Thickness of tray

Thickness of tray parts is usually determined by the corrosion- and erosion-resistance requirements and material used. Thicknesses are usually specified in sheet-metal gages. 

Other methods for estimating the cost of vessels and fractionators can be used, but weight is usually the best. The cost of fractionators can be correlated as a function of the volume of the vessel times the shell thickness, with an addition for the cost of trays based on their diameter (Reference 13). Fractionator costs can also be correlated based on the volume of the vessel with the operating pressure as a parameter. This requires a great deal of data and does not give as good a correlation as weight. Hall et al. (Reference 14) present curves of column diameter vs. cost. 

Cap skirt clearance between cap and tray floor, in. Metal thickness of valve, in. 

Fig. 1.71. Synopsis of Tict and desorption rates (DR) of the two tests in Fig. 1.63 (1) and Fig. 1.64 (4) and comparison with two other tests (2) carried out as (1) but with activated pressure control at 0.36 mbar and (3) only one tray used (instead of three trays in Fig 1.63), which has been placed at such a slope that the thickness of the product has been 0.5 cm at one side and 0.9 cm at the other. The course of the pressure (see Figs. 1.63 and 1.64) permits quantitative judgment of the SD. The DR data measure, independent of the chosen process data, the amount of desorbed water per hour in % of the solid content. It is visible, that a DR value of 5 %/h in test (4) is reached in 6.2 h, in test (2) in 10.2 h, in test (1) in 13.5 h, but in test (3) the time cannot be estimated. Because of the unequal product thickness, the DR values can change (9.5 h), the desorption process is not uniform for such a product.

Test run The results of this run are only shown in Fig. 1.71 in curves 3. In this run the shelf with the tray was inclined in such a way that uniform thickness of 7 mm was changed from 5-9 mm. Otherwise, the conditions equaled those of the second test (Fig. 

The process data from manifold installations can hardly be transferred to chamber-type plants. This applies, practically, also to the process transfer from belljar-type installations to chamber plants. Results obtained in laboratory plants of the chamber type must be analyzed carefully, if they are be transferred to another plant. If the product, the layer thickness of the product and the vials or trays are identical, the following conditions should be observed and compared ... 

Tb is the thickness of the shell at the bottom, Tp is thickness required for the operating pressure, D is the diameter of the shell and tray, L is tangent-to-tangent length of the shell... 

Example 11 Pressure Drop, Sieve Tray For the conditions of Example 9, estimate the pressure drop for flow across one tray. The thickness of the tray metal is 2 mm. The superficial F-factor is 2.08 m/s kg/mph... 

Test run the results of this run are only shown in Figure 1.71 in curves 3. In this run the shelf with the tray was inclined in such a way that a uniform thickness of 7 mm was varied from 5 to 9 mm. Otherwise, the conditions were the same as those in the second test (Figure 1.64). The ice temperature during main drying was similar but the DR value of 5.5%/h at 9 h shows the variation of thickness of the layer. A DR of 0.5%/h was reached not in 10 h, but in 13 h. The test also showed (not in the figure) that the product temperature (T ) varied at 9 h from 0 to +22 °C. 

Fig. 1.71. Synopsis of 7"ice and desorption rates (DR) of the two tests in Figure 1.63 (1) and Figure 1.64 (4) and comparison with two other tests (2) carried out as (1) but with activated pressure control at 0.36 mbar and (3) only one tray used (instead of three trays in Figure 1.63), which was placed at such a slope that the thickness of the product was 0.5 cm on one side and 0.9 cm on the other. The DR...

Success of rate-based multistage separation modeling is ultimately tied to underlying equipment hydrodynamics performance correlations for tray or packed columns. For example, the thickness of the film... 

Fig. E13.2a A fifteen-compartment flat tray with wall thickness of 2.5 mm.

The prime variables affecting the orifice coefficient, Cv, are the fractional hole area and the ratio of tray thickness to hole diameter. More than 20 published correlations are available for evaluating Cv (12). Fair et al. (18) and Van Winkle (5) recommend the correlation by Liebson et al. (48 Fig. 6.21a). The Hughmark and O Connell correlation (66) is preferred by Ludwig (4) and Chase (30),... 

Type of tray Hole diameter, in Tray thickness Number of passes... 

Applications for these foamed products are many. An example is meat trays that are normally produced from PS foamed sheet with a thickness of approximately 0.095 in. and a density of about 5 lb/ft3. These trays are manufactured with little skin. The meat should not stick to the plastic when frozen, nor should the meat juice penetrate into the tray, and the tray should not break when handled. Strength is achieved by correcdy orienting the sheet resulting in cells that are round from a plan view. The cell size, which is determined by the amount and type of nucleating agent, is kept fairly fine to give the trays a soft, glossy appearance. 

The decision about which method of cooling has to be used will be based on the results of the analysis of structures described above. It will further depend on the thickness of the product and the type of container used flasks, vials, syringes, trays. Table 3 shows various possibilities. 

Oven and Tray Dryers Scale up from tests with an oven or single tray at identic conditions (temperature, airflow or pressure, layer thickness, and agitation, if aiw). The total area of trays required is then proportional to the mass of material to be dried, compared to the small-scale test. 

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