Patent GB-805262-A (GB)
Title: Improvements in or relating to cyclic water gas generators
Inventor: GRISENTHWAITE ARTHUR TURNER
IPC: C10J1/213
Filed: 1954-08-13
Abstract: 805,262. Water-gas generators. POWERGAS CORPORATION Ltd. Nov. 9, 1955 [Aug. 13, 1954], No. 23515/54. Class 55 (1). In a water gas generator operating on " blow " and " run " the steam supply is limited during the commencing stage of an uprun period and subsequently progressively increased throughout either the uprun or total run periods. As shown an auxiliary valve 23 is inserted in the steam supply line 21 so that on opening the main steam valve 22 only a limited steam supply passes to the generator 1, the valve 23 being steadily opened, e.g. by hydraulic or pneumatic means or linkage from a mechanical operator. During the " blow " air supplied at 6 passes through valve 7 and conduit 5 to the grate 4 of generator 1. The blow gases pass upwardly through the fuel bed, conduit 8, branch 9 and valve 10 to the stack 11. At the end of the " blow " the valve 7 is closed and valve 22 opened fully. During the subsequent short purge period steam passes via three-way valve 24 and conduits 25, 5 to the grate 4 to form water gas which displaces the " blow " gases and drives them to the stack 11. Then valve 10 is closed and three-way valve 14 set to connect conduits 12, 15. Steam passing at the minimum rate forms water gas which passes through conduits 8, 12, 15, wash-box 16, valve 17 and conduit 18 to the auxiliary equipment for cooling and cleaning the gas. During the uprun the valve 23 is progressively opened so that the steam rate increases and the output of gas is substantially constant. At the commencement of the down-run, valve 24 is reversed and valve 14 set to connect conduits 13, 15. Steam now passes through conduits 26, 8, to the top of the fuel bed the resultant water gas passing through conduits 5, 13, valve 14 and conduit 15 to the wash-box 16. The valve 23 may be fully open at the end of the uprun and be maintained fully open during the downrun. Alternatively the valve 23 may be only partly open at the end of the uprun and continues opening, preferably at a slower rate, during the downrun. In a modification the valve 23 is shunted by a permanently open by-pass. In another form, an auxiliary valve is placed in line 25 but a pre-set valve only in line 26. In a further form, Fig. 7, a valve 30 is provided to supply extra steam during the purge period. In another form, Fig. 5, two main control valves 22a, 22b are provided and also two auxiliary valves 23a and 23b. Valves 22a, 23a are used during the uprun and valves 22b, 23b during the downrun. A carburetter and superheater may be inserted between the top gas outlet of the generator 1 and the conduit 8 so that blue water gas produced during the uprun is enriched in the carburetter by the cracking of petroleum oil therein and during the backrun steam is passed through the superheater and carburetter in the reverse direction. In a complete gasification plant fed with bituminous coal, a retort is superimposed on the gas generator and during the " blow " hot gases pass through flues in the walls of the retort before passing to the stack. During the uprun, blue water gas passes through the heated coal in the retort carrying away with it the distillation gases produced. During the downrun steam passes first downwards through the flues in the walls of the retort and then through the fuel in the generator. Specification 153,051, [Class 55 (i)], is referred to.