Agitation of vessels using air lift pump - having gas bell above recirculation tube to reuse gas for pumping forward

摘要

Vessel is agitated by means of a gas (esp air) lift pump located in the centre of the vessel; above which is a gas bell which collects the air rising from the inlet pipe and feeds it forward to a second air lift pump which pumps the liquid to the next stage of the process. In the line between the gas bell and the second lift pump, a flow control mechanism is installed. The vessel can be divided into several sections with liquid feeding from one to the next and with the air from one zone being collected and reused to agitate the zone above before finally discharging to atmosphere. Appts. is useful for agitating slurries suspended in liquids. In multistage operations, it avoids the need for differences in level between stages or the need to stagger the mounting of the vessels. Ensures that a uniform slurry is pumped from each stage and allows a single air supply to be used to mix and to pump forward without the excessive energy required when the recycling pump is given enough head to pump forward the whole recycle. In one form, several stages can be included in a single vessel.