Concentric Pipe Sprayer Layout for Uniform Coating in Small Bores
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current systems for spraying coating agents into the inner walls of pipes, particularly in heat exchangers, face challenges due to decreasing pipe diameters, requiring larger sprayer diameters and inefficient shut-off mechanisms, leading to coating agent escape and unsuitable spray patterns.
Innovation Solution
A system with a concentric hose connection design, where the outer hose carries air and the inner hose carries the coating agent, allowing for a reduced sprayer diameter and precise centering, along with a three-way valve for quick shut-off, enabling efficient coating in small pipes without dripping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the spray gun diameter is reduced to fit small-diameter pipes, then the adaptability to small pipes is improved, but the coating agent and air supply system becomes more complex
Solution Approach 1:
The patent applies nesting by placing the inner hose (carrying coating agent) inside the outer hose (carrying air). This nested configuration allows both hoses to be transmitted through a single small-diameter spray gun while maintaining separate functional channels, thus reducing the spray gun diameter to fit small pipes without compromising the dual-supply system
2Ease of manufacture
If conventional side-by-side hose arrangement is used, then the hose connection is simple, but the spray gun diameter becomes too large for small pipes
Solution Approach 1:
Instead of arranging hoses side-by-side which increases the cross-sectional diameter, the patent nests the inner hose within the outer hose. This configuration reduces the overall diameter to that of the outer hose only, making the spray gun compact enough to enter small-diameter pipes while keeping the connection assembly straightforward
3Manufacturing precision
If the spray gun is centered in the pipe, then the coating uniformity is improved, but the positioning mechanism becomes more complex
Solution Approach 1:
The patent creates a radially symmetric flow field by introducing air through the outer hose and coating agent through the inner hose, both flowing coaxially toward the spray nozzle. This symmetric configuration naturally centers the spray pattern within the pipe without requiring complex mechanical centering mechanisms, as the fluid dynamics itself provides the centering effect
4Loss of substance
If quick shut-off of coating agent is achieved, then the loss of coating agent is reduced, but the valve control system becomes more complex
Solution Approach 1:
The patent extracts the shut-off function from the spray gun location and places it at the delivery station where a three-way valve controls the coating agent supply. By locating the valve at the source rather than at the spray gun, the system achieves quick shut-off to prevent coating agent escape while keeping the spray gun itself simple and maintenance-free
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
Enables uniform, imperfection-free coating in pipes with internal diameters as low as 11 mm, with reduced maintenance and improved spray pattern uniformity, preventing coating agent escape and ensuring precise alignment for effective pipe protection.
Implementation Method 1
The hose connection comprises two hoses arranged one inside the other, with the outer hose carrying the air and the inner hose carrying the liquid coating agent
Implementation Method 2
the coating material, supplied via the hose connection, is sprayed out with the aid of air, also supplied via the hose connection
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The invention relates to a system for spraying a liquid coating agent onto the inner walls of pipes with the aid of air, comprising: a needleless spraying apparatus (1) for the coating agent, which spraying apparatus has separate connections (12, 11) for coating agent and air, and which can be introduced into the particular pipe and moved in the longitudinal direction thereof; a stationary supply station (3) for providing the pressurised coating agent and pressurised air; and a hose connection (4) for coating agent and air between the supply station and the spraying apparatus that is movable in the pipe; wherein the hose connection (4) has an outer hose (41) for the air and an inner hose (42) for the coating agent, which inner hose is inside the outer hose and the outer diameter of which inner hose is smaller than the inner diameter of the outer hose.