Are used for using the outgoing flue gas heat from boilers, hot-air heaters, furnaces, and so on. Complementary water heaters are designed to increase the efficiency of all types of boilers, but they can also be used as another source of hot flue gas.
It works on the principle of removing heat from the flue gas and transferring it back into the combustion process, i.e. into the combustion air.
The basic element of tubular heaters are tubes. Parallel tubes are connected by means of a so-called tube plate which are steel plates with holes to elongate the tubes in these holes. To the tube plates are welded tubes and together form the bundle. This whole assembly is covered with the steel sheathing. Blowers can be used for cleaning.
As a heat exchanger surface it uses molded plates stacked into bundles. The plates have gaps between them that make up the space for the air flow. Flue gas flows through the cavities in the plates. This whole assembly is covered with the steel sheathing.
It works on the principle of removing heat from the flue gas into the water and from the water transferring it back into the combustion process, i.e. into the combustion air.
The air heater is two blocks. One takes heat from the flue gas and the other transferring the heat to the air needed for combustion. The pressure unit of the air heater is made from finned tubes with the inlet and outlet chamber for each block. This whole assembly is covered with a steel sheathing.
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