Circulating-type apparatus

A high-pressure circulation-type apparatus was designed and constructed to investigate the vapor-liquid equilibria (VLE) of systems containing limonene, linalool and supercritical carbon dioxide. VLE data of binary and ternary systems of these compounds can be determined in the ranges of pressure and temperature of interest for the deterpenation of cold-pressed orange oil. The preliminary results obtained for the binaries CC -linalool and C02-limonene were compared to data already published with acceptable accuracy and well correlated by a modified Soave-Redlich-Kwong (SRK) equation of state. 

In this work, the basis for a proper answer to the selectivity problem between the two cited compounds is set. For this purpose, a high-pressure vapor-liquid equilibria circulation-type apparatus was designed and constructed. Some vapor-liquid equilibria (VLE) data of the binary systems C02-limonene and C02-linalool were determined and compared with data available in the literature. The results obtained were accurately correlated by a modified SRK equation of state that avoids the use of critical constants [16]. 

The schematic diagram of the high-pressure vapor-liquid equilibrium circulation-type apparatus is shown in Fig.l. The main piece of the equipment is a high-pressure phase equilibrium cell of approximately 100 cm3. The apparatus includes a compressed-air actuated piston-pump that allows to circulate one or both phases to bring the vapor and liquid in close contact with each other. This pump, the cell and all the related valves were placed in a constant-temperature water bath to have and to keep uniformely the desired temperature. 

Figure 1. High-pressure vapor-liquid equilibria circulation-type apparatus.

Reducibilities of the catalysts were examined by a closed circulation type apparatus. The catalyst was heated at a constant rate of 2.5°/minute up to 470°, kept at this temperature for 2 hours, and then heated up to 550° and again kept at the same temperature for 2 hours. 

Labodest circulation-type apparatus with Cottrell pump... 

Circulating-type apparatus for work at reduced pressiu-es, evaporating capacity 1001/h H O... 

Isoteniscope. (a) Schematic diagram of the apparatus, which must be connected to the ballast bulb and manometer shown in Fig. 2. A temperature controller is also needed, or a commercial circulating-type temperature control bath can be used. 

Landlocked fluid circulation in apparatuses allows reusing a fluid in contact devices of scrubbers and by that to device out its charge on clearing of gas to 0.5kg/m, that is, in 10 and more times in comparison with other types of wet-type collectors. 

In xonu- of tin- more rerent types of apparatus the system of prism is surrounded by a doilldr j,i kr-t, through which water at constant temperature may la circulated, il t aifli thr- hiuyro rr-fr.u tometer (tee p. ffi). 

B A type test under a circulating dust-air mixture the apparatus to be tested is operated at rated load/no load periodically for at least... 

Figure 15 shows typical results of axial voidage profile measurements (Li and Kwauk, 1980 Li et al, 1981). Experiments were conducted by using different solids materials in a Type A apparatus, 90 mm i.d. and 8 m high. Voidages were calculated from pressure gradient measurements. Solids circulation rate was controlled by a pneumatically actuated pulse feeder (see Section III in Chapter 7). 

Most on-line procedures involving microwaves that are conducted with a view to coupling a microwave treatment (usually digestion) with a detector (usually of the atomic type) for the determination of analytes use either a domestic oven [37-40] or a commercial focused system [41-43] plus appropriate connections. Usually, the coupling is done by inserting a Teflon coil in the oven in order to circulate the suspended solid sample to be subjected to the microwaves [44]. Some systems use domestic or commercial focused systems where the solid sample is directly placed in the sample vessel [45] and an aspiration system is used after the microwave treatment to transfer the extract to the determinative instrument used [37,46] or to an apparatus employed in some other step of the analytical process [40,43]. 

A variation of this system is the fixed basket apparatus shown in Fig. 6.13. Here the gas and liquid reactants are circulated by means of the impellers, placed above and below the catalyst bed, through the catalyst that is held in the circular basket. This type of reactor, however, is usually used for vapor phase reactions.27... 

The apparatus and methods are described in detail in the previous paper (4) and elsewhere (5-6). It is of the dual recirculation-type and is comprised, in part, of a central pressure vessel through which both liquid and vapor phases are continuously recirculated. Samples of the liquid and vapor phases are removed from the circulation loops and analyzed by gas chromatography. 

It has been shown that the actual amount of heat transmitted will depend on a great many factors and will vary considerably with the type of apparatus and the kind of liquor. Outside of water distillation, the extreme limits in actual practice are probably 8 lb. per hour per square foot for electrolytic caustic liquor from 25 to 48° in a vertical-tube evaporator and 62 lb. evaporation per hour per square foot for malt extract from 5 to 30°Bd. in a rapid circulation film type evaporator with steam at 5 lb. and a vacuum of 28 in. Practical results of various liquids are given in later paragraphs, p. 375 et seq. 

---