Fuel Tank Cleaning via Contaminated Layer Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydrocarbon storage tanks face issues such as tank rust, fuel polymerization, condensation, and microbial growth, leading to contamination and phase separation, especially when switching from mineral oil-based fuels to alcohol/petrol fuels, which prolongs downtime during cleaning and requires effective methods to reclaim usable fuel.
Innovation Solution
A method involving transferring the most contaminated fuel layer to an external vessel for separation and treatment using multiple passes through a fuel cleaning apparatus, including the use of a dip tube, magnetic field, and detergent to loosen biological material, allowing parallel processing and efficient removal of contaminants, with an apparatus comprising a mobile vessel, pump, and circuit for fuel conditioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pumping and filtering contaminated fuel through a filtration system, then particulate materials are removed from hydrocarbon fuel, but the process takes time and prolongs tank downtime
Solution Approach 1:
The fuel cleaning process is divided into two independent parallel streams: (1) transferring and settling the most contaminated lower fuel layer in an external vessel, and (2) treating the remnant tank fuel through the filtration system. This segmentation allows simultaneous processing of different fuel portions, reducing total downtime while maintaining fuel quality through targeted treatment of contaminated portions.
2Reliability
If treating all fuel through multiple passes with filtration system, then fuel is cleaned effectively, but processing time increases
Solution Approach 1:
The most contaminated lower fuel layer is extracted and separated from the remnant tank fuel before treatment. By removing the heaviest contaminated portion first and allowing it to settle in an external vessel, the remaining fuel requires less intensive treatment, reducing the number of filtration passes needed and accelerating overall processing while maintaining fuel cleanliness standards.
3Reliability
If using heavy filtration to remove all contaminants, then fuel purity is improved, but usable fuel is discarded along with contaminants
Solution Approach 1:
Different treatment intensities are applied to different fuel layers based on their contamination levels. The most contaminated lower layer receives intensive treatment including settling and multiple filtration passes, while the cleaner upper layers undergo lighter treatment or are returned to service with minimal processing. This localized quality approach maintains fuel purity where needed while preserving usable fuel that would otherwise be discarded.
4Productivity
If transferring contaminated fuel layer to external vessel for separation, then parallel processing is enabled and time is saved, but additional equipment and complexity are required
Solution Approach 1:
The external vessel serves multiple functions: it acts as a transfer container for the contaminated fuel layer, provides a settling chamber for gravity separation of water and solids, and functions as a temporary storage vessel during parallel processing. This multi-functionality reduces the need for separate dedicated equipment for each step, thereby limiting the increase in system complexity while enabling parallel processing and improving productivity.
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 downtime by enabling parallel processing and reclaiming usable fuel, effectively removing sludge, biofilms, microbes, sediment, and water, while minimizing filter usage and ensuring safe waste transport.
Implementation Method 1
The most contaminated layer is at the bottom of the tank. Once transferred from the storage tank this layer is allowed to separate by gravity into a heavier water layer containing solids and a lighter hydrocarbon layer also containing solids.
Implementation Method 2
Once transferred from the storage tank this layer is allowed to separate by gravity into a heavier water layer containing solids and a lighter hydrocarbon layer also containing solids.
Implementation Method 3
separate by gravity into a heavier water layer containing solids and a lighter hydrocarbon layer
Implementation Method 4
It may also be subjected to a magnetic field which improves the physical condition of the fuel.
Implementation Method 5
The detergent is intended to loosen films of biological material adhering to the tank surface.
Implementation Method 6
The dirty fuel may be subjected to a vortex flow in order to remove water and suspended solids such as floating colonies of fungus or bacteria.
Data Source
AI summary
Liquid hydrocarbon storage tanks are cleaned by transferring the most contaminated lower fuel layer to an external vessel on a treatment truck where separation into a contaminants portion and a fuel portion occurs. The remnant fuel in the storage tank is cleaned by multiple passes through an external circuit on the truck. The fuel from the vessel is sometimes returned to the remnant fuel to be cleaned. The contaminants are discarded. The initial separation shortens the cleaning cycle. A flexible dip tube stiffened by a guide rod allows probing of the storage tank floor.