As the most common type, it is used for liquid-to-liquid, gas-to-gas and gas-to-liquid heat exchange. The hightemperature fluid comes in through the inlet, located in center of the main body, to flow from outside to the inside. Due to this counter flow, high-efficiency heat exchange is available and can be used for a tiny difference in temperature. Any type of installation (vertical or horizontal) is possible according to the usage. This type is suitable for reboilers and evaporators for all kinds of fluid especially in the vacuum status and a lowpressure condition. The flow rate of air is maintained at a proper level even for a large volume, and the pressure loss is minimized. It can be used for multi purposes by vertically connecting three units in a row. This type is suitable for cooling and heating of gas and the condenser for processing large-volume gases (at a low pressure or vacuum) and mixture of gas and/or liquid. The low-temperature fluid comes in through the inlet, located on the side of the main body, to flow to inside along the spiral fluid passage while the high-temperature fluid comes in through the top and vertically flows to the bottom. The both ends of the heat transfer plates on the side of the low-temperature fluid passage is blocked by welding, and the high-temperature plates are all opened. In most cases, this type of heat exchanger is installed vertically, but horizontal installation is also available according to the usage. This type is mostly used for the liquid-vapor exchanges such as heaters, coolers and condensers, and has wide range of use. The low-temperature fluid comes in through the side of the main body to spirally flow into the inside while the high-temperature vapor comes in through the top. And the flowed-in air is distributed evenly to the front and center parts of the opened spiral-typed fluid passage, which generates combined flow in the spiral and axis directions. The condensed liquid and the non-condensed gas are discharged separately to different outlets. The condenser on the top can be installed on the top of column or the reactor of kettle without piping work as the size of the connection part of the inlet for incoming vapor can be adjusted according to the size of the outlet to which the spiral-typed heat exchanger. Air comes into the pipes of the center to be divided into the spiral flow, axial flow and/or mixture of the two types of flow. The cooling fluid comes in through the surface of the main body to spirally flow into the center, and discharged through the top. The condensed liquid is generated in the main body or collected in the condensed liquid-collecting part of the main body.