Vortex Mixing Device for Down-flow Hydroprocessing Reactors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Down-flow hydroprocessing reactors face challenges with poor interbed fluid mixing, leading to temperature maldistribution, catalyst deactivation, and reduced reactor performance due to limited space and high pressure drops in existing mixing devices.
Innovation Solution
A vortex-type mixing device with a reduced vertical footprint, featuring inwardly-directed vanes between top and base plates, which enhances mixing of gas and liquid phases while minimizing pressure drop, suitable for retrofit and new reactor designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing mixing devices are used in down-flow hydroprocessing reactors, then fluid mixing between catalyst beds is achieved, but the devices occupy excessive vertical space and create high pressure drops
Solution Approach 1:
The mixing device is divided into multiple functional components: a distribution plate for even fluid distribution, a mixing chamber with baffle plates for controlled mixing, and a collection plate for uniform flow to the next bed. This segmentation allows each component to perform its function efficiently within a compact vertical space, reducing the overall device height while maintaining effective mixing.
Solution Approach 2:
The invention transitions from vertical mixing approaches to a predominantly horizontal mixing mechanism within a shallow vertical profile. The baffle plates are arranged to create horizontal flow patterns and eddies that achieve thorough mixing without requiring significant vertical distance, thus reducing the vertical footprint while maintaining mixing effectiveness.
2Reliability
If existing mixing devices are used in down-flow hydroprocessing reactors, then fluid mixing between catalyst beds is achieved, but the devices create high pressure drops that reduce reactor efficiency
Solution Approach 1:
The baffle plates are strategically positioned and dimensioned to create localized mixing zones where turbulence and eddies are generated only where needed for effective mixing. The spacing, height, and orientation of the baffles are optimized to achieve thorough mixing while minimizing flow resistance and pressure drop across the entire device.
Solution Approach 2:
The invention optimizes geometric parameters including baffle plate height, spacing, and angle; distribution plate aperture size and distribution; and chamber dimensions. These parameter changes create an optimal balance between mixing intensity and flow resistance, achieving effective mixing with minimal pressure drop.
3Reliability
If more mixing space is provided between catalyst beds, then better fluid mixing and temperature distribution are achieved, but the reactor volume for catalyst loading is reduced
Solution Approach 1:
The mixing device uses dynamic flow patterns created by the baffle plates to achieve thorough mixing within a compact space. The baffles generate turbulent flow, eddies, and recirculation zones that continuously redistribute fluids and heat, achieving uniform temperature distribution without requiring a large static mixing volume that would reduce catalyst loading space.
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 device achieves effective fluid mixing, reduces pressure drop, and improves reactor performance by optimizing mixing in limited interbed spaces, enhancing catalyst lifetime and throughput.
Implementation Method 1
The mixing device is a vortex-type design. This type of mixer collects the liquid and gas streams flowing downward through the reactor, and introduces them into a circular chamber where they make several rotations before being passed downward
Implementation Method 2
Another type of mixer is a centrifugal or vortex-type design
Implementation Method 3
Designs for mixing devices vary, including baffle mixer designs such as ribbon blenders and disk-and-donut type mixers that promote mixing through changing the direction of the fluid and gases
Data Source
AI summary
An improved vortex-type mixing device for a down-flow hydroprocessing reactor is described. The device provides improved overall mixing efficiency of an existing mixing volume in the mixing of gas and liquid phases in two-phase systems while reducing the pressure drop through the device, as compared with prior art devices. Typical hydroprocessing applications include hydrotreating, hydrofinishing, hydrocracking and hydrodewaxing.