Distillation steam trap

Steaming-out the steam distillation apparatus. After the cleaned steam -distillation apparatus (Fig. 88) has been assembled, it is essential to pass steam through it for some time to remove readily soluble alkali. All the taps on the apparatus are opened and the water in the steam generator boiled vigorously. The steam will gradually pass into the apparatus. After a few minutes, the tap of the tap-funnel C may be closed and soon afterwards the tap Ti of the steam-trap finally the tap Tj of the funnel G may be closed, Steaming-out should then be continued for not less than one hour, the receiver J not being in place. 

During this process some water will have condensed in the steam-trap D and also in the distillation bulb F. If at the end of the steaming-out process, the Bunsen burner is removed from the generator A, the pressure in A will be reduced owing to steam condensation, and the liquid in F will be sucked back into D provided that the benL-over tube is carefully adjusted, the bulb F may be almost completely emptied of liquid as desired. Finally the condensed water in the steam-trap D may be run out by op ing the tap Tj. 

Distillation of the ammonia. The ammonia which has been liberated quantitatively in the bulb F must now be distilled completely into the receiver J. The tap Ti on the steam-trap is therefore closed and tap T2 opened so that the steam is delivered into the bulb F, which at the same time is heated directly with the flame of a micro-Bunsen... 

The steam supplied to the shell of a distillation column reboiler was very wet, as there was only one steam trap on the supply line although at least three were needed. In addition, condensate in the reboiler drained away only slowly because the level in the drum into which it drained was only 1.4 m below the level in the reboiler. 

You now have steam going through your distillation setup, and as soon as product starts to come over, you ll be doing an external steam distillation. Periodically open the steam trap drain (Caution — HOT ) and let the condensed steam out. 

There are many types of steam traps you can use with your distillation setup. I ve shown one (Fig. 81), but this is not the only one, and you may use something different. The point is to note the steam inlet and the trap drain, and how to use them. 

Replace the thermometer with the steam-inlet tube. To start the steam distillation, heat the flask containing the mixture with a Thermowell to prevent water from condensing in the flask to the point where water and product splash over into the receiver. Then turn on the steam valve, making sure the screw clamp on the bottom of the trap is open. Slowly close the clamp, and allow steam to pass into the flask. Try to adjust the rate of steam addition and the rate of heating so the water level in the flask remains constant. Unlike ordinary distillations, steam distillations are usually run as fast as possible, with proper care to avoid having material splash into the receiver and to avoid having steam escape uncondensed. 

The sample solution is placed in a still with an oxidizer which oxidizes chloride to CI2. The chlorine is steam-distilled and trapped in a receiver containing an acidified solution of Methyl Red (formula 16.1). The oxidation of Methyl Red by chlorine results in a partial bleaching of the solution, thus orovidins a basis for an indirect method of determining chloride [6]. 

Carbon dioxide is often ignored in steam systems. However, when absorbed in water, it forms carbonic acid, which can be corrosive to all parts of the steam and condensate system. Its potential presence is frequently overlooked in the design of heat exchangers, steam traps, condensate systems, deaerators, and water-treating systems. Most steam systems require continual addition of makeup water to replace losses. Makeup water must be adequately treated, by demineralization or distillation, to remove carbonates and bicarbonates. If these are not removed, they can be thermally decomposed to carbon dioxide gas and carbonate and hydroxide ions. The ions will normally remain in the boiler water, but the caron dioxide will pass off with the steam as a gas. When the steam is condensed, the carbon dioxide will accumulate since is is noncondensable) be passed as a gas by the steam trap or if the condensate and carbon dioxide are not freely passed by the steam trap, become dissolved in the condensate and form carbonic acid. If carbonic acid is formed it can have a pH approaching 4 and be very corrosive to copper and steel. Even if both the gas and condensate are passed freely by the steam trap, the gas will become soluble in the condensate when subcooling occurs. If oxygen is present, the corrosion rate Is accelerated. 

Valves, piping, and vessels Pumps, compressors, fans, and blowers Steam turbines and motors Heat exchangers and cooling towers Boilers and furnaces Reactors and distillation columns Instrumentation Basic hand tools Lubrication, bearings, and seals Flares, mixers, and steam traps... 

Hi Norman. We have a distillation tower that floods. Delta P on trays below feed point is stable delta P above feed (trays 16-22), increase from 9 to 19 KPA. Condenser and reflux drum is internal in tower, and we cannot measure the reflux rate. Yesterday, bypassed steam trap on reboiler outlet, and flooding stopped. Conclude that flooding tower due to defective steam trap. What s your opinion Note tower fractionation also improved after trap bypassed. 

Decant the ethereal solution from the yellow aldimine stannichloride which has separated, rinse the solid with two 50 ml. portions of ether, and transfer the solid to a 2-5 litre flask fitted for steam distillation and immersed in an oil bath at 110-120°. Pass steam through a trap (compare Fig. 11,40, 1,6) to remove condensed water, then through a superheater heated to 260° (Fig. I, 7, 2), and finally into the mixture (2). Continue the passage of y steam until the aldehyde is completely removed (4-5 litres 8-10 hours). Filter the white soUd at the pump, and dry in the air. The resulting p-naphthaldehyde, m.p. 53-54°, weighs 12 g. It may be further purified by distillation under diminished pressure (Fig. II, 19, ) -, pour the colourless distillate, b.p. 156-158°/15 mm., while hot into a mortar and powder it when cold. The m.p. is 57- 58°, and the recovery is over 90 per cent. 

In a i-l. three-necked flask are mixed 150 g. (r.63 moles) of /3-hydroxyethyl methyl sulfide (p. 54) (Note i) and 200 g. of dry chloroform (Note 2). The flask is placed on a steam bath and is fitted with a dropping funnel, a mechanical stirrer, and a condenser. The condenser is fitted with a trap to remove the vapors of hydrogen chloride and sulfur dioxide (page 2). A solution of 204 g. (1.7 moles) (Note 3) of thionyl chloride in 200 g. (135 cc.) of dry chloroform is added dropwise to the /3-hydroxyethyl methyl sulfide over a period of about two hours (Note 4). The reaction mixture is stirred vigorously during this addition and for about four hours after the addition is complete. The chloroform is distilled on the steam bath and the residue is distilled under reduced pressure. The yield is 135-153 g- (75 5 per cent of the theoretical amount) of a product boiling at 55-s6°/3o mm- (Note 5). 

B. a-Hydroxyphenazine (demethylalion). A solution of 4.2 g. (0.02 mole) of a-methoxyphenazine, from A above, in 125 ml. of 55% hydrobromic acid (Note 7) is placed in a 250-ml. round-bottomed flask fitted with a reflux condenser. The flask is immersed in an oil bath, and the solution is heated to 110-120° for 5 hours the evolved gases are absorbed with water in a trap. The reaction mixture is cooled to room temperature, diluted with about 125 ml. of water, almost neutralized with sodium hydro.xide (Note 8), and extracted six times with 30- to 40-ml. portions of ether. The combined ether extracts arc extracted with 25-ml. portions of 10% sodium hydroxide solution (Note 9) until no more purple sodium salt is remox ed from the ether. The aqueous extracts are combined, made acid to litmus with dilute acetic acid, and re-extracted four times with 50-ml. portions of ether. The combined ether extracts are dried over anhydrous sodium sulfate, and the ether is removed by distillation on a steam bath. The residue is recrystallized as follows It is dissolved in the least possible amount of hot alcohol, water... 

Water can be trapped behind heat exchanger baffles and then suddenly vaporized by circulation of hot oil. It can also be trapped in dead-ends and U-bends in pipework (see Section 9.1.1). Such U-bends can form when one end of a horizontal pipe is raised by thermal expansion. The trays in a distillation column were damaged during startup when hot gas met water, from previous steaming, dripping down the column [3J. Section 17.12 describes an incident somewhat similar to a foamover. 

Fig. II, 41, 4 is an apparatus for the continuous steam distillation of a liquid which is heavier than water. The aqueous mixture is placed in the flask A of relatively large capacity the receiver B consists of a distilling flask (provided with a stopcock at the lower end), the capacity of which is less than the volume of the liquid in A, and is placed several inches higher than the opening in the wide vertical tube C. The lower end of the funnel D must-be below the side arm of the receiver in order to prevent bubbles of the heavy liquid from collecting on the surface of the steam distillate and being carried back to the flask A. The rubber tube E for the returning aqueous liquor must at some point be lower than the entrance to the tube C so that a trap of liquid will be formed and prevent the vapours from A entering the side tube.

Figure 8.2 Different apparatus used for steu distillation. A aodified Gaman steam distillation apparatus A, steam generation flask B, sample chamber C, splash head D, condenser B, delivery tube F, separatory funnel. B = micro steam distillation apparatus A, boiling flask B, collection bulb C, water return arm D, Condenser. C - steam distillation apparatus using a Dean and Stark type trap. D = Nielsen-Kryger steam distillation apparatus.

B. Pyridine-N-oxide. The acetic acid solution is evaporated on the steam bath under the pressure of a water aspirator, and the residue (180-190 g.) is distilled at a pressure of 1 mm. or less in an apparatus suitable for collecting a solid distillate (Note 5). The vacuum pump must be protected with a Dry Ice trap capable of holding about 60 ml. of acetic acid, which distils as the pyridine-N-oxide acetate dissociates at low pressure. Heat is provided by an oil bath, the temperature of which is not allowed to rise above 130° (Note 6). The product is collected at 100-105°/1 mm. (95-98°/0.5 mm.). The yield is 103-110 g. (78-83%) of colorless solid, m.p. 65-66° (sealed capillary). The base is deliquescent and must be stoppered immediately. 

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