Powder Spray Nozzle Using Suction Feed for Uniform Filter Coating
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Solution Overview
Problem
Existing methods for treating filters to improve filtration efficiency during the early life, regeneration, and soot loading stages of diesel and gasoline particulate filters are limited by the controllability, flexibility, and durability of the treatment process, particularly in maintaining even distribution and adhesion of dry powders without the need for binders or high-temperature sintering.
Innovation Solution
A powder spraying system and nozzle that utilize a suction force at the powder outlet to feed dry powder through a straight conduit, eliminating the need for gas flow in the supply conduit, promoting homogeneous mixing and adhesion of dry powders like fumed alumina or metal compounds, which form metal oxides upon thermal decomposition, enhancing filtration efficiency and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gas flow is used to entrain and convey dry powder through the supply conduit to the spray nozzle, then the powder can be delivered to the filter, but the system becomes more complex and energy-consuming, and the powder distribution uniformity decreases due to premature dispersion
Solution Approach 1:
The invention extracts the gas flow function from the powder conveyance process. Instead of using gas to entrain and convey powder through the supply conduit, the system allows powder to move under gravity alone, reserving gas flow exclusively for the spraying action at the nozzle. This separation simplifies the overall system and reduces energy consumption while maintaining powder delivery capability.
Solution Approach 2:
The invention prepares the powder for spraying by conveying it through a straight conduit without premature dispersion. The powder is held in a ready state at the nozzle inlet, where it will be instantly dispersed by the gas flow only at the moment of spraying. This preliminary positioning without early dispersion ensures uniform powder distribution on the filter surface.
2Adaptability or versatility
If curved conduits are used to transport powder to the spray nozzle, then the system can accommodate spatial constraints, but powder blockages increase and distribution uniformity decreases
Solution Approach 1:
The invention segments the powder transport function from the spraying function. The supply conduit is dedicated solely to gravity-driven powder movement to the nozzle, while the spraying function (including dispersion and application) occurs at the nozzle exit. This segmentation allows the use of straight conduits for reliable powder transport while maintaining spatial flexibility through proper nozzle positioning and orientation.
Solution Approach 2:
Instead of using curved conduits to adapt to spatial constraints and risking blockages, the invention inverts the approach by using straight conduits and adapting to spatial constraints through nozzle positioning and gravity-assisted powder flow. The powder is delivered straight to the nozzle and then sprayed in the required direction, reversing the conventional approach of curving the conduit to achieve the spray direction.
3Reliability
If binders or high-temperature sintering are used to enhance powder adhesion to the filter, then filtration durability improves, but the process complexity and energy consumption increase
Solution Approach 1:
The invention uses a disposable-like approach to adhesion enhancement by incorporating adhesion promoters directly into the powder coating material. Instead of requiring durable, high-temperature sintering processes to create permanent bonds, the system achieves sufficient adhesion through the chemical properties of the powder itself, accepting that the coating may require reapplication over time. This reduces energy consumption and process complexity.
Solution Approach 2:
The invention changes the chemical parameters of the powder material by incorporating adhesion promoters or using materials with inherent adhesion properties. This allows the powder to bond to the filter surface at lower temperatures or without sintering, achieving adequate adhesion for filtration durability while avoiding the high energy input required for traditional sintering processes.
4Manufacturing precision
If liquid aerosol and atomization processes are used to coat the filter, then coverage uniformity improves, but the process requires additional equipment and drying steps increasing complexity
Solution Approach 1:
The invention replaces the liquid aerosol atomization mechanical system with a dry powder spray system. Instead of using liquid carriers that require atomization, drying ovens, and complex fluid handling equipment, the system directly sprays dry powder using gas flow at the nozzle. This substitution maintains coating uniformity through proper powder dispersion while eliminating the need for liquid handling and drying infrastructure.
Solution Approach 2:
The invention uses pneumatic principles to achieve uniform powder coating. Gas flow is used to disperse the dry powder and carry it to the filter surface, creating a uniform coating through controlled pneumatic delivery. This approach replaces liquid-based aerosol systems with a gas-based pneumatic system, eliminating the need for atomization equipment and drying ovens while maintaining coating quality.
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 achieves improved filtration efficiency, durability, and even distribution of dry powders on filter channels, reducing energy consumption and preventing blockages, while maintaining high adhesion without binders or high-temperature sintering.
Implementation Method 1
a gas flowing through the second conduit and out of the gas outlet produces a suction force at the powder outlet to promote flow of a dry powder through the first conduit and out of the powder outlet and the nozzle outlet
Implementation Method 2
the feeding of the supply conduit from a terminal part of the source of dry powder is carried out by gravity assisted by the suction force generated in the spray nozzle
Implementation Method 3
the powder outlet and the gas outlet being orientated to promote mixing of the gas with the dry powder
Implementation Method 4
metal compounds for forming by thermal decomposition a metal oxide
Data Source
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AI summary
A powder spraying system comprises a source of dry powder (4), a spray nozzle (25), and a supply conduit (16) connecting the source of dry powder with the spray nozzle. The spray nozzle comprises a nozzle body (50) having a nozzle outlet (51), a first conduit (52) for dry powder, and a second conduit (53) for gas. The first conduit extends between a powder inlet (54) in communication with the supply conduit and a powder outlet (55). The second conduit extends between a gas inlet (56) and a gas outlet (57), the gas outlet being located in proximity to the powder outlet such that a gas flowing through the second conduit and out of the gas outlet produces a suction force at the powder outlet to promote flow of a dry powder through the first conduit and out of the powder outlet and the nozzle outlet. The powder outlet and the gas outlet are orientated to promote mixing of the gas with the dry powder. The first conduit (52) is a straight conduit between the powder inlet (54) and the powder outlet (55).