摘要:
A plurality of structured packing bricks are positioned in a column having a longitudinal axis to form one or more structured packing beds. Each brick is formed from a plurality of corrugated plates disposed in parallel relation and having opposed ends that form end surfaces of the bricks. At least one end surface, and normally both end surfaces, of the bricks are inclined at an angle to the column axis so each brick has an end surface that engages and overlaps the inclined end surface of a horizontally adjacent brick. The inclined end surfaces include openings formed by the plate corrugations and, due to the overlapping positioning of adjacent end surfaces, liquid is able to flow vertically downwardly from openings in one brick end surface into openings in the adjacent brick end surface. These angle end surfaces also disrupt the vertical flow of vapor so that vertical channeling of vapor along the end surfaces is disrupted. The shape of the packing bricks can include trapezoidal and parallelogram.
摘要:
A vapor-liquid contact tray (16) is provided with an upstream downcomer (46) and a downstream downcomer (48) which form a two-stage downcomer. The discharge outlet (62) of the upstream downcomer (46) feeds liquid into the downstream downcomer (48) to help seal the discharge outlet (58) of the downstream downcomer (48) against vapor entry at lower liquid flow rates and to allow positioning of the discharge outlet (58) above the height of the weir (66) on the underlying tray (16). Because the upstream downcomer (46) does not discharge liquid directly onto the underlying tray deck (40), the area of the tray deck (40) underlying the upstream downcomer (46) can contain vapor flow apertures (68) to increase the active area and mass transfer efficiency of the tray (16).
摘要:
A regenerative thermal oxidizer is provided with a combustion chamber and a plurality of heat transfer columns. Heat transfer media within the columns include solid surfaces which define vapor flow passages. To permit higher volumetric vapor flow rates nearer the combustion chamber, the passages are larger in cross-sectional area and the solid surfaces have less total surface area in those portions of the heat transfer media nearer the combustion chamber than in those portions away from the combustion chamber. The larger cross-sectional area of the passages and reduced area of the solid surfaces decreases the resistance to vapor flow and allows the passages to accommodate the higher volumetric flow rate of the vapor stream passing through the hotter portions of the heat transfer media. The relatively smaller cross-sectional area of the passages and increased area of the solid surfaces in that portion of the heat transfer media located away from the combustion chamber allows for more efficient heat transfer between the media and the vapor stream in those cooler portions of the heat transfer media.
摘要:
A vapor-liquid contact tray and downcomer assembly is provided with ramps which serve to impart a horizontal directional flow to the liquid exiting the downcomer and/or the vapor passing through the tray. The downcomer includes a bottom plate which closes the outlet region of the downcomer and includes a plurality of ramps which redirect the downwardly flowing liquid to include a horizontal component in the direction of liquid flow across the underlying tray. The downcomer receiving area in the underlying tray can include valves having floating caps which shield the associated openings in the tray against liquid weeping and redirect the vertical movement of the vapor streams to a generally horizontal momentum.
摘要:
A mass transfer or heat exchange column is provided with a vapor distributor having, in one embodiment, a plenum which circulates a vapor stream about the inner periphery of the column. The plenum has a plurality of spaced apart outlet ports which allow portions of the vapor stream to be introduced into the open column interior at a plurality of locations. The vapor streams exiting the plenum have sufficient velocity to cause turbulent mixing of the streams, thereby providing a more uniform distribution of the vapor across the horizontal cross section of the column. The ascending, uniformly distributed vapor is then able to interact more efficiently with liquid in an overlying zone which may include trays or random or structured packing. In another embodiment, the vapor distributor defines a flow channel of decreasing cross-sectional area that is in communication with a generally open bottom of the distributor. The decreasing area of the flow channel forces the vapor stream out the bottom of the distributor in a uniform manner for more even distribution across the horizontal cross section of the column.
摘要:
A saddle-type random packing element for use in a vapor-liquid tower which packing comprises an arcuate body having generally parallel, upright flanges on either side, the arcuate body having a plurality of alternating, generally parallel, inner and outer arched rib elements extending transversely between the flanges. The method of manufacture of the packing element comprises slitting a flat metal sheet to form rib elements, bending the sheet to form the upright flanges, the arched rib elements and then into the arcuate shape of the packing.
摘要:
A process for the production of alkyl formates such as methyl formate from the reaction of a carbon monoxide containing gas and an alkyl alcohol, such as methanol, is disclosed. The process features low conversions of alkyl alcohol to alkyl formate, high catalyst concentrations, higher reaction zone temperatures, improved process thermal efficiencies, and reduced apparatus requirements.