Evaporators sketches

In a boiler, with the continued application of heat, steam under pressure is produced via a combination of steam bubble formation (nucleate boiling) and direct evaporation at the steam-water interface (convective boiling), as shown in the sketch of different generated steam flow forms in Figure 1.1. 

The sketch below shows a distillation column that is heat-integrated with an evaporator. Draw a conirot concept diagram which accomplishes the following Directives (a) In the evaporator, temperature is controlled by steam, level by liquid product, and pressure by auxiliary cooling or vapor to the rcboiler. Level in the condensate receiver is controUed by condensate. 

Given 10,000 Ib/hr of 700°F cycle exhaust gas passing through a heat recovery boiler (HRB) (a) How much 150 psia, 400°F steam can be produced (b) How much heat is transferred from the gas to the steam (c) What is the exhaust temperature of the gas leaving the HRB and (d) Sketch the T-Q (temperature-heat) diagram for the HRB. Assume a gas side mean heat capacity of 0.25 Btu/lb, °F, an evaporator pinch temperature of 30°F, a feedwater temperature of 60°F, and an evaporator drum pressure of 180 psia to allow for pressure losses. 

Figure 9.12 contains sketches for several different models of pores that will be useful in our discussion of capillary condensation. Figure 9.12a is the simplest, attributing the entire effect just described to variations in pore radius with the depth of the pore. That is, when liquid first begins to condense in the pore, the larger radius Ra determines the pressure at which the adsorption-condensation occurs. Once the pore has been filled and the desorption-evaporation branch is being studied, the smaller radius Rd determines the equilibrium pressure. Although bottlenecked pores of this sort may exist in some cases, this model seems far too specialized to account for the widespread occurrence of hysteresis. 

The whole apparatus is baked as efficiently as possible without evaporating large quantities of the manometric fluid or test substance, and is finally sealed off. The apparatus is returned to the vertical position and wholly immersed in a thermostatic bath. The level of the manometer liquid should be exactly equai under these conditions. The apparatus is then arranged as shown in the sketch with bulb B in solid carbon dioxide or liquid nitrogen. When equilibrium is attained the difference of level in the manometer limbs is observed with a cathetometer. The thermostat temperature is readjusted and the process repeated. ... 

A simple sketch of the cooling system, periodically updated, showing the water/energy/dissolved solids/saturation indices/chemical treatment in and out (based on water analyses, calculations of evaporative loss, blowdown, makeup, etc., and instrument readings) can help focus attention on what is happening in the system and provide ideas for better management. An example is shown in Figure 10.1. 

Fig. 25. (a) Sketch of a possible set-up to perform microcontact measurements using one microelectrode and an extended counter-electrode. The microelectrode is contacted under the microscope by a sharp needle, (b) Set-up for two microelectrodes, (c) Evaporated Au microelectrodes on SrTiC>3 and the needlelike tungsten tip to contact the electrodes. Such a configuration is used to perform spatially resolved bulk conductivity measurements (Sec. 6.2). (d) Ag-coated YBajCujOs+s-microelectrodes on a SrTiC>3 polycrystal contacted by two tungsten tips. The corresponding local grain boundary measurements are discussed in Sec. 6.3. 

Figure 18 (a) Sketch of evaporated gold contacts for Hall measurements on single crystals of (TMTSF)2X (b) masking arrangement used for evaporation of gold. 

Fuse, Liquid-Metal, Self-Healing. When mercury replaces the filament of an exploding-wire fuse, it. will break contact by vaporizing upon application of an overvoltage, then make contact by condensing when (he overload disappears. This happens within a heavy-walled capillary tube connecting two reservoirs (see sketch). Evaporation forces mercury from the capillary to break the. circuit Experimental quartz glass and pyrex tubes exhibit da-... 

Fig. 25 Sketch of suggested transition from spherical morphology to perpendicularly oriented cylinders upon evaporation of the PS-selective solvent 1,4-dioxane. Reprinted with permission from [186]...

The experimental apparatus closely resembled that used by Chen and Churchill (J) and by Bernstein and Churchill (3) for premixed air and propane vapor, except that a longer combustion tube was used to assure complete evaporation and combustion. The apparatus consisted of a fuel supply and atomization system, an air supply system, and a combustion chamber with insulation and guard heaters as sketched in Figure 1. 

Ethvlene reactor, 573.574.588.593 circulating sand, 593 flame reactor, 573 Evaporators, 208-211 backward and forward feed, 211 heat transfer coefficients, 211 sketches, 209-211 thermal economy, 210 Extended surfaces, heat transfer, 188... 

Mixers. See also Agitation blend time, 290 dimensionless groups, 290 gas dispersion, 296-301 in line type, 300,301 liquids, power and speed need, 293,295 powders and pastes, 301,303,304 power number, 290-292 quality characterization, 290-292 suspension of solids, 295-299 tank desien. 287.288 Moisture c tent, critical, 237 Molecular distillation, 425-427 equipment sketches, 427 Hickman still, 427 operating conditions, rate of evaporation. 

Another possibility is the sputter ion source. Here inside the source gaseous ions are accelerated to the reflector electrode containing an insert made of the element to be vaporized. Due to the sputtering effect, the material evaporates and is converted into ions. This technique is universal and applicable for all elements. Fig. 17 shows a sketch of a sputter source ... 

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