Patent GB-734125-A (GB)
Title: Improvements in or relating to a snuffing system associated with apparatus for the conversion of hydrocarbons
Inventor: KILPATRICK MYRON ODEN
IPC: B01J8/12
Filed: 1951-01-12
Abstract: A snuffing system associated with apparatus for the conversion of hydrocarbon vapours by contacting them with a flowing mass of hot pebbles, comprises fluid - pressure - actuated valves (e.g. valves operated by compressed air) mounted in the lines for introducing the hydrocarbon vapours, the fuel for heating the pebbles, and purge-gas (e.g. steam) into the apparatus, each valve communicating with a fluid supply line having pressure-release means, which causes the hydrocarbon and fuel valves to close and the purge-gas valve to open, when the pressure in the fluid supply line falls below a predetermined minimum value.  In the Figure, pebbles flow down through heater 11, throat 13, and reactor 12; and are then recirculated to the top of the heater by elevator 18, which is operated by an electric motor (not shown).  The pebbles are heated, as they pass down the heater, by direct contact with combustion gases generated at burner 21, which is supplied with <PICT:0734125/III/1> fuel and air through lines 22 and 23 respectively.  The gases leave the heater through stack 25.  Hydrocarbon gas is introduced into reactor 12 through line 26; and the converted gas is discharged through line 33 into tank 34, where it is quenched with water introduced through line 36.  The cooled product is withdrawn from tank 34 through line 39.  Gravitometer 76, which is in communication with line 39 and with valve 77 in fuel-line 22, maintains the relative density of the cooled product stream at a substantially constant value.  The gravitometer 76 may also control the rate of circulation of the pebbles.  In order to prevent air leakage into the system, the suction-pressure on line 39 is maintained at a constant value, at least as great as atmospheric, by turbo-blower 41 which is operated by steam supplied through line 44.  The speed of the blower is automatically regulated by control 42 which is connected to steam-valve 43.  When the speed of the blower has been reduced to its minimum operational limit, pressure-controller 45 opens valve 46 in line 47, thereby permitting part of the hydrocarbon effluent to be returned to line 39.  Under extreme conditions, when blower 41 and return-line 47 are unable to maintain the pressure in line 39, controller 48 operates valve 49 in line 51 to admit maintenance gas into line 39.  Under emergency conditions, the reactor and heater are purged with steam, supplied through lines 61, 72, 26 and 22, by the opening of valves 74 and 80.  These valves, and also fuel-valve 98, hydrocarbon-feed-valve 27, maintenance-gas-valve 49, suction-blower-steam-valve 43, water-valve 37 and air-blower-steam-valve 81, are operated by compressed air; the various controls being connected to air supply line 91.  The snuff system operates automatically in case of failure of air supply at any point in the air supply line; and it may be operated manually from switches 92 and 93.  In either case, valves 94 and 95 operate to shut off the compressed air, and vent the line 91 through line 96. Simultaneously valves 98, 27, 49, 43, 37 and 81 are closed, and purge-valves 74 and 80 are opened.  Valves 46 and 54 are also opened, so that the purge-gas discharged from the reactor, flows to atmosphere via lines 47 and 55, thus by-passing blower 41. Furthermore, the electric power for the unit motors (not shown) is cut out by switch 97; and damper 85 in stack 25 is opened completely by control 84.  The control of the hydrocarbon conversion itself by a gravitometer is the main feature of the invention of Specification 734,111. Specification 734,176 also is referred to.