Fluidized Bed Granulation Vacuum Suction
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Solution Overview
Problem
Existing fluidized bed reactors for producing granules like urea or ammonium nitrate face inefficiencies in energy consumption due to high temperatures generated by blowers used for fluidization, leading to increased energy use for air cleaning and exhaust, and require pre-heating of ambient air in winter, which complicates the process.
Innovation Solution
The reactor design incorporates downstream air moving devices to draw air into the granulation compartment, creating a vacuum exceeding the pressure drop, eliminating the need for blowers and allowing for lower inlet temperatures, thus reducing energy consumption and improving cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If blowers are used to blow air into the granulation compartment, then fluidization is achieved, but energy consumption increases due to heat generation
Solution Approach 1:
Instead of blowing air into the granulation compartment using blowers, the invention inverts the approach by using downstream air moving devices (exhaust fans) to draw air through the granulation compartment. This creates a suction-based fluidization system that eliminates the heat generation problem associated with blower operation while maintaining effective fluidization of the granule bed.
Solution Approach 2:
The invention replaces the mechanical blowing system (blowers) with a suction-based system (exhaust fans positioned downstream). This substitution fundamentally changes the fluid dynamics approach, using negative pressure rather than positive pressure to achieve fluidization, thereby eliminating the harmful thermal effect of blower motor heat.
2Power
If higher temperatures are used for fluidization air, then heat removal capacity increases, but more air is required for cooling
Solution Approach 1:
The invention changes the temperature parameter of the fluidization air by eliminating the heat source (blower motors). By using downstream exhaust fans instead of upstream blowers, the air enters the granulation compartment at ambient temperature rather than being pre-heated by motor heat, thereby reducing the temperature parameter and consequently reducing the quantity of air needed for cooling purposes.
3Temperature
If more air is used for fluidization and cooling, then cooling efficiency improves, but energy consumption for exhaust fans and scrubbers increases
Solution Approach 1:
The invention converts the previously harmful effect of motor heat generation into a beneficial outcome. By positioning air moving devices downstream rather than upstream, the system eliminates unnecessary heating of the fluidization air. This converts what was previously a harmful thermal effect into a benefit, reducing the cooling load and thereby reducing energy consumption for exhaust fans and scrubbers while maintaining adequate cooling efficiency.
4Ease of manufacture
If ambient air is used for fluidization, then process simplicity is maintained, but pre-heating is required in winter
Solution Approach 1:
The invention extracts the heat generation function from the fluidization air supply system by removing the upstream blower motors that caused thermal heating. By taking out this heat-generating component and replacing it with downstream exhaust fans, the system maintains process simplicity while eliminating the need for winter pre-heating, as the air remains at or near ambient temperature throughout the process.
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 approach reduces energy consumption by minimizing the heating of fluidization air, lowers pre-heating requirements, and enhances evaporation and cooler capacity, resulting in improved process efficiency and reduced energy expenditure.
Implementation Method 1
the downstream air moving devices have a capacity to generate a vacuum in the granulation compartment exceeding the total pressure drop between the air inlets and the downstream air moving devices
Implementation Method 2
The fluidized bed is fluidized by blowing a fluidization gas, usually air, through the bed of nuclei
Implementation Method 3
Air used for fluidization removes excess heat from the fluidized bed
Implementation Method 4
The nuclei grow by solidification and crystallization of the sprayed urea liquid on them, to form granules of a desired average size
Data Source
AI summary
Method and fluidized bed reactor for the production of granules, such as granules of urea or ammonium nitrate. The reactor comprises at least one granulation compartment with air inlets, and an air moving device downstream the granulation compartment, e.g., downstream one or more scrubbers. The air moving device is configured to draw air through said one or more air inlets into the granulation compartment.