Patent GB-923928-A (GB)
Title: Improvements in processes for the recovery of vapours of solvents
Inventor: VICTOR IRVING
IPC: D06F43/08
Filed: 1959-03-31
Abstract: <PICT:0923928/III/1> A process for the recovery of volatile organic solvent vapours used in a container for cleaning materials, comprises intermittently introducing said vapours to an adsorbent in an enclosed vessel in such a concentration that the contacted part of said adsorbent is heated to a temperature above ambient temperature, and admitting air at ambient temperature to said vessel between the intervals of vapour introduction to reduce the temperature of said adsorbent, the amount of said air being such that the adsorptive capacity of the adsorbent is increased.  As shown in Fig. 5, a load of fabrics is placed in washer-extractor 114 and door 118 is closed for washing. Thereafter the valve in casing 122 is opened, door 118 is opened and inflowing air sweeps the solvent vapours through ducts 126, 128 to fan 44 and thence to the adsorption apparatus 10 for adsorption by carbon.  After flushing washer 114 with fresh air, the fabrics are transferred to dryer 130, door 134 closed and the cage 132 rotated when a closed circuit of air is passed through the tumbling garments.  When drying is completed, the damper in casing 156 is opened and concurrently the mechanical linkage 152 opens damper 150 allowing ambient air to enter and pass through the garments, duct 158, main duct 128 and then to adsorption apparatus 10.  After flushing casing 130 and rotating cage 132, the latter is brought to rest and the fabrics are removed for final finishing. While the washer-extractor 114 and dryer 130 are in use the discharge dampers 124 and 154 are closed and air is drawn in through pick up ducts 160 and 162 due to the negative pressure caused by the fan. When doors 118 and 134 and dampers 160 and 162 are open the pressure in duct 128 approaches barometric pressure and dampers 168 will close floor ducts 160, 162 to prevent contents of duct 128 from escaping into the surrounding atmosphere.  The adsorbed solvent vapours are removed from the adsorbent carbon by passing steam there through.  In modifications of the process one or two dryers and adsorbers may be used.  Figs. 1, 6, 7 and 8 (not shown) give details of the apparatus used in the above process which is claimed in Specification 923,929.ALSO:A process for cleaning fabric comprises intermittently introducing volatile organic solvent vapours to an adsorbent in an enclosed vessel in such a concentration that the contacted part of said adsorbent is heated to a temperature above ambient temperature and admitting air at ambient temperature to said vessel between the intervals of vapour introduction to reduce the temperature of said adsorbent, the amount of said air being such that the adsorptive capacity of the adsorbent is increased.  As shown in Fig. 5, a load of fabrics is placed in washer extractor 114 and door 118 is closed. Cage 116 is slowly rotated and solvent from reservoir 120 is circulated into contact with the fabrics.  When washing is <PICT:0923928/IV(a)/1> completed, solvent circulation is terminated and cage 116 is rapidly rotated to extract liquid solvent from the fabrics after which the valve in casing 122 is opened, door 118 opened and inflowing air sweeps the solvent vapours through ducts 126, 128 to fan 44 and thence to the adsorption apparatus 10 for adsorption by carbon.  After flushing washer 114 with fresh air the fabrics are transferred to dryer 130, door 134 closed and the cage 132 rotated when a closed circuit of air is passed through the tumbling garments.  When drying is completed, the dumper in casing 156 is opened and concurrently the mechanical linkage 152 opens dumper 150 causing ambient air to enter therethrough which then passes through the garments, duct 158, main duct 128 and to adsorption apparatus 10.  After flushing casing 130 and rotating cage 132, the latter is brought to rest and the fabrics are removed for final finishing.  While one batch of fabrics is being tumbled in casing 130 and another is being treated in washer extractor 114, the discharge dampers 124 and 154 are closed and air is drawn in through pick-up ducts 160 and 162 due to the negative pressure caused by the fan.  During transfer of fabric from the vessels 114 and 130, the doors thereof and dampers 160 and 162 will be open and a maximum demand for the influx of air will occur.  Hence the pressure in duct 128 approaches barometric pressure and dampers 168 in floor ducts 160 and 162 will close to prevent contents of duct 128 from escaping into the surrounding atmosphere.  The adsorbed solvent vapours are removed from the adsorbent carbon by steam.  In modifications of the process one or two dryers and adsorbers may be used.  Figs. 1, 6, 7 and 8 (not shown) give details of the apparatus used in the above process which is claimed in Specification 923,929.