2.8.5 Flushing Apparatus
Eighteen Nos per unit Apparatus Flushing Boxes of capacity 2.5 T/hr. for Eco. Hopper, 1.25 T/hr for Eco. Hopper bypass and 2.5 T/hr for Air Preheater Hoppers shall be designed to effectively transport the ash in slurry form to slurry pipe/trench.
The flushing apparatus shall be provided with jetting nozzles at strategic points, in order to form thorough slurry and to prevent the ash particles from settling. The ash slurry formed shall be led to an intermediate transfer tank through an adequately sized discharge/over flow pipe.
The design shall ensure a water seal against atmospheric air leakage into economizer ash hoppers at the time of ash removal. Approx. 260 mm water seal will be maintained, however the exact figure shall be known after the Boiler supplier is finalised and confirmed to successful bidder.
The dimensions of different parts shall be designed for the intended service with sufficient margin. The flushing apparatus shall be installed under the economizer hoppers at elevations. The temperature of ash at economizer ash hoppers is 350°C.
Flushing apparatus shall be provided with necessary steel support base, insert plates etc. for mounting installation.
The material of construction of various parts shall be as follows:
|
Body |
10 mm thick M.S. to IS:2062 |
|
Liners |
8 mm thick replaceable stainless steel liners of hardness 300-350 BHN. |
|
Nozzles |
Body :Cast Iron/Mild Steel |
|
|
Tip steel of: Anti corrosive steel tool /stainless hardness not less than 550 BHN. |
shivajichoudhury
