Liquid Sealed Pump Impeller Design for Vacuum Stability
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Solution Overview
Problem
Existing liquid sealed pumps face issues with vacuum loss due to vapor formation in the extension tube, leading to potential flooding of the motor and bearings, as described in U.S. Pat. No. 4,772,183, which compromises the seal and requires additional maintenance.
Innovation Solution
A liquid sealed pump design incorporating a dynamic turbo tech impeller with a semi-open face and extended snout, featuring an annular fluid containment chamber with a sealing fluid supply and return conduit, and weep holes in the shaft sleeve to maintain a constant fluid level and prevent aeration, utilizing the pumped fluid as a seal without mechanical seals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vacuum is used in the extension tube to prevent fluid flooding, then the motor and bearings are protected, but the vacuum may be lost due to vapor formation causing flooding
Solution Approach 1:
The patent replaces the vacuum-based sealing system with a liquid seal system. Instead of maintaining a vacuum in the extension tube, the invention introduces a liquid seal chamber that maintains a liquid barrier to prevent vapor formation and maintain sealing. This substitution eliminates the instability of vacuum conditions while providing reliable protection against fluid flooding.
Solution Approach 2:
The patent introduces a liquid seal as an intermediary substance between the pump components and the pumped fluid. This liquid seal acts as a mediator that prevents direct contact between the pumped fluid and critical components, while also preventing vapor formation that would compromise the vacuum. The liquid seal chamber provides a controlled environment that maintains sealing without relying on vacuum stability.
2Reliability
If shaft packing or mechanical seals are used to prevent fluid leakage, then the fluid is contained, but maintenance requirements increase and cost increases
Solution Approach 1:
The liquid seal system is designed to be self-regulating and maintenance-free. The liquid seal automatically maintains the sealing barrier through its own weight and pressure differential, eliminating the need for periodic adjustment or replacement of mechanical components. The system self-corrects for minor variations in operating conditions without requiring human intervention or maintenance.
Solution Approach 2:
The liquid seal uses a simple, inexpensive liquid barrier that can be easily replenished if needed, replacing complex and expensive mechanical seal assemblies. The liquid seal chamber design allows for simple refilling or replacement of the sealing liquid, making the system more economical and easier to maintain compared to traditional mechanical seals.
3Reliability
If mechanical seals are used to prevent leakage, then fluid containment is achieved, but the device complexity increases
Solution Approach 1:
The patent extracts and eliminates the complex mechanical seal components from the pump system. By removing the mechanical seal assembly, shaft packing, and associated adjustment mechanisms, the invention simplifies the overall device structure. The liquid seal chamber is a simple cylindrical component that replaces the complex mechanical sealing system, reducing parts count and structural complexity while maintaining effective leakage prevention.
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 ensures a reliable liquid seal, minimizing leakage and maintaining pump efficiency even when dry, allowing particles up to ¼″ in size to pass through, and providing a highly efficient flow rate with reduced maintenance needs.
Implementation Method 1
a liquid seal can be used instead of shaft packing or mechanical seals, which is much more economical and requires little to no maintenance. U.S. Pat. No. 4,772,183 to Durden, which is incorporated herein by reference, described using a liquid seal that relies on a vacuum in the extension or support tube to keep tube clear of oil or fluid and prevent flooding of motor or motor bearings
Implementation Method 2
The pump preferably includes a motor, a drive shaft, an impeller, a pump housing that includes an inlet portion and an outlet portion
Data Source
AI summary
A pump for pumping a fluid includes a motor, a drive shaft, an impeller, a pump housing having an inlet and an outlet portion, and an extension tube extending between the motor and the pump housing. Preferably, a portion of the fluid to be pumped is contained within the extension tube at a relatively constant level to provide a seal.