Small scale apparatus

Small scale apparatus with interchangeable ground glass joints (compare Section 11,56) are available commercially. One set of apparatus ( A) is based largely upon BlO and B14 joints, although occasionally a larger size joint is used as in the steam distillation apparatus shown in Fig. XII, 3, 1. 

This subject is dealt with ab initio in the author s book entitled Elementary Practical Organic Chemiairy. Parti. SmaU Scale Preparations. (Longmans, Green and Co. Ltd., 1957.) The treatment is comprehensive and includes a detailed account of small scale apparatus of novel design. 

Alternatively, ATH could be measured in a closed vessel calorimetric test, but the pressures used in the small-scale apparatus would need adjusting to account for any difference in gas volume to sample mass ratio from the full-scale reactor.. . 

Small scale apparatus with interchangeable ground glass joints (compare Section 11,56) are available commercially. One set of apparatus ( A)... 

Gas flow is usually quoted in terms of velocity (cm/s) or mass flow (standard cmVs). Velocity may be measured by a venturi tube pointing into the flowing stream with a pressure transducer or manometer connected to the venturi tube. The two schemes which are more attractive for small-scale apparatus are... 

Once ignited, the greater the flammability of a material, the FIGURE 21.11 Temperature index greater will be the hazard associated with it. A small-scale apparatus, flammability test which is very extensively used for plastic... 

RTD data from a small-scale apparatus cannot be used for larger-scale units. Ross86 has shown this for hydrodesulfurization in a trickle-bed reactor wherein the prevailing flow regimes in small- and large-scale reactors may be different. 

A convenient, small-scale apparatus of this type has been described... 

This method describes a small-scale apparatus test procedure for comparing the relative rate of burning and the extent and time of burning of cellular polymeric materials. 

In KIER, the process was studied from 2004. Our first target is to demonstrate continuous hydrogen production using a small-scale apparatus ( 20 t/h) at atmosphere condition in 2006. Figures 1 and 2 show the schematic flowsheet of tlie small-scale apparatus and mass balance, respectively. After a successful demonstration using a small-scale apparatus, we will carry out the continuous hydrogen production using a laboratoiv scale apparatus ( 1,000 t /h) at pressure condition in 2007-2009. 

In the small-scale apparatus, the area of BED cell is about 600cm , and 13 numbers of membranes (membrane length, 15cm) pack in membrane reactor. Two membrane reactors will be connecting to a series. 

The small-scale apparatus will be built up in Oct. 2005. The apparatus was designed to produce hydrogen at the maximum rate of 20Nt /h, and is made of glass and Teflon. The operation will be carried out at atmosphere condition. A higher iodine concentration of Hix solution will be handled with an apparatus. The closed-loop operation technique for continuous hydrogen production will be developed using this apparatus. The experiments will start in November 2005. 

Figure 5 shows KIER s R D plan for the IS process. Studies on the closed-loop operation technologies at atmosphere condition using the small-scale apparatus will be carried out until 2006. Studies on process improvement and collection of data in each reaction will be carried out until 2010 for the laboratory and pilot scale equipment that will demonstrate hydrogen production at the rate of l,000N-t/h and 30 100Nm7h, respectively. 

Figure 1. Schematic flowsheet of the small-scale apparatus... 

For water and dilute aqueous solutions the bubbles are generally uniformly distributed in the liquid at low gas flow rates [132]. The bubble size distribution is relatively narrow and the bubbles rise uniformly through the column. This is known as homogeneous flow and is sketched in Fig 8.3. Homogeneous bubbly flow may occur in small scale apparatus with superficial gas velocities below 5 (cm/s). 

Methods for calculating the limiting velocity for plate colunms of laboratory size have, as far as the author is aware, not been published. The formulae valid for industrial columns prove to be inapplicable to small-scale apparatus. Experience shows that plate columns can be submitted to only about one third of the load that can be applied to packed colunms of the same diameter this is due to the resistance resulting from (a) the liquid present on the plates and (b) the restrictions in the vapour passages. 

Not all compositions of slush hydrogen are flowable. The maximum solid content for a flowable mixtures appears from early experiments to be just above 50% solid by weight. The calculations in this paper are based on the thermodynamic data P 3] and a flowable mixture of exactly 50% solid to simplify computation, though it is expected that in actual use maximum advantage would be taken of the highest possible solid content. Slush hydrogen with 50% solid has been successfully transferred through tubes in small scale apparatus. 

This effect is shown in Table 4.1 which compares the rate of heat loss from different sized vessels with that in small-scale apparatus. ... 

This standard test method specifies the use of a small-scale apparatus to assess the noncombustibility behavior of budding construction materials under the test conditions. The standard test apparatus consists of two concentric, vertical refractory tubes, 76-mm and 102-mm (3 and 4-in.) in inside diameter and 210 to 250-mm (8.5-10-in.) in length. Electric heating coils outside the larger tube are used to apply heat. A controlled flow of air is admitted tangentially near the top of the annular space between the tubes and passes to the bottom of the inner tube. The top of the inner tube is covered. Temperatures are measured by thermocouples at the center (1) between the two concentric tubes, (2) close to specimen location, and (3) sample surface. 

These standard test methods specify the use of small-scale apparatus to quantify the fire properties of materials. The apparatuses specified are ... 

The shape of the adsorption front may change as the front moves through the bed, and the mass transfer zone may broaden or diminish. As described by Kast (1988), linear or concave isotherms tend to broaden, and convex Langmuir and Preundlich isotherms quickly achieve a constant pattern. This means that the shape of the front no longer changes during its motion through the adsorber, and that the HTZ is constant. For a constant pattern of behavior, measurements on a small scale apparatus can be used for the scale-up to a full-sized adsorber. 

It will be noted that for the pure components the agreement is good. In the intermediate composition range much lower foam densities were noted on the small-scale apparatus on which mass transfer was occurring. On the large-tray apparatus, without mass transfer, there was still, however, a significant change in foam density with composition. 

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