Cold Spray Nozzle with Preheating Region for Powder Efficiency
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Solution Overview
Problem
The existing cold spray system nozzle designs face inefficiencies in spray efficiency due to limited raw material powder consumption, leading to resource and energy waste, and are prone to temperature-related issues such as oxidation and nozzle durability problems when using external microwave heating.
Innovation Solution
A cold spray nozzle with a convergent shape part featuring a preheating region and convergent region, equipped with a built-in electric heater unit, which prolongs the raw material powder's heating time and ensures efficient temperature elevation, improving spray efficiency and nozzle durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional cold spray nozzle is used, then the raw material powder can be sprayed, but the spray efficiency is low and raw material powder is wasted
Solution Approach 1:
The patent applies preliminary action by heating the raw material powder before it enters the supersonic flow region. The heating device preheats the powder in the heating chamber, ensuring that particles arrive at the substrate with optimal temperature for deformation and bonding, thereby improving spray efficiency and reducing material waste.
Solution Approach 2:
The patent changes the temperature parameter of the raw material powder by introducing a heating device. The powder is heated to a specific temperature range (below melting point) before injection, which optimizes its deformation characteristics upon impact and improves adhesion to the substrate, thereby enhancing spray efficiency.
2Temperature
If external microwave heating is used to heat raw material powder, then temperature can be elevated, but oxidation and nozzle durability problems occur
Solution Approach 1:
The patent uses an inert gas as an intermediary medium to heat the raw material powder. The inert gas flows through the heating chamber and transfers thermal energy to the powder particles while preventing oxidation. This mediator approach allows temperature elevation without the harmful effects of direct microwave heating or oxidation.
Solution Approach 2:
The patent creates an inert atmosphere in the heating chamber by filling it with inert gas (such as nitrogen or argon). This inert environment prevents oxidation of the raw material powder during heating while still allowing thermal energy transfer, thereby maintaining nozzle durability and preventing material degradation.
3Productivity
If the convergent shape part length is increased to improve heating, then spray efficiency improves, but device complexity increases
Solution Approach 1:
The patent segments the nozzle into distinct functional regions: a heating chamber with inert gas injection, a convergent section, and a divergent section. This segmentation allows each part to perform its specific function optimally while keeping the overall design manageable and not excessively complex.
Solution Approach 2:
The convergent shape part serves multiple functions: it acts as a flow conduit, a heating zone (when combined with the heating device), and a pressure transition region. By making this component multi-functional, the patent avoids adding separate structures for each function, thereby limiting the increase in device complexity.
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 improved nozzle design enhances spray efficiency by effectively heating the raw material powder, reducing waste and extending nozzle lifespan, while maintaining operational efficiency and handling ease.
Implementation Method 1
the nozzle is provided with a heating device at the preheating region and the heating device is a built-in electric heater unit in the inside wall surface of the convergent shape part
Implementation Method 2
a convergent shape part, a throat part and a conical divergent shape part widen forward from the throat part used for making a raw material powder which is introduced at a inlet of the nozzle which locates in the convergent shape part shoot as a supersonic flow
Data Source
AI summary
The object of the present invention is to provide a cold spray method in which spray efficiency is improved by using a device comprising a similar construction to the conventional ones with minor change in conditions. The cold spray method employs the nozzle for cold spray system which comprises a convergent shape part, a throat part and a conical divergent shape part widen forward from the throat part used for making the raw material powder introduce from a inlet of the nozzle which locates in the convergent shape part into and shoot the powder as a supersonic flow by using a working gas having temperature equal to or lower than a melting point of the raw material powder from a spout provided at the tip of the divergent shape part, wherein the convergent shape part is composed of a preheating region and a convergent region.