System with a direct contact desublimating heat exchanger and temperature regulation
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Solution Overview
Problem
Current systems for separating condensable vapors like carbon dioxide from light gases in direct contact heat exchangers face issues with heat-transfer inhibiting mass accumulation, such as frosting or fouling, which complicates temperature control and efficiency in desublimation processes.
Innovation Solution
Incorporating a mixing chamber with a stirring mechanism to mix streams of varying temperatures, allowing them to reach a uniform temperature, which is then recycled back to the desublimating heat exchanger, thereby preventing fouling and maintaining efficient heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If low temperatures are used for desublimation in a direct contact heat exchanger, then carbon dioxide can be effectively separated from light gases, but heat-transfer inhibiting mass accumulation such as frosting or fouling occurs on equipment surfaces
Solution Approach 1:
The patent extracts the harmful freezing process from the heat exchanger by introducing a separate mixing chamber where streams are mixed before re-entry. This prevents the harmful mass accumulation on heat exchanger surfaces while maintaining the necessary low-temperature desublimation process for effective CO2 separation
Solution Approach 2:
The mixing chamber acts as an intermediary between the heat exchanger and the process stream. By mixing streams of different temperatures in this intermediate chamber, the system prevents direct contact between extremely cold surfaces and the process stream, thereby preventing fouling while maintaining separation efficiency
2Stability of the object's composition
If streams of varying temperatures are mixed directly, then temperature uniformity can be achieved, but equipment freezing and fouling may occur during the mixing process
Solution Approach 1:
The mixing chamber serves as an intermediary environment where temperature mixing occurs in a controlled manner. This intermediate chamber prevents equipment freezing by providing a buffer zone where thermal equilibrium is achieved without direct exposure of equipment to extreme temperature differentials
3Productivity
If a mixing chamber is added to prevent fouling, then heat transfer efficiency is maintained, but device complexity increases
Solution Approach 1:
The patent combines multiple functions into the mixing chamber: temperature mixing, stream homogenization, and fouling prevention all occur in this single integrated component. This merging approach maintains heat transfer efficiency while minimizing the increase in overall system complexity
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 effectively prevents fouling and maintains consistent temperature control, enhancing the efficiency of the desublimation process by ensuring uniform temperature streams are recycled back into the system, thus addressing the issues of heat-transfer inhibition and equipment freezing.
Implementation Method 1
The NVHEL cools the process stream and causes the condensable vapors to desublimate, thereby forming a slurry of desublimated solids and the NVHEL
Implementation Method 2
Incorporating a mixing chamber with a stirring mechanism to mix streams of varying temperatures, allowing them to reach a uniform temperature
Data Source
AI summary
A process to prevent fouling using a desublimating heat exchanger is disclosed. An outlet stream from the desublimating heat exchanger may be split into a plurality of parallel streams. The parallel streams may be sent through a plurality of discrete unit operations, and the unit operations may change the temperature of at least one of the parallel streams. Parallel streams of differing temperature may emerge from the unit operations. The parallel streams which are of a similar temperature may be mixed to form a warm stream and a cool stream. The warm stream and the cool stream may be sent to a mixing chamber. A mixed stream of substantially uniform temperature may emerge from the mixing chamber, and the mixed stream may be recycled back to the desublimating heat exchanger. The mixing chamber may be separate from the desublimating heat exchanger, or the parallel streams of differing temperature may be mixed in the desublimating heat exchanger.