Spray trap

A spray trap should be placed between the flask and the condenser otherwise some isonitrosoketone will be carried over. The checkers Used a Kjeldahl Connecting Bulb, Cylindrical Type, illustrated as item 2020 in the Pyrex Catalog, L.P-21 for 1941. 

The use of insecticide-sprayed trap trees is very labour intensive. For this reason we developed traps for the bark beetles. During the summer of 1978 we tested and evaluated more than 15 different cylindrical traps. The best trap is a black, rigid, drainpipe of polyethylene (12,5 x 135 cm). The pipe has 900 holes (diam. 3,5 mm) a lid covers its top while its bottom has a funnel and a collection bottle. 

A 3-1. Erlenmeyer flask is fitted with an inlet tube reaching nearly to the bottom of the flask and an exit tube and is placed in a hood. A solution of 200 g. of tetrabutylammonium iodide512 (0.54 mol) in 1500 ml. of chloroform is placed in the flask. The solution is cooled in an ice-water bath, and tank chlorine which has been passed through a 500-ml. gas-washing bottle containing 250 ml. of 18 M sulfuric acid and a similar empty-bottle spray trap is passed into the solution through the inlet tube. The color... 

Add the absorbing solution to the absorber, attach the spray trap, and attach to the outlet of the combustion chamber. Increase the... 

Shut down the Wickbold apparatus by turning off the nitrogen, hydrogen, and oxygen in this order. Remove the absorber. Wash the spray trap and the cool combustion chamber with a stream of water into the absorber. 

In the distillation of substances of low volatility at atmospheric and reduced pressures a short column is all that is employed and its function is mainly to act as spray trap. Coarse packing, placed on a gauze support, is used plate columns are unsuited for such purposes. It is obvious that the column should be provided with a heating jacket and that no part of the apparatus, from the stiU pot to the condenser, should be unheated, so that there may be no partial condensation. The receivers should also be capable of being warmed. A useful measure is to heat the take-off valve by radiation from an infrared source or by a hot air blower (hair dryer), so as to prevent it from sticking. Better still is the use of magnetic valves. 

Simple unrectified distillation is used in the laboratory chiefly for the recovery of solvents and other contaminated liquids, and for performing initial separations on large amounts of mixtures. The only apparatus needed for this purpose is a flask, a stiU head with a ground-in thermometer and components for condensation, vacuum connection and collecting the distillate. It is frequently advisable to include a spray trap consisting of a short section — say 5 to 10 cm — of column. Fig. 238 demonstrates the wide range of possibilities offered by the use of readily available parts [9]. 

Smooth vertical tvbes, with diameters of 20—50 mm, are now rarely used for. separations, except as spray traps in simple distillations. Their HETP will not be lower than about 10 cm unless the load is small, say less than 30 ml/h. Attempts have therefore been made to improve their efficiency by increasing their surface area. The Wurtz (r/. Fig. 15) and Young columns, consisting, respectively, of series of simple and pear-shaped bulbs, produce a better separation, but have a laiger holdup. Data for unfilled columns are given in Table 55. 

When working with gases at varying pressures (high vacuum to slightly above atmospheric pressure), a manometer of the type shown in Fig. 24 should be used. One side of this manometer is connected to the atmosphere via a mercury spray trap which... 

Fig. 216. Preparation of hydrogen thiocyanate, o) Pyrex gas generator, two liters ft) spray device with two capillary nozzles and stopcock . spray trap P) dryii tube,...

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