Control system for sulfur process

Claim 1

A process for the production of sulfur comprising passing a first stream containing hydrogen sulfide into a combustion zone, passing a second stream containing oxygen into said combustion zone to therein convert a portion of the hydrogen sulfide of said first stream to sulfur dioxide, withdrawing the resulting combustion products from said combustion zone, passing the withdrawn combustion products to a reaction zone and therein reacting hydrogen sulfide and sulfur dioxide contained in said combustion products to produce sulfur, withdrawing the reaction effluent from said reaction zone, separating the thus withdrawn reaction effluent into a liquid sulfur stream and a stripped gas stream, utilizing a pressure sensor to measure the pressure of said first stream and establish a first signal representative thereof, utilizing a flow sensor to measure the flow rate of said first stream and establish a second signal representative thereof, utilizing analytical apparatus to determine the ratio of the concentration of hydrogen sulfide in said stripped gas stream to the concentration of sulfur dioxide in said stripped gas stream and establish a third signal representative thereof, utilizing control system components to establish a fourth signal responsive to said second and third signals, and utilizing control system components to control the rate of flow of said second stream responsive to the lower of said first and fourth signals to maintain the desired ratio of hydrogen sulfide to oxygen fed to said combustion zone despite any changes in the pressure of said first stream and any variation in the concentration of hydrogen sulfide in said first stream and in the concentration of oxygen in said second stream.