Large Tank Cleaning via Combustion-Heated Sludge Injection
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Solution Overview
Problem
Current methods for cleaning large oil tanks are inefficient in reducing pollutant emissions, are costly, and require excessive nitrogen for inerting, while being energy-intensive and time-consuming, with a focus on minimizing hydrocarbon explosions and environmental impact.
Innovation Solution
A method and device that utilize a closed-loop process where extracted gases and aerosols are combusted to heat and liquefy the sludge, using the heat to reintroduce it into the tank under high pressure to break down sediments, with minimal inert gas use, and subsequent steps involving flushing with light oil and aqueous solutions to remove hydrocarbons and inorganic components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If traditional flushing procedures are used to remove residual sludge, then the sludge can be removed from the tank, but significant amounts of hydrocarbon gases are released into the atmosphere causing pollution and safety risks
Solution Approach 1:
The patent converts the harmful hydrocarbon gases that would normally be vented into a beneficial resource by combusting them in a combustion chamber to generate heat. This heat is then used to heat the residual sludge in the tank, turning a pollution problem into a useful heating source that accelerates the cleaning process while reducing emissions
Solution Approach 2:
The patent changes the temperature parameter of the sludge by heating it to elevated temperatures (e.g., 50-100°C or higher). This temperature increase reduces the viscosity of the heavy hydrocarbons in the sludge, making it more fluid and easier to pump and remove from the tank, thereby improving cleaning efficiency while minimizing emissions
2Reliability
If nitrogen is used for inerting the tank before cleaning, then explosion risk is reduced, but the cost and time required for the cleaning process increases
Solution Approach 1:
The system generates its own inerting capability by producing combustion exhaust gas (containing CO2 and H2O) in-situ through the combustion chamber. This self-generated inert gas is then introduced into the tank to displace oxygen and create a safe atmosphere, eliminating the need for external nitrogen supply and reducing both cost and time
Solution Approach 2:
The patent recovers and utilizes the combustion exhaust gas (which would normally be discarded as waste) as a valuable inerting medium. The exhaust gas containing CO2 and H2O is redirected into the tank to maintain safe oxygen levels, transforming a waste product into a functional safety component that reduces dependency on external nitrogen
3Productivity
If the residual sludge is heated to reduce viscosity and improve flow, then pumping efficiency increases, but energy consumption increases
Solution Approach 1:
The patent merges the heating function with the combustion process by using the same combustion chamber that generates inert gas to also produce thermal energy. The heat from hydrocarbon combustion is transferred to the sludge through heat exchangers or direct injection of heated combustion gases, combining two essential functions (inerting and heating) into a single integrated system that reduces overall energy consumption
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 pollutant emissions, particularly CO2, is more cost-effective, uses less nitrogen, and is more energy-efficient, allowing for faster tank cleaning while ensuring safety and environmental compliance.
Implementation Method 1
gases located above the residual sump in the tank's gas space are extracted and combusted. The heat obtained in this process is used to continuously heat a portion of the residual sump
Implementation Method 2
The heat obtained in this process is used to continuously heat a portion of the residual sump, which has been extracted via a suction line, and at least a partial flow of this heat is reintroduced into the residual sump
Implementation Method 3
This stream is then reintroduced into the large tank at high pressure through nozzles. The pressure is set high enough to significantly agitate and simultaneously heat the residual sump remaining in the large tank
Implementation Method 4
By forcibly injecting a heated quantity of residual sump, the residual sump is agitated so strongly that aerosols are constantly formed, which in turn rise into the gas space and are extracted there
Implementation Method 5
gases located above the residual sump in the tank's gas space are extracted and combusted. The heat obtained in this process is used to continuously heat a portion of the residual sump
Data Source
Figure 1
AI summary
In the method for cleaning a large tank, a volumetric flow of gas is extracted by suction from the gas chamber (34) of the large tank (20) and burned in a combustion chamber system (48). At least part of the exhaust gas thereby produced is returned by way of an exhaust-gas line (60, 62) into the gas chamber (34), in which a subatmospheric pressure is maintained. By way of a suction-extraction line (73), a mass flow of residual sump matter (30) is removed from the large tank (20) and fed to a heat exchanger (56), which is connected by way of a circuit (54) to a heating coil (52) of the combustion chamber system (48). The heated mass flow of residual sump matter (30) is directed into the large tank (20) under a high pressure of at least 20 bar onto a partial region of the mass of residual sump matter (30) that is in the large tank (20) through injection nozzles (24) that end in the gas chamber (34) and are directed onto the residual sump matter (30). When this happens, the mass of residual sump matter (30) that is in the large tank (20) is gradually moved, heated and agitated, thereby forming aerosols, which are a constituent of the gas in the gas chamber (34) and are extracted by suction as a volumetric flow by way of the gas line (32).