Sinking solids

Solids suspension (suspending sinking solids or incorporating floating solids)... 

Fig. 1.1 Multicompartmental model world, schematic overview. Dashed arrows denote sinks, solid arrows exchange processes.

Fig. 34. Comparison of radial temperature profiles for WS packed with full cylinders, with and without heat sinks solid symbols are for temperatures averaged over fluid and solid, open symbols for temperatures averaged over fluid alone.

Single-wall nanotubes (SWNTs), 12 232, 13 852, 26 737 Single-wall tanks, 24 296 Singular value decomposition, 6 28 S—I—N junctions, 23 821 Sinking solids, lifting and distribution of, 16 692-694 Sinoatrial node, 5 80... 

The Sorticanter has a scroll with reversing pitch on one side, which skims a floating solids layer off the top of the carrier hquid, usually an aqueous brine of intermediate density. Sinking solids are scrolled out similarly to normal decanter centrifuges, and liquid is discharged under pressure via a stationary but variable impeller. The Sorticanter is utihzed in the plastics recycling industry. 

For suspension of sinking solids, it is important to provide liquid velocities directed to the tank floor for an effective sweeping action. Hydrofoils perform well in this duty. However, if the solids have any tendency to be sticky and cling to the blades, the effectiveness of a hydrofoil can be reduced. This can reduce its versatility as a multipurpose impeller. 

Solid phase growth is used where only structural phase transformations occur and long-range transport of atoms or removal of product species is not required. This is necessary because in solids atoms caimot move very far and the solid material must serve as its own atom source and sink. Solid phase growth is only applied significantly in current semiconductor processing for crystallization of amorphous materials or solid phase reactions, as in formation of silicides by reaction of a metal with silicon. 

Reduce Resonant Vibration. Metal stmctures are induced to vibrate at their natural frequencies when driven mechanically by attachment to some other vibrating stmcture, by impact of solid objects, or by turbulent impingement of a fluid (including air). Examples are stainless steel sinks driven... 

Drum Separators Very coarse solids, up to 0.3 m (12 in), are often processed in a drum separator of the type shown in Fig. 19-32. This is similar to a ball-mill shell with hfters permanently attached to the wall. Medium and feed enter at one end, and the float product flows out through the discharge trunnion, while the sink is lifted by the rotation of the drum to a stationaiy launder, through which it is flushed out. Modifications of this type include division of the shell into two compartments, which permits simultaneous operation at two different piup densities resulting in various grades of products. The two-compartment revolving drum is illustrated in Fig. 19-32. 

In most circumstances, it can be assumed diat die gas-solid reaction proceeds more rapidly diaii die gaseous transport, and dierefore diat local equilibrium exists between die solid and gaseous components at die source and sink. This implies diat die extent and direction of die transport reaction at each end of die temperature gradient may be assessed solely from diermodynamic data, and diat die rate of uansport across die interface between die gas and die solid phases, at bodi reactant and product sites, is not rate-determining. Transport of die gaseous species between die source of atoms and die sink where deposition takes place is die rate-determining process. 

For any method of heat transfer to take place, a temperature difference is necessary between two faces of a solid body, or at the boundaries of a gas or vapor. Flear transfer will take place only from a high-temperature source to a lower-temperature sink and is an irreversible process unless acted upon by another agency, as is the case with the refrigeration process. 

Regenerator The hot and cold fluids pass alternately through a space containing solid areas/particles, which provide alternately a heat sink and a heat source. An example of the rotating-type matrix is a cooling tower. 

WEB A solid with an irregular shape and a mass of 11.33 g is added to a graduated cylinder filled with water (d = 1.00 g/mL) to the 35.0-mL mark. After the solid sinks to the bottom, the water level is read to be at the 42.3-mL mark. What is the density of the solid ... 

In a number of these processes, a liquid heat- and mass-transfer medium is in direct contact with the catalyst and the reaction mixture. The main function of the liquid is to act as a heat sink and as a medium for convective heat transfer. However, since the liquid may be assumed to cover the solid particles and in this way act as a barrier between the gaseous and the solid phases, it must therefore also function as a mass-transfer medium. 

Various types of intermediate behaviour embodying features of more than one of these effects can be visualized. In addition to the considerations (i)—(iii) above, the interface may behave as a source or sink for the creation and/or annihilation of imperfections such as lattice defects and electrons, which can be important participants in the overall change (for clarity, such effects have not been included in Fig. 8). The decomposition characteristics of many solids are influenced by externally supplied energy such as irradiation, cold working, etc. 

FIGURE 5.19 As a result ot its open structure, ice is less dense than liquid water and floats in it (left). Solid benzene is denser than liquid benzene and "bpnzenebergs" sink in liquid benzene (right). 

Aluminum foam can be used as a porous medium in the model of a heat sink with inner heat generation (Hetsroni et al. 2006a). Open-cell metal foam has a good effective thermal conductivity and a high specific solid-fluid interfacial surface area. 

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