Method and system of maintaining a liquid level in a distillation tower
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional distillation technologies face challenges in maintaining a predetermined liquid level in cryogenic distillation towers, leading to inefficient separation of solid contaminants from hydrocarbons, as existing liquid level indicators are unreliable due to plugging, temperature, and pressure conditions.
Innovation Solution
A distillation tower system with a controlled freeze zone section, including a melt tray assembly, underflow weir, overflow weir, and covering element, which alters the liquid flow to maintain a predetermined liquid level, ensuring reliable melting of solid contaminants and preventing plugging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional liquid level indicators are used in cryogenic distillation towers, then liquid level measurement is attempted, but the indicators become unreliable due to plugging, temperature, and pressure conditions
Solution Approach 1:
The patent replaces conventional mechanical liquid level indicators with a differential pressure measurement system that uses pressure sensors to detect liquid level changes. This substitution eliminates the plugging problem inherent in mechanical indicators by using electronic sensing elements that are not susceptible to physical blockage by solid contaminants in the cryogenic environment.
Solution Approach 2:
The patent introduces differential pressure as an intermediary measurement parameter to indirectly determine liquid level. Instead of directly measuring liquid level with indicators that plug, the system measures pressure differences across a known height and calculates liquid level from these pressure readings, using pressure as a mediator that does not suffer from plugging issues.
2Productivity
If liquid level is not properly maintained in the controlled freeze zone, then operation is simplified, but separation efficiency decreases and solid contaminants may exit the zone
Solution Approach 1:
The patent implements a feedback control system where differential pressure measurements of liquid level are continuously monitored and fed back to control liquid flow into the controlled freeze zone. This automatic feedback mechanism maintains the optimal liquid level without requiring complex manual intervention, balancing separation efficiency with operational simplicity.
Solution Approach 2:
The system uses the process fluid本身的 differential pressure to self-diagnose and control liquid level, eliminating the need for external complex control systems. The pressure difference across the liquid column provides automatic information about liquid level, which can be used to regulate flow without additional sophisticated instrumentation.
3Reliability
If the liquid level fluctuates in the melt tray assembly, then the system is easier to operate, but solid contaminants may not fully melt and may plug the discharge line
Solution Approach 1:
The patent uses differential pressure feedback to continuously monitor and stabilize liquid level in the melt tray assembly. By detecting pressure changes that indicate level fluctuations and automatically adjusting liquid flow, the system ensures sufficient liquid is always present to melt solid contaminants completely, preventing discharge line plugging while maintaining easy operation.
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 system effectively maintains a stable liquid level, ensuring efficient separation of hydrocarbons from contaminants by ensuring all solid contaminants melt and do not exit the controlled freeze zone, thereby improving the quality of hydrocarbon production.
Implementation Method 1
altering a flow of the liquid in the melt tray assembly such that the liquid flows from a bottom melt tray assembly portion of the melt tray assembly to a top melt tray assembly portion of the melt tray assembly
Implementation Method 2
maintaining a predetermined liquid level of liquid in a melt tray assembly of the controlled freeze zone section... ensuring all solid contaminants melt
Implementation Method 3
separating a feed stream in a distillation tower... separation of contaminants from hydrocarbons is difficult... cryogenic separation of contaminants, such as acid gas, from a hydrocarbon
Implementation Method 4
The separation of CO2 from methane by distillation involves temperature and pressure conditions that result in solidification of CO2... formation and subsequent melting of solids during the separation
Data Source
AI summary
The present disclosure provides a distillation tower that may include a stripper section constructed and arranged to separate a feed stream at a temperature and pressure at which the feed stream forms no solid; a controlled freeze zone section constructed and arranged to separate the feed stream at a temperature and pressure at which the feed stream forms a solid; a melt tray assembly in the controlled freeze zone section that includes a liquid; an underflow weir in the controlled freeze zone section that alters a flow of the liquid in the melt tray assembly; an overflow weir in the controlled freeze zone section that works with the underflow weir to alter the flow of the liquid in the melt tray assembly and is adjacent to the underflow weir; and a covering element in the controlled freeze zone section that is connected to and extends from the underflow weir.