Condenser installation

The "Neutralizer of this house consisted of a closed stainless steel vessel, provided with a jacket, agitator and water-cooled reflux condenser installed above the kettle to prevent the loss of acetone... 

The phenanthrenequinone oxime 54 was built in four steps from the two benzenoid precursors 52 and 53. Beckmann rearrangement of 54 furnished the cyano-acid 55. The latter, after reduction to the corresponding cyano-aldehyde, was homologated by Knoevenagel condensation with malonic acid to give, after reduction, hydrolysis and esterification, the diester 56. This compound underwent Dieckmann condensation, installing the seven-membered C-7 ketone 57 in 69% yield after hydrolysis and decarboxylation of the intermediate (3-ketoester. 

Split System Air Conditioner - An air conditioning system that comes in two to five pieces one piece contains the compressor, condenser, and a fan the others have an evaporator and a fan. The condenser, installed outside the house, connects to several evaporators, one in each room to be cooled, mounted Inside the house. Each evaporator is individually controlled, allowing different rooms or zones to be cooled to varying degrees. 

A combination of two cooling systems may sometimes be found as well, for instance in plants which have both a number of smaller process coolers and large turbine waste steam condensers installed. Whereas the latter are operated with sea water wherever possible, the former are normally combined into a small open or closed loop. 

Modify existing reboiler/condenser install a new reboiler/condenser in parallel. Additional condensers can also be installed in series at the expense of more reboiler duty... 

Figure 11.10 Surface condenser installed with steam jet ejectors values shown are the current operating conditions.

Loss of volatile vapor out vent, apparent undersized area for condensation of immiscible liquids lack of subcooling of condensate/condenser installed horizontally instead of vertically. 

Some distillation columns with partial condensers are constructed with the condenser installed at the top of the column inside the shell. There is usually no reflux drum. Vapor flows upward through the tubes of the condenser. The condensate liquid flows downward and drops into a liquid distributor above the top tray. These dephlegmatoi systems are frequently used when very toxic or dangerous chemicals are involved because it avoids potential leak problems with pumps and extra vessels and fittings. 

The temperature differences AT at each point in the condenser are smaller than for the condensation of inert gas free pure vapour. Particularly at the end of the condenser (after the main amount of condensation, heat is dissipated), the condensation temperature drops to very low values. It can easily be seen that in these cases, it is very important to run the coolant in counterflow to the condensing vapour. Sometimes, such condensers are constructed with a special under-cooling section where the remaining inert gas-vapour mixture is forced to flow to the coldest place of the condenser. Installations of the most diverse forms are made, in order to achieve this purpose. However, in such installations, dead corners can form when the flow is not directed properly. There the inert gas collects and blocks the vapour away from the heat exchange surface, so that parts of the surface remain unused. 

Example A.4.1 The purchased cost of a distillation column is 1 million, and the reboiler and condenser are 100,000. Calculate the annual cost of installed capital if the capital is to be annualized over a 5-year period at a fixed rate of interest of 5 percent. 

A variation of the Madelung cyclization involves installing a functional group at the o-methyl group which can facilitate cyclization. For example, a triphenylphosphonio substituent converts the reaction into an intramolecular Wittig condensation. The required phosphonium salts can be prepared by starting with o-nitrobenzyl chloride or bromide[9]. The method has been applied to preparation of 2-alkyl and 2-arylindoles as well as to several 2-alkenylindoles. Tabic 3.2 provides examples. 

Dust Filter. The cloth or bag dust filter is the oldest and often the most reHable of the many methods for removing dusts from an air stream. Among their advantages are high (often 99+%) collection efficiency, moderate pressure drop and power consumption, recovery of the dust in a dry and often reusable form, and no water to saturate the exhaust gases as when a wet scmbber is used. There are also numerous disadvantages maintenance for bag replacement can be expensive as well as a sometimes unpleasant task these filters are suitable only for low to moderate temperature use they cannot be used where Hquid condensation may occur they may be hazardous with combustible and explosive dusts and they are bulky, requiring considerable installation space. 

N2, and traces of PH, CO2, E, and S large furnaces generate off-gas at a rate of about 120—180 m /min. In most installations the off-gas is passed through a series of Cottrell electrostatic precipitators which remove 80—95% of the dust particles. The precipitators ate operated at temperatures above the 180°C dew point of the phosphoms. The collected dust is either handled as a water slurry or treated dry. Einal disposal is to a landfill or the dust is partially recycled back to the process. The phosphoms is typically condensed in closed spray towers that maintain spray water temperatures between 20 and 60°C. The condensed product along with the accompanying spray water is processed in sumps where the water is separated and recycled to the spray condenser, and the phosphoms and impurities ate settled for subsequent purification. 

When low boiling ingredients such as ethylene glycol are used, a special provision in the form of a partial condenser is needed to return them to the reactor. Otherwise, not only is the balance of the reactants upset and the raw material cost of the resin increased, but also they become part of the pollutant in the waste water and incur additional water treatment costs. Usually, a vertical reflux condenser or a packed column is used as the partial condenser, which is installed between the reactor and the overhead total condenser, as shown in Figure 3. The temperature in the partial condenser is monitored and maintained to effect a fractionation between water, which is to pass through, and the glycol or other materials, which are to be condensed and returned to the reactor. If the fractionation is poor, and water vapor is also condensed and returned, the reaction is retarded and there is a loss of productivity. As the reaction proceeds toward completion, water evolution slows down, and most of the glycol has combined into the resin stmcture. The temperature in the partial condenser may then be raised to faciUtate the removal of water vapor. 

Based on dryer cost alone, indirect-heat dryers are more expensive to build and install than direct-heat dryers designed for the same duty. As environmental concerns and resulting restrictions on process emissions increase, however, indirect-heat dryers are more attractive because they employ purge gas only to remove vapor and not to transport heat as well. Dust and vapor recovery systems for indirect-heat dryers are smaller and less cosdy to supply heat for drying, gas throughput in direct-heat dryers is 3—10 kg/kg of water evaporated indirect-heat dryers require only 1—1.5 kg/kg of vapor removed. System costs vary directly with size, so whereas more money may be spent for the dryer, much more is saved in recovery costs. Wet scmbbers ate employed for dust recovery on indirect-heat dryers because dryer exit gas usually is close to saturation. Where dry systems are employed, all external surfaces must be insulated and traced to prevent vapor condensation inside. 

High in stalled co.sts. The incremental piping required for the steam supply system and the condensate return system must be installed, insulated, and, in the case of the supply system, additional steam traps are often required. The tracer itself is not expensive, but the labor required for installation is relatively high. Studies have shown that steam tracing svstems typically cost from 50 to 150 percent more than a comparable electric tracing system. 

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