Abstract: Apparatus for detecting the presence of combustible vapors, e.g., natural gas, in the air utilizes an aluminum heat sink having a sealed reference chamber and a sensing chamber through which samples of air are continuously drawn. Separate unsupported platinum filaments that change in resistive value as a function of combustible gas which comes in contact therewith are located within the two chambers. The bottom of the sensing chamber has an input passage and an output passage with a wire mesh screen covering both passages. A solid non-porous plate having an outer perimeter slightly smaller than the inner perimeter of the sensing chamber is located above the wire mesh screen. The electrical circuitry of the apparatus includes a filament burn-out detection circuit and an unbalanced wheatstone bridge that goes through balance to the reverse unbalanced condition only if a combustible vapor comes into contact with the sensing filament.

Abstract: A low temperature purification system is provided which is particularly adapted for use to mechanically purify in a continuous operation solutions containing solids and dissolved substances. The purification system includes a solution supply means, and a centrifugal vacuum evaporator to which the solution to be purified is fed. Drive means is operatively connected to the evaporator for subjecting the solution within the evaporator to centrifugal acceleration and causes the solids in the solution to be displaced outwardly of the axis of rotation of the solution and the liquid of the solution to be displaced inwardly toward the axis of rotation. Outlet means is embodied in the evaporator for discharging the solids therefrom. The liquid as it is being displaced inwardly is simultaneously subjected to a reduced pressure to produce vapor which is conducted to a condenser means wherein the vapor is condensed to a substantially pure liquid.

Abstract: A method of removing immiscible fluids such as oil spills from the surface of bodies of water which comprises placing an adsorbant compound on the water survace in contact with the immiscible fluid and maintaining contact between the surface of the immiscible fluid and the adsorbant material until the immiscible fluid is adsorbed. The adsorbant compound consists of an admixture comprising from between about 30% and 70% by weight of lead slag mineral wool, with the balance being a finely divided natural stone substance containing substantial quantities of iron, aluminum, and magnesium oxides, including such natural stones as trap rock, basalt and gabbro. The lead slag mineral wool is treated with a hydrophobic-oil-soluble hydrocarbon chain substance, such as oleic acid to wet the surface of the mineral wool prior to mixing with stone flour. The lead slag mineral wool is preferably fragmented into nodules having a diameter of, for example, from 1/2 inch to 1 inch.