Silo with Screw conveyor to transport Desulfurization ash

- Oct 24, 2019-


The desulfurization ash is composed of :

(1)  desulfurizer slaked lime Ca(OH)2,dry powder,purity ≥90%,particle size about 300 mesh to 500 mesh, bulk desntiy is 0.4t to 0.5t/m3,temperature is ambient,moisture is ≤2%.

(2) The main components of the circulating ash are calcium sulfate, calcium sulfite, calcium carbonate and unreacted slaked lime produced by the desulfurization reaction of slaked lime, and waste ash from a small amount of glass furnace (burning natural gas or heavy oil), dry powder, bulk density 0.3t ~ 0.8t / m3; material temperature: 200 ~ 350 ° C; flue gas moisture content of about 5% ~ 10%.

Technical requirements :

1. Sealing is Skeleton oil seal + air sealing +Graphite packing.

2. Sealing gasket is glass fiber.

3. Screw blade is made of WNM400 which is equal to HARDOX450, thickness 8mm;

4. The silo’s shell thickness is 6mm which is made of 16MN,reinforcement plate is 6MM and made of Q235B.

5. Silo’s flange thickness is 16mm.Silo volume is 11m3,diameter 2.2m.

6. Screw inner shaft is 16MN.

7. Screw shell thickness is 6mm which is made of 16MN.

8. There set up one piece of expansion joint.

9. Need one piece of manual slide valve ,size is DN400.

10. Surface painting color is RAL9006.

Working principle :

After the silo with conveyor  is put into operation, it is connected with the cyclone separator. The temperature of the flue gas in the separator is about 320-400 ° C, and the negative pressure is about -1000-2500 Pa. The circulating desulfurizer ash is rotated by the cyclone into the circulation silo, and then uniformly returned to the desulfurization tower by the circulating screw conveyor to desulfurize again. The circulating feed screw conveyor is a twin shafted screw conveyor which is controlled by the frequency converter. In the automatic input state, the start and stop of the lower screw  conveyor is controlled by the low level signal, and the start and stop of the upper screw conveyor is controlled by the high level signal and the feed pump valve signal of the pneumatic ash conveying system.