摘要:
A heat exchanger comprising helically wound tube bundles is disclosed. The helically wound tube bundles are joined with tube sheets to define a primary working fluid system that is fluidically isolated from a secondary working fluid system. The tube sheets and tubes are formed of the same material, which facilitates their joining by means of joints that are substantially galvanic corrosion-resistant joints.
摘要:
A radial flow plate-fin heat exchanger includes a plurality of heat exchange units connected together to form an annular shaped core. The core has a plurality of first fluid passageways that are circumferentially spaced from one another and that extend generally axially from a first end of the core to a second end. Each of the first fluid passageways is defined at least in part by a plurality of fins that include graphite foam. The core also has a plurality of second fluid passageways that are circumferentially spaced from one another and that extend generally radially from the central fluid passageway through an exterior wall of the core. The second fluid passageways are separated from the first fluid passageways so that a first fluid that flows through the first fluid passageways does not mix with a second fluid that flows through the second fluid passageways.
摘要:
A heat exchanger comprising helically wound tube bundles is disclosed. The helically wound tube bundles are joined with tube sheets to define a primary working fluid system that is fluidically isolated from a secondary working fluid system. The tube sheets and tubes are formed of the same material, which facilitates their joining by means of joints that are substantially galvanic corrosion-resistant joints.
摘要:
A chemical, biological, radiological, and nuclear weapons detection system is disclosed that comprises an array of spatially-disparate hazardous material sensors that all feed into a centralized system control center. This enables the embodiment to receive and coordinate in one place all of the hazardous material sensors spread over a wide area, and, therefore, enables an alarm to be quickly issued in the event of a real attack. To accurately reduce false alarms, the illustrative embodiment requires that at least N of M neighboring stations report an alarm for the same hazardous material within an interval of time, and that the values of at least one of N and M change and are based on at least one environmental factor.
摘要:
A chemical, biological, radiological, and nuclear weapon detection system is disclosed that heightens its acuity and alertness when it senses that a chemical, biological, radiological, or nuclear weapon attack is more likely. For example, it is well understood that a chemical gas attack is likely to be less effective when it is raining than when it is clear because the rain will suppress and dilute the chemical agent. Therefore, the likelihood of a chemical gas attack is higher when it is clear. In light of this and similar knowledge, the illustrative embodiment checks for evidence of an attack more frequently and with great acuity than when the ambient environmental (e.g., meteorological, etc.) characteristics (e.g., whether is it precipitating or not, whether it is sunny or not, etc) suggest that an attack is more likely. This enables the embodiment to conserve consumables that are used in detecting attacks for when the attacks are more likely.
摘要:
Shell-and-tube heat exchangers that utilize one or more foam heat transfer units engaged with the tubes to enhance the heat transfer between first and second fluids. The foam of the heat transfer units can be any thermally conductive foam material that enhances heat transfer, for example graphite foam. These shell-and-tube heat exchangers are highly efficient, inexpensive to build, and corrosion resistant. The described heat exchangers can be used in a variety of applications, including but not limited to, low thermal driving force applications, power generation applications, and non-power generation applications such as refrigeration and cryogenics. The foam heat transfer units can be made from any thermally conductive foam material including, but not limited to, graphite foam or metal foam. In an embodiment, the heat exchanger utilizes tubes that are twisted around a central foam heat transfer unit.
摘要:
Heat exchangers are described that employ fins made of a heat conducting foam material to enhance heat transfer. The foam fins can be used in any type of heat exchanger including, but not limited to, a plate-fin heat exchanger, a plate-frame heat exchanger or a shell-and-tube heat exchanger. The heat exchangers employing foam fins described herein are highly efficient, inexpensive to build, and corrosion resistant. The described heat exchangers can be used in a variety of applications, including but not limited to, low thermal driving force applications, power generation applications, and non-power generation applications such as refrigeration and cryogenics. The fins can be made from any thermally conductive foam material including, but not limited to, graphite foam or metal foam.
摘要:
A technique for joining porous foam material, such as graphite, metal or ceramic foam, to a substrate is described. The substrate can be metal, a thermoset plastic or a composite material. The substrate has a melting point below that of the foam material. The two are joined together by using the foam to apply heat locally at the surface of the substrate. Some or all of the foam is heated to the appropriate temperature at or above the melting point of the substrate material. The foam and the substrate are then brought together, with the heat from the foam melting or softening the substrate material so that the substrate material infuses into the pores of the foam. As the foam cools below the melting point temperature, the substrate material solidifies to create a mechanical bond between the foam and the substrate.
摘要:
A new microfluidic system comprising an automated prototype insulator-based dielectrophoresis (iDEP) triggering microfluidic device for pathogen monitoring that can eventually be run outside the laboratory in a real world environment has been used to demonstrate the feasibility of automated trapping and detection of particles. The system broadly comprised an aerosol collector for collecting air-borne particles, an iDEP chip within which to temporarily trap the collected particles and a laser and fluorescence detector with which to induce a fluorescence signal and detect a change in that signal as particles are trapped within the iDEP chip.
摘要:
A chemical, biological, radiological, and nuclear weapons detection system is disclosed that comprises an array of spatially-disparate hazardous material sensors that all feed into a centralized system control center. This enables the embodiment to receive and coordinate in one place all of the hazardous material sensors spread over a wide area, and, therefore, enables an alarm to be quickly issued in the event of a real attack. To accurately reduce false alarms, the illustrative embodiment requires that at least N of M neighboring stations report an alarm for the same hazardous material within an interval of time, and that the values of at least one of N and M change and are based on at least one environmental factor.