Flow Pattern Transition Pipe for Pneumatic Conveyance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pneumatic conveyance systems in gasification processes often experience unstable flow patterns due to plug flows, leading to overheating issues, as the solid feed discharged from vessels tends to form high concentration and low concentration parts, which are extremely unstable, necessitating a transition to a stable flow pattern.
Innovation Solution
A flow pattern transition pipe with a first expansion section increasing in diameter, followed by a shrink section and a third section with a smaller identical diameter, designed to reduce superficial velocity and change the flow pattern from plug flow to uniform flow, ensuring carrier gas velocities are below saltation and above pick-up velocities, respectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional straight pipe is used for pneumatic conveyance, then the device structure is simple, but the flow pattern remains unstable with plug flows causing overheating
Solution Approach 1:
The pipe is divided into three distinct sections: a first expansion section (102) with increasing diameter, a second shrink section (104) with decreasing diameter, and a third pipe section (106) with constant smaller diameter. This segmentation allows each section to perform a specific function in transforming the flow pattern from unstable plug flow to stable uniform flow, thereby improving conveyance reliability without excessive complexity.
Solution Approach 2:
The invention changes the geometric parameters of the pipe along its length - specifically the inner diameter varies through the expansion and shrink sections. This parameter change creates the necessary flow conditions to transform plug flow into uniform flow, stabilizing the conveyance while maintaining a relatively simple structural implementation.
2Productivity
If the pipe diameter is constantly large, then the conveyance capability is high, but the carrier gas velocity becomes too low causing plug flow instability
Solution Approach 1:
Different sections of the pipe have different diameter characteristics tailored to specific functions: the first expansion section has increasing diameter to reduce velocity and transform flow pattern, the second shrink section increases velocity to maintain stability, and the third section maintains constant smaller diameter for sustained uniform flow. This local differentiation of pipe quality allows simultaneous optimization of conveyance capability and flow stability.
Solution Approach 2:
The pipe structure transitions from static uniform diameter to dynamic varying diameter. The expansion and shrink sections create a dynamic flow environment that actively transforms the flow pattern from unstable plug flow to stable uniform flow, while the third section maintains a dynamic balance at the optimized smaller diameter for sustained conveyance stability.
3Stability of the object's composition
If the pipe diameter is reduced to increase carrier gas velocity, then the flow pattern stability improves, but the conveyance capability decreases
Solution Approach 1:
The first expansion section performs a preliminary action of reducing carrier gas velocity and transforming the flow pattern before the material enters the shrink and constant diameter sections. This preliminary transformation of the flow regime ensures that subsequent sections can maintain stable uniform flow at optimized conveyance conditions, rather than requiring continuous high velocity that would reduce conveyance capability.
Solution Approach 2:
The three-section design ensures continuous useful action throughout the pipe: the expansion section continuously transforms flow pattern, the shrink section continuously adjusts velocity, and the third section continuously maintains stable uniform flow. This continuous action sequence ensures both flow stability and sustained conveyance capability without interruption or loss of efficiency.
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 transition pipe effectively reduces flow fluctuations to less than 10%, stabilizing the flow pattern from plug flow to uniform flow, enhancing conveyance stability and preventing overheating in gasification systems.
Implementation Method 1
carrier gas velocity at the maximum inner diameter end of the first section lower than a saltation velocity
Implementation Method 2
carrier gas velocity at the minimum inner diameter end of the second section higher than a pick-up velocity
Data Source
AI summary
A flow pattern transition pipe for use in a pneumatic conveyance system is provided. The flow pattern transition pipe comprises a first expansion pipe section gradually increasing in inner diameter in an axial direction, a second shrink pipe section following the first section from a maximum inner diameter end of the first section and gradually reducing in inner diameter in an axial direction away from the first section, and a third pipe section following the second section from a minimum inner diameter end of the second section, with a substantially identical inner diameter smaller than a minimum inner diameter of the first section. An axial length of the first section is from about three to about five times of the axial length of the second section.