Fluid Bed Reactor Trays with Wiper and Perforations
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Solution Overview
Problem
Existing fluid bed drying technologies face inefficiencies in uniformly distributing drying medium through the product bed, leading to incomplete drying and uneven fluidization, particularly when handling thermally-inhibited starches and flours.
Innovation Solution
A fluid bed reactor design featuring vertically spaced trays with perforated materials and a wiper system that directs product through radial slots as the trays rotate, allowing a controlled flow of heated gas to fluidize the product, ensuring uniform drying and preventing product passage through perforations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gas flow is increased to improve drying efficiency, then drying rate increases, but product bed fluidization becomes uneven and product may pass through perforations
Solution Approach 1:
The drying chamber is divided into multiple zones with vertically spaced trays, each receiving controlled gas flow. This segmentation allows independent control of fluidization in different sections, preventing uneven fluidization while maintaining high overall drying efficiency.
Solution Approach 2:
Different regions of the system use trays with differently sized perforations tailored to local requirements. Areas requiring gentler fluidization have smaller perforations, while other areas use larger perforations, ensuring uniform drying across the entire product bed without product loss.
2Manufacturing precision
If tray rotation speed is increased to improve product distribution, then product moves more uniformly, but product may be thrown off tray and lost
Solution Approach 1:
The tray design incorporates radial slots that direct product movement in a controlled radial direction rather than allowing random centrifugal ejection. This dimensional control of product flow paths ensures uniform distribution while containing product within the tray boundaries.
Solution Approach 2:
A wiper system acts as an intermediary between the rotating tray and product, guiding product through radial slots and preventing direct ejection. The wiper mediates the interaction between rotational force and product, achieving uniform distribution without product loss.
3Productivity
If perforation size is increased to improve gas flow, then fluidization efficiency increases, but product passes through perforations and is lost
Solution Approach 1:
Trays are designed with locally optimized perforation sizes matched to specific drying requirements. Areas requiring high fluidization have larger perforations, while areas handling finer or more valuable products use smaller perforations, preventing product loss while maintaining overall efficiency.
Solution Approach 2:
The system employs porous trays with controlled pore sizes and distributions. These porous materials provide sufficient gas flow for efficient fluidization while their controlled pore structure prevents product particles from passing through, solving both requirements simultaneously.
4Productivity
If multiple trays are added to increase processing capacity, then drying throughput increases, but device complexity and space requirements increase
Solution Approach 1:
Multiple drying functions are merged into a single integrated vertical structure where trays share common support mechanisms and gas distribution systems. This combining approach increases throughput while minimizing the additional complexity that would result from separate drying units.
Solution Approach 2:
The system transitions from horizontal expansion to vertical stacking of trays, utilizing the vertical dimension to increase processing capacity. This dimensional change allows multiple trays to occupy a compact footprint, increasing throughput without proportionally increasing device complexity or space 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
This design achieves efficient and uniform drying of thermally-inhibited starches and flours by maintaining a suspended product bed and preventing product packing, resulting in reduced drying time and improved moisture removal, as demonstrated by experiments with waxy corn starch.
Implementation Method 1
the perforated material permits a gas to flow up out of the top surface of the tray; and wherein the flow of gas out of the top surface of the tray at least partially fluidizes product on the top surface of the tray
Implementation Method 2
at least one wiper associated with the plurality of trays which directs product on a top surface of a respective tray down through at least one radial slot in each respective tray as each respective tray is rotated by the motor
Implementation Method 3
a fan, wherein gas is caused to flow out of the top surface of each tray by the fan
Data Source
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AI summary
In one embodiment of the present invention a fluid bed reactor is provided, comprising: a housing, at least one tray disposed within the housing, at least one motor operatively connected to the at least one tray, wherein the motor rotates the at least one tray; and at least one wiper associated with at the at least one tray which directs product on a top surface of a respective tray down through at least one radial slot in each respective tray as each respective tray is rotated by the motor. At least one of the trays is at least partially perforated material which a gas to flow up out of the top surface of the tray, at least partially fluidizing product on the top surface of the tray.