Abstract: An ammonia synthesis converter for small production units which provides full access for routine maintenance and catalyst replacement while providing adequate catalyst pressure drop to ensure kinetic performance and reduce heat leak from the catalyst beds. A shell has a removable top head and an annular basket is removably mounted in the shell. First and second catalyst beds are disposed in the annular zone of the basket for axial down-flow in series. A quench gas is introduced into effluent from the first catalyst bed and the resulting mixture into a top of the second catalyst bed. A feed-effluent interchanger in the inner basket zone is adapted to receive effluent from the second catalyst bed and indirectly heat a feed to the first catalyst bed. Also, methods of operating and servicing the converter.

Abstract: An ammonia synthesis converter for small production units which provides full access for routine maintenance and catalyst replacement while providing adequate catalyst pressure drop to ensure kinetic performance and reduce heat leak from the catalyst beds. A shell has a removable top head and an annular basket is removably mounted in the shell. First and second catalyst beds are disposed in the annular zone of the basket for axial down-flow in series. A quench gas is introduced into effluent from the first catalyst bed and the resulting mixture into a top of the second catalyst bed. A feed-effluent interchanger in the inner basket zone is adapted to receive effluent from the second catalyst bed and indirectly heat a feed to the first catalyst bed. Also, methods of operating and servicing the converter.

Abstract: Disclosed is an in situ design for a runoff rain gauge 14 comprising an elevated storage pan 18 for storing precipitation above grade, a splitter pan 28 for partitioning the split of flow from storage to runoff and infiltration, a saturation cup 40 for measuring surface saturation of the infiltration resistance medium and a saturation cap 42 and splitter balance line 38 for communicating water levels in the saturation cup 40 to the splitter pan 28.

Abstract: Disclosed is a runoff rain gauge 100 which includes a collector tube 104, soil infiltration resistance medium 108, a runoff resistance flow element 113, a standard rain gauge 102, and runoff collection tube 114. Precipitation enters the collector tube 104 and is divided to flow into the infiltration medium 108 and runoff collection tube 114 via flow element 113. Total precipitation is read in standard rain gauge 102, runoff in tube 114, and soil infiltration in medium 108 is calculated by the difference between total precipitation and the runoff. Also disclosed are a runoff rain gauge 100 comprising: a seal leg 150 downstream from the runoff resistance flow element 113; a collector tube 104 mounted directly to the ground so that the bottom of the soil infiltration resistance medium 108 contacts the ground surface; and/or a horizontal capillary tube in the runoff resistance flow element 113 to insure self-sealing via capillary forces.

Abstract: Disclosed is a runoff rain gauge 100 which includes a collector tube 104, soil infiltration resistance medium 108, a runoff resistance flow element 113, a standard rain gauge 102, and runoff collection tube 114. Precipitation enters the collector tube 104 and is divided to flow into the infiltration medium 108 and runoff collection tube 114 via flow element 113. Total precipitation is read in standard rain gauge 102, runoff in tube 114, and soil infiltration in medium 108 is calculated by the difference between total precipitation and the runoff.

Abstract: A fixed bed, dual-zone radial flow catalytic reactor is disclosed. In particular, the catalyst bed configuration includes a first freeboard outwardly radial flow catalyst zone in series with a second inwardly radial flow zone separated by an interconnecting substantially impermeable catalyst chute to accommodate catalyst settling while preventing hot spots and/or fluidization in the freeboard area. A gas distributor divides the freeboard zone into segments including a bypass segment and one or more catalyst segments. The radial flow of gas through each segment is essentially unaffected by the level of catalyst so that the flow pattern is not adversely affected by catalyst setting in the freeboard zone.

Abstract: A vertical, cold wall, three bed ammonia converter having upper and lower shell and tube heat exchangers wherein the lower heat exchanger is disposed axially within the upper, annular catalyst bed and preheated synthesis gas from the heat exchangers is initially converted in the middle catalyst bed which is penetrated by first, second, and third coaxial pipes. Partially converted gas from the middle catalyst bed flows upwardly through the annulus formed by the second and third axial pipes through the hot side of the lower exchanger and is then divided for parallel flow through the upper catalyst bed and, by way of the annulus formed by the first and second axial pipes, the lower catalyst bed. Converted gas from the upper and lower catalyst beds is then combined and introduced to the hot side of the upper feed/effluent exchanger.

Abstract: A horizontal, cold wall, multi-bed ammonia converter having two, shell and tube interchangers for cooling reaction gas streams leaving respectively the first and second catalyst beds with incoming reactant gases wherein each of the interchangers is vertically oriented and physically located between catalyst beds. The catalyst beds are adiabatic, slab-shape beds defined in part by side portions of the inner wall of the converter and are arranged for downward, transverse flow of reacting gases. Longitudinal conduits and baffling in cooperation with the arrangement of catalyst beds and interchangers provide serial flow of gas through the cold side of each of the interchangers, a first catalyst bed, the hot side of one of the interchangers, a second catalyst bed, the hot side of the other interchanger, a third catalyst bed, and, optionally, a fourth catalyst bed.