The heat exchanger (10) includes a ceramic matrix composite (12) (stable at temperatures up to 1,650 C.) surrounding and defining a hot fluid conduit (14). A hardenable material (18) having a high thermal conductivity is formed into a heat transfer layer (16) surrounding the ceramic matrix composite (12). A metal pipe (20) is coextensive with the heat transfer layer (16) and defines at least a portion (22) of at least one cool fluid passage (24, 34, 54) defined adjacent to and in heat exchange relationship with the heat transfer layer (16) so that a fluid passing through the cool fluid passage (24, 34, 54) absorbs heat passing through the heat transfer layer (16) from the hot fluid passing through the hot fluid conduit (14).

A heat exchanger includes an inner tube extending longitudinally along a central axis and having an inner surface bounding a product chamber and an outer surface having a plurality of channels disposed at circumferentially spaced intervals in alternating relationship with a plurality of fins about the circumference of the outer surface of the inner tube; and a longitudinally extending outer tube disposed coaxially about and circumscribing the inner tube in radially spaced relationship, the outer tube having an inner surface contacting the plurality of fins of the inner cylinder, the outer surface being welded to the fins at a plurality of weld locations.

A heat exchanger includes a bundle of tubes, which can be inserted into a tubular housing. Exhaust gas can flow through the tubes. A coolant duct can be arranged between the tubes. The bundle of tubes can have at least one grid-like securing structure which supports the bundle in the housing. The behavior of the heat exchanger with respect to vibrations is affected by outwardly curved metallic springs attached to the bundle of tubes which may be deformed in the opposite direction to the insertion direction of the bundle into the housing. The spring force is directed against the housing in order to dampen vibrations. The heat exchanger can also include an elastic device for permitting a change in length caused by temperature changes.

A flame cell of a flame arrestor may include a body of a first material having a first end, a second end, and a plurality of channels formed in the body and extending from the first end to the second end of the body. The flame cell may also include an element of a second material coupled to the body, the second material being different from the first material. The element may be configured to draw heat away from fluid flowing through the plurality of channels.

The heat exchanger (10) includes a ceramic matrix composite (12) (stable at temperatures up to 1,650 C.) surrounding and defining a hot fluid conduit (14). A hardenable material (18) having a high thermal conductivity is formed into a heat transfer layer (16) surrounding the ceramic matrix composite (12). A metal pipe (20) is coextensive with the heat transfer layer (16) and defines at least a portion (22) of at least one cool fluid passage (24, 34, 54) defined adjacent to and in heat exchange relationship with the heat transfer layer (16) so that a fluid passing through the cool fluid passage (24, 34, 54) absorbs heat passing through the heat transfer layer (16) from the hot fluid passing through the hot fluid conduit (14).

Provided are a method and apparatus for reducing a refrigerant pressure difference within an HVAC system having a controller, one or more compressors, and at least two paths of refrigerant piping comprising alternative paths for refrigerant flow through the HVAC system. A valve is coupled to each refrigerant piping path for permitting, or preventing, refrigerant flow through each of the alternate paths of refrigerant piping. The controller may open at least one valve for a defined period of time in response to a triggering input to allow a refrigerant pressure difference within the HVAC system to dissipate across the opened valve.

A heat transfer element includes curved mounting surfaces configured to mate with an outer surface of a pipe for attachment thereto; and a channel configured to receive a tracer therein. The heat transfer element is configured to effect conductive heat transfer from the tracer to the pipe, or to process flowing through the pipe, when attached with heat transfer cement (HTC) to both the pipe and the tracer. A system includes a pipe and a tracer; HTC; and a heat transfer element having curved mounting surfaces configured to mate with an outer surface of the pipe and attached thereto via the HTC, and a channel in which the tracer is received and secured via HTC. The heat transfer element is configured to effect conductive heat transfer from the tracer to the pipe, or to process flowing through the pipe, when attached with HTC to both the pipe and the tracer.

A split air conditioner has a cabinet with a fan and evaporator for mounting within a structure. The cabinet includes one or more movable dampers or movable filters positioned in the flow path between the air inlet and the outlet for selectively filtering contaminants from the air to provide a greater or lesser degree of filtration of the air. The movable filters include sliding and/or pivot mounting structure which may accommodate stacking multiple filters with different filtering characteristics. The system may operate in a filtering only mode with no cooling, a cooling only mode with no filtering, or a combination of cooling and selective filtering.

A heat transfer element includes curved mounting surfaces configured to mate with an outer surface of a pipe for attachment thereto; and a channel configured to receive a tracer therein. The heat transfer element is configured to effect conductive heat transfer from the tracer to the pipe, or to process flowing through the pipe, when attached with heat transfer cement (HTC) to both the pipe and the tracer. A system includes a pipe and a tracer; HTC; and a heat transfer element having curved mounting surfaces configured to mate with an outer surface of the pipe and attached thereto via the HTC, and a channel in which the tracer is received and secured via HTC. The heat transfer element is configured to effect conductive heat transfer from the tracer to the pipe, or to process flowing through the pipe, when attached with HTC to both the pipe and the tracer.

A heat transfer element includes curved mounting surfaces configured to mate with an outer surface of a pipe for attachment thereto; and a channel configured to receive a tracer therein. The heat transfer element is configured to effect conductive heat transfer from the tracer to the pipe, or to process flowing through the pipe, when attached with heat transfer cement (HTC) to both the pipe and the tracer. A system includes a pipe and a tracer; HTC; and a heat transfer element having curved mounting surfaces configured to mate with an outer surface of the pipe and attached thereto via the HTC, and a channel in which the tracer is received and secured via HTC. The heat transfer element is configured to effect conductive heat transfer from the tracer to the pipe, or to process flowing through the pipe, when attached with HTC to both the pipe and the tracer.