Downflow Reactor Mixing Device with Longitudinal Opening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluid mixing and distribution devices in downflow catalytic reactors face challenges in achieving homogeneous fluid distribution across the distribution plate, leading to imbalanced flow rates and potential hot spots due to gas flow rates affecting liquid distribution, resulting in inefficient heat exchange and catalyst deactivation.
Innovation Solution
A compact mixing and distribution device with a mixing zone and exchange chamber configuration, where the exchange chamber is longer than the mixing chamber, creating a ceiling with longitudinal openings for fluid passage, and horizontal panels above the chimneys to manage gas flow and ensure uniform fluid distribution, along with lateral passage sections and deflectors to balance flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a compact mixing and distribution device is used with mixing zone and distribution zone at the same level, then device bulkiness is reduced, but gas flow may drive liquid fluids onto the distribution plate and dry certain zones, resulting in imbalanced flow rate distribution
Solution Approach 1:
The device is segmented into distinct functional zones: a mixing zone for fluid mixing, an exchange chamber for temperature exchange, and a distribution zone for fluid distribution. This segmentation allows each zone to perform its specific function optimally while maintaining compact overall dimensions, resolving the contradiction between compactness and distribution homogeneity.
Solution Approach 2:
The patent introduces a vertical dimension by stacking the mixing zone, exchange chamber, and distribution zone at different heights rather than placing them side-by-side. This vertical arrangement reduces the horizontal footprint and device bulkiness while maintaining adequate space for proper fluid distribution through the exchange chamber's temperature exchange function.
2Manufacturing precision
If exchange chamber length L2 is increased to prevent fluid drying, then device bulkiness increases, but compactness is compromised
Solution Approach 1:
The exchange chamber utilizes the vertical dimension to provide adequate length for temperature exchange without increasing horizontal footprint. By arranging the mixing zone above and the distribution zone below the exchange chamber vertically, the patent achieves sufficient exchange chamber length for preventing fluid drying while maintaining compact overall device dimensions.
Solution Approach 2:
The exchange chamber performs preliminary temperature exchange action on the fluid mixture before it reaches the distribution zone. This preliminary action ensures that the fluid is properly conditioned (preventing drying) before distribution, allowing the use of a moderately sized exchange chamber that balances both homogeneity and compactness requirements.
3Reliability
If quench fluid injection is increased to cool reaction fluid, then thermal runaway is prevented, but temperature gradient homogeneity becomes difficult to maintain
Solution Approach 1:
The cooling function is segmented and distributed through multiple quench fluid injection points located at different positions within the mixing zone and exchange chamber. This distributed injection approach prevents localized over-cooling while ensuring overall thermal homogeneity, resolving the contradiction between preventing thermal runaway and maintaining temperature gradient homogeneity.
Solution Approach 2:
The exchange chamber design allows for feedback-based temperature control where the temperature exchange between quench fluid and reaction fluid is optimized to maintain homogeneous axial temperature gradient. The chamber's structure enables effective heat exchange that responds to temperature variations, ensuring both thermal runaway prevention and temperature homogeneity.
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 configuration enhances fluid distribution homogeneity and thermal efficiency, preventing hot spots and maintaining catalyst activity by managing gas flow effectively and ensuring balanced fluid distribution across the catalyst bed.
Implementation Method 1
The exothermic nature of the reactions makes it necessary to maintain a homogeneous axial temperature gradient over the reactor cross section... allowing a homogeneous temperature distribution in the fluids over a reactor cross section and cooling of the reaction fluids to a desired temperature
Implementation Method 2
said ceiling comprising at least one longitudinal opening suitable for the passage of the fluids from said exchange chamber to said distribution zone (C)
Implementation Method 3
The configuration of the mixing zone makes it possible for the fluids to be mixed in the mixing chamber and for said mixture to flow to the exchange chamber. The mixing between the reaction fluid and the quench fluid continues to take place in the exchange chamber
Data Source
AI summary
Fluid mixing and distribution device for a downflow catalytic reactor, the said device comprising a mixing zone comprising at least one fluid-mixing space of length L1′ and a fluid-exchange space of length L2′, situated underneath and superposed with said mixing space, it being understood that the length L2′ of the said exchange space is strictly greater than the length L1′ of the said mixing space so as to create a roof at the level of the said exchange space, the said roof comprising at least one longitudinal opening suited to the passage of the following its from the said exchange space to the said distribution zone.