Abstract: A bismuth projectile comprising bismuth and a non-alloying metal and/or a polymer. A method for making a projectile comprising injection molding molten or partially molten bismuth and, optionally, a non-alloying metal and/or a polymer to form a projectile.

Abstract: The present invention comprises a heat exchanger and method for sealing a heat exchanger tube to a header of the heat exchanger. The method comprises melt-bonding the tube to a header of the heat exchanger to form a bond and sealing the bond with a sealant material to form a seal.

Abstract: An injector system for a rocket motor, such as hybrid rocket motors, comprises a plenum having at least one element, wherein at least a portion of the at least one element is porous.

Abstract: A tube and shell heat exchanger having inlet and outlet manifolds, a plurality of tubes extending between the manifolds and a shell extending between the manifolds and enveloping the tubes. The tube and shell heat exchanger has at least one baffle through which the tubes pass to locate and maintain the tubes in a spaced apart relationship. The baffle is comprised substantially in the shape of a helix of polymeric material that extends from the axis of the helix to the periphery of the helix. The tubes pass through the material in a spaced apart relationship with respect to each other and are spaced apart from the axis of the helix. The tube and shell heat exchanger is particularly intended for marine applications.

Abstract: A process for the manufacture of a heat exchanger from a thermoplastic polymer especially a polyamide, is disclosed. The heat exchanger comprises two generally planar panels formed from a composition of the polymer, bonded together to form a labryinth of fluid passages between the panels that extend between inlet and outlet means. The labyrinth occupies a substantial proportion of the area of the panels. The process comprises coating a first panel with a first coating in a pattern corresponding to the fluid passages of the labyrinth, and coating the second panel with a second coating composition in at least those areas where a bond is to be formed with the first panel. The coating compositions are selected so that under the influence of heat, the second coating composition will bond to the polymer composition but not to the first coating; thus the first coating acts as a resist coating. The coated panels are brought into contact and heated so as to effect bonding, and then the passages are expanded e.g.