Corrosion-proof self-preheating coal savers

The utility model is a corrosion-proof self-preheating coal saver, comprising a coal saver, a feed water preheater, a first pipe which is connected with the outlet of the feed water preheater and the inlet of the coal saver, a second pipe which is connected with the outlet of the coal saver and the inlet of the feed water preheater and a third pipe which is connected with the outlet of the feed water preheater, and the outlet of the feed water preheater is also connected with the boiler feed pipe. The utility model takes the boiler feed water as intermediate heat carrier to carry out open type heat exchanging through the pipes between the coal saver and the feed water preheater, the heat carrier enters (low-temperature section)coal saver through the feed water preheater preheating then recover the heat to let the feed water preheater utilize, then the boiler feed water enters the boiler-steam dome or high-temperature section of the coal saver. The utility model makes use of high temperature feed water at the outlet of the(low-temperature section)coal saver to preheat the inlet of the low-temperature feed water by self and the utility model avoids the low-temperature corrosion of the coal saver. The coal saver is run at the non low-temperature corrosion state, so the utility model has long lifespan and low maintenance cost.