Counterflow Rotary Cooler With Nested Tubes to Prevent Splashing
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Solution Overview
Problem
Existing rotary coolers for granular solids suffer from inefficiencies such as water splashing, freezing issues in cold climates, and potential personnel injury from high-temperature splashing, with previous designs requiring higher coolant flow rates and horsepower due to suboptimal temperature profiles.
Innovation Solution
A counterflow rotary cooler design where cooling fluid enters the annulus between inner and outer tubes at one end, flows towards the other end, and returns through the inner tube, while the granular material flows in the opposite direction, maintaining a substantial temperature differential for efficient cooling, with optional insulation layers to minimize heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If cooling water enters the cooler at the first end and flows through the inside of cooling tubes to the opposite second end, then the cooling process is simple and direct, but water splashes everywhere creating a wet and messy process with freezing problems and potential personnel injury from high-temperature splashing
Solution Approach 1:
The patent employs nested tubes where an inner tube is positioned inside an outer tube. The cooling water flows through the inner tube in one direction while the granular material flows through the annulus between the inner and outer tubes in the opposite direction. This nested configuration contains the cooling water within the inner tube, preventing splashing while maintaining effective heat transfer through the tube walls.
Solution Approach 2:
The patent implements counterflow cooling where the cooling water and granular material flow in opposite directions. The cooling water enters at the first end, flows through the inner tube toward the second end, while the hot granular material enters at the second end and moves toward the first end through the annulus. This inversion of flow directions optimizes the temperature gradient along the heat exchange path, maintaining efficient cooling while containing water within the tube system.
2Productivity
If cooling water makes multiple passes between the first and second ends through inner and outer tubes, then water remains contained and cooling efficiency improves, but the device complexity increases with multiple nested tubes and rotary joints
Solution Approach 1:
The patent uses a nested tube configuration where the inner tube is positioned coaxially within the outer tube. The inner tube carries cooling water in one direction while the annulus between the tubes carries the granular material in the opposite direction. This nested structure enables multiple passes of cooling water through the same physical space, increasing cooling efficiency without requiring separate tube bundles for each pass.
Solution Approach 2:
The single nested tube assembly performs multiple functions simultaneously: the inner tube conveys cooling water, the annulus conveys granular material, and both the inner tube outer surface and annulus serve as heat transfer surfaces. The rotary joint at one end provides both sealing and rotational movement capability, enabling the entire assembly to rotate while maintaining fluid connections.
3Temperature
If the coolest cooling fluid is used to cool the coolest granular material, then the temperature differential is maintained for effective cooling, but the cooling fluid flow rate requirements increase resulting in larger pumps and higher horsepower requirements
Solution Approach 1:
The patent implements counterflow cooling where the cooling water and granular material move in opposite directions through the heat exchange surfaces. The cooling water enters at the first end, flows through the inner tube toward the second end, while the hot granular material enters at the second end and moves toward the first end through the annulus. This arrangement maintains a relatively constant temperature differential along the entire heat exchange path, maximizing heat transfer efficiency.
Solution Approach 2:
The patent extends the heat transfer path by utilizing both the inner tube outer surface and the annulus as active heat exchange surfaces. The cooling water flows through the inner tube while heat is transferred through the tube wall to the granular material in the annulus. This multi-dimensional heat transfer approach increases the effective heat transfer area without proportionally increasing flow rate requirements.
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
Achieves improved temperature control and safety by maintaining a significant temperature gradient between the coolant and granular material, reducing the need for high flow rates and horsepower, and minimizing heat transfer between tubes.
Implementation Method 1
the cooling fluid in contact with the inner surface of the outer tube is flowing in a first direction, from the first end to the second end, while the granular material being cooled at the outer surface of the outer tube is flowing from the second end to the first end
Implementation Method 2
this is a counterflow arrangement, with the cooling fluid flowing in the opposite direction to that of the granular material being cooled
Data Source
AI summary
A counterflow rotary cooler including an elongated rotary vessel having first and second ends, at least one inner tube nested inside one outer tube and defining an annulus space between said inner and outer tubes, with cooling water flowing from said first end to said second end through said annulus and then returning to said first end through the inner tube.