Cooling coil

Electrolysis cell. This is shown in Fig. VI, 31, 1 and is almost self-explanatory. The cylindrical cell of Pyrex glass (6" long by 2 " diameter) is cooled by immersion in a cooling bath. The electrodes consist of two platinum plates (4 cm. X 2-5 cm. X 0-3 mm.), which are placed about 2 mm. apart. The temperature of the electrolyte is maintained at 30-35° by means of the internal cooling coil and also by immersion of the cell in ice-water. A current of 1 5-2 0 amperes is passed until the electrolyte becomes slightly alkaline, which normally takes about 20-50 per cent, longer than the calculated time on the basis of the current and the amounts of acid employed. It is advantageous to reverse the direction of the current occasionally. 

Pentaerythritol may be nitrated by a batch process at 15.25°C using concentrated nitric acid in a stainless steel vessel equipped with an agitator and cooling coils to keep the reaction temperature at 15—25°C. The PETN is precipitated in a jacketed diluter by adding sufficient water to the solution to reduce the acid concentration to about 30%. The crystals are vacuum filtered and washed with water followed by washes with water containing a small amount of sodium carbonate and then cold water. The water-wet PETN is dissolved in acetone containing a small amount of sodium carbonate at 50°C and reprecipitated with water the yield is about 95%. Impurities include pentaerythritol trinitrate, dipentaerythritol hexanitrate, and tripentaerythritol acetonitrate. Pentaerythritol tetranitrate is shipped wet in water—alcohol in packing similar to that used for primary explosives. 

A mathematical model of the operating characteristics of a modem HLW storage tank has been developed (60). This model correlates experimental data for the rate of radiolytic destmction of nitric acid, the rate of hydrogen generation owing to radiolysis of water, and cooling coil heat transfer. These are all functions of nitric acid concentration and air-lift circulator operation. 

Eigure 3 is a flow diagram which gives an example of the commercial practice of the Dynamit Nobel process (73). -Xylene, air, and catalyst are fed continuously to the oxidation reactor where they are joined with recycle methyl -toluate. Typically, the catalyst is a cobalt salt, but cobalt and manganese are also used in combination. Titanium or other expensive metallurgy is not required because bromine and acetic acid are not used. The oxidation reactor is maintained at 140—180°C and 500—800 kPa (5—8 atm). The heat of reaction is removed by vaporization of water and excess -xylene these are condensed, water is separated, and -xylene is returned continuously (72,74). Cooling coils can also be used (70). 

Process. A typical indirect hydration process is presented in Eigure 1. In the process, propylene reacts with sulfuric acid (>60 wt%) in agitated reactors or absorbers at moderate (0.7—2.8 MPa (100—400 psig)) pressure. The isopropyl sulfate esters form and are maintained in the Hquid state at 20—80°C. Low propylene concentrations, ie, 50 wt %, can be tolerated, but concentrations of 65 wt % or higher are preferred to achieve high alcohol yields. Because the reaction is exothermic, internal cooling coils or external heat exchangers are used to control the temperature. 

Fig. 10. Wet high, intensity magnetic separator using cryogenically cooled coils and a stationary matrix where A is the feed control for top-fed or retention time control for underfed operation and B is the feed control for underfed or retention time control for top-fed operation.

Distillers vary masking procedures, but generally conform to basic principles, especially in the maintenance of sanitary conditions. The cooking and conversion equipment is provided with direct or indirect steam, propeller agitation, and cooling coils. 

A typical bourbon fermentation continues for 72 hours at a fermentation temperature within the 31—35°C range. Many fermentation vessels are equipped with agitation and/or cooling coils that facHitate temperature control. Significant increases in yeast numbers occur during the first 30 hours of fermentation. Over 75% of the carbohydrate is consumed and converted to ethanol. Within 48 hours, 95% or more of the ethanol production is complete. 

Fig. 10. The Groth ZG 5 centrifuge. R, rotor R, stationary shaft T, Teflon seal K, K, chambers for gas scoops S, S2, scoops V, gas supply M, manometer Z, Z2, tapping points for enriched and depleted gas P, P2, vacuum chambers E, electromagnet for eddy current heating Tb, Tb2, temperature measuring devices K, cooling coil and D, D2, labyrinth seals.

FIG. 11 91 Effect of circulation ratio on the overall heat-transfer coefficient of an air-cooling coil. 

Cooling coils can be incoiporated more readil) into plate devices. 

Tnternaf cooling coil immersed in fluidized 0Qwder... 

Figure 1. A, Dewar flask B, sintered glass filter C, metal cooling coil D, water inlet E, water outlet F, reaction vessel < , quartz immersion well /f, pyrex filter /, lamp ...

Styrene and solvent are blended together and then pumped to the top of the first reactor which is divided into three heating zones. In the first zone the solution is heated to start up the polymerisation reaction but because of the exothermic reaction in the second and third zones of the first reactor and the three zones of the second reactor Dowtherm cooling coils are used to take heat out of the system. By the time the reaction mixture reaches the third reactor the polymerisation reaction has started to slow down and so the reaction mixture is reheated. 

The negative value in the area indicates that the first stage of the CFSTR requires a cooling coil. 

A cross sectional area heat transfer area of heating or cooling coil,... 

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