Wagon tippler Arrangement

For coal handling plant wagon tippler arrangement is provided in most of the power plants where bottom discharge wagon are not feasible

Wagon tipplers are at present are available to unload 20 tips per hour of 55 ton capacity wagons

Below plow feeder either vibrating feeders or apron feeder is provided based on lump size and hopper bottom opening

For hauling wagons either beetle charger or side charge armers are provided

Hopper length in case of wagon tippler is of 13000 m and 6 m wide

Generally two wagon tipplers are provided one on each side of hopper

In case of wagon tippler hopper depth goes up to 10/11 metres below rail level

It is very difficult to give cost idia of this system as RCC quantity / unit rates varies from location to location .

However average cost of system having 2 wagon tipplers , two side arm charger with RCC hopper , dust suppression system , electrical controls etc shall be in range of 5.5 million US dollars

Dear Banerjee

It is very difficult to give cost idia of these two systems . As i was involved in power plant consultancy where i was evaluting both systems i am giving you some rough idia. More over cost depends upon various other systems and project requirements

Track hopper system

At pit head power plants marry go round system is provided

Wagon is unloaded while moving with slow speed on to 100-150m long track hopper

Below track hopper plow feeder arrangement can be provided to unload ooal to coal conveyors.

In most of power plants where track hopper is provided two nos of plow feeders with two nos of unloading conveyors are provided in India.

In case of plow feeder track hopper depth is restricted to 6-7 meters .

The best plow feeders I have used is of Louise west Germany make rotary discharge machine

However average cost of system having 100 meter long hopper , two Louise make plow feeders of 1200 tph capacity , dust suppression system , electrical controls etc shall be in range of 5.0 million US dollars

cheers

A R SINGH ■

Mr Banerjee

First of all you pl findout whether bottom discharge wagons will be available or closed will be available for this project. for giving cost idea complete information is required

for example

unloading rate from wagons required

how much maximum coke will be required per day

what is conveyor capacity below track hopper/ w t hopper

what systems to want to include while comparing prices

lot of civil work is rquired for cost estimation soil bearing capacity and water table is must for detailed cost estimates

A R SINGH ■

Dear Shri Banerjee,

Presently, I do not have direct answer to your question about the relative cost of the two systems. However looking at 350m length of the track hopper, possibly you may find it expensive.

In our country many times, the type of wagons which can be made available / committed is decided by the Railway Authorities, in view of transportation work pressure. As you are analysing for both the type of wagons, it implies that the Railway Authorities have given you green signal that you have freedom to get the coke in bottom discharge wagons as well as in regular wagons. Such choice is rarely given by the Railways for other items like coal, etc to maintain committed continuity of supplies. I hope you have already checked on this point.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Dear Mr banarjee

In case you are considering single conveyor below track hopper you can provide two conveyors below track hopper to reduce the length of hopper.

A R SINGH. ■

Dear Shri Banerjee,

I presume you will be familiar with NTPC use of bottom discharge wagons in a merry-go-round arrangement. In this system, the track hopper length is quite small. I do not remember the exact figure but it is somewhere around 125 m or so. In this system, the wagons are fitted with automatic gate opening system. The gate operation i.e. opening and closing is actuated by mechanism (rail) along the track. In this system, when a wagon of the rack enters on track hopper, it’s gate will be opened automatically. Simultaneously, the rack is moving at slow speed. The speed is such that when the wagon travels from entry point to the exit point of track hopper, the contents of the wagon gets discharged automatically by gravity. Thus in this system, the time taken by wagon rack to get unloaded is short, just the passage time of entire rack over track hopper. This system is being extensively used by NTPC in India. If need be you can get the exact information by seeing the NTPC nearby installation.

In the event if you do not intend to have such tailor made unloading system for wagons, then please mention how you intend to open the gates and unload the wagons. Suppose if you plan to do this manually, the track length need not be so long. If I consider rack of 40 wagons its length will be approximately 548 m, so if you decide to unload this in 3-position activity, i.e. firstly you are positioning 1/3rd of rack on track hopper. Then count the time interval for opening and closing the gates in accordance with the number of people you are employing to do this function. Then, position the successive portion of the rack and add up all the time. Then check whether this total time is less than 3 hours. One third of rack length is 183m, i.e. hopper of say 190 m will be necessary in above analysis.

For unloading purpose, one can deploy two persons (one on each side) at the rear end of segment and two persons (one on each side) at the forward end of segment. Both these teams can start operating and closing the gate towards the center. It would be inconvenient to elaborate this procedure further here. In case you deploy double the strength, then you can further reduce the unloading time.

It would be inconvenient to further elaborate this procedure but it appears that you may need hopper length which is remarkably less than 350m length. The shunting locomotive remains attached (available) as soon as one section of rack is unloaded and for repositioning (pulling forward) the entire rack by hopper length.

If need be you can communicate to me by email.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Dear Mr Banerjee

For opening bottom discharge wagons you have to open wagon gates by line side equipment

Open hopper car with rapid (pneumatic) bottom discharge doors, air-braked. BOBRN and BOBR are most often used for carrying coal to thermal power plants, and also for stone, track ballast, etc. Each wagon holds some 60t of coal loaded from the top and unloaded from the bottom by means of the pneumatically operated doors.

The door-opening mechanism is triggered by lineside devices running on a 24DC source. As the wagons in a rake pass by the triggering devices, their doors open and their contents are unloaded into the hopper below the tracks (the 'merry-go-round' system). The versions used by the power plants have 12 bottom doors, whereas IR uses variants that have 8 doors.

·Tare: 25.6t

·Payload: 55.68t, 57.2m3

·Length over headstock: 9.671m

·Height: 3.735m

·Width: 3.5m

As explained By Mr mulani 125 m long track will be suitable for emptying 50-55 wagons in 3 hours time.

your unloading conveyor rate from hopper should be 1200 tph to symultanously empty the hopper

A R SINGH ■

# Average time required to finish unloading of 58 wagons (rack length 720 meter) having track hopper length around 210 meter with automatic gate opening system.

# Average moving speed required ?

Please forward your comments... ■

Dear Rajesh

Wagon is unloaded while train moves over the track hopper at slow speed say about at 5km /hour

Train speed will be function of unloading rate and time

Unloading hopper lenght needs to suit wagon dump time vs speed plus extra for door opening

Hopper capaicty needs to be at least two times the Rake capacity

In case you consider 790 m train length it will pass over the 210 m long track hopper at speed of 5km/hour in 12 minutes

The main important point is your hopper shall have enogh capacity to unload coplete rake

A R SINGH ■

Thanks Mr. A R Singh ■

Originally Posted by rajesh29rathod

# Average time required to finish unloading of 58 wagons (rack length 720 meter) having track hopper length around 210 meter with automatic gate opening system.

# Average moving speed required ?

Please forward your comments...

I am a latecomer to this forum,but when this subject is seen I want to add,

There are track hopper systems in India, just 4 wagon length,unloading 58 wagons of thermal coal int 40mts to one hr.

Below the the hopper Belt feeder has been provided and the system designed for 20million tons per/annum is working satisfactorily for the last 12 years.

Rgds,

Narayanan Nalinakshan ■