Solids transport in flue gas desulfurization system
View Patent ↗A solids transport system for use in a flue gas desulfurization system is disclosed. Flue gas can be recycled from downstream and used as a fluidizing gas for transporting solids between different locations. Exemplary systems include fluidization slide gravity conveyors, fluidization pads in bins, and in hoppers. The flue gas is generally already at an elevated temperature, reducing power consumption needed to heat the fluidizing gas.
1. A flue gas desulfurization system, comprising:
a main flue gas path that extends through an absorber vessel, a particle collection device downstream of the absorber vessel, and a stack;
a solids transport system for recycling solid alkaline particles from the particle collection device to the absorber vessel, the solids transport system including at least one fluidized surface, wherein the at least one fluidized surface is created using flue gas, or a combination of flue gas and fluidization air, such that the capacity of at least one air heater and/or at least fan/blower is reduced or is eliminated; and
a flue gas recycle path having at least one take-off point that sends flue gas from the main flue gas path to the solids transport system, the flue gas being used as a fluidizing gas to produce the at least one fluidized surface.
2. The system of claim 1 , wherein the at least one take-off point is located upstream of the absorber vessel in the main flue gas path.
3. The system of claim 1 , wherein the at least one take off point is located downstream of the absorber vessel and upstream of the particle collection device in the main flue gas path.
4. The system of claim 1 , wherein the main flue gas path includes a fan downstream of the particle collection device and upstream of the stack.
5. The system of claim 4 , wherein the at least one take-off point is located downstream of the particle collection device and upstream of the fan in the main flue gas path.
6. The system of claim 4 , wherein the at least one take off point is located downstream of the fan and upstream of the stack in the main flue gas path.
7. The system of claim 1 , wherein the main flue gas path includes an air preheater that is downstream of a boiler and upstream of the absorber vessel, and the at least one take-off point is located upstream of the air preheater.
8. The system of claim 1 , wherein the solids transport system includes a slide leading from the particle collection device, the slide having the at least one fluidized surface.
9. The system of claim 1 , wherein the solids transport system includes a distribution bin that receives recycled solid particles from the particle collection device, the wherein at least one fluidized surface being located in the distribution bin.
10. The system of claim 1 , wherein the solids transport system includes a slide leading from the particle collection device to a distribution bin, the slide and the distribution bin each having a fluidized surface.
11. The system of claim 1 , wherein the solids transport system includes a hopper, the hopper having a fluidized surface.
12. The system of claim 1 , further comprising an air stream that is mixed with the flue gas recycle path so that a mixture of flue gas and air is used as the fluidizing gas.
13. The system of claim 1 , wherein the flue gas recycle path has a plurality of take-off points.
14. A method for recycling solid particles in a flue gas desulfurization system that has a main flue gas path extending through an absorber vessel and a particle collection device downstream of the absorber vessel, comprising:
separating solid particles from clean gas in the particle collection device;
recycling solid alkaline particles from the particle collection device to the absorber vessel using a solids transport system that includes at least one fluidized surface, wherein the at least one fluidized surface is created using flue gas, or a combination of flue gas and fluidization air, such that the capacity of at least one air heater and/or at least fan/blower is reduced or is eliminated;
wherein recycled flue gas is sent from the main flue gas path to the solids transport system through a flue gas recycle path comprising at least one take-off point, and the recycled flue gas is used as a fluidizing gas to produce the at least one fluidized surface upon which the solid particles travel.
15. The method of claim 14 , wherein the at least one take-off point is located upstream of the absorber vessel in the main flue gas path.
16. The method of claim 14 , wherein the at least one take-off point is located downstream of the absorber vessel and upstream of the particle collection device in the main flue gas path.
17. The method of claim 14 , wherein the main flue gas path includes a fan downstream of the particle collection device and upstream of a stack.
18. The method of claim 17 , wherein the at least one take-off point is located downstream of the particle collection device and upstream of the fan in the main flue gas path.
19. The method of claim 17 , wherein the at least one take-off point is located downstream of the fan and upstream of the stack in the main flue gas path.
20. The method of claim 14 , wherein the solids transport system includes a slide leading from the particle collection device, or a distribution bin that receives recycled solid particles from the particle collection device, or a fluidized hopper, and wherein the at least one fluidized surface is located in the slide, the distribution bin, or the hopper.
21. The method of claim 14 , further comprising the step of mixing the recycled flue gas with air to form a mixture of flue gas and air that is used as the fluidizing gas.
22. The method of claim 14 , wherein the flue gas recycle path has a plurality of take-off paths.
23. A flue gas desulfurization system, comprising:
a main flue gas path that extends through a circulating dry scrubber absorber vessel, a particle collection device downstream of the absorber vessel, and a stack;
a solids transport system for recycling solid alkaline particles from the particle collection device to the circulating dry scrubber absorber vessel, the solids transport system including at least one fluidized surface, wherein the at least one fluidized surface is created using flue gas, or a combination of flue gas and fluidization air, such that the capacity of at least one air heater and/or at least fan/blower is reduced or is eliminated; and
a flue gas recycle path having at least one take-off point that sends flue gas from the main flue gas path to the solids transport system, the flue gas being used as a fluidizing gas to produce the at least one fluidized surface.
24. The system of claim 23 , wherein the at least one take-off point is located upstream of the circulating dry scrubber absorber vessel in the main flue gas path.
25. The system of claim 23 , wherein the at least one take-off point is located downstream of the circulating dry scrubber absorber vessel and upstream of the particle collection device in the main flue gas path.
26. The system of claim 23 , wherein the main flue gas path includes a fan downstream of the particle collection device and upstream of the stack.
27. The system of claim 26 , wherein the at least one take-off point is located downstream of the particle collection device and upstream of the fan in the main flue gas path.
28. The system of claim 26 , wherein the at least one take-off point is located downstream of the fan and upstream of the stack in the main flue gas path.
29. The system of claim 23 , wherein the main flue gas path includes an air preheater that is downstream of a boiler and upstream of the absorber vessel, and the at least one take-off point is located upstream of the air preheater.
30. The system of claim 23 , wherein the solids transport system includes a slide leading from the particle collection device, the slide having the at least one fluidized surface.
31. The system of claim 23 , wherein the solids transport system includes a distribution bin that receives recycled solid particles from the particle collection device, the at least one fluidized surface being located in distribution bin.
32. The system of claim 23 , wherein the solids transport system includes a slide leading from the particle collection device to a distribution bin, the slide and the distribution bin each having a fluidized surface.
33. The system of claim 23 , wherein the solids transport system includes a hopper, the hopper having a fluidized surface.
34. The system of claim 23 , further comprising an air stream that is mixed with the flue gas recycle path so that a mixture of flue gas and air is used as the fluidizing gas.
35. The system of claim 23 , wherein the flue gas recycle path has a plurality of take-off points.