Abstract: Apparatus for removing particulate matter from an enclosure having an internal space and an opening into the internal space, comprising: a cover positionable adjacent the opening so that the cover covers the opening; a gas source external to the internal space; an inlet conduit that in use extends through the cover and is adapted to direct gas from the gas source to at least one gas outlet within the internal space whereby particulate matter within the internal space is dislodged and entrained in gas within the internal space; a source of partial vacuum adapted to maintain a partial vacuum within the enclosed space and to draw gas and particulate matter entrained therein from the internal space firstly through an outlet conduit and then through a particulate matter separation means comprising at least one filter; a sensor for sensing concentration of particulate matter in gas leaving the enclosed space; a display adapted to provide to a user information on concentration of particulate matter leaving the inter

Abstract: A multiple hearth furnace in which in a gas space above at least one hearth an annular baffle is provided above the rabble arms of that hearth. The annular baffle modifies gas flow in the gas space, in particular gas residence times above the hearth. This in turn can enhance performance of the furnace, for example in respect of carbon monoxide emissions.

Abstract: A multiple hearth furnace in which in a gas space above at least one hearth an annular baffle is provided above the rabble arms of that hearth. The annular baffle modifies gas flow in the gas space, in particular gas residence times above the hearth. This in turn can enhance performance of the furnace, for example in respect of carbon monoxide emissions.