dynamics by making the stroke length of the plunger adjustable rather than fixed. The stroke adjustment mechanism allows the stroke length to be dynamically changed based on operating conditions (line pressure and discharge flow rate). The control unit calculates the optimal stroke length and the stroke adjustment mechanism implements this adjustment, enabling the system to adapt to varying conditions and maintain precise discharge timing
Solution Approach 2:
The patent implements parameter changes by modifying the stroke length parameter of the plunger based on detected line pressure and discharge flow rate. The control unit calculates the required stroke length adjustment and the stroke adjustment mechanism changes the stroke length parameter accordingly. This dynamic parameter adjustment allows precise control of discharge timing and effective pulsation suppression
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 solution achieves higher precision in pulsation suppression and maintains a constant flow rate, even with variations in line pressure, by dynamically adjusting the stroke length of the plunger to match the line pressure, ensuring stable fluid delivery.
Implementation Method 1
The cam mechanism converts a rotational motion of a drive motor into a reciprocating motion
Implementation Method 2
When the plunger moves backward (return motion), a pressure of the pump chamber is decreased, the intake valve is opened in response thereto, and liquid is introduced into the pump chamber. When the plunger moves past a bottom dead center and moves forward (forward motion), the pressure of the pump chamber is increased, and the discharge valve is opened
Data Source
Figure 1
Figure 2
Figure 3
AI summary
When a pipe pressure P_L of a common discharge pipe (36) during an independent discharge step in which only one reciprocating pump among a plurality of reciprocating pumps (20, 40) discharges a fluid to the common discharge pipe (36) differs from internal pressures P_OR1, P_OR2 in pump chambers (220, 240) of the respective reciprocating pumps (20, 40) at discharge step start point angles θ2, θ5 that are determined to correspond to a cam angle θ of a cam mechanism (16) with respect to the predetermined reciprocating pumps (20, 40), a stroke adjustment mechanism (80) adjusts, on the basis of a pressure difference ΔP therebetween, effective stroke lengths of cross heads (28, 48) connected to plungers (26, 46) of the predetermined reciprocating pumps (20, 40) so that the internal pressures P_OR1, P_OR2 in the pump chambers (220, 240) reach the pipe pressure P_L at the discharge step start point angles θ2, θ5.