Patent GB-349065-A (GB)
Title: Improvements in apparatus for decomposing salts or the like
IPC: B01J8/10
Filed: 1930-01-11
Abstract: <PICT:0349065/III/1> <PICT:0349065/III/2> <PICT:0349065/III/3> Apparatus for decomposing salts or the like comprises a reaction chamber having a plurality of stirrers and a spraying device therein, a siphon device for intermittently supplying a regulated quantity of acid or other reagent to said spraying device, and a dust catcher furnished with a dangling dust collector through which the decomposition gases escape.  A reaction chamber 1 is provided with stirrer arms 3, 4 mounted on shafts 5, 6, which rotate in opposite directions.  The stirrers are spaced equidistantly along the shafts, each in angular advance of the next by 90 DEG .  The charge of salt or the like is thrown up beneath an acid spray from nipples 10 of the supply pipe 9.  Acid from an inlet 13 flows into the lower part of a chamber 15 having a valve 16, an air inlet 17 and byepass 17a.  The valve is controlled by a ballfloat 18 which is raised and lowered by liquid in a chamber 22, closed except for a central well 23 containing the float. Pivoted levers 19, 20 open the valve when the float rises.  Acid flows in by pipe 24, filling the chamber 22, the air in chamber 15 being byepassed.  The float now opens the valve 16 and the acid is driven from the chambers 15, 22, starting a siphon 25 into a chamber 26, connected to the supply pipe 9 and vented to the atmosphere by pipe 27.  The float falls, closing the air valve, and as soon as the siphon breaks, chambers 15, 22 refill and the process repeats.  A dust catcher 29 has its front wall 31 slanting in to form a restricted opening 30 communicating with the interior of chamber 1. A link chain fabric 32, hanging from the top, and contacting with the bottom of wall 31, collects dust rising from the chamber and, owing to the vibration caused by the stirrers, shakes it down again. Baffles 33, 36, 37 and a door 35 are also provided.  The reaction chamber is preferably mounted in an oil-heated furnace.  Combustion products of an oil burner 42 in the rear wall of the furnace pass over, then under the reaction chamber and out to a stack 44.  The interior may have an insulating lining 45.  The salt to be decomposed is heated to a temperature above the boiling point of the acid to be produced and volatilized, but below the melting point of the salts used or produced, before acid is supplied.  The rate of supply is regulated so that the amounts of heat consumed and supplied are closely balanced and the contents of the reaction chamber remain dry and substantially neutral.  Sodium chloride or nitrate may be treated with sulphuric acid to obtain a normal sulphate, heating being continued after all the acid, which may be preheated, is added. Organic salts such as calcium acetate may be decomposed in this way, and calcium fluoride reacted with sulphuric acid at temperatures not exceeding 200 DEG  C.  In this latter case, for example, the apparatus may be formed of malleable iron.ALSO:Apparatus for decomposing salts or the like comprises a reaction chamber having a plurality of stirrers and a spraying device therein, a siphon device for intermittently supplying a regulated quantity of acid or other reagent to said spraying device, and a dust catcher furnished with a dangling dust collector through which the decomposition gases escape. A reaction chamber 1 is provided with stirrer arms 3, 4 mounted on shafts 5, 6 which rotate in opposite directions.  The stirrers are spaced equidistantly along the shafts, each in angular advance of the next by 90 DEG .  The charge of salt or the like is thrown up beneath an acid spray from nipples 10 of the supply pipe 9.  Acid from an inlet 13 flows into the lower part of a chamber 15 having a valve 16, an air inlet 17 and byepass 17a.  The valve is controlled by a ball-float 18 which is raised and lowered by liquid in a chamber 22, closed except for a central well 23 containing the float.  Pivoted levers 19, 20 open the valve <PICT:0349065/IV/1> <PICT:0349065/IV/2> <PICT:0349065/IV/3> when the float rises.  Acid flows in by pipe 24 filling the chamber 22, the air in chamber 15 being byepassed.  The float now opens the valve 16 and the acid is driven from the chambers 15, 22 starting a siphon 25 into a chamber 26, connected to the supply pipe 9 and vented to the atmosphere by pipe 27.  The float falls, closing the air valve, and as soon as the siphon breaks, chambers 15, 22 refill and the process repeats.  A dust catcher 29 has its front wall 31 slanting in to form a restricted opening 30 communicating with the interior of chamber 1.  A link chain fabric 32, hanging from the top, and contacting with the bottom of wall 31, collects dust rising from the chamber and, owing to the vibration caused by the stirrers, shakes it down again.  Baffles 33, 36, 37 and a door 35 are also provided.  The reaction chamber is preferably mounted in an oil-heated furnace.  Combustion products of an oil burner 42 in the rear wall of the furnace pass over, then under the reaction chamber and out to a stack 44.  The interior may have an insulating lining 45.  The salt to be decomposed is heated to a temperature above the boiling-point of the acid to be produced and volatilized, but below the melting-point of the salts used or produced, before acid is supplied.  The rate of supply is regulated so that the amounts of heat consumed and supplied are closely balanced and the contents of the reaction chamber remain dry and substantially neutral. Sodium chloride or nitrate may be treated with sulphuric acid to obtain normal sodium sulphate, heating being continued after all the acid, which may be preheated, is added. Organic salts such as calcium acetate, may be decomposed in this way, and calcium fluoride reacted with sulphuric acid at temperatures not exceeding 200 DEG  C.  In this latter case, for example, the apparatus may be formed of malleable iron.