Modular Reaction Chamber with Removable Sleeve for Backmixing Control
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Solution Overview
Problem
Existing chemical reactors face challenges in achieving a narrow residence time distribution and high specific heat exchange surface area while minimizing backmixing and fouling, especially in compact, modular designs for continuous processing of multiphase reactions.
Innovation Solution
A modular reaction chamber design with a removable sleeve in the floor opening and an agitator shaft that can transmit torque, allowing for flexible adaptation and reduced backmixing, along with a modular structure that supports intensive mixing and heat exchange through a double-walled casing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a cascade of series-connected continuously operated stirred tanks is used, then a narrow residence time distribution is achieved, but the apparatus structure becomes less compact
Solution Approach 1:
The reaction system is divided into multiple reaction chambers (at least two) connected in series, each chamber acting as an independent mixing zone. This segmentation allows the system to achieve narrow residence time distribution through sequential processing while maintaining a more compact overall structure compared to traditional cascade tanks.
Solution Approach 2:
The agitator shaft is designed to extend through multiple reaction chambers, with agitator elements positioned in each chamber. This nested configuration allows a single shaft to drive mixing in multiple chambers, reducing the number of separate drive mechanisms and creating a more compact apparatus structure while maintaining effective mixing in each zone.
2Manufacturing precision
If very small openings between adjoining compartments are used, then backmixing is minimized, but pressure drop increases and discharge of solids is no longer possible
Solution Approach 1:
The floor opening is designed with asymmetric dimensions (width different from length) to create different flow characteristics in different directions. This local quality variation allows the opening to provide adequate passage for solids discharge while creating flow patterns that minimize backmixing, achieving both goals simultaneously rather than requiring extremely small openings.
3Ease of operation
If high agitator rotary speed is used, then mixing performance is improved, but degree of back-mixing increases
Solution Approach 1:
The mixing action is segmented across multiple chambers rather than concentrated in a single chamber. Each chamber provides a mixing zone, and the sequential arrangement ensures that material progresses through each zone in order. This allows effective mixing at moderate speeds while the chamber boundaries prevent excessive back-mixing that would occur at high speeds in a single chamber.
Solution Approach 2:
The system transitions from single-chamber mixing to multi-chamber sequential mixing, adding the dimension of spatial progression. Material flows through chambers in sequence rather than mixing in a single volumetric space, which allows mixing to occur effectively without the high back-mixing degrees associated with high-speed agitation in a single chamber.
4Area of stationary object
If microstructured apparatuses are used, then specific heat exchange surface area is increased, but the apparatus is not suitable for reactions with long residence time
Solution Approach 1:
The reaction system is segmented into multiple chambers that can be arranged in series to achieve long residence times. Each chamber can incorporate heat exchange surfaces, and the cumulative effect of multiple chambers provides both the required residence time and adequate heat exchange area, overcoming the limitation of microstructured apparatuses designed for short residence times.
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 design achieves a high specific heat exchange surface area, reduces backmixing, and allows for flexible adaptation to various process conditions, enhancing product quality and reactor efficiency in continuous chemical reactions.
Implementation Method 1
the agitator shaft, at the beginning thereof and/or at the end thereof, is adapted to absorb reversibly a torque provided by means of a further shaft and/or to transmit a torque to a further shaft
Implementation Method 2
a modular structure that supports intensive mixing and heat exchange through a double-walled casing
Data Source
AI summary
A reaction chamber for a chemical reactor comprises a casing (100) of the reaction chamber, a floor (200) of the reaction chamber having an opening (300) located in the floor, an agitator shaft (400) located in the chamber and having at least one agitator element (500), connected thereto, wherein the agitator shaft (400), seen in the longitudinal direction, has a beginning (600) and an end (700). In the opening (300) of the floor (200) a removable sleeve (800) is provided, which projects out of the reaction chamber. The sleeve (800) is arranged in alignment with the axis of rotation of the agitator shaft (400). The internal diameter of the sleeve (800) is greater than the diameter of the agitator shaft (400) and the agitator shaft (400), at the beginning (600) thereof and/or at the end (700) thereof, is adapted to absorb reversibly a torque provided by means of a further shaft and/or to transmit a torque to a further shaft. Using such a reaction chamber, it is possible to build up modular chemical reactors having decreased backmixing.