Abstract: Apparatus for use in a multi-stage system in which a fluid being treated is passed in succession through a first stage A, a second stage B, a third stage C, etc. includes a controlled system of valved interconnections that permits the direction of flow within each stage to be reversed while preserving the original sequence ABC . . . in which the fluid progresses from stage to stage. The stages may be reaction chambers in which chemical or photo-chemical reactions are carried out or the stages may be filters that need to be reverse-flushed at intervals. In accordance with the invention, a second set of inter-stage connections is provided, in addition to the original connections used for forward flow. In the second set, the inlet and outlet ports are located at opposite ends of each stage from the inlet and outlet ports used in the original connections.

Abstract: A replaceable wiper cartridge is described which is held captive within a shuttling scraper of a type known in the art which is pushed axially through a cylindrical reaction chamber intermittently to remove reaction products from the inside surface of the reaction chamber and from the outside surface of a smaller coaxial tube that extends the length of the reaction chamber. The replaceable wiper cartridge has an annular shape that is obliquely cut to permit a slight radial expansion to accommodate the smaller coaxial tube and to engage it in a tight sliding grip so as to scrape from the smaller tube any deposits.

Abstract: An oxidation chamber used for irradiating an incoming liquid containing unwanted organic pollutants has a structure that facilitates automatic self-cleaning at intervals. A modular construction is used, and three basic types of modules are employed. One of the modules is a TEFLON.RTM. lined carbon steel pipe through which a shuttling scraper is forced at intervals. The shuttling scraper includes an annular wiper that simultaneously cleans the inside surface of the surrounding tubular module as well as the outside surface of an enclosed quartz tube. The annular wiper sealingly engages the quartz tube and the tubular module so that it is driven like a piston by the full pressure of the liquid. When the shuttling scraper has reached the end of the tubular module, it parks itself in a position that causes only minimal pressure drop.

Abstract: An oxidation chamber used for irradiating an incoming liquid containing unwanted organic pollutants has a structure that facilitates automatic self-cleaning at intervals. A modular construction is used, and three basic types of modules are employed. One of the modules is a TEFLON.RTM. lined carbon steel pipe through which a shuttling scraper is forced at intervals. The shuttling scraper includes an annular wiper that simultaneously cleans the inside surface of the surrounding tubular module as well as the outside surface of an enclosed quartz tube. The annular wiper sealingly engages the quartz tube and the tubular module so that it is driven like a piston by the full pressure of the liquid. When the shuttling scraper has reached the end of the tubular module, it parks itself in a position that causes only minimal pressure drop.

Abstract: A series of staggered baffles defines a serpentine flow path consisting of a number of segments through the oxidation chamber. Within each segment, a group of high intensity ultraviolet lamps is mounted, and a reagent inlet is provided at the upstream end of each segment, thereby permitting the processing of a liquid containing a hazardous compound through a sequence of chemical reactions carried out in the presence of intense ultraviolet radiation within the various segments of the flow path. Within each segment a different reagent may be used along with a different intensity of ultraviolet radiation.

Abstract: A control circuit utilizing the impedence transforming attributes of ballast/filter networks is disclosed for energizing high intensity gas discharge lamps, wherein the output amplitude and/or duty cycle of a power frequency waveform produced by a switching inverter is controlled using feedback techniques. A basic embodiment teaches the use of energy removal from the input inductor of a low pass ballast/filter positioned between a switching inverter operating at 30 kHz and a gas discharge lamp load to serve as a feedback source, while an alternate embodiment teaches the use of this feedback source as a signal for controlling the duty cycle of the constant frequency square waves produced by the inverter.

Abstract: In an oxidation chamber for treating wastewater, an ultraviolet lamp is mounted inside a quartz tube that is surrounded by the wastewater in the oxidation chamber. During operation, the quartz tube becomes quite hot and becomes coated with a film of slime that reduces transmission of the ultraviolet radiation into the wastewater. This results in gradually decreasing efficiency of operation until its becomes necessary to interrupt the operation of the chamber and to remove the quartz tube so that it can be cleaned to restore the transmission.In accordance with the present invention it has been found advantageous to apply a thin layer of fluoroethylene propylene (FEP) to the outer surface of the quartz tube. It has been found that the FEP layer is less suspectible to the deposition of slime than is the unprotected quartz tube, and that the slime is more easily removed from the FEP layer than from an unprotected quartz tube.

Abstract: An oxidation chamber for use in the treatment of organically contaminated water and waste liquids includes a lamp seal assembly that accommodates the thermal expansion of an ultraviolet lamp while at the same time protecting the lamp from direct contact with the liquid being treated. The lamp seal assembly facilitates replacement of burned out lamps and cleaning of the protective tube that surrounds the lamp. In another aspect of the invention, a specially designed family of baffles and distributors are provided so that the chamber can accommodate a wide range of flow rates simply by replacing one set of distributors by a different set of distributors.

Abstract: An oxidation chamber for use in the treatment of organically contaminated water and waste liquids includes a lamp seal assembly that accommodates the thermal expansion of an ultraviolet lamp while at the same time protecting the lamp from direct contact with the liquid being treated. The lamp seal assembly facilitates replacement of burned out lamps and cleaning of the protective tube that surrounds the lamp. In another aspect of the invention, a specially designed family of baffles and distributors are provided so that the chamber can accommodate a wide range of flow rates simply by replacing one set of distributors by a different set of distributors.

Abstract: The circuit includes a low-impedance source of a symmetrical alternating voltage wave composed of a fundamental and odd harmonics, and further includes a transmission line having a delay equal to an odd number of quarter cycles of the fundamental, having one end connected to the low-impedance source and the other end connected to the load. The circuit should be useful wherever it is desired to maintain the flow of current constant in spite of variations in the load resistance.