Happy Belt Feeders
Hi Harish kumar R,
Good Question. As I understand it the situation is as follows
1 - What comes in must equal what goes out. That is OK for a belt conveyor. But what is a "belt feeder"? To my mind it is a short conveyor belt which runs in a flooded condition.
2 - With a "belt feeder coveyor" what goes in may not always be what comes out? What is above the belt feeder, it's feeding geometry? How well does the coal product flow? I have run flooded feeders directly onto the main belt conveyor running at some 1.5 m/s.
3 - The catalogue say belt feeders are designed to run at an average 0.6 m/s. Does that mean special feeders cannot be run faster than that.
My gut feel is that the feeder is a critical item of plant performence. If you are not sure of how to handle the design then I would strongly urge you to pay someone with experience to do the job for you. The risks of an inadequate feed rate are too high for a "do it yourself" approach.
Talk to the Technical Department of some Vendors. They will be pleased to response to your telephone or email enquiry.
Also talk to Maintenance Engineers at other Coal Handling facilities near you. The will not harm you. Most will be happy to give you some useful tips.
But at the end of the day - you must take the responsibility. Are you sufficiently confident to take the risk. ■
Belt Feeder Design Considerations
Harish kumar R,
While my response may be too late to help with your application, I thought I would respond for anyone with a similar issue in the future. Note that feeding coal, or any other
A belt feeder is normally a conveyor to which devices and/or sensors are applied to control or modulate the amount of material being fed into a downstream process. I am going to make the assumption that you will controlling the speed of the belt and resulting throughput (Feedrate) of the feeder based on a signal from a weighing device in the conveyor. If this is a volumetric application and no weighing device is present, my response may not be as useful.
Some of the factors which affect the maximum belt speed for an accurate and repeatable belt feeder include:
Weigh Span - This is the theoretical area where the material is being weighed. In theory, the longer the weigh span length, the faster the belt can travel.
Integrator/Controller - The sample rate and resolution of this device will influence the maximum belt speed also. The faster the control device can sample the weight signal the faster the belt can run.
Speed Encoder/Sensor - This device will send pulses or other type of signals to the Control Device in order to determine the amount of belt travel and belt speed. The mounting location of the Encoder/Sensor is important as the diameter of the pulley or idler the sensor is mounted to affects the RPM of this device. The resolution (typically pulses/second) will also affect the maximum belt speed.
Material Handling - To make the task of controlling the feedrate easier, the belt loading should be as consistent as possible. This normally requires a source of material that is always present in an infeed and a method to shear the material to a consistent profile on the belt. If there are gaps in the material on the belt or peaks and valleys, the resulting control and accuracy may not be as good. In addition, if the belt speed is too fast, this can result in too thin a layer of material on the belt causing weighing errors.
At a minimum, a feeder requires good material handling, an accurate weighing system, an accurate belt travel detection system and an intelligent control algorithm for it to operate correctly. The belt speed is a critical design value that affects all of these criteria. There are some very good belt feeder companies who provide professional services to modify conveyors to make them belt feeders. As mentioned by another person, this can be a critical part of the process and should be considered very carefully.
Merrick Industries offers proposals at no charge to turn conveyors into weigh belts or weigh belt feeders. We offer drop-in weigh modules and consider all of the factors above and can evaluate your conveyor design for a possible weighing application. We also offer customer designed weigh belt feeders for most applications.
Merrick Industries, Inc. Merrick Info E-mail ■
Re: Maximum Speed For Belt Feeders
Thank you very much for your time Mr. John and Mr. Shagndink ■
Maximum Speed For Belt Feeder
Dear Mr. Harish,
If you say belt feeder then you have to ristrict the speed at 0.5 m/sec. You cannnot use 35 deg. troughing idler. You can use long centre roller with small side roller with 20 deg. troughing along with very high skirt to get desired capacity.
As it is belt feeder I presumed that it is located below the hopper & it has to take care of the following.
1. Column load of hopper.
2. Shear force to run the feeder.
Regards.
A.Banerjee ■
Re: Maximum Speed For Belt Feeders
Dear Harish Kumar,
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http://www.fey-lamellenringe.de
please reach me with your requirement.
Siladitya Ganguly
Regal Services
Kolkata
09830070039 ■
Re: Maximum Speed For Belt Feeders
We are designing a rail wagon loading system for iron ore pellets and would like to use weigh belt feeders if there is economic advantage in capital & operational costs.
Low head room for installation is one consideration leading to overall lower height of facility and consequent investment.
Will the high rate of loading required (2000 tph) be a constraint for using weigh belt feeder? Given the limitation of belt speed to 0.6m/s as discussed above, what will be the implication on the size of feeder and accuracy of weighing system?
2000 cubic meter capacity bunker is envisaged above the feeder. Bulk density of iron ore pellet is 2 t/cum. Dia of pellets- 16mm
Would welcome some pointers that can guide discussions with potential suppliers. ■
Weight Problem
Originally Posted by sidsahu
Low head room for installation is one consideration leading to overall lower height of facility and consequent investment.
Will the high rate of loading required (2000 tph) be a constraint for using weigh belt feeder? Given the limitation of belt speed to 0.6m/s as discussed above, what will be the implication on the size of feeder and accuracy of weighing system?
2000 cubic meter capacity bunker is envisaged above the feeder. Bulk density of iron ore pellet is 2 t/cum. Dia of pellets- 16mm
Would welcome some pointers that can guide discussions with potential suppliers.
If you are dealing with low head room to begin with an apron feeder for the tonnage desired would be a better way to manage it as you have an overhead bunker with 4000 tons plus but you have not given any dimensions for the bunker
A 24 inch apron feeder taking all the material out of the bunker and
will move a lot of any material period at a low speed and high volume en mass.
34 tons a minute is a lot for any weigh belt feeder: a big if is what happens when the belt splice breaks or the vulcanized seam separates.
an apron feeder will give you a better transition to one or more weigh feeders.
lzaharis ■
Re: Maximum Speed For Belt Feeders
Forget about the 35 deg troughing angle and switch to flat rollers or 20 deg troughing at the very ends.
1 m/s is not common (normally 0,4 to 0,6 m/s) but I have seen 108" feeders running at up to 1.2 m/s. You want the material coming off the feeder to always "fall down" and fall on the same spot, regardless of speed and feed rate (tph) which always can vary.
So, to achieve this situation at up to 1 m/s with the outcoming material always falling at the same spot, you will need a discharge pulley diameter of at least 800 mm. This will provide for a constant downfall curve at up to 1 m/s. ■
Re: Maximum Speed For Belt Feeders
Originally Posted by sidsahuLow head room for installation is one consideration leading to overall lower height of facility and consequent investment.
Will the high rate of loading required (2000 tph) be a constraint for using weigh belt feeder? Given the limitation of belt speed to 0.6m/s as discussed above, what will be the implication on the size of feeder and accuracy of weighing system?
2000 cubic meter capacity bunker is envisaged above the feeder. Bulk density of iron ore pellet is 2 t/cum. Dia of pellets- 16mm
Would welcome some pointers that can guide discussions with potential suppliers.
It is difficlt to control flow of pellets by a feeder which will allow rolling of pellets from any open apperture when flow is to be stopped.
Pellets flow freely from a chute and flow can be contolled on / off basis by hydraulically or pnumatically operated shutter closing the chute opening. We had to replace vibrating feeders / appron feeders installed for feeding on to a tunnel conveyor (used in a system for loading pellets into barges (from an open stockpile. ■
Feeder Skirt
Originally Posted by Harish kumar RI am designing a belt feeder to convey coal at 450 TPH, having 35 deg troughing,1200mm wide belt and BD of 850 Kg/cu.m. while I was calculating the capacity for optimum selection I found that the feeder has to run at 1 m/s. but I am in doubt for the maximum speed for belt feeders. Many of readymade belt feeder manufacturers suggests a maximum speed of 0.6m/s. I request you to give me an idea about the influencing factors for Belt feeder speed selection.
Reference to your belt feeder, how are you going to design a feeder skirt arrangement between feed hopper and feeder. Could you detail the design. ■
Maximum speed for Belt feeders
Hi everybody,
I am designing a belt feeder to convey coal at 450 TPH, having 35 deg troughing,1200mm wide belt and BD of 850 Kg/cu.m. while I was calculating the capacity for optimum selection I found that the feeder has to run at 1 m/s. but I am in doubt for the maximum speed for belt feeders. Many of readymade belt feeder manufacturers suggests a maximum speed of 0.6m/s. I request you to give me an idea about the influencing factors for Belt feeder speed selection. ■