Ejector type

Figure 6-2 suggests a few of the many uses to which ejector type units are used in industry. 

The powder is supplied to the gun by a powder pump at a uniform and consisfent rate. There are two types of powder pumps ejector type, using the venturi principle, and auger pumps, which use positive displacement. A corona charging system is most widely used to electrostatically charge the powder. The electrostatic spray gun has several functions ... 

Gas chamber pressure, ps, can be calculated from this equation through iteration. Factor B depends on the mixing tube/nozzle diameter ratio for a given ejector type and needs to be determined experimentally. 

In order to reduce attrition, recirculation of the particles can be achieved by the gas bubbles (gas lift) instead of by mechanical agitation (bubble column, see Fig. 8.2). External liquid recirculation offers the possibility of improving the gas-liquid mass transfer by special liquid ejector types. In the case of gas and liquid upflow a three-phase fluidized bed reactor is produced. Here particles of a few millimeters are needed to retain them in the reactor and allow separation from the gas/liquid phase. 

ElgozaU A, Linek, V, Eialova M, Wein O, Zahradnik J. (2002) Iirfluence of viscosity and surface tension on performance of gas-liquid contactors with ejector type gas distributor. Chem. Eng. Sci., 57 2987-2994. 

Hansen AG, Na TY. (1966) Optimization of jet pump systems. ASME-EIC Fluids Eng. Conf., Paper No. 66-EEA4. American Society of Mechanical Engineers, New York, USA. Havelka P. (1997) Mass transfer capacity of gas-liquid reactors with ejector-type gas distributors. Ph.D. Thesis, Prague Institute of Chemical Technology, Czech Repubhc. cf. Dierendonck et al. (1998). 

Zahradnik J, Kratochvil J, KaStdnek F, Rylek M. (1982) Hydrodynamic characteristics of gas-liquid beds in contactors with ejector type gas distributors. Collect. Czech. Chem. Communications, 47 1939-1949. 

FIGURE 11.9 Vacuum system (steam ejector type) and condensate collection. 

The turbine setting, see Fig. X-15, incorporates the state-of-the-art in moisture separation systems for turbines [X-7 and X-8]. The low-pressure cylinder incorporates a dedicated next to last separation stage, which has moisture collection grooves on the convex surface of the peripheral part of a turbine rotor blade. It also incorporates a roof-type shroud and an ejector-type moisture trap. The next to last stages of the high- and medium-pressure turbine parts provide for the dehydration of steam, which is accomplished through the use of a jet and the turbine rotor blades of special design. 

The selection of the most effective demolding principle is dependent on the order and is always a fundamental decision. Depending on this choice is whether the parts are damaged during demolding or remain usable. The principal ejector types are ... 

---