Abstract: A natural or LP gas-fired laminated griddle top structure providing an even distribution of heat over its cooking surface is disclosed. The griddle top includes an upper plate formed from a relatively thick iron or steel plate and a plurality of relatively thick lower plates formed from a dissimilar material having a high thermal conductivity. A thermal break is provided between adjacent lower plates and each lower plate has a channel provided therein for the receipt of a temperature sensing device. In addition, laterally extending grooves are provided in the bottom surface of the lower plates increasing the resulting heat transfer surface improving the thermal efficiency of the griddle top. One or more natural or LP gas-fired burners and associated controls are provided adjacent each lower plate permitting the entire cooking surface to be maintained at the same temperature or portions thereof to be maintained at different temperature, if desired.

Abstract: Both an apparatus and method are provided for vaporizing a liquid cryogen and super heating the resulting vapor into a heated gas. The apparatus includes a combustion-type heat source which may burn a fuel such as propane that generates water-containing combustion gases, and a vaporizer coil having an inlet conduit for receiving a flow of a liquid cryogen, such as liquid carbon dioxide, and an outlet conduit for expelling vaporized cryogen. An annular casing surrounds but is spaced apart from the vaporizer coil. The casing isolates the vaporizer coil from contact with water-containing combustion gases generated by the heat source, thereby preventing the formation of unwanted water and ice on the coil, while at the same time transferring heat from these gases to the coil by thermal radiation. A superheating coil is serially connected to the vaporizer coil to further heat the vaporized cryogen.

Abstract: A fluid heater and method are disclosed for heating a heat transfer fluid flowing within a heater tube using reradiative and convective heat transfer while avoiding direct flame impingement on the heater tube. The heater tube is separated from the flame by a heat shield that cools the flame temperature and reradiates heat energy to the heater tube. The combustion products are directed around the shield and into contact with the heater tube.

Abstract: A compact heat exchanger for a fuel-fired heating furnace. The heat exchanger has a radiative heat transfer section including at least one firetube for containing flue gases as the air to be heated passes over the firetube and a convective section including a shell-and-tube heat transfer apparatus arranged to receive flue gases from the firetube in the shell region and the air to be heated after it passes over the firetube in the tubes.