Expanded metal plate

Solenoid magnetic separators are designed for batch-type, cyclic, and continuous operation. Devices which can use matrices of expanded metal, grooved plates, steel balls, or filamentaiy metals have been designed. Continuous separators with capacities to 600 t/h for iron ores (similar to the Brazilian hematite) are commercially available (Sala International Inc.). Selection of the method of operation is apphcation-dependent, being based on variables such as temperature, pressure, volume of magnetics in the feed, etc. 

In such cases basket anodes are frequently used. These have a relatively large surface and work at a low driving voltage due to their special construction. A cylinder of platinized titanium-expanded metal serves as the basket to which a titanium rod is welded. This serves as the current lead and carrier, and ends in a plastic foot that contains the cable lead and at the same time serves as the mounting plate. The expanded metal anode exhibits a very uniform anode current density distribution, even at large dimensions, in contrast to the plate anode. The reason is the many comers and edges of the metal that make the point effect only evident at the outer edges of the anode. 

Flame arresters are fitted in the vent lines of equipment that contains flammable material to prevent the propagation of flame through the vents. Various types of proprietary flame arresters are used. In general, they work on the principle of providing a heat sink, usually expanded metal grids or plates, to dissipate the heat of the flame. Flame arrestors and their applications are discussed by Rogowski (1980), Howard (1992) and Mendoza et al. (1988). 

Heraeus markets a multicathode metal depletion system. In the system, one or two anodes face a large number of permeable cathodes, e.g. in form of copper strips similar to expanded metal. [90,234a], Plattner and Comninellis have developed large scale reactors total plate electrode surface ca. 20 m2, cf. ref. [140]. 

The SCR catalyst designed for FCCU regenerator flue gas service is a homogenous monolith, typically made from 1 mm thick material. Some catalysts are extruded clays that receive a wash coat of titanium dioxide before impregnation of the vanadium and tungsten metals. Another type involves painted plates of expanded metal... 

Fig 1 shows the situation, at some time after the start of detonation, for a 1-D system consisting of a semi-infinite expl slab, initially in contact with a metal plate on one side and vacuum on the other side, with detonation started simultaneously all along the original HE-vacuum boundary As indicated, the plate moves to the right at a velocity V and product gases expand into vacuum (in Appendix A it is shown that expansion into air is negligibly different from expansion into vacuum) at velocity -U. The coordinate system used assigns x = 0 to the product/vacuum boundary and x = 2 to the position of the plate at time t. Then, as taken directly from Ref 14 ... 

Suppose we want to know the mass per unit area mg, momentum g(x) of the detonation products expanding in the direction of the metal plate in a 1-D system. The Gurney assumption of linear distribution of gas velocities enables us to compute all these quantities. The derivations of the necessary equations are given in Appendix G. Here we present only the final results, namely ... 

Batch units are frequently cylindrical shelf-type dryers equipped with heating and cooling coils or plates. Designs for belter heal input, that is, spikes or expanded metal sheet that penetrate the frozen mass or movable heated shelves compressing the frozen materials, have met with some success. 

Chemelec cell — An electrolytic cell with electrodes (both anode and cathode) made from expanded metal or simple metal plates. The cell is filled with inert particles, which are floated when the electrolyte solution enters the cell from the bottom. This causes effectively turbulence with increased - mass transport. This cell is employed in wastewater treatment especially from galvanic operations. 

Constructional details of a modem lead-acid cell for locomotives in coal mines are given in Fig. 6.67. A copper expanded metal lattice parallel with the negative plate considerably lowers the internal resistance of the cell. The total view of a 540V 80 Ah lead-acid accumulator for locomotives in coal mines is given in Fig. 6.68. 

Some of these will be discussed here with various attributes that they possess. Aside from the conventional substrates, others that are currently under development are short contact time (SCT) reactors that consist of screens, mesh, or expanded metal that are typically fabricated from high-temperature FeCrAl alloys. Reticulated foams that combine the very low pressure drop of monoliths with the improved transport of SCT reactors are often used. There are flat plate and microchannel reactors and recently microelectromechanical system (MEMS) reactor geometries that have been fabricated. In comparison to monolith or pellet beds, SCT substrates seem to allow Prox reactors to operate at significantly lower water concentrations before the onset of the hydrogen oxidation reaction, that is, the high-temperature steady state. 

Cathode. Because iron is an inexpensive material and has a rather small hydrogen overvoltage, iron cathode is generally utilized, in the form of a mesh, perforated plate, or expandable metal sheet. 

Fig. 13.21. Expanded-metal grid ribbon used for continuous plate production of automotive batteries.

If you think thermodynamics relates mostly to expanding gases inside steam engines and has few practical, everyday applications, just look around. Some applications are probably within your reach right now, in the form of battery-operated devices—laptop computer, palm organizer, DVD remote, and, of course, wristwatch and calculator—or in the form of metal-plated jewelry or silverware. The operation and creation of these objects, and the many similar ones you use daily, involve the principles we cover in this chapter. 

---