Abstract: Apparatus for treating gas comprises a casing (100) containing a gas scrubber section (118) and an electrostatic precipitator section (120) located above the scrubber section. A partition (136) may be located within the casing (100) to separate the precipitator section (120) from the scrubber section (118). The casing has a gas inlet (102) for supplying gas to the scrubber section, a gas outlet (104) for exhausting gas from the precipitator section, a scrubbing liquid inlet (106) for supplying scrubbing liquid to the precipitator section, and a scrubbing liquid outlet (126) for draining scrubbing liquid from the scrubber section. In one embodiment the partition comprises a set of apertures (138) through which scrubbing liquid drains from the precipitator section into the scrubber section, and a set of gas passages (140) for conveying gas from the scrubber section to the precipitator section.

Abstract: A method for the removal of a fluorinated gas from a gas stream (1) comprising the steps of: conveying the gas stream (1) containing the fluorinated gas to a combustion region (2), decomposing the fluorinated gas in the combustion region (2), entraining a calcium salt (4) capable of reacting with the fluorinated gas decomposition products into the gas stream to react with the fluorinated gas decomposition products to form calcium fluoride and then removing (10) the calcium fluoride salt from the gas stream.

Abstract: A method for scrubbing a halogen-containing gas, comprises contacting the halogen-containing gas with water at a temperature of at least 30° C., the gas optionally subsequently being subjected to a further treatment step comprising contacting it with water at a temperature of less than 30° C. and/or a gas dilution step. An apparatus for carrying out the method comprises a hot wash chamber (6) and optionally a cold wash chamber (7) and/or a gas dilution device (13).

Abstract: Apparatus is described for treating a gas stream. The apparatus comprises a gas passage (72) for receiving the gas stream, a plurality of hollow cathodes (94) located about the gas passage (72), means for supplying to the hollow cathodes (94) a gaseous source of reactive species for reacting with a component of the gas stream, means for applying a potential to the hollow cathodes (94) to form the reactive species from said source, and a reaction chamber (110) for receiving the gas stream and the reactive species.

Abstract: A multi-stage vacuum pump comprises, between adjacent stages of the pump, a continuous ignition source for igniting a fuel within a pumped fluid. This can ensure that the concentration of the fuel in fluid exhaust from the pump is below its lower explosive limit.

Abstract: Apparatus for the combustive destruction of noxious substances comprises an annular combustion zone (C14) surrounded by the exit surface of an inwardly fired foraminous burner (C32) and surrounding the exit surface of an outwardly fired foraminous burner (C42), means (C12) for injecting a gas stream containing at least one noxious substance into the combustion zone, and means for supplying fuel gas and oxidant to the foraminous burners to effect combustion at the exit surfaces.

Abstract: In a method of operating a microwave plasma abatement apparatus comprising a microwave generator, and a gas chamber for receiving microwave energy from the microwave generator and within which a plasma is generated using the microwave energy, the amount of microwave energy that is not absorbed within the gas chamber is monitored, and the power of the microwave energy generated by the microwave generator is adjusted in dependence on the monitored microwave energy.

Abstract: A trap device comprises means for separating a liquid compound from a waste stream exhaust from a process chamber, means for collecting the liquid compound separated from the waste stream, means for selectively isolating the collected liquid compound from the waste stream, and means for evaporating the collected liquid compound to return the compound in gaseous form to the waste stream. This can enable a volatile liquid to be collected at a defined location, isolated from the waste stream, and, when so desired, returned to the waste stream in the form of a gas for subsequent abatement.

Abstract: A microwave plasma reactor (10) comprises a reactor chamber, a microwave resonant cavity (14) located within the reactor chamber, a waveguide (16) for conveying microwave radiation to the resonant cavity, the waveguide having a convergent tapered portion, means for forming an electromagnetic standing wave within the resonant cavity from the microwave radiation for initiating and sustaining a plasma within the resonant cavity, the resonant cavity having a gas inlet and a gas outlet, and conduit means extending from the gas outlet for containing a plasma conveyed from the resonant cavity with a gas flowing from the gas inlet to the gas outlet.

Abstract: A method is described of treating a gas stream exhausted from an atomic layer deposition (ALD) process chamber to which two or more gaseous precursors are alternately supplied. Between the process chamber and a vacuum pump used to draw the gas stream from the chamber, the gas stream is conveyed to a gas mixing chamber, to which a reactant is supplied for reacting with one of the gaseous precursors to form solid material. The gas stream is then conveyed to a cyclone separator to separate solid material from the gas stream. By deliberately reacting a non-reacted precursor to form solid material upstream from the pump, reaction within the pump of the non-reacted precursor and a second non-reacted precursor subsequently drawn from the chamber by the pump can be inhibited.

Abstract: Apparatus for treating a gas stream comprises a plasma abatement device (10). A wet electrostatic precipitator (20,22) is provided upstream from the abatement device (10) to remove particulates from the gas stream to inhibit clogging on the inlet of the abatement device. An additional wet electrostatic precipitator (24) may be provided downstream from the abatement device (10) for removing from the gas stream particulates generated within the abatement device (10).

Abstract: A plasma reactor (10) comprises a microwave resonant cavity (12) having a gas inlet (18) and a gas outlet (20), a waveguide (14) for conveying microwave radiation to the resonant cavity, and a plasma torch (40) for injecting into the resonant cavity a plasma stream containing ions for reacting with a gas flowing from the gas inlet (18) to the gas outlet (20).

Abstract: Apparatus is described for treating an effluent fluid stream from a semiconductor manufacturing process tool. The apparatus comprises a combustion chamber, means for heating the combustion chamber, and a nozzle for injecting the effluent stream into the combustion chamber. The apparatus is configured to enable a fuel and an oxidant to be selectively injected into the effluent stream as required to optimise the combustion conditions for a particular effluent stream. In one to embodiment, a lance projecting into the nozzle selectively injects an oxidant into the effluent stream, and a sleeve surrounding the nozzle selectively injects a fuel into the effluent stream.

Abstract: A method for the abatement of one or more pyrophoric gases in a gas stream, which includes introducing water in to the gas stream and/or mixing the gas stream with preheated air and introducing the gas stream in to a container in which the pyrophoric gases are abated.

Abstract: A process for the combustive destruction of noxious substances in a gas stream which comprises injecting the gas stream into a heated chamber with sufficient oxygen to allow substantially complete combustion therein, wherein hydrogen is also present in the chamber as a fuel gas.

Abstract: A method for the abatement of one or more pyrophoric gases in a gas stream, which comprises introducing water in to the gas stream and/or mixing the gas stream with preheated air and introducing the gas stream in to a container in which the pyrophoric gases are abated.

Abstract: A process for the combustive destruction of noxious substances from a gas stream in which the gas stream and added fuel gas as a mixture into a combustion zone that is surrounded by an exit surface of a foraminous gas burner. A fuel gas and air/oxygen mixture are simultaneously supplied to the foraminous gas burner to effect combustion at the exit surface. The resulting combustion product stream is discharged from the combustion zone. The oxygen is added to the gas stream and the fuel gas prior to the introduction of the mixture to the combustion zone and the oxygen/fuel gas mixture burns at the point of injection.