Upgrading of the steam soot blowing self-regulating valve for Furnace A# at Lunan Chemical Industry

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Lunan Chemical’s upgrade of the steam soot-blowing automatic control valve for Furnace A# Author/Source: Lunan Chemical Date: 2022-06-14 Clicks: 20 From June 7th to 8th, the thermoelectric project team from Lunan Chemical’s Instrumentation Section 4 successfully completed the upgrade of the steam soot-blowing automatic control valve for Furnace A#. This valve is the steam control valve at the outlet of the 0.7Mpa pressure reduction station for Furnace A#, and it is a key valve used for steam purging during boiler operation. The valves installed at the beginning of operation used PS2 actuators, and their feedback rods frequently came loose due to frequent automatic adjustments on site, which prevented the valves from functioning. Moreover, these valves were located on the pipelines of the pressure reduction station atop Furnace A#, and it took maintenance personnel about seven to eight minutes to reach the site where the problem occurred by climbing stairs, which posed significant difficulties for process management. Through an in-depth understanding of the valve logic, along with the feedback from process engineers, instrument technicians and technical staff from the process workshop held numerous discussions to ultimately determine a specific upgrade plan. The new valve is equipped with an SVI AP intelligent positioner, which not only responds quickly to signals from the control room but also enables the independent transmission of both analog and digital feedback signals from the valve to the control room. Moreover, this locator is being used “for the first time” in our sector! In line with process safety requirements, normally closed solenoid valves from Asco are used for the gas lines on site, enabling an emergency shutdown function for the valves. During on-site selection, a handwheel device was ultimately chosen to achieve \"dual redundancy\" for chemical process safety, enabling greater flexibility to adapt to various operating conditions as well as the requirements for the stable operation of Furnace A#. After a day of installation, piping, and debugging, the project team successfully completed the renovation, completely eliminating the safety risks associated with valve regulation in that area.