Abstract: Embodiments provide a combustion structure that can achieve stable combustion by addressing the aforementioned drawbacks in the prior art such as low flam stability, backfire, deflagration, blockage and/or any other drawbacks. The combustion chamber structure in accordance with the disclosure can include: a grate structure including a first set of elongated components, a fire retention structure including a second set of elongated components. The first set of first elongated components can be arranged along an axial direction within the combustion chamber structure. The second set of elongated components can be arranged along the axial direction in a same direction as the first elongated components. The second set of elongated components can be configured to generate a negative pressure zone within the combustion chamber. The first set of elongated components can form apertures that can be aligned with apertures formed by the second set of elongated components.

Abstract: A heat exchanger in which the main component is formed of a plurality of elongated strips of rigid heat conductive material. The strips are generally transversely aligned and wound into a coil formation in which each of the surfaces of each strip is disposed in facing relation to the opposite surface of an adjacent strip in the coil. Each pair of facing surfaces is ridged to provide passage defining portions and force transmitting portions with certain of the strips having both end edges thereof sealingly secured to the corresponding end edges of an adjacent strip so as to define a longitudinal fluid passage having a coil formation other of the strips have both end edges thereof disposed out of sealing engagement with corresponding end edges of the adjacent strip so as to define a transverse fluid passage.

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: A forced circulation heater equipped with a blower burner is provided with a horizontally extending exhaust gas duct and with a heat exchanger disposed within the exhaust gas duct. The heat exchanger is constructed as a plate block and includes upright water tubes. A storage vessel is disposed above the heat exchanger and heating system header connections and return connections extend directly into the storage vessel. The heat exchanger together with its upright water tubes is incorporated into the horizontally extending exhaust duct to extend over the entire cross section thereof with the tubes of the heat exchanger being connected to the storage vessel.