Multi-Zoned Paddle Screen for Fiber Slurry Separation
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Solution Overview
Problem
Conventional systems for separating fiber from a slurry, such as those used in corn wet milling processes, are inefficient, require multiple stages, and are prone to screen blinding, leading to high capital and maintenance costs, as well as significant downtime due to the need for frequent high-pressure washing.
Innovation Solution
A multi-zoned paddle screen apparatus with a stationary first screen section and a larger diameter second screen section, where the second screen section has a larger diameter than the first, allowing for efficient pre-washing, filtering, and dewatering of fiber in a single self-contained device, reducing the need for multiple stages and minimizing energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple washing stages with separate dedicated devices are used to remove starch and gluten from fiber, then the separation efficiency is improved, but the device complexity and capital costs increase significantly
Solution Approach 1:
The patent combines multiple washing stages and filtering functions into a single integrated paddle screen device. The apparatus includes a first screen section for initial filtering and a second screen section for washing and dewatering, all within one continuous device that processes fiber through multiple stages without requiring separate dedicated devices for each function.
Solution Approach 2:
The paddle screen device performs multiple functions simultaneously: it filters fiber from slurry, washes fiber with wash water, removes starch and gluten, and dewateres the fiber. This multi-functional approach eliminates the need for separate pressure screens, washers, and dewatering devices that would otherwise be required.
2Ease of manufacture
If conventional paddle screen devices with uniform diameter screens are used, then the structure is simple, but the dewatering efficiency is insufficient and fiber mats form
Solution Approach 1:
The patent applies different screen diameters to different zones of the paddle screen device. The first screen section has a smaller diameter optimized for initial filtering, while the second screen section has a larger diameter optimized for washing and dewatering. This local differentiation of screen properties allows each zone to perform its specific function efficiently without compromising overall structural simplicity.
3Reliability
If high-pressure washing is applied frequently to prevent screen blinding, then the screen reliability is maintained, but the downtime and energy consumption increase
Solution Approach 1:
The patent employs rotating paddles that dynamically move through the slurry and wash water, creating continuous agitation and preventing fiber mat formation on the screen surface. This dynamic action reduces screen blinding compared to static screens, allowing longer operation between high-pressure washing cycles and reducing both downtime and energy consumption.
4Quantity of substance
If additional dewatering devices are added after the paddle screen, then the fiber dryness is improved, but the device complexity and operational costs increase
Solution Approach 1:
The paddle screen device is designed to perform dewatering as an integrated function within the second screen section. The larger diameter second screen, combined with the rotating paddles and wash water injection, achieves sufficient fiber dewatering without requiring separate post-dewatering devices such as screw presses or centrifuges, thereby reducing overall device complexity while maintaining acceptable fiber dryness.
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 apparatus effectively separates fiber from starch and gluten, achieving a dryer product with reduced energy consumption and lower operational costs by utilizing a stepped or conical configuration that allows for efficient dewatering and reduces the formation of fiber mats, thereby minimizing the need for additional dewatering devices.
Implementation Method 1
The movement of the paddles relative to the drum loosens the fiber from the outer wall and reduces plugging of the screen openings. Also, the centrifugal force created by the rotating paddles provides a higher filtration pressure as compared to the pressure screens.
Implementation Method 2
The screen includes openings sufficiently sized so as to permit the water, starch, and gluten (any other constituents smaller than the openings) to flow through the screen, but prevent the fiber from flowing therethrough, thus essentially filtering the fiber from the slurry.
Implementation Method 3
the second screen section is larger in diameter than the first screen section... utilizing a stepped or conical configuration that allows for efficient dewatering and reduces the formation of fiber mats
Data Source
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AI summary
A multi-zoned paddle screen apparatus (100) is disclosed for separating fiber from a liquid medium during, for example, a grain wet mill or dry grind process. The apparatus includes a housing (106) having first and second zones (108a, 108b) situated adjacent one another along a length (L) of the housing (106). First and second screen sections (102a, 102b) having a plurality of openings (104) may be situated lengthwise within the housing (106) corresponding with the first and second zones (108a, 108b), respectively. The first and second screen sections (102a, 102b) have a circular cross-section, and the second screen section (102b) has a larger diameter than the first screen section (102a). An elongated shaft (130) situated lengthwise within the screen sections (102a, 102b) includes first and second conveyors (128a, 128b), which correspond with the first and second zones (108a, 108b), respectively, having a plurality of paddles (132). Each conveyor (128a, 128b) is configured to move material in a direction along a length of the screen (102a, 102b). There may be more than two zones (108a, 108b).