摘要:
An improved method is described for thermally bonding contacting pieces of a thermoplastic material provided in a variable volume confined space surrounded by a combustible gas. The combustible gas is ignited and explosion diffused externally of the pieces of thermoplastic material and thus heats the pieces without damage sufficiently to produce interbonding when the heated pieces are compacted in the confined space. The heated pieces are compacted isostatically or non-isostatically using various apparatus which reduce the volume of the confined space. Preferably a moveable piston is provided in a cylinder to form the confined space for the pieces. The driving means for the piston can be a combustible gas which is ignited or non-combustible gas under pressure or a resilient means or other mechanical means. The products of the method are in the form of a porous mass composed of the interbonded pieces which are undamaged by the explosion.
摘要:
An explosion treatment apparatus useful for confined shock exposure of materials as for removal of sand cores from finished castings and, in particular, cores in permanent mold castings in which a horizontally axised index device successively presents plural and substantially similar cavities to a position at which sealing, evacuating, fueling and ignition occur. This results in an explosion which occurs upon closure of each chamber. After the confined explosion, the cavity is opened and all cavities are indexed so that the fired cavity can be unloaded, the previously unloaded cavity can be dumped, the next adjacent cavity can be reloaded, and the reloaded cavity is presented to closure.
摘要:
A method for the heating of a fluid stream flowing in the pores of a body of specially prepared porous reticulated vitreous carbon which does not crack or substantially change in electrical resistance with time when heated to elevated temperature in air is described. The body is composed of electrically conductive rigid, interconnected and multidirectional continuous strands of vitreous carbon forming a rigid porous, three dimensional skeletal structure. The body as an electrical resistance element has current conductive paths between at least two regions; is shaped to provide particular cross-sections along the conductive paths; and has electrical connector means attached at the regions of the body so that current can be distributed through the body. The electrical resistance element is particularly useful as a heating element for air flowing through the pores in electrically powered room space heaters, hair dryers, hand dryers and the like and can also function as a self-cooling resistor. In a like manner, electromagnetic energy is used to heat a body of the porous vitreous carbon so as to heat a fluid stream flowing through the pores.
摘要:
A body of a specially prepared, porous vitreous carbon which does not crack or substantially change in electrical resistance with time when heated to elevated temperatures in air and which is used in a method or apparatus to heat a fluid stream flowing in the pores of the body as a result of natural convection or pumping of the fluid is described. The body is composed of electrically conductive rigid, interconnected and multidirectional continuous strands of vitreous carbon forming a rigid porous, three dimensional skeletal structure. The body as an electrical resistance element has current conductive paths between at least two regions; is shaped to provide particular cross-sections along the conductive paths; and has electrical connector means attached at the regions of the body so that current can be distributed through the body. The electrical resistance element is particularly useful as a heating element for air flowing through the pores in electrically powered room space heaters, hair dryers, hand dryers and the like and can also function as a self-cooling resistor. In a like manner, electromagnetic energy is used to heat a body of the porous vitreous carbon so as to heat a fluid stream flowing through the pores.
摘要:
A body of a specially prepared, porous vitreous carbon which does not crack or substantially change in electrical resistance with time when heated to elevated temperatures in air and which is used in a method or apparatus to heat a fluid stream flowing in the pores of the body as a result of natural convection or pumping of the fluid is described. The body is composed of electrically conductive rigid, interconnected and multidirectional continuous strands of vitreous carbon forming a rigid porous, three dimensional skeletal structure. The body as an electrical resistance element has current conductive paths between at least two regions; is shaped to provide particular cross-sections along the conductive paths; and has electrical connector means attached at the regions of the body so that current can be distributed through the body. The electrical resistance element is particularly useful as a heating element for air flowing through the pores in electrically powered room space heaters, hair dryers, hand dryers and the like and can also function as a self-cooling resistor. In a like manner, electromagnetic energy is used to heat a body of the porous vitreous carbon so as to heat a fluid stream flowing through the pores.
摘要:
An improved method is described for thermally bonding contacting pieces of a thermoplastic material provided in a variable volume confined space surrounded by a combustible gas. The combustible gas is ignited and explosion diffused externally of the pieces of thermoplastic material and thus heats the pieces without damage sufficiently to produce interbonding when the heated pieces are compacted in the confined space. The heated pieces are compacted isostatically or non-isostatically using various apparatus which reduce the volume of the confined space. Preferably a moveable piston is provided in a cylinder to form the confined space for the pieces. The driving means for the piston can be a combustible gas which is ignited or non-combustible gas under pressure or a resilient means or other mechanical means. The products of the method are in the form of a porous mass composed of the interbonded pieces which are undamaged by the explosion.
摘要:
The preparation of three dimensional skeletal structures using the step of deforming rounded beads to form a mold or matrix is described. A filler material is introduced and then rigidified to form the skeletal structure. The deformable beads are composed of materials which deform upon compression or expansion due to pressure from adjacent beads and included, for instance, metals, waxes, salts, polymers, and ceramic compositions in their plasticly deformable states. The filler material which rigidifies to form the skeletal structure can be composed of solidifiable materials such as metals, polymers, or ceramic compositions. The solid material volume of the skeletal structure so formed upon removal of the beads is between about 2% to 20% of a corresponding volume of a non-skeletal solid material. The corresponding porosities representing the interconnected void volumes are between about 80% and 98% of a corresponding volume of a non-skeletal solid material. The skeletal structures so formed can be flexible, semiflexible or rigid and are useful as heat exchangers, catalyst supports, distillation tower packings, filters and the like.
摘要:
The preparation of three dimensional skeletal structures using the step of deforming rounded beads to form a mold or matrix is described. A filler material is introduced and then rigidified to form the skeletal structure. The deformable beads are composed of materials which deform upon compression or expansion due to pressure from adjacent beads and included, for instance, metals, waxes, salts, polymers, and ceramic compositions in their plasticly deformable states. The filler material which rigidifies to form the skeletal structure can be composed of solidifiable materials such as metals, polymers, or ceramic compositions. The solid material volume of the skeletal structure so formed upon removal of the beads is between about two percent (2%) to twenty percent (20%) of a corresponding volume of a non-skeletal solid material. The corresponding porosities representing the interconnected void volumes are between about eighty percent (80%) and ninety-eight percent (98%) of a corresponding volume of a non-skeletal solid material. The skeletal structures so formed can be flexible, semiflexible or rigid and are useful as heat exchangers, catalyst supports, distillation tower packings, filters and the like.