Angled Flow Passages for Turbulent Mixing in Particle Counters
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Solution Overview
Problem
Existing particle counters with laminar gas flow in the evaporation unit face limitations in response speed due to slow mixing of the gas flow with vaporized working liquid, leading to reduced detection efficiency and increased dwell time of particles.
Innovation Solution
The introduction of multiple flow passages distributed evenly over the circumference of the feed channel, angled at more than 90°, generates turbulent flow in the evaporation unit, enhancing mixing with vaporized working liquid and allowing for equalized gas flow rates, thereby increasing the response speed of the particle counter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laminar gas flow is used in the evaporation unit, then the gas flow structure is simple and stable, but the mixing speed with vaporized working liquid is slow, reducing response speed
Solution Approach 1:
The patent introduces a flow passage angled at more than 90° relative to the feed channel direction, creating dynamic turbulent flow conditions. This angular configuration causes the gas flow to mix vigorously with vaporized working liquid, transforming the static laminar flow into dynamic turbulent flow that accelerates mixing and improves response speed while maintaining flow stability through controlled turbulence.
Solution Approach 2:
The patent changes the flow regime parameter from laminar to turbulent by introducing the angled flow passage. This parameter change fundamentally alters the mixing characteristics, enabling faster mass transfer between gas flow and vaporized working liquid, thereby improving response speed without sacrificing flow stability.
2Ease of manufacture
If heating elements are positioned on the radial outside of the channel, then the structure is simple, but the vapor concentration is highest at the radial outside where gas flow velocity is lowest, reducing mixing efficiency
Solution Approach 1:
The angled flow passage creates dynamic turbulent mixing that overcomes the static velocity profile limitation. The turbulence generated by the >90° angle introduction causes vigorous mixing throughout the cross-section, ensuring efficient contact between vapor and gas flow even in regions where laminar velocity would be low.
3Speed
If high gas flow rate is used, then the detection speed increases, but the laminar flow structure prevents adequate mixing with vaporized working liquid
Solution Approach 1:
The patent changes the flow regime parameter from laminar to turbulent by introducing the angled flow passage. This parameter change fundamentally alters the mixing characteristics, enabling faster mass transfer between gas flow and vaporized working liquid, thereby improving response speed without sacrificing flow stability.
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
This configuration results in accelerated mixing and reduced diffusion losses, enabling faster detection of particles with consistent dwell times across the device, allowing for quick adjustments to detection limits and optimal particle size determination.
Implementation Method 1
As a result of the further development according to the invention, in particular a turbulent flow is generated in the evaporation unit. When the vaporized working liquid flows through the vaporization unit, eddy zones are formed, which greatly accelerate the mixing of the particle-carrying gas flow with the vaporized working liquid.
Implementation Method 2
a particle-carrying gas flow - ie a flowing aerosol - is directed into an evaporation unit in which a working liquid, for example butanol, is heated and evaporated. The vaporized molecules of the working liquid accumulate on the particles to be measured
Implementation Method 3
In a condensation unit, the particle-carrying gas flow is cooled down with the molecules of the working liquid. The particles of the gas flow serve as condensation cores, which increases their effective diameter again and thus simplifies the detection of the particles.
Data Source
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AI summary
The invention relates to a device for condensing steam at condensation nuclei, in particular for a particle counter, having an inlet via which a particle enters a feed channel as a gas flow carrying condensation nuclei, a saturation channel, an evaporation unit which extends at least over part of the length thereof and in which a working fluid in the saturation channel can be evaporated, and an outlet which leads to a measuring unit. In this case, at least one flow passage from the feed channel to the saturation channel is provided. The at least one flow channel is oriented at an angle of more than 90° relative to the direction of extent of the feed channel.