Standpipe Gas Inlet and Drain Device for Solids Flow Control
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Solution Overview
Problem
Existing systems face challenges in maintaining a pressure balance and controlling the flow of solids in solids flow loops, particularly in fluidized bed combustion and chemical looping systems, leading to inefficiencies and potential clogging due to gas entrainment and pressure differentials.
Innovation Solution
A system comprising a standpipe with gas inlets to adjust the solids-to-gas ratio, a sealpot for fluidizing and transporting solids, and a drain device to remove excess gas from the standpipe, ensuring a controlled flow by increasing the solids-to-gas ratio before the sealpot, thereby maintaining a pressure balance and preventing backflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gas is injected into the standpipe to facilitate solids flow, then the solids flow improves, but the solids-to-gas ratio decreases causing clogging
Solution Approach 1:
The standpipe is divided into multiple sections with separate gas injection points, allowing gas to be introduced at specific locations to facilitate solids flow without overwhelming the entire system. This segmentation enables localized gas-solids interaction that maintains overall solids-to-gas ratio control.
Solution Approach 2:
The system dynamically adjusts gas flow rate and pressure parameters at different standpipe locations to optimize solids flow while maintaining adequate solids-to-gas ratio. By changing these parameters locally rather than uniformly, the system achieves improved flow without clogging.
2Reliability
If pressure differential is increased to prevent backflow through the sealpot, then backflow prevention improves, but pressure balance control becomes difficult
Solution Approach 1:
Pressure sensors monitor the pressure differential across the sealpot and provide feedback to a control system that automatically adjusts gas flow rates and valve positions. This closed-loop feedback mechanism maintains the optimal pressure balance to prevent backflow while keeping the system easy to operate.
Solution Approach 2:
A bypass line with a control valve is introduced as an intermediary pathway that allows fine-tuning of pressure balance. This bypass enables precise control of the pressure differential across the sealpot without requiring direct manipulation of main process parameters.
3Productivity
If gas flow rate is increased to maintain positive solids flow, then solids transport improves, but gas entrainment increases causing system inefficiency
Solution Approach 1:
Multiple smaller gas injection points are distributed along the standpipe rather than using a single high-flow injection. This segmentation delivers gas more uniformly to the solids, maintaining positive flow while reducing excessive gas entrainment and associated energy losses.
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 enables precise control of solids flow, preventing clogging and maintaining efficient operation by adjusting the gas content in the solids flow, ensuring a stable pressure balance and effective fluidization, thus enhancing overall system performance.
Implementation Method 1
a sealpot having an inlet fluidly coupled to the standpipe and an outlet fluidly coupled to a riser, the sealpot being configured to fluidize the solids received from the standpipe and to transport the solids to the riser
Data Source
AI summary
A system includes a standpipe for receiving a flow of solids therethrough, the standpipe having at least one inlet configured to receive a gas for decreasing a solids-to-gas ratio of the flow, a sealpot having an inlet fluidly coupled to the standpipe and an outlet fluidly coupled to a riser, the sealpot being configured to fluidize the solids received from the standpipe and to transport the solids to the riser, and a drain device fluidly coupled to an outlet in the standpipe, the outlet being located upstream from the inlet of the sealpot. The drain device is configured to remove the excess gas from the flow of solids within the standpipe to increase the solids-to-gas ratio of the flow prior to the solids entering the sealpot.