Segmented Vibratory Deck for Fluidized Bed Drying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fluidized bed drying systems face challenges with materials exhibiting extended falling rate drying and case hardening characteristics, as they often result in rapid drying rates that lead to case hardening, forming an impenetrable moisture barrier, and require extended residence times at controlled temperatures, which existing technologies struggle to manage effectively.
Innovation Solution
A vibratory fluidized bed dryer with a deck having at least two zones of different open area percentages, allowing for varying superficial velocities, and a vibration generator to control the conveying speed, which reduces airflow requirements and prevents case hardening by maintaining a uniform bed temperature and residence time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional fluidized bed drying systems use uniform aperture decks, then the drying rate is high, but case hardening occurs forming an impenetrable moisture barrier
Solution Approach 1:
The deck is segmented into multiple zones with different open area percentages. The first zone has a first open area percentage providing high drying rate, while the second zone has a second open area percentage that prevents case hardening. This segmentation allows different regions of the bed to experience different airflow conditions, resolving the contradiction between high drying rate and prevention of case hardening.
Solution Approach 2:
Different zones of the deck are assigned different local qualities in terms of aperture density. The first zone has higher aperture density for rapid drying, while the second zone has lower aperture density to maintain moisture gradient and prevent case hardening. This local differentiation allows each zone to perform its specific function optimally.
2Object-affected harmful factors
If extended residence times are used to prevent case hardening, then case hardening is reduced, but drying time increases
Solution Approach 1:
The drying process is segmented into two zones: the first zone provides rapid initial drying, while the second zone maintains lower airflow to prevent case hardening. This spatial segmentation eliminates the need for extended residence times because the prevention of case hardening occurs simultaneously with the drying process in the second zone, rather than requiring a separate extended time period.
Solution Approach 2:
The first zone applies excessive drying action (high airflow) to achieve rapid moisture removal, while the second zone applies partial action (lower airflow) sufficient to prevent case hardening without requiring extended time. This partial action in the second zone is enough to maintain the moisture gradient needed to prevent case hardening while keeping the overall drying time short.
3Loss of time
If mechanical obstructions are used to control bed depth and residence time, then residence time is controlled, but device complexity increases
Solution Approach 1:
The invention extracts the residence time control function from mechanical obstructions and transfers it to the aperture distribution pattern. By removing the need for mechanical obstructions and using only the segmented aperture deck, the device complexity is reduced while maintaining effective residence time control through the different airflow rates in the two zones.
Solution Approach 2:
The mechanical system of obstructions is replaced with a pneumatic/control system based on aperture distribution. The segmented deck with different open area percentages controls residence time through airflow management rather than physical barriers, substituting a simpler aperture-based mechanism for complex mechanical obstruction systems.
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 effectively reduces the risk of case hardening while maintaining a high degree of fluidization and drying rate, achieving uniform moisture and temperature profiles without the need for mechanical obstructions, thus optimizing the drying process for materials like synthetic rubbers and polymers.
Implementation Method 1
a vibration generator coupled to the deck
Implementation Method 2
air passes to fluidize the bed of materials on the deck
Implementation Method 3
air passes to fluidize the bed of materials on the deck
Implementation Method 4
drying systems and methods, and, in particular, to fluidized bed drying systems and methods
Data Source
AI summary
A vibratory fluidized bed dryer includes a deck with a surface on which a bed of materials is formed, the deck having apertures through which air passes to fluidize the bed of materials on the deck, a source of air coupled to the apertures in the deck to supply air to the bed through the apertures in the deck, and a vibration generator coupled to the deck. The deck has at least two zones, each zone having a different open area percentage, such that the air passing through each zone produces a different superficial velocity.