Continuous Polymer Solution Evaporation via Flash Degassing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing polymerization processes are energetically inefficient, generate high emissions, and require significant steam and water consumption, making them environmentally unfriendly and costly, especially when dealing with temperature-sensitive polymers that cannot be produced using current methods without special additives.
Innovation Solution
A continuous method involving direct evaporation of solvents and volatile components in mixing kneaders with one or two stirring shafts, followed by degassing in a kneader with controlled temperature and additive use, allowing for over 98% solvent recycling and reduced emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If coagulation and stripping processes are used to remove solvent, then solvent removal is achieved, but energy consumption increases significantly
Solution Approach 1:
The patent utilizes phase transition of the solvent from liquid to vapor through evaporation in a flash chamber, followed by condensation in a heat exchanger. This phase change process enables energy-efficient solvent removal by recovering latent heat during condensation to preheat the polymer solution, thereby reducing overall energy consumption while maintaining high productivity
Solution Approach 2:
The patent implements a feedback mechanism where the condensed solvent vapor is used to preheat the incoming polymer solution in a heat exchanger. This heat recovery system creates a closed-loop energy feedback that reduces the energy required for evaporation, resolving the contradiction between energy consumption and solvent removal efficiency
2Loss of substance
If mechanothermal drying with pressing and atmospheric drying is used, then polymer separation is achieved, but water consumption and emissions increase
Solution Approach 1:
The patent extracts the solvent removal process from the traditional multi-stage mechanothermal drying sequence and implements it as a single-stage flash evaporation process. By taking out the solvent in vapor form through phase transition, the process eliminates the need for subsequent water-intensive drying and pressing operations, reducing water consumption while maintaining separation efficiency
Solution Approach 2:
The patent converts the harmful effect of solvent vapor (which would normally be an emission) into a beneficial resource by condensing it in a heat exchanger to provide heating energy for the incoming polymer solution. This transforms potential environmental harm into useful energy, reducing both emissions and water consumption
3Productivity
If high temperatures are used for solvent evaporation, then evaporation rate increases, but polymer degradation occurs
Solution Approach 1:
The patent applies preliminary action by preheating the polymer solution using heat recovered from condensed solvent vapor before the evaporation stage. This preliminary heating reduces the temperature difference required during flash evaporation, enabling efficient solvent removal at lower temperatures that prevent polymer degradation
Solution Approach 2:
The patent uses flash evaporation where the polymer solution is rapidly evaporated in a single quick stage rather than gradual heating. This rushing through the evaporation process at elevated temperature for a very short duration prevents thermal degradation while achieving high evaporation rates, as the polymer is exposed to high temperature conditions only momentarily
4Device complexity
If complex separation processes are used for stripping agent and solvent, then complete separation is achieved, but device complexity increases
Solution Approach 1:
The patent merges the solvent evaporation and condensation processes into an integrated flash evaporation system where the condensed vapor is directly used for preheating. This combination eliminates the need for separate complex separation units for stripping agent and solvent, reducing device complexity while maintaining complete separation through the phase transition mechanism
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 process significantly reduces energy and water consumption, enhances efficiency, and allows for the production of temperature-sensitive polymers without auxiliary components, achieving nearly complete solvent removal and minimizing environmental impact.
Implementation Method 1
a low-viscosity mixture of substances is first pre-concentrated in an evaporation loop with contact heat
Implementation Method 2
pre-concentrated in an evaporation loop with contact heat
Implementation Method 3
the viscosity in this aggregate is sufficient to provide the evaporation energy, mostly via friction, to over 90% of the fluid supplied to the solution (e.g. solvents) to evaporate
Implementation Method 4
the removal of the solvent is achieved by adding water to the extruder
Data Source
AI summary
In a process for the continuous treatment of polymer solutions in an evaporator and/or degasser with a continuous product and gas space, the supply of input product or recycled condensate into the product space of the mixing kneader is to be distributed over the length of the product space.