Positive Displacement Pump Drive System with Self-Regulating Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing positive displacement pumps face challenges in maintaining a constant flow rate and preventing damage during overpressure conditions, particularly when the outlet manifold becomes blocked, leading to potential motor and pump damage.
Innovation Solution
The drive system incorporates a housing with an internal pressure chamber filled with a working fluid, a reciprocating member, and fluid displacement members, utilizing a sequencing mechanism to ensure one displacement member is always in a pumping stroke while the other is in a suction stroke, and includes pull chambers to prevent overpressurization, eliminating the need for downstream dampeners and pressure relief valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single fluid displacement member is used in a positive displacement pump, then the pump structure is simpler, but the flow rate becomes pulsating and less constant
Solution Approach 1:
The pump is divided into multiple independent fluid displacement members (at least two) that operate in parallel, each capable of independent suction and pumping strokes. This segmentation allows continuous flow delivery while maintaining relatively simple individual component designs.
Solution Approach 2:
The fluid displacement members are configured to operate in alternating periodic cycles, where one member performs suction while another performs pumping, and vice versa. This periodic coordination eliminates flow pulsations and achieves constant downstream flow rate.
2Device complexity
If no pressure relief mechanism is provided, then the pump structure is simpler, but the motor and pump can be damaged during overpressure conditions
Solution Approach 1:
The system incorporates pressure relief mechanisms and control features that activate before damage can occur. When outlet pressure exceeds a predetermined threshold, the system automatically initiates pressure relief actions to protect the motor and pump components.
Solution Approach 2:
The pump includes pressure sensing and control mechanisms that continuously monitor outlet pressure and provide feedback to regulate the pumping action. This feedback system enables automatic adjustment to prevent overpressure conditions while maintaining efficient operation during normal conditions.
3Reliability
If downstream dampeners and pressure relief valves are added, then overpressure protection is improved, but the device complexity and energy loss increase
Solution Approach 1:
The pressure relief and flow control functions are integrated into the pump's drive system and fluid displacement members themselves, rather than being separate downstream components. This merging eliminates the need for additional dampeners and external pressure relief valves, reducing overall system complexity.
Solution Approach 2:
The pump system is designed to self-regulate pressure and flow through inherent features of the fluid displacement members and drive mechanism, eliminating the need for external protective devices. The system automatically maintains safe operating parameters without additional downstream protection components.
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 system provides a pulseless flow of process fluid, self-regulates pressure, and prevents damage during overpressure conditions, ensuring a constant downstream flow rate and reducing the risk of motor and pump damage, while enhancing energy efficiency and diaphragm life.
Implementation Method 1
an internal pressure chamber filled with a working fluid and defined by the housing
Implementation Method 2
When the fluid displacement member is drawn in, a suction condition is created in the fluid flow path, which draws process fluid into a fluid cavity from the inlet manifold
Implementation Method 3
The fluid displacement member then reverses direction and forces the process fluid out of the fluid cavity through the outlet manifold
Data Source
AI summary
A drive system for a pump includes a housing and a fluid displacer and a reciprocator configured to mechanically displace the fluid displacer through respective suction strokes. The housing and fluid displacer define an internal pressure chamber configured to be filled with a working fluid having a charge pressure. The internal pressure chamber is configured such that the working fluid exerts the charge pressure on the fluid displacer during both the suction stroke and a pressure stroke of the fluid displacer.