SUMMARY
Unlike for the bounded domain, the minimum fluidization velocity of the unbounded fluidization domain has not been well developed. The aimed of the research is to formulate the minimum jet (holes) velocity (voc) theoretically and experimentally as the criteria for unbounded domain fluidization. Physical experiments were conducted for bounded and unbounded fluidizations of 20 cm to 45 cm thickness of sand bed. The bounded fluidization was carried out using a transparent vertical tube, whilst the unbounded fluidization was conducted on a transparent box. The fluidization discharge and pressure were measured. Empirical equations on jet holes velocity based on the experiment was developed. It was found that voc depends on the required superficial velocity at the surface of sediment deposit (vc) and flow rate loose factor (y) due to unbounded domain conditions. The vc is greater than the minimum fluidization velocity in bounded domain (vmf). The conservative values of velocity conversion factor (ks) were found to be approximately 2.0.