Edge cooling

Figure 17. Schematic of the axially symmetrical temperature gradients generated in an edge-cooled window fitted with AR coatings when traversed by a laser beam.

Figure 18. Calculated temperature gradients in a CVD diamond and a ZnSe windows, edge cooled and with AR coatings.

Figure 26. Results from a theoretical thermal model showing the predicted temperature rise at the center of an edge cooled diamond window for a 1 MW incident microwave beam. Results are shown for different values of dielectric loss and for two different cooling diameters assuming an exposed aperture of 100 mm diameter [66].

Why is it necessary to keep the cutting edge cool when regrinding a cold chisel ... 

Standard Review Plan 9.5.5, "EDG cooling water system. ... 

The typical stack construction for PEM (and other) fuel cells is a series-connection of cells with bipolar plates interposed between adjacent cells (or membrane-electrode assemblies). The bipolar plate must provide for electronic conduction from one cell to the next isolation of fuel on one side from oxidant (air) on the other side and distribution of fuel and air reactants to the respective adjacent anode and cathode. In an edge-cooled stack of the type described above, the bipolar plate also contributes to heat rejection by conducting heat laterally to its tinned edges, where forced-air convection is employed. 

Shearing edge Cooling plate Spacer sleeve... 

Figure 6-28 shows the geometry of the narrow flat plate, and Figure 6-29 shows the maximum temperature difference in the active area (temperature in the center - temperature at the edge of the active area) as a function of flow field width and plate thermal conductivity (Q = 0.279 W/cm, d p = 1.8mm). The maximum temperature difference in the active area should be limited to <5-10 C. In that case, edge cooling is limited by the... 

Drawdown from the die to nip is typically ca 10%. Sheet extmsion requires that the resin be of high melt viscosity to prevent excessive sag of the melt between the die and the nip. The melt should reach the nip before touching any other part of the middle roU to prevent uncontrolled cooling of the resin. The appearance of the lower surface of the sheet is deterrnined by the middle roU, ie, its poHsh, surface temperature, and freedom from condensed materials. The upper surface is cooled by air and has a more glossy appearance. Neither the top roU nor the bottom roU greatly affect the appearance of the top surface of the sheet. Edges of the sheet are trimmed. 

Several plants employ cooled-belt flakers. These consist of flexible steel belts, ca 1-m wide and up to 50-m long, that have short mbber skirting at the edges. Molten pitch flows from a thermostatically controlled tank over a weir to give a flat thin sheet on the belt, which is cooled from below by water sprays. At the end of the belt, the solid pitch is broken up by rotating tines. The pitch flakes are drained and transported to a covered storage silo by belt conveyor, during which time the surface moisture evaporates. 

FIG. 5-4 Heating and cooling of a solid slab having a large face area relative to the area of the edges. 

FIG. 5-5 Heating and cooling of a solid of infinite thickness, neglecting edge effects. (This may he used as an approximation in the zone near the surface of a body of finite thickness.)... 

---