Re: Looking For Dust-Controlled, Drive-Over Lime Hopper
Dear KenPavlich,
Your requirement / problem is not clear from your description. Please describe in more detail to look for possible solution. ■
Drive-Over Lime Hopper
Dear Ken,
A typical and commonly used solution is to equip the dump hopper with Burnley baffles. If you are not familiar with this device, it consists of an array of hinged baffles, mounted below the road grid, which allow the passage of the dumped material but resrict the outward flow of displaced air. The system is used in conjunction with dust control exhaust (located below the baffles) and is very effective when used properly.
The hoppers must be designed to have sufficient freeboard above the dust collection ducts so that they are not submerged by dumped material. (Truck drivers tend to dump their full load as quickly as possible and fill the hopper above the road grid). Bottom dumped rail wagons are generally better controlled. A web search will probably get you in touch with the supplier. There is a similar product called Flex-flow supplied by Torit-DCE.
Good luck,
Michael Reid. ■
Re: Looking For Dust-Controlled, Drive-Over Lime Hopper
I agree with Michaels comment using the baffle system. There is a caveate. The fast dump cycle will cause a lot of gas displacement. The baffles, being held open for flow, can allow pressurized gas to escape. Therefore, the free cavity must be of sufficient size.
I assume the B-Baffles are mounted horizontally. A study of the gas vector and magnitude is instructive. Vertical baffles can give further aid, but require added free space.
Lawrence Nordell
Conveyor Dynamics, Inc.
www.conveyor-dynamics.com ■
Penta Industrial Corporation
Please refer to www.penta.net for modular drive over dump arrangements for the outlined situation.
We can adapt the standard equipment for your application and criteria.
Benjamin Cardwell
Product Manager ■
Re: Looking For Dust-Controlled, Drive-Over Lime Hopper
We have been installing several of the requird unloading systems already including the dust supression equipment.
We do not have modluar systems for this type of application but can adapt an existing plant arrangement easily.
Youcan contact me anytime under
mobil phone: +43 664 20 21 695
Email: w.zieri@fmw.co.at
Email: wizi@aon.at ■
Re: Looking For Dust-Controlled, Drive-Over Lime Hopper
In my view you should use pneumatic conveying from the truck dump hopper to the silo or to the final destination. The conveying rate of this pneumatic conveyor can be as high as you need. This will be a much simpler system than the mechanical system that you are thinking of.
Regards,
Amrit Agarwal
Pneumatic Conveying Consultants
www.powderandbulk/pcc.com ■
Dust Controlled Drive-Over Hopper
Road dump unloading is very quick, typically less than 5 mins. per truck. If you have several 40 tonne trucks lined up to empty, you will need a conveying system capable of more than 500 t/h.
Michael Reid. ■
Re: Looking For Dust-Controlled, Drive-Over Lime Hopper
500 tons/hr = 1MM lbs/hr is not impossible for pneumatic conveying , but such a huge conveying rate may not be needed.
Belt and bucket conveyors are ancient technologies, should be avoided if at all possible.
Amrit Agarwal
Pneumatic Conveying Consultants ■
Re: Looking For Dust-Controlled, Drive-Over Lime Hopper
Ken,
I have witnessed a cement truck unloading in less than 3 min with a 35 ton payload using a closed circuit bottom dump. The truck discharge system was not optimized (ie horizontal bottom).
The bottom dump previously used a pneumatic extraction which took over 5 min.
The client is modifying the truck bottoms to enhance the rate. They expect the discharge rate may be in the range of 2-2.5 min or about 15t/m. Thus, your 40 t would discharge in about 2.7-3 min.
The dump discharge is sealed.
The design details can be obtained.
The belt feeder/screw/airslide can/do feed the bucket elevator with the rate you suggest.
An incline belt/high angle conveyor will be costly especially at the low tonnage. If you make it a high tonnage, but momentary, then the per average tonnage cost will be even higher.
We have the skills to model the solid and gas flow mechanics in bins and chutes as well as bucket elevators......
Lawrence Nordell
President
Conveyor Dynamics, Inc.
www.conveyor-dynamics.com
email: nordell@conveyor-dynamics.com ■
Re: Looking For Dust-Controlled, Drive-Over Lime Hopper
Ken,
Update correction on my previous response.
The pneumatic flow rate was 35 t/ 35min not 35 t/ 5 min. The increased rate with the new unloading system in 10 times the pneumatic system and uses less power.
There is no receiving hopper and no dust.
Sorry for the confusion.
Lawrence Nordell ■
Looking for dust-controlled, drive-over lime hopper
I am working with a client who has two sites that each receive about 200,000 tpy of pebble lime via pneumatic trucks and pneumatic transfer into 1,000 ton storage silos. We are investigating the possibility of reducing truck cycle time by moving away from pneumatic discharge to bottom dump hopper trailers.
We believe that this will require a covered, or possibly even enclosed drive-over, bottom dump arrangement. In order to control fugitive dust during discharge into the drive-over hopper, I suspect that the hopper, or at least the space between the truck's discharge doors and the grizzley, will require some dust control equipment. The system would of course include a hopper discharge feeding a covered conveyor capable of emptying the 40 ton hopper into the silo before the next truck is in position to discharge. In one case the conveyor would simply be an inclined conveyor to the top of the silo, and in the other case there would be a requirement to use either a bucket elevator or pneumatic conveying. I am requesting contacts of individuals or companies that might be able to help us fast-track this project. Specifically, are there firms that have modular systems that could be used in this application? ■