Abstract: Activated carbon regeneration is carried out in a downwardly moving bed with superheated steam moving upwardly through the bed. The superheated steam is maintained in a closed loop which comprises the steam treatment vessel, a steam pump and a steam superheater. The superheated steam is supplied at low pressure (e.g. less than about 10 psig) and provides the heat for volatilizing water and desorbed organic volatiles. The resulting dry, partially regenerated activated carbon may be re-used directly, but preferably is treated in a vacuum chamber to remove residual water and additional adsorbate.

Abstract: Method and apparatus for in-situ regeneration of particulate adsorbent in a vessel including: heating the adsorbent, passing inert gas through heated absorbent to collect vaporized adsorbate, chilling the inert gas to condense adsorbate, thereafter lowering the pressure within the vessel, collecting withdrawn gases containing volatilized adsorbate, and chilling the withdrawn gases to condense adsorbate.

Abstract: Apparatus for removing a contaminant from a container having a liquid inventory including the contaminant as a minor ingredient and having an elevated temperature at the top of the liquid inventory. A treatment vessel contains a supply of particulate adsorbent for the contaminant. A first conduit connects the top of the container with the treatment vessel. A second conduit connects the treatment vessel with the bottom of the container. The temperature difference between the top and bottom of liquid in the container provides the driving force for continuing movement of liquid from the top of the container through the first conduit, the treatment vessel and the second conduit back to the bottom of the container. The apparatus is particularly useful for removing PCB from retrofilled transformers containing minor quantities of PCB.

Abstract: A two-chamber vessel provides for separate treatment of a fluid stream with particulate solids. Separate means are provided to introduce and remove particulate solids into each chamber. Separate means are provided to introduce and recover fluids from each chamber. The chambers may be operated in series or in parallel or for unrelated treatments. In a preferred embodiment, all of the inlet conduits for both chambers are presented at one end of the vessel.

Abstract: A gas/solids contacting device provides a light-weight, easily installed unit for contacting gases with particulate solids and permits the removal of spent solids and introduction of replacement solids. A solids contacting chamber is maintained between a pair of generally parallel foraminous surfaces which are inclined at an angle greater than the angle of repose of the particulate solids to be confined in the solids-containing chamber. The devices may be connected in parallel or in series and will function with the gas flowing upwardly or downwardly through a bed of particulate solids within the solids-containing chamber. Gas distributor means are provided to promote uniform low velocity gas flow through the solids bed. Retractable or removable support legs may be included.

Abstract: A fluid-solids contacting device is provided in tanks which can be essentially filled with particulate solids treating medium. An improved fluid distributor element is provided in such vessels including a tube-defining-frame such as a helix which is anchored to a fluid inlet or outlet pipe and which is covered with a fabric sleeve secured annularly to the pipe end. Where the pipe is an inlet pipe, all of the fluid must flow through the sleeve and is distributed over the area of the sleeve within the fluid-solids treating vessel. Where the pipe is an outlet pipe, the fluids leaving the tank must pass through the sleeve before entering into the outlet pipe. In both cases the flow distribution of the fluid within the tank is improved.

Abstract: In a process for regenerating the activated carbon and in the purification of brown phosphoric acid or alkali phosphates obtained via the so-called wet process employing mineral acid digestion of crushed phosphate rock, the activated carbon used to filter brown H.sub.3 PO.sub.4 is removed from service, washed with water, the initial washings being recovered to reclaim phosphoric acid, and then steeped in a basic aqueous solution, e.g., aqueous alkali hydroxide, alkali carbonate, ammonium hydroxide, loweralkyl amines or loweralkanol amines. After again water washing the activated carbon, to remove residual base, the activated carbon is either returned to service or steeped in an aqueous solution of mineral acid, e.g., sulfuric, hydrochloric, or nitric acid, again washed with water to remove residual acid and returned to service. Usually, the acid steep need not be employed with every base cycle to maintain good decolorization, although if desired the acid steep can be used with each caustic cycle.