Abstract: Apparatus for control of cooking foods temperature by sensing their temperature with thermistors, which form part of a first electrical circuit that induces a magnetic flux in an electromagnet, a second electrical circuit that induces, in the electromagnet, a flux of opposite direction to the former, the resultant flux (larger flux minus smaller flux) generating a magnetic pull on the electromagnet's armature.The armature is linked to an on/off switch that forms part of a third electrical circuit that contains an alarm.Spring actuated forces on the armature oppose the magnetic pull. Increase in food temperature brings an increase of current intensity in the first circuit, which causes the magnetic pull to decrease.At the pre-selected controlled temperature of the food, the magnetic pull is slightly smaller than the opposed springs forces. At this point the armature separates from the core, putting the third circuit's switch on and activating the alarm.

Abstract: Outdoors and indoors air streams are induced to travel in opposite directions through the adjacent passages of a plate-fin heat exchanger. A water stream is simultaneously induced to circulate through the passages occupied by the cooler of the air streams. Heat is transferred across adjacent passages, causing vaporization of a portion of the water stream into its accompanying air stream, thus keeping the cooler stream saturated with water vapor. The hotter air stream is cooled and dehumified while the cooler one increases in temperature and humidity content. Very close temperature approaches can thus be achieved at the heat exchanger, with the resultant economies in the energy requirements for ventilation.

Abstract: The closure of the rim space between the floating roof periphery and the tank shell is effected by a permanently magnetized circular strip and a circular curtain. The magnetized strip is held by magnetic pull against the shell.Linkage means between the floating roof and the magnetized strip cause the latter to follow the vertical displacements of the former.

Abstract: A cylindrical, open top, collapsible container is loosely fitted inside the tank. The bottom of this container floats on the liquid and its lateral surface folds or unfolds upon the rise or fall in the liquid level. The annular gap between the container and the tank's shell is connected to a bladder. The bladder is expanded or contracted in the required amounts by mechanical linkages between the floating bottom and said bladder.

Abstract: A polyhedrical shaped liner, mounted vertically inside a cylindrical storage tank, is fixed to the inner top of the tank.The lower portion of the liner is fixed to a rigid frame which is free to displace in the vertical direction.Means, located on equidistant horizontal narrow strips of the liner, restrain the strips from displacing radially inwards but allow them to move in the vertical direction.Means, that apply forces directed vertically upwards over the rigid frame and of sufficient magnitude to produce critical compressive stresses in the liner, are provided.These critical compressive stresses induce buckling of the portions of the liner comprised between successive narrow strips and folding of the liner in-situ is achieved.

Abstract: Relatively dilute SO.sub.2 containing gases, such as tail gases from sulfuric acid plants, combustion gases from high sulfur fuels, and the like, are treated with a solvent, such as water, at approximately atmospheric pressures to dissolve the SO.sub.2, and the solution is then stripped at subatmospheric pressure with a gas, such as air, or a reducing gas if the SO.sub.2 is to be finally recovered as sulfur. The sub-atmospheric pressure may be attained by expansion of the stripping gas in a suitable gas expansion machine, and the stripped gas is then recompressed to a pressure, such as substantially atmospheric, at which final utilization of the stripped SO.sub.2 takes place.