High Gravity Rotating Bed Reactor for Polyamine Mixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing polymethylene-polyphenyl-polyamine in the polyurethane industry face challenges with non-uniform mixing of formaldehyde and aniline, leading to by-products, local overheating, and pipe blockages, which affect product quality and efficiency, especially in large-scale continuous production.
Innovation Solution
A method utilizing a high gravity rotating bed reactor for mixing formaldehyde and aniline hydrochloride, combined with a condensation stirred vessel, to achieve rapid and uniform dispersion, enhancing mass and heat transfer, and micro-mixing, thereby improving the condensation reaction process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional mixing apparatuses (mixing pump, jet mixer, dynamic mixer, or static mixer) are used to mix formaldehyde and aniline, then the mixing process is simple to operate, but the mixing effect deteriorates due to high viscosity and laminar flow pattern, resulting in local excess of formaldehyde, by-products, and pipe blockages
Solution Approach 1:
The patent applies parameter changes by utilizing the high-speed rotation of the rotor (500-3000 rpm) to generate centrifugal force, transforming the mixing mechanism from conventional low-speed mechanical mixing to high-speed rotational mixing. This parameter change enables molecular-level dispersion of formaldehyde in aniline hydrochloride solution, achieving uniform mixing without increasing operational complexity
Solution Approach 2:
The patent employs dynamics by using a rotating rotor that creates dynamic mixing conditions through centrifugal force and turbulent flow. The rotor's rotation generates strong shear forces and eddy currents that continuously renew the mixing action, preventing local overheating and ensuring uniform distribution of reactants throughout the reaction medium
2Manufacturing precision
If formaldehyde and aniline are not mixed at the molecular level rapidly, then the reaction process is easier to control, but local excess of formaldehyde occurs, producing by-products and net-like high polymers that affect product quality
Solution Approach 1:
The high-speed rotating rotor generates mechanical vibrations and turbulent flow patterns that enhance mass transfer and accelerate molecular-level mixing. The vibrational effects created by rapid rotation break up concentration gradients and prevent local excess of formaldehyde, ensuring uniform reaction conditions and high product quality while maintaining fast reaction speed
Solution Approach 2:
The patent utilizes phase transitions in the form of turbulent flow to laminar flow conversion within the reaction system. The rotor creates turbulent mixing zones where rapid molecular dispersion occurs, then allows transition to controlled laminar flow for steady-state reaction, achieving both rapid mixing and controlled reaction progression
3Reliability
If the reaction mixture has high viscosity and flows in laminar pattern, then the flow is stable and easy to control, but the mixing effect deteriorates and local overheating occurs, increasing by-products and causing pipe blockages
Solution Approach 1:
The patent transforms the static laminar flow into dynamic turbulent flow through the rotating rotor. The rotor's rotation creates time-varying flow patterns with eddy currents and mixing zones that maintain overall flow stability while achieving intensive local mixing. This dynamic approach prevents local overheating by continuously renewing the mixing action throughout the reaction volume
Solution Approach 2:
The rotor acts as an intermediary element between the pump and the reaction vessel, introducing a new mixing mechanism. The rotor transfers mechanical energy from the drive system to the reaction mixture, creating centrifugal force-driven flow patterns that enhance mixing efficiency while maintaining overall system stability and preventing pipe blockages
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 reduces impurities, prevents pipe blockages, and stabilizes product quality by ensuring rapid and uniform mixing, allowing for higher formaldehyde proportions and lower impurity content, resulting in improved reactor efficiency and product quality with reduced power consumption.
Implementation Method 1
a high gravity rotating bed reactor for mixing formaldehyde and aniline hydrochloride
Implementation Method 2
a condensation stirred vessel, to achieve rapid and uniform dispersion, enhancing mass and heat transfer
Data Source
AI summary
The present invention provides a method of preparing polymethylene-polyphenyl-polyamine (briefly referred to as polyamine, DAM), in which a high gravity rotating bed is used as the mixing reactor of formaldehyde and aniline hydrochloride, the mixing solution of aniline hydrochloride and circulation solution and the formaldehyde are fed into the high gravity rotating bed reactor proportionally to carry out mixing and condensation reaction under a condition of a very high gravity; the materials leaving the high gravity rotating bed reactor is introduced into a stirred vessel to proceed with the pre-condensation reaction and obtain a condensation solution; and the process steps of heating, molecular rearrangement, neutralization, water washing and purification, etc. are completed to obtain the refined DAM. With the method according to the present invention, the main by-products is obviously reduced in the condensation process, the phenomenon of deposit attaching to the inner walls of circulation pipes and heat exchanger and blockage are prevented in the condensation process, the impurity content is low in the refined DAM, and the subsequent product MDI has a lighter color, the product quality is stable and may be improved to a certain extent.