The ST100 thermal mass flow meter series from Fluid Components International (FCI), electronics manufacturer, provides accurate measurement of air and fuel gasses to optimise the performance of boilers used by sulphur recovery units (SRUs)
Dangerous toxic sulphur levels are present in various forms during the production and refining of hydrocarbon fuels (crude oil), including sulphur dioxide (SO2) gas and hydrogen sulphide gas (H2S). The sulphur found in crude oil products is toxic and poses a serious hazard to workers, equipment and facilities and must be removed during the production process.
The typical SRU Claus sulphur removal process operation consists of a burner system for the combustion of sulphur-rich sour gas (acid gas) followed by a catalytic converter for the production of harmless sulphur powder, water and waste gas (tail gas).
The operation of SRUs requires close control of the ratio between the H2S acid gas, the tail gas and the available oxygen (air) as crucial to the effective operation of the system. The air feed for the SRU system includes a main air feed and a trim air feed to closely control the boiler’s total air feed.
The meter is ideal for measuring air feed control. It provides direct gas mass flow measurement and requires no additional sensors or flow calculating devices. The instrument’s no-moving-parts design also virtually eliminates wear, breakage and maintenance.
The meter is developed with a graphical, multivariable backlit LCD display. The reading continuously displays all process measurements and alarm status for easy on-site viewing by technicians, and it has the ability to query for service diagnostics.
The meter’s electronics include a user-selectable and programmable data logger. Readings are stored in an internal micro-SD card that can be removed. The micro-SD card has a two GB capacity capable of storing approximately 21mn readings. The recording time base is user selectable with a maximum rate of one reading per second.
The logging feature is selectable via the front panel menu or via the serial port and configuration software tools.
The meter uses constant power thermal mass flow sensing technology that measures flow with 100:1 turndown in ranges from 0.006 to 1850 SCFM[ 0.01 to 3140 NCMH]. The transmitter/electronics are mounted with the flow body or can be mounted at a distance of 1000 feet [305 m] away. The transmitter enclosure is NEMA4X/IP67 rated and available in painted aluminium or stainless steel.
