Alstom Sizhou has been researching and developing dry slag handling system for fluidized bed boiler since 1994. So far, its products have been applied by nearly one hundred users for over 200 sets of their fluidized bed dry slag handling system, including the whole set of equipments for slag cooling, conveying, storage and discharging etc. Design, manufacture and operation experiences of more than 200 sets of equipments pave a good way for R&D of coal powder boiler dry slag handling system.  
Advantages of Dry Slag Handling  
Heat remains of bottom slag can be reclaimed; it is possible for incomplete combusted substances to go on burning with heat reclaimable;  
Water conservative and environment friendly as there is no water consumption in the course of slag cooling and conveying-environmentally and water saving;  
Ash/slag can be combusted completely with low content of carbon, which reserved the activity of the slag for its comprehensive utility;  
The system is simple without follow-up ash/water handling system;  
There is no trouble of dry slag to be frozen, even in cold area of the north;  
Many kinds of follow-up conveying are applicable and adaptable for various complex fields.  
Working Principle of Air Cooling Dry Slag Handling System  
This system is for the continuous operation of air cooling dry slag remover. Hot slag falls down the conveying belt of slag remover and conveyed at a low speed on the conveying belt. Under the negative pressure( as far as the coal powder boiler concerned, the normal operation is in negative pressure), controlled few ambient cool air enters into the air cooling dry slag remover conversely, and the ash slag is gradually cooled and combusted completely. After sufficient heat exchange between cool air and hot ash/slag, the air absorb the heat generated by boiler radiation and ash/ slag and rise to about 300～400℃(equals to secondary venting temperature of boiler) and enter into the hearth, while the slag temperature reduces to about 100 ℃  
   Generally speaking, impact on the boiler air intake from cooling air flow is  controlled within allowable surplus coefficient of the air, so the hot air after temperature raise shall be transferred to hearth and will not affect the normal operation of the boiler. However, if it asks highly for the boiler air surplus coefficient, hot air may be transferred to the air feed system of boiler for reuse

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