Coker Furnace Outlet Isolation for Online Pigging and Spalling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current systems for on-line pigging and spalling of coker furnace outlets lack the capability to safely manage high temperatures and pressures, leading to potential failures and safety concerns, as existing piping and valve systems are not robust enough to handle the conditions required for effective on-line spalling and pigging operations.
Innovation Solution
A method and system that involves the use of high pressurized steam to maintain constant pressure across valves, isolate vents, and disconnect tube coils for safe pigging, utilizing a double block and purge system to ensure safe hazardous energy isolation and prevent valve leakage or failure, allowing for both on-line pigging and spalling operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If existing piping and valve systems are used for on-line spalling, then the system can operate at normal temperatures, but the piping and components fail pressure containment when exposed to higher temperatures required for effective spalling
Solution Approach 1:
The patent applies parameter changes by transitioning from normal operating conditions to elevated temperature and pressure conditions during on-line spalling operations. The system is designed to withstand these parameter changes through proper material selection and stress analysis, enabling the piping and valves to maintain pressure containment reliability even when exposed to temperatures up to 1250°F during the spalling process
Solution Approach 2:
The patent implements preliminary action through pipe stress analysis conducted before on-line spalling operations. This analysis determines whether the piping system can withstand the thermal and mechanical stresses of spalling, and if not, identifies necessary modifications such as adding expansion joints, changing support configurations, or upgrading materials before the high-temperature operation begins
2Use of energy by stationary object
If conventional low alloy materials are used in on-line spalling, then the system can operate at lower costs, but the materials operate in their creep range requiring higher alloy materials to meet regulatory requirements
Solution Approach 1:
The patent addresses material selection by evaluating both conventional low alloy materials and higher alloy materials for on-line spalling applications. When low alloy materials would operate in their creep range, the system transitions to higher alloy materials that can withstand the elevated temperatures without excessive creep, ensuring compliance with regulatory requirements while maintaining cost-effectiveness through proper material matching to service conditions
3Loss of time
If on-line pigging is performed, then downtime is reduced, but safe hazardous energy isolation and component safety factors become more difficult to ensure
Solution Approach 1:
The patent applies segmentation by dividing the piping system into isolated segments during on-line pigging operations. Double block and bleed valve arrangements create discrete isolation zones, allowing pigging activities in one segment while maintaining safe pressure containment in other segments. This segmentation enables continuous operation with reduced downtime while ensuring adequate safety factors through physical isolation
Solution Approach 2:
The patent uses intermediaries such as purge lines and bleed valves between blocked valves during on-line pigging. These intermediary components provide safe pressure relief paths and verification mechanisms that maintain hazardous energy isolation, allowing pigging operations to proceed without compromising the safety factors of the overall system
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
Enables safe and efficient on-line pigging and spalling of coker furnace tubes, reducing downtime and maintaining operational safety by ensuring that valves and components can withstand the necessary temperatures and pressures, thus preventing coke buildup and ensuring worker safety.
Implementation Method 1
introducing high pressurized steam from a third pressurized steam source through the second line to maintain a constant pressure against one side of first and second closed valves positioned in fluid communication with the vent
Implementation Method 2
The steam flow, upon leaving the furnace, rejoins the process fluid furnace effluent from the passes which remain in service. Then, the temperature of the steam and the tube passes which are to be decoked are raised. This temperature increase continues until reaching a temperature far in excess of normal operations. This may be as high as 1250 F depending on the tube material, thickness.
Implementation Method 3
introducing water from a water source to the pigging unit for driving a pig through the tube coil
Data Source
AI summary
Systems and methods for safe on-line pigging decoking of a coker furnace tubes and which also permits on-line spalling operations.