Spouted bed with a draft tube without gas inlet nozzle or orifice

In general, gas is injected into the spouted bed in the form of high velocity gas jet through a small opening such as inlet nozzle or orifice. The use of small opening causes the pressure drop of the system to increase. Furthermore, it causes large amount of gas to pass only through the spout without percolating in the annulus. In this study, gas was fed into the spouted bed with a draft-tube at a uniform velocity over the whole cross section of the vessel, without using the gas inlet nozzle or orifice. The pressure drop became lower and the flow ratio of gas which passed through the annulus considerably increased.