Patent ID: 6264836
Filing Date: 2001-07-24
Classification: C02F,Y02W

Abstract:
A method of decontaminating a fluid contaminated with UV-sensitive microorganisms and/or organic compounds, comprising the steps of:(1) providing an apparatus comprising:(A) a single UV reactor module or a plurality of UV reactor modules, each UV reactor module comprising:(a) an influent flow conduit;(b) a variable speed pump disposed in the influent flow conduit, the pump being capable of rotating at a speed determined by a pump-speed control signal;(c) a UV reactor disposed in the influent flow conduit downstream of the variable speed pump, the UV reactor having an interior chamber containing.(i) a reactor flow passage disposed downstream of and in fluid communication with the influent flow conduit, the reactor flow passage having an inlet and an outlet;(ii) a UV flashlamp disposed in the reactor flow passage and capable of emitting one or more pulses of ultraviolet light having a wavelength in the UV-C range, wherein the flashlamp emits the one or more pulses at a UV intensity and pulse repetition rate determined by a lamp-output control signal; and(iii) at least one UV transmission detector disposed at a location in the reactor flow passage so as to measure UV transmissivity of a portion of a substream of the fluid passing proximate to said location, the detector being capable of generating an output signal indicative of the measured UV transmissivity; and(B) a system-wide control module disposed in independent electrical communication with each UV reactor module, the control module being capable of generating said pump-speed control signal and the lamp-output control signal and of receiving the UV transmissivity output signal, the control module being programmable to generate additional pump-speed control signals and lamp-output control signals in response to the UV transmissivity signal;wherein the control module is preprogrammed to send a first pump-speed control signal to the pump in each UV reactor module to cause the pump to rotate at a speed sufficient to provide a predetermined first flow rate through the influent flow conduit and the reactor flow passage;further wherein the control module is preprogrammed such that as a fluid substream flows through the reactor flow passage, the control module sends a first lamp-output control signal to the UV flashlamp in each UV reactor module to cause the flashlamp to emit one or more pulses of ultraviolet light at a predetermined first energy per pulse, the one or more pulses of ultraviolet light having a wavelength in the Uv-C range;(2) directing flow of a substream of the fluid through the influent flow conduit, the substream passing through the influent flow conduit at the predetermined first flow rate; and(3) directing flow of the substream through the reactor flow passage from the inlet to the outlet thereof such that the substream passes proximate to the UV flashlamp and proximate to the UV transmission detector, the substream flowing through the passage at the predetermined first flow rate; wherein during flow of the substream through the flow passage, a portion of the substream is exposed to the one or more pulses of ultraviolet light emitted by the UV flashlamp in response to the first lamp-output control signal generated by the control module; the UV transmission detector measuring UV transmissivity of a portion of the substream passing proximate to the detector and transmitting a UV transmissivity output signal to the control module indicative of the measured UV transmissivity, wherein the control module is preprogrammed to analyze said UV transmissivity signal to determine whether the portion of the substream subjected to the one or more pulses of ultraviolet light received a targeted UV dose, further wherein if said portion of the substream did not receive the targeted UV dose, the control module is preprogrammed to send (i) a second pump-speed control signal to effect a second flow rate in the influent flow conduit and the reactor flow passage, and/or (ii) a second lamp-output control signal to effect emission of one or more pulses of ultraviolet light at a second UV intensity and/or a second pulse duration; wherein the second flow rate and/or the second UV intensity and/or the second pulse duration are such subsequent portions of the substream exposed to the one or more pulses of ultraviolet light receive said targeted UV dose.