Ice cream a partial list of ice cream-like frozen desserts and snacks: In 2006, some commercial ice cream makers began to use liquid nitrogen in the primary freezing of ice cream, thus eliminating the need for a conventional ice cream freezer. Brands are Dippin' Dots. The preparation results in a column of white condensed water vapour cloud. The ice cream, dangerous to eat while still "steaming" with liquid nitrogen, is allowed to rest until the liquid nitrogen is completely vapourised. Sometimes ice cream is frozen to the sides of the container, and must be allowed to thaw. Good results can also be
Gas–liquid contactor is higher for equipment with higher values of gas–liquid interface surface area, so gas–liquid contactors with high surface area (e.g. packed column, spray tower) are often preferred when it is important to lower the cost of the equipment. Liquid hold-up is also an important factor for the economy of the process, because for low values of liquid hold-up a bigger equipment is needed to have the same heat and mass transfer velocity. For this reason, gas–liquid contactors with low liquid-hold-up (e.g. falling-film column) in general are not used at industrial scale. Gas–liquid contactor A gas–liquid contactor is a particular chemical