Abstract: A heat exchange apparatus is provided with an indirect evaporative heat exchange section. The indirect evaporative heat exchange section includes a series of serpentine tubes, and an evaporative liquid is passed downwardly onto the indirect heat exchange section. The evaporative liquid is collected in a sump and then pumped upwardly to be distributed again across the indirect heat exchange section. An improved heat exchange apparatus is provided with a top and a bottom indirect evaporative heat exchange section including a series of serpentine tubes A secondary system to distribute evaporative liquid below the first indirect heat exchange section and a direct heat exchange section may be provided between the two indirect heat exchangers.

Abstract: A homogeneous foam is obtained by providing a plate formed with numerous capillary tubes which divide a gas stream into elementary gas components spaced equidistantly from one another upon entering a foaming composition. The gas stream is controllably interrupted to obtain a succession of gas doses supplied to the plate in a time and pressure-controlled manner; the plate is controllably displaced to allow gas bubbles to separate from the plate between consecutive gas doses.

Abstract: A system which reduces the transmission of noxious fumes into the surrounding air during the application of a heated liquid roofing product on a roof. A mobile tanker or kettle contains a supply of the heated liquid. The air space within the tanker or vessel above the liquid product communicates with a mobile filtration unit by a first duct. A rooftop carrier for the liquid product has a fume collection hood which communicates with the filtration unit by a second duct. A blower in the filtration unit creates negative pressure which draws the noxious fumes from the tanker or vessel and carrier through the ducts and into and through the filtration unit. The filtration unit has a series of airtight chambers mounted on a mobile truck bed, each containing a different type of filtering medium to remove various components of the noxious fumes as the fumes move through the filtration unit.