Re: Blending Coal In Thermal Power Stations
U may have a chance
At the local port here, they have stockpile dischahrgers with flow control gates and shear gates to blend coal for export...ratio 4:1
U have said what needs to be done.
U may need a small surge hopper and belt feeder to give U the required rate for the HCV coals. The accuracy depends on yr process to handle flucuations
For more mixing, look at the bunker distribution eg chevron??
Cheers
James ■
Re: Blending Coal In Thermal Power Stations
Can you define the goal of blending:
1. Blend to meet the varying load (supply coal i.e., to follow the load that could change between day and night) or
2. Provide a fixed blend to meet the base load operation?
3. What other constraint is to be met (opacity, slagging etc.) by the blends?
4. Also, the domestic coal being cheaper, should its use be maximized?
It is good to know that you are already keeping coals segregated and have the capability to do so with the imported coal as well. I have been involved in installing coal tracking and dynamic blending software at several plants in US. We use Coalogic to track all the coals in the yard to deliver the "target spec" coal to the boiler in real-time. This also includes modeling of the flow of the bunkers so that the blend is actually what should go to the boiler and not just to the bunkers.
Also, our approach eliminates the need for physical pre-blending and uses the dynamic blending concept through modeling. Physical blending is expensive, difficult and reduces the yard flexibilities.
If you have interest, let us discuss further. let us continue the dialog. I would like to see your yard diagram to give you a good assessment of how to handle your problem.
Best regards,
Vas ■
Re: Blending Coal In Thermal Power Stations
If you have a steep shortfall in the local supply then it is prudent to assume that your blending situation is shorterm & you will eventually be mainly dependant on the better imported coal. Your choices then will be whether to upgrade the boilers, just let them burn out or import lower grade coal. Blending relies on the availability of lower grade fuel, in your case anyway. If the local mine cannot supply then someone had not matched the boiler life to the recoverable deposits at the planning/feasibility stage. Something like that. You can only suck it & see. ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Blending Coal
Dear Mr Ravindra,
Sounds like what you propose would work, but while both S/R's are in reclaiming mode wouldn't this restrict any stacking operations that you may like to do at the same time.
We supply static reclaim feeders that are used to blend different coals for feed into power stations.
One, two or more of our reclaim feeders can be used simultaneously to blend coal. Speeds are variable so you could be loading 500tph from one machine and say 1000tph from another.
Our reclaim feeders can be fed by dozer or wheel loaders with capacities up to around 4000 tph.
Our reclaim feeders can also be used as emergency reclaimers when the main reclaim system is inoperative.
If this is of interest to you please take a look at our web site www.stamler.co.uk where you can find a few application examples.
If still interested we would be very pleased to hear from you.
Regards,
Max D Freier
Managing Director European Division ■
Lödige Ploughshare Mixer For Homogenisation Of Coal
Dear Mr. Ravindra,
Lödige has worked for decades in the field of mixing technology.
Lödige is specialized in the production of Ploughshare® Mixers
for mixing bulk materials and our machines are used throughout
the world in almost every brach of industry.
The Lödige Plougshare-Mixers is a synonym for functional mixing.
We delievered more than 15.000 mixers for a wide range of
applications.
The mixing of coal is a well known application for Lödige. For example for the mixing of different sizes of coal together with some oil or dust for the coking plant the Lödige Mixer are in operation.
Attached we send you our flyer of the Lödige Continuous Mixer Type KM-D. This mixer normally works for high capacities. What is
the planned capacity of your project? If it d
Please give us more information about your project and let us discuss if the Lödige Mixer is a good solution for this process.
Please do not hestitat to contact me.
Regards
Markus Becker, Gebrüder Lödige GmbH, Germany ■
Re: Blending Coal In Thermal Power Stations
Mr. Ravindra, my solution to your problem involves the use of our In-Line blender. Our In-Line blender consists of a stack of three Archbrreaking Diamondback (ABD) hopper designed provide a complete blend in one pass through without the use of agitators or other mixing devices. It requires metered feed streams which can come from from your S/R's. The back mixing capability of this approach is minimal. If long time variations in reclaimer rate are an issue, an additional In-Bin blender step can be added to smooth out the variations again in one pass. ABD hoppers are patented (Dr. JR Johanson) and are in coal service primarily in the USA.
If you are interested in discussing this further, please contact me and visit our web site.
Regards,
Lee Dudley
President
Diamondback Technology, Inc.
805-544-3775 x15
805-549-8282 FAX
415-793-1255 cell
ldudley@diamondbacktechnology.com
www.diamondbacktechnology.com ■
Blending coal in thermal power stations
Hello,
This is a query with regard to requirement of blending of coal in existing power stations whose coal handling plants are not designed considering blending.
The power stations are linked to specific mine and coal is brought to the power plant in captive railway system and unloaded in track hopper . Each station has minimum two track hoppers. Coal received is (-)250 mm size. This coal is conveyed to a crusher house where ist size is reduced to (-)20 mm.
After crusher house coal can be conveyed either to stockyard or to boiler bunkers. Coal reclaimed from the stockyard cannot be sent back to the stockyard and can go only to bunkers.
Each power plant has a stockyard with minimum 15 days coal consumption volume. Minimum two nos rail mounted ,travelling, cantilevered boom, slewing and luffing bucket wheel type stacker cum reclaimer operating in conjunction with a tripper are provided over two nos yard conveyors which serve to bring coal to the S/R for stacking as well as receiving reclaimed coal. These two yard conveyors feed coal onto common reclaiming stream of conveyors which carry coal to the boiler bunkers. Essentially ant blending requirement must be met either during the process of stacking or has to achieved during reclaiming. The stockpile cross section is trapezoidal with a base of 37 metres and a height of 10 metres. Minimum four such piles each of 500 metres length are available.
Since there is a steep shortfall in supply of coal from linked mine import of coal may have to be resorted to. The linked coal has a calorific value in the range of 3000-3500 Kcal/kg while the imported coal is likely to have a calorific value of 6000 Kcal/ kg. Since the boiler is not designed to receive such high calorific value coal, there is need to blend it with linked mine coal.
Coal from imported sources will be moved from the port to the power plant by the state railway system. The arrival of rakes by this system cannot be predicted and coal as and when received in rakes either single or bunched will have to be unloaded and sent to stockpile. Hence a planned creation of blended stockpile using chevron or windrow method of linked and imported coal may not be feasible.
What is thought of is to keep 3 piles of linked mine coal and one pile of imported coal and use both S/Rs in reclaiming mode and adjust the capacity in line with blend requirement and feed the reclaimed coal onto the reclaim conveyor which will carry one layer of imported coal with another layer of linked coal (Since both yard conveyors will be feeding a common reclaim conveyor). Now, this reclaimed coal will reach the boiler bunker after passing through 3 transfer points passing through chute work in each transfer point and hopefully getting mixed up reasonably.
Is it likely to work?
Any suggestions.
G. Ravindra ■