Conveying baffle

Conveying-screen diyers are fabricated with conveyor widths from 0.3- to 4.4-m sections 1.6 to 2.5 m long. Each section consists of a sheet-metal enclosure, insulated sidew s and roof, heating coils, a circulating fan, inlet-air distributor baffles, a fines catch pan under the... 

Soft solids, most of which are biological waste such as sewage, are difficult to convey up the beach. Annular baffles or dams have been commonly used to provide a pool-level difference wherein the pool is deeper upstream of the baffle toward the clarifier and lower downstream of the baffle toward the beach. The pool-level difference across the baffle, together with the differential speed, provide the driving force to convey the compressible sludge up the beach. This has been used effectively in thickening of waste-activated sludge and in some cases of fine clay with dilatant characteristics. 

The water and liquors from washing and sulphitation of TNT contain some TNT both dissolved and suspended. For recovering the latter the water and wash liquor are conveyed to labyrinth tanks equipped with baffles barring the passage of suspended TNT, which settles at the bottom. In this way a certain amount of lower grade TNT may be recovered. 

With baffles Horizontal drum Double cone revolving around long axis Twin shell Cube Twin rotor Turbine Paddle mixer Sifter (turbosifter) Attrition mill Elevator loading Pneumatic conveying Vibrating... 

In cases where a uniform gas flow has simply been split for purposes of conveyance, it may be necessary to include baffles, turning vanes, or other flow devices, depending upon the intended entry configuration. In some instances, model studies are recommended to determine proper performance requirements particularly when it is felt that stratification of gas flows are anticipated. 

The Hildebrandt extractor consists of a U-shaped screw conveyer with a separated helix in each of the downward, horizontal, and upward sections. Solids are fed to one leg and fresh solvent is fed to the other to give countercurrent flow. In a Dorr classifier, soUd is introduced near the bottom of a sloping tank and is gradually moved up by means of a rake. The solvent enters at the top and flows in the opposite direction of the sohd and passes under a baffle before finally being discharged over a weir. A number of these units can be connected in series to give countercurrent flow. 

Conveying-screen dryers are fabricated with conveyor widths from 0.3- to 4.4-m sections 1.6 to 2.5 m long. Each section consists of a sheet-metal enclosure, insulated sidewalls and roof, heating coils, a circulating fan, inlet air distributor baffles, a fines catch pan under the conveyor, and a conveyor screen (Fig. 12-51). Table 12-23 gives approximate purchase costs for equipment with type 304 staimess-steel hinged conveyor screens and includes steam-coil heaters, fans, motors, and a variable-speed conveyor drive. Cabinet and auxiliary equipment fabrication is of aluminized steel or stainless-steel materials. Prices do not include temperature controllers, motor starters, preform equipment, or auxiliary feed and discharge conveyors. These may add 75,000 to 160,000 to the dryer purchase cost (2005 costs). 

Soft solids, most of which are biological waste such as sewage, are difficult to convey up the beach. Annular baffles or dams have been commonly used to provide a pool-level difference wherein the pool is... 

How does axial circulation, a precondition for large-space mixing, take place in an unbaffled tank A purely rotational motion would be useless. Answer A boundary layer is formed at the wall due to the van der Waals and the viscosity forces, which is kept there by the shear stress. The tank contents therefore rotates more slowly than the stirrer, and the centrifugal forces of the stirrer convey the liquid radially outwards. (It has been found that axial rotation immediately almost completely fails, when a friction-reducing tenside is added [572].) The deceleration of the tank contents is much more effective with baffles (stream crossways to the baffle surfaces) than by hydrodynamic boundary layers (stream parallel past the wall surface). 

P. Todtenhaupt [547] investigated the homogenization characteristic of a stirred column with 5 stirrers on the same shaft and flow from bottom to the top. Turbine, cross-beam, MIG and propeller stirrers were used. The stirred column was provided with round baffles, but did not possess partition trays between the individual stirred sections. Turbine stirrers performed the best and propeller stirrers conveying downwards the worst. For these two stirrer types the following process relationships apply ... 

Safety professionals give many names to the incidents to which a causation model would apply accidents, incidents, mishaps, near-misses, occurrences, events, illnesses, fires, explosions, windstorms, drownings, electrocutions, and so on. Pat Clemens, a prominent safety consultant, has said that the language used by safety practitioners lacks words to convey precise and understood meanings. It s probable that the people with whom safety professionals try to eommunicate are baffled by the many terms used to describe hazards-related incidents. 

Marked axial dispersion in both the liquid and solid phases has been observed in continuous countercurrent leaching systems. The solid-phase dispersion is probably caused by nonuniform conveying and by backmixing caused by the baffles which are used to prevent solid beds from turning en masse. VnliD n values of 16.1 m and 20 m, respectively, have b n repotted for sugar beet extraction in tower and slope extractors. Local fiow nonuniformity and larger-scale flow maldistribution are the primary factors that cause axial dispersion in the extract. 

Drum dryers are widely used and consist of a heated drum in which the material being dried is conveyed firom one end to the other by gravity and built-in baffles. For industrial processes, the dryers are heated either directly by a hot stream of air or gas, or indirectly by an external source. The material is heated up in just a few seconds, but remains for much longer in the drum dryer, enabling simultaneous sterilization and cell decomposition. 

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