Shaping Air Ring Geometry for Stable Rotary Atomizer Coating
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Solution Overview
Problem
Existing rotary atomizing head-type sprayers face challenges in achieving high coating efficiency due to coating material particles failing to reach the object, scattering, and turbulence, which are exacerbated by increased electric field intensity, reduced rotational speed, or altered flow rates, leading to decreased productivity and film quality.
Innovation Solution
A rotary atomizing head-type sprayer with specific dimensions and configurations, including a shaping air ring with controlled radial gap, taper angle, and air jetting units, stabilizes airflow and directs coating material particles effectively without altering rotational speed or flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the flow rate of shaping air is increased to improve particle straightness, then particle trajectory control improves, but turbulence increases causing particles to fail to reach the object
Solution Approach 1:
The shaping air ring is designed with non-uniform gap dimensions: the front side gap (0.1-1.0mm) is smaller than the rear side gap (1.0-3.0mm). This local differentiation allows the front side to provide strong particle straightening while the rear side reduces turbulence intensity, resolving the contradiction between trajectory control and coating efficiency
Solution Approach 2:
The patent optimizes specific parameters including the radial gap dimensions of the shaping air ring, the taper angle (≤25°), and the relative positions of air jetting units. These parameter changes create a controlled airflow field that maintains particle straightness while minimizing disruptive turbulence
2Manufacturing precision
If the coating distance is shortened to improve electric field strength and particle straightness, then coating efficiency improves, but the object cannot be reached due to centrifugal forces and turbulence
Solution Approach 1:
The shaping air ring is positioned to act on particles before they are affected by centrifugal forces and turbulence. The front side jetting unit pre-aligns particles in the radial direction, creating a stable trajectory that allows close-distance coating to be effective
Solution Approach 2:
The shaping air ring acts as an intermediary device between the rotary atomizing head and the object. It mediates the conflicting forces by providing a controlled airflow field that counteracts centrifugal forces and reduces turbulence, enabling particles to reach the object even at short distances
3Manufacturing precision
If the rotational speed of the rotary atomizing head is reduced to improve particle control, then particle scatter decreases, but productivity decreases
Solution Approach 1:
The patent uses pneumatic fields (shaping air jetting units) to control particle trajectories instead of relying solely on mechanical control through rotational speed. This allows high rotational speeds to be maintained for productivity while pneumatic forces ensure uniform particle distribution and reduced scatter
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 enhances coating efficiency to 98% or higher by minimizing material scatter and turbulence, maintaining productivity, and ensuring uniform film thickness distribution.
Implementation Method 1
A rotary atomizing head-type sprayer with specific dimensions and configurations, including a shaping air ring with controlled radial gap, taper angle, and air jetting units, stabilizes airflow and directs coating material particles effectively
Implementation Method 2
high voltage is applied to the coating material, and electrostatic coating is performed by causing the charged coating material particles to fly along the lines of electric force formed between the coating material particles and the object to be coated
Implementation Method 3
a rotary atomizing head that is mounted on the front end of the rotary axis and that has an outer circumferential surface that expands into a cup shape as well as an inner circumferential surface to diffuse the coating material supplied from the feed tube with a discharge edge located at the front end to discharge the coating material
Data Source
AI summary
Inner cylinder surface of shaping air ring may be formed to a uniform inner diameter dimension. After first shaping air discharge unit has been formed as an annular gap, the gap dimension may be set to 0.1 to 1.0 mm. Front end of shaping air ring is positioned 0.1 to 10.0 mm from discharge edge of rotary atomizing head. The radial width dimension of front end is set to 2 mm or less. Front outer cylinder surface of shaping air ring has a taper angle β of 25° or less in relation to the axis line O-O, expanding toward the rear side.