Jacketed coil

Commonly used heat-transfer surfaces are internal coils and external jackets. Coils are particularly suitable for low viscosity Hquids in combination with turbine impellers, but are unsuitable with process Hquids that foul. Jackets are more effective when using close-clearance impellers for high viscosity fluids. For jacketed vessels, wall baffles should be used with turbines if the fluid viscosity is less than 5 Pa-s (50 P). For vessels equipped with cods, wall baffles should be used if the clear space between turns is at least twice the outside diameter of the cod tubing and the fluid viscosity is less than 1 Pa-s (10... 

Implement procedures for leak/pressure testing of jacket, coil or heat exchanger prior to operation... 

Cooling system failure could occur due to failure of pumps or controls supplying cooling media to the reactor vessel jacket, coils, or overhead reflux condensers. Piping to or from the condensers could become plugged or any of the heat exchange surfaces could become excessively fouled. 

The heat transfer term envisions convection to an external surface, and U is an overall heat transfer coefficient. The heat transfer area could be the reactor jacket, coils inside the reactor, cooled baffles, or an external heat exchanger. Other forms of heat transfer or heat generation can be added to this term e.g, mechanical power input from an agitator or radiative heat transfer. The reactor is adiabatic when 7 = 0. 

Wire and cable jacketing, electrical and communication cable jacketing, coil cables... 

Dynamic. The coolant is assumed to be perfectly mixed as would be the situation in a circulating cooling water system. The holdup of the coolant is specified, so the dynamics of the jacket, coil, or external heat exchanger are taken into consideration. 

Hydrogenation reactions are frequently run in fed-batch reactors. The chemical component to be hydrogenated is charged to the reactor vessel. The hydrogen is then fed into the vessel on pressure control. The temperature of the reactor is controlled by manipulating the flowrate of coolant to the jacket, coil, or external heat exchanger. Thus this system has two manipulated variables (the flowrate of hydrogen and the flowrate of coolant) and two controlled variables (pressure and temperature). 

Considerable heat evolution accompanies the nitration reaction, oxidation increases it, and the heat of dilution of the sulfuric acid increases it still further. Increased temperature favors dinitration arid oxidation, so the reaction must be cooled to keep it under control. Good heat transfer can be assured by the use of jackets, coils, and good agitation in the nitration vessel. Nitration vessels are usually made of stainless steel, although cast iron stands up well against mixed acid. 

Routine cleaning of steam jackets, coils, and other reactor cooling auxiliaries. 

Cummings and West (Cll) Jacket Coil 30-in. diameter vessel—no baffles. 12-in. impellers eurved-blade (2 on same shaft in some runs) and pitched-blade turbines. 2—ft. diameter coil of 1-in. diameter tubing. = 0.40(Nn.) (ATp,) M = 1.01(ATit.) (Arp,)WO,/io),M 300-6 X 10 200-6 X 10 ... 

Calculate the jacket + coil heat-transfer rate, Qj + Qc. 

There are many different designs of condenser available, and the type used depends upon the nature of the reaction involved. The most common designs of condenser are the Liebig condenser (Fig. 9.25a), the coil condenser (Fig. 9.25b), the double-jacketed coil condenser (Fig. 9.25c), and the cold-finger condenser (Fig. 9.25d). Other condensers available tend to be simple modifications of these three types. 

The Liebig condenser, the coil condenser, and the double-jacketed coil condenser are similar in design and function. They are water-cooled via connection to a cold-water tap, in the case of the Liebig condenser the water flows in at the bottom and flows out at the top giving a jacket of cold water around the condenser stem and leading to a cold surface on the inside. Any volatile materials in the reaction condense on the cold outer surface and run back into the reaction mixture. The coil condenser functions in a similar way except that the cold surface is now on the inside of the condenser. This can offer an advantage in particularly humid locations because there is less tendency for atmospheric moisture to condense on the outside of the condenser and run down over the reaction vessel. The double-jacketed coil... 

If we heat a liquid by means of closed-in steam, that is, by means of a jacket, coil, or similar arrangement, steam is ultimately evolved from that liquid. There is no reason why this steam should not be conducted into the jacket of another pan or through a steam coil or similar arrangement, and made to heat up a further quantity of liquid and produce steam again, though of lower temperature and pressure. An arrangement of such a system is practically feasible, and is. known as multiple-effect evaporation. Two apparatus coupled together represent what is termed double-effect three, triple-effect four, quadruple-effect, etc. It is possible thus to utilise heat for... 

Surface area for process heat transfer is made available by means of jackets, coils, baffles, and plates. When these fail to adequately meet process requirements, pumps and external heat exchangers are commonly used. Under certain conditions, condensers can be designed to remove process heat through the refluxing of a solvent or reactant. 

The same two alternatives that do not affect the distribution of chemicals apply for the addition of heat to endothermic reaction operations. In this case, the diabatic operation in Figure S.lOd involves the addition of heat in ways similar to the removal of heat. Jackets, coils, and heat exchanger designs are very common. Also, interheaters between stages, as in Figure S.lOe, are used in many situations in place of intercoolers. 

Density of the reactor contents Mean thermal capacity of the reactor contents Overall heat transfer coefficient Area for heat transfer (jacket + coil)... 

Evaporator operation Deposition of salt deposits on heat transfer surfaces (tubes, jackets, coils) shall be minimised by controlling concentration of solutions. 

When the heating is to be done for achieving 150 °C and higher temperatures, the pressure of steam to be employed is more than 10 kg/cm. This needs thick-walled vessels, jackets, coils, pipelines, besides requiring approval of statutory authorities. Superheated steam is better used for power generation rather than heating. 

Stab-Kugel-Modell chem jacketed coil condenser... 

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