Spouted bed with draft tube

Xu, M., A Theoretical and Experimental Investigation of Spouted Beds with Draft Tubes, Ph.D. Dissertation, West Virginia University, Morgantown, WV (1993)... 

Figure 1 Schematic representation of some industrial granulators, (a) Conventional fluid bed granulator, (b) Conventional spouted bed granulator, (c) Spouted bed with draft tube, (d) High shear rotor granulator.

The modelling results confirmed the experimental findings by Stocker et al. (1989), where a spouted bed with draft tube pilot plant has been utilized for ultrapyrolysis of propane. The applied study confirmed the outstanding features of the reactor configuration. 

Figure 21. Spout-fluid bed with draft tube...

Muir, J., Berruti, F. and Behie, L.A. (1990) Solids circulation in spouted and spout-fluid beds with draft tubes , Chem. Eng. Comm., 88, 153-171. 

R.K. Stoecker, A. Rastogi, L.A. Behie, W.Y. Svreck, M.A. Bergougnou, A computer simulation of propane cracking in a spout-fluid bed reactor with draft tube, in K. Ostergaard, A Sorensen (Eds.), Fluidization V, Engineering Foundation, New York, 1986, pp. 465 172. 

The NMGBF has similarities to two filter types the spouted bed and the fluidised bed filter. Geometrically the NMGBF is a spouted bed with a draft tube in the central spout jet region as shown in Figure 3. 

The i-ICFB originated from the spouted bed with a draft tube. Preliminary hydrodynamic studies by Milne... 

Stocker RK, Eng JH, Svrcek WY, Behie LA. Gas residence time distribution studies in a spouted bed with a draft tube. In Grace JR, Shemilt LW, Bergougnou MA, eds. Fluidization VI. New York Engineering Foundation, 1989, pp 269-276. 

A typical spouted bed reactor with draft tube is illustrated in Figure 18. 

The Wurster process is a type of spouted bed with a draft tube and fluidization flow around the jet (Figure 1.4). The jet consists of a spray nozzle that injects air and droplets... 

This concept was first called a recirculating fluidized bed by Yang and Kearins (1974). Several other names have also been used to describe the same concept the fluid-lift solids recirculator (Buchanan and Wilson, 1965), the spouted fluid bed with a draft tube (Y ang and Keaims, 1983 Hadzismajlovic et al., 1992), the internally circulating fluidized bed (Milne et al., 1992 Lee and Kim, 1992) or simply a circulating fluidized... 

Multiple Draft Tubes. Studies in the past always concentrate on beds with a single draft tube. A literature survey failed to uncover any reference on operation of multiple draft tubes. Even in the area of conventional spouted beds, the references on multiple spouted beds are rare. Foong et al. (1975) reported that the multiple spouted bed was inherently unstable due to pulsation and regression of the spouts. Similar instability was also... 

Yang, W. C., and Keaims, D. L., Studies on the Solid Circulation Rate and Gas Bypassing in Spouted Fluid-Bed with a Draft Tube, Can. J. Chem. Eng., 61 349 (1983)... 

However, for small scale equipment, Cheng (1993) and Xu (1993) measured the circulation times of a single tagged particle in a 150 mm diameter fluidized bed coater with a draft tube and found that typical circulation times were between 2-10 seconds. Robinson and Waldie (1978) made similar measurements in a 6" diameter conventional spouted bed and found mean circulation times in the range of 3-6 seconds. 

Fig. 1 Schematic drawing of the typical fluid bed processors. (A) Simple fluid bed (B) tumbling fluid bed and (C) spouted bed processor assisted with a draft tube.

FIGURE 15.3 Spouted bed dryer with a draft tube and an air-permeable attachment 1, tangential air feed 2, draft tube 3, dryer body 4, air-permeable attachment. 

The wheat drying studies were carried out in a spouted bed predryer of rectangular cross section equipped with a draft tube, and also in a cylindrical afterdryer (Tables 15.1 and 15.2). The experimental conditions and the data of the... 

A number of prototype SBDs have been used to dry shelled com. One pilot-plant dryer has a designed capacity of 100-kg water/h, based on 10% moisture ranoval. This dryer is suitable for drying at two levels and for carrying out cooling after the drying. Accordingly, the equipment consists of a unit of smaller capacity (300 x 400 mm) and is equipped with a gas inlet nozzle and a draft tube, and of a spouted bed dryer of a CTOss section of 0.32 m (800 x 400 mm) developed with two gas inlet nozzles [21]. The main characteristics of the shelled... 

Drying of Shelled Corn in a Continuous Spouted Bed Dryer Equipped with a Draft Tube and an Inner Conveying Screw... 

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