BACKGROUNDAdjustment of the vapour split in a divided wall column (DWC) is agreatchallenge. In order to resolve this problem, a vapour splitter was proposed and the properties and performance of the vapour splitter were examined in a number of experiments. RESULTSGas flow rates and vapour split changed significantly with blade angle in the range 50-10 degrees. When the liquid flow rates on both sides were the same, the vapour split reduced with increasing liquid flow rate. The gas flow rate decreased with increase of liquid flow rate in the same side. The vapour split increased when the gas velocity decreased. When the V-type cap angle was 50 degrees the gas nonuniformity was minimum. The gas nonuniformity also varied with blade angle, but fortunately remained at a low level. CONCLUSIONThe device can adjust the vapour split regardless of operating conditions. The gas is distributed uniformly before entering the packed bed. There are some limitations to this device, but the results indicate that the prospects of our vapour splitter are promising. (c) 2014 Society of Chemical Industry