Mixing baffle

Corrective Action Use tracer dye to conflrm and identify exact nature of problem. Check clarifier internals such as mixing baffles and modify as needed. Cause Low density floe. 

Fixing as constants those variables that are not open to change (for example, selecting a particular type of coating pan, spray gun, mixing baffle design, pan loading, etc.). 

Such reactions can take place predominantly in either the continuous or disperse phase or in both phases or mainly at the interface. Mutual solubilities, distribution coefficients, and the amount of interfadal surface are factors that determine the overall rate of conversion. Stirred tanks with power inputs of 5-10 HP/1000 gal or extraction-type equipment of various kinds are used to enhance mass transfer. Horizontal TFRs usually are impractical unless sufficiently stable emulsions can be formed, but mixing baffles at intervals are helpful if there are strong reasons for using such equipment. Multistage stirred chambers in a single shell are used for example in butene-isobutane alkylation with sulfuric acid catalyst. Other liquid-liquid processes listed in Table 17.1 are numbers 8, 27, 45, 78, and 90. 

In stirred tanks for gas-liquid mixing, baffles are essential to create axial flow and maintain overall... 

Internal baffles are used to improve mixing in fluids that tend to rotate along with the impeller rather than being mixed. Baffles reduce the flow of fluids to speeds much lesser than that of the impeller. This increase in shear provides additional turbulence leading to improved mixing of the fluids. Baffles are typically designed to have a width of 1/12 to 1/10 of the vessel diameter and are located slightly off of the internal vessel wall to prevent accumulation of the material. 

These contactors provide corn pone ms that rotate around the vertical axis of the column (see Fig. 7.6-1). Generally, a rotational drive is provided at the top of the contactor. The rotational frequency can be ndjuated to increare the interfacial area and the rate of mass transfer between the two phrees. To reduce vertical mixing, baffles are often inserted within Ihe column and interspersed between the rotating internals. A number of designs are commercially available. 

A major problem was the distribution of liquid on the tray and the obtaining of uniform vapor composition in the catalyst beds as the mixture was carried upward through the beds. This was solved successfully by installing the disc-and-doughnut type of vapor-mixing baffles between the trays and the catalyst beds. The overlapping part of the disc and dough-... 

Figure 25 Schematic diagram of room calorimeter test (ISO 7905). 1. Room. 2. Gas burner ignition source. 3. Room exit door. 4. Hood. 5. Fire gas mixing baffles. 6. Gas sampling, temperatures, and velocity probes, smoke measuring sensors. 7. Exhaust fan. Note Furniture calorimeter is similar but without room. Test. specimen is burned directly under hood (NT Fire 032).

Additional physical properties and mass-transfer correlations are sometimes needed to determine the performance of the well-mixed baffled device. The viscosity of the two-phase dispersion, p, and its density, p ix 1° determined from (Treybal, 1963)... 

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