Sub-sonic Steam Injection Nozzles for Viscous Slurry Heating
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Solution Overview
Problem
Conventional methods for heating viscous oil sands slurries using steam injection face issues such as poor heat transfer, vibration, and premature failure of equipment due to cavitation and erosion, particularly when using supersonic steam velocities.
Innovation Solution
A system for direct steam injection into viscous oil sands slurries that maintains sub-sonic steam velocities by controlling the steam injection pressure ratio between the slurry back-pressure and steam supply pressure, minimizing vibration and erosion, and optionally using a static mixer downstream to enhance heat transfer without channeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If steam is injected at supersonic velocities to reduce vibration, then vibration is reduced, but erosion of steam injection and static mixing components is accelerated
Solution Approach 1:
The patent changes the velocity parameter of steam injection from supersonic to sub-sonic range. This parameter change simultaneously reduces both vibration and erosion, resolving the technical contradiction by finding an optimal velocity range that avoids the harmful effects of supersonic injection while maintaining effective steam-slurry mixing and heat transfer
2Productivity
If static mixing modules are used to increase contact area between steam and bitumen froth, then heat transfer efficiency is improved, but premature wear and component failure occur
Solution Approach 1:
The patent changes the flow regime parameter by maintaining sub-sonic steam velocities, which prevents the violent cavitation and erosion that cause premature failure of static mixing components. This allows the mixing modules to operate effectively for extended periods while maintaining high heat transfer efficiency
Solution Approach 2:
The patent employs wear-resistant liner components that can be replaced when worn, protecting the main expensive mixing module structure. This allows the use of effective static mixing geometry while managing erosion through replaceable sacrificial components
3Temperature
If steam injection is used to heat viscous slurries, then heat transfer is achieved, but cavitation and localized erosion-corrosion occur
Solution Approach 1:
The patent changes the pressure and velocity parameters of steam injection to sub-sonic conditions. This parameter change prevents the formation and violent collapse of cavitation bubbles, eliminating localized erosion-corrosion while maintaining effective heat transfer from steam to slurry
Solution Approach 2:
The patent uses an intermediary approach by controlling the steam injection parameters to create a gentler mixing regime. The sub-sonic steam injection acts as a mediator that transfers heat effectively without creating the extreme pressure fluctuations that cause cavitation and erosion-corrosion
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 extends the lifespan of steam injection and mixing components, reduces vibration and erosion, and maximizes heat transfer efficiency while avoiding equipment damage and environmental risks.
Implementation Method 1
The steam releases latent heat energy to heat the fluid to a desired temperature
Implementation Method 2
heating the slurry by injecting steam in-line with the viscous fluid
Implementation Method 3
as steam condenses
Data Source
AI summary
A system and method is provided for direct condensing steam heating of oil sands process slurry streams including viscous bitumen froth and tailings products streams. Slurry viscosities greater than that of water increase cavitation and vibration issues. High solids content exacerbate component erosions. Difficult, and competing, steam and slurry interactions are managed by steam nozzle arrangements and management of steam injection at sub-sonic velocities based on a ratio of the slurry back-pressure Pb and steam supply delivery pressure Po.