Abstract: A radar attenuator shield for a space vehicle is described having an open shell of radar attenuating material presenting a smooth external surface on one side and open on the opposite side in the general shape of a bathtub. The space vehicle is ensconced within the open side for minimizing radar echo. In a preferred embodiment the external surface of the radar attenuator shield is in the form of a semi-cylinder with one-fourth of a sphere at each end thereof.

Abstract: This invention relates to a novel solvent, N-2-methoxyethyl-2-pyrrolidone, that can be used in two ways. First, in the pure or undiluted form, it absorbs hydrogen sulfide and other sulfurous gases selectively and simultaneously dries the gas. Second, when mixed with an alkanolamine and water, it is a superior absorbent of mercaptans, sulfides, and disulfides, and removes acid gases. The chemical structure of N-2-methoxyethyl-2-pyrrolidone is shown below.

Abstract: The alkanolpyridines, as physical solvents, compare favorably, as a family, with sulfolane in their absorption of hydrogen sulfide and mercaptans. The data show absorption differences of the alkanolpyridines diluted with water, as compared with the alkanolpyridines mixed with amine. Both sets of data indicate an absorption performance substantially equal to, or better than, the performance of sulfolane. The chemical structure of pyridine is shown below. This structure is shown with the understanding that the alkanolpyridines would have the propanol or carbinol radicals, which are also shown, or other alkanol radicals substituted at the 2, 3 or 4 position.

Abstract: An aqueous solution of a zinc salt is used to selectively remove hydrogen sulfide from a gas mixture. An insoluble basic zinc compound is added to the solution to regenerate, or replenish, the salt. A dispersant is added to both decrease the surface tension of the liquid and reduce the degree of hydration of the basic compound, thereby retarding significantly the agglomeration, settling and loss of the basic zinc compound.

Abstract: A fluid fuel burning system is mounted in a firetube and generates heat of combustion which is transferred to industrial fluid flowing through a vessel in which the firetube is mounted. The air for combustion flows into the burner as primary air mixing with the fluid fuel and a secondary air which is regulated as it flows to the combustion being completed downstream of the burner. The regulation is carried out with a damper positioned in the entrance to the firetube.

Abstract: A heat source and an element to be heated are immersed in a common liquid heat exchange medium. Baffles are arranged to guide the heated portion of the liquid upward and toward the heated element and guide the cooled portion of the liquid downward and toward the heat source in such a manner as to avoid conflict between the two flows to maximize the heat exchange between the source and element.

Abstract: A foamed ceramic slab is bonded to a three-layer polyimide RAM substrate to roduce a radar absorber capable of at least 10db absorptivity of the range 3 to at least 10 GHZ and of withstanding very high temperatures, for example, 3,000.degree. F for 80 seconds or 900.degree. F for 10 minutes, while weighing only about 5.0 lbs/sq. ft.

Abstract: A firetube is mounted in a body of liquid to transmit heat to the liquid. A burner of fluid fuel is attached to one end of the firetube to discharge products of combustion into the firetube. The cooled products are discharged from the other end. The last portion of the firetube in the liquid bath has a series of tubes mounted through its walls. Liquid of the bath passes through the tubes and is heated by the products of combustion in contact with the tubes from within the firetube.

Abstract: An interference type radar attenuator is described formed of a plurality of thin sheets having selected admittance values. The sheets are spaced apart by thin plastic spacer members having a shape memory so that the sheets can be compressed together by deforming the plastic spacers for very tight packaging and, upon release of the packaging, the sheets return to a spaced relation for effective radar attenuation. A similar structure is useful in space vehicles for thermal shielding and as a meteroid bumper.