GB690648A - Method and apparatus for cooling granular contact material and the application thereof in a hydrocarbon conversion process - Google Patents

Abstract

<PICT:0690648/III/1> <PICT:0690648/III/2> <PICT:0690648/III/3> <PICT:0690648/III/4> <PICT:0690648/III/5> Granular contact material, particularly hot regenerated catalyst from a hydrocarbon conversion process, is subjected to indirect cooling by passing it as a gravitating compact bed through a cooler, the cooling surfaces of which are cooled over their entire area by a circulating coolant liquid, the degree of cooling of the granular material being controlled by varying the volume of compacted solid in contact with the cooling surface. The said volume may be varied by passing the material through more or less of a number of cooled channels or by varying the height of a bed of the materials in contact with horizontal, vertical or sloping cooling tubes. In Fig. 2 a number of tubes 56 are cooled externally by a coolant entering through 59 and leav <PICT:0690648/III/6> <PICT:0690648/III/7> ing through 57. The operable number of tubes is controlled by a slidable sleeve 51 which varies the horizontal area of the pile 60(a) of contact material. The cooling tubes may also be inclined. Alternatively, as shown in Fig. 5, the operable number of tubes 101 is automatically controlled by a device responsive to the outlet temperature which varies the number of feeders 97 through which material is fed from a storage vessel 96 at the temperature of the coolant fluid passing in at 102 and out at 103 as controlled by a device 106 responsive to a thermocouple 107. The feeders 97 may be replaced by an iris diaphragm placed between the storage vessel 96 and the cooling tubes 101. In Fig. 8 the cooler is provided with horizontal cooling tubes 51 and the height of the compact bed in contact therewith is varied by raising or lowering telescopic extensions 54 of the feed tubes 53. Similarly, in Fig. 10, perforated closed-end feed tubes 91 are surrounded by rotatable sleeves 92 the perforations of which can be aligned with perforations on the inner tube 91 at varying heights, thus varying the depth of the bed and the operable number of cooling pipes 94. Fig. 11 shows a device with vertical cooling tubes 111, more or less of the height of which is in contact with an inclined gravitating bed, the depth of which is controlled by sliding gate-valve 108. In the utilization of the above devices in hydrocarbon conversion, as shown in Fig. 1, a gravitating bed of solids passes successively through a heater and regenerator 10 (where it is contacted with preheated air and fuel), a reactor 13 (fed with hydrocarbons to be converted from pipes 14 and a purge gas such as steam from pipe 27) and a cooler 29 as above described, the solids being recycled through leg 31. The products of the conversion, quenched with water injected at 16, are withdrawn at 17 and further quenched in a vessel 18 through which a bed of cooled solid gravitates from a vessel 46, air is passed to the latter through pump 47, this air burning off carbonaceous deposits and, by its excess, cooling the solid after passing through vessel 18 and a cooler 39 as above described, the solids are recycled. The products from the quencher 18 are separated into vapour and oil in a water quencher 20, the water being recycled after separation of the oil or being passed to the reactor 13 with the reactants if these be liquid. A converter system employing adiabatic regeneration is shown in Fig. 3 wherein catalyst flows successively from a hopper 87 to a reactor 70, regenerator 74 and cooler 80. The cooled, regenerated catalyst, lifted in leg 82, is hydrated in hopper 87 and the degree of cooling and heat of hydration are correlated to provide adequate heat stored in the solids for the endothermic conversion in reactor 70. Catalyst to oil ratio of 1 to 20, space velocities of 0.5 to 20 V/V/hr. and reaction temperatures of 850-950 DEG F are referred to.