A jigging machine is used on commercial fishing boats, whoopsy!

The problem you appear to have is from gravity and even the smallest apron feeder sized to the width of your conveyor will solve this issue as it moves all the material from the rear of a bin to the front and nothing is allowed to back up and arch from compaction.

a linear screener like those made by EZ-screen would eliminate a lot of problems following a very small apron feeder the width of the upper belt would resolve it as it will regulate the flow in a very slow and effective forward motion alllowing a tiny fraction to be delivered at any time.

ez-screen.com

amking.com RCR apron feeders

metso.com NICO apron feeders

lzaharis ■

I am not referring to a short conveyor belt type of feeder system.

I am referring to a steel track "apron feeder" which uses a type of overlapping dozer track designed plate to

create the bed on which the material is carried from back to front which creates

mass flow, and is regulated by a stationary gate that can be raised or lowered to

regulate flow.

And as such the single pad has a limit to carrying the amount of material which

the gate allows to pass under it will carry a limited amount of iron ore and not

flood and blind it in the course of movement.

The steel track apron feeder has an electric motor drive which is used with a reduction gear box to

create a very low final drive bed speed to the final drive sprockets to carry the material. and you will be able to order what ever speed motor and gear box

with few if any issues.

lzaharis ■

An apron feeder will be much less

troublesome versus a belt feeder.

The apron feeder is much more

compact with its installation

versus a conveyor belt feeder.

with no issues of belt wandering

and stretching, drive pulleys, lagging

etc.

I can tell you from my experience

about a very small apron feeder we

used for 21 years in halite.

The apron feeder ran flawlessly

and in those years we replaced only one motor

and one of the pillow block bearings for the sprockets.

Its easy enough to find a used apron feeder for sale

and you dont have to deal with belt splices and the

leakage of fines is minor versus a conveyor that

will have carry back due to the very high speeds that

conveyor belt feeders have typically. and the apron feeder will only

have a small amount of ore coming over the end of the

feeder with no flooding.

The skirting arrangement for an apron feeder is vertical

and it allows easy control of the material and keeps

it in place on the apron with no overflow.

The apron feeder has no impact idlers to change or grease( if used)instead of impact bars)

The apron feeder has a flat amperage draw versus a belt feeder as the work level is flat with no spikes due to the apron feeders reduction gearing and final drive.

the track of the apron feeder is held in tension by the drive sprockets and passive sprockets and the upper and lower rollers in the carriage with no loss of alignment due the apron chain which is part of the aprons inidvidual plate.

The apron feeder can be geared to a crawl if so desired with the the properly sized reduction unit

If the bins are close enough it may be worth your while to use one apron feeder for both bins and simply keep one bin empty while the other one is working. ■

If your conveyor is in line with the screen you may like to consider a 'spreader chute'. This is essentially a section of a cone over which the material flows and is spread from a narrow to a wide stream as it flows down the conical surface. ■

Dear Mr. Peter,

You can think of about following two methods which are often used to spread the feed while feeding into crusher or screen. This means conveyor material discharge width is say 1 m and crusher rotor width is 2 m, etc.

1) The material discharge from the conveyor is finally made to impact / land on bottom face of say 60 degree inclined chute. On this bottom face steel flats are welded in a flaring manner that is they flare out in direction of the forward motion. The flaring angle is limited to about 5 degree. This has been frequently used for feeding of coal into crushers, in many coal handling plants in India. The material expansion magnitude cannot be very huge like 1:3 or 1:4, etc. The expansion by 1:2 could be reliable / practical.

2) The other method is to use flat pan vibrating feeder which actually works as spreader and not feeder. The material discharge from the conveyor is finally made to impact / land on bottom face of say 60 degree inclined small / medium length chute. The vibrating feeder is installed at the bottom of the chute. The vibrating feeder inclination and size is such that its regular discharge rate at usual layer thickness is more than the inflow rate. Thus this vibrating feeder will never allow the material to accumulate in the chute and it will spread the material and continue discharge at partial layer height. In this case you can achieve spreading ratio as per your choice by using corresponding length of tray etc. Such method has been also used for feeding crushers, screens etc.

The aforesaid methods have been frequently used as a part of crusher house or screen house layout.

The other option is to create a hopper prior to vibrating feeder. But in this case the hopper has to be of comparatively more capacity, because it will be subjected to complication arising out of difference in feed rate and discharge rate and consequent frequent tripping of the entire incoming system, when suddenly hopper gets fully filled. In this case if feeder discharge rate is kept more, then it becomes arrangement as per sr. no. 2, functionally, and hopper will be only acting as a chute, without storage.

Regards,

Ishwar G Mulani.

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

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India.

Tel.: 0091 (0)20 25871916

Email: parimul@pn2.vsnl.net.in ■

A JEFFREY EM PAN FEEDER would do the job nicely, easily, and fairly easy to fit in.

check out their website. I am not a sales agent for them but, they will do the job excellent.

FMC em feeder WILL also do this job and basically a Jeffries but a different colour.

Not overly large in size but, will nicely and uniformly feed your material to your machines and CONTROL the feed rate by volume and hopper design incorporated in the FEEDER design itself.

AN EXCELLENT knowledgeable company out of Woodruff SC i believe. ■

A simple JEFFREY EMF will do that job quite readily....or a FMC EMF...same thing different colour.

Cable susspended, easy to install, control FEED RATE by volumetric designed chutework which comes with feeder......comes in various widths....

check this LINK OUT: http://www.jeffreyrader.com/feeders/

GOOD LUCK

George Baker - MODERATOR.

Nice work Izaharis.... ■

" However my concern with such a spreader chute is that if belt tracking or loading of the feeding conveyor belt is off center then the feed onto the spreader plate will be preferential to one side. Then the spreader plate will exagerate the problem and eventually load up one side of the Jigging machine preferentially."

The only solution is good maintenance and operational practices to eliminate improper operation of belt conveyor feeding the jig.

Vinayak Sathe

vinayak.sathe@gmail.com ■

When I was reading the first posting in this topic, my first thought was a vibrating feeder. Usually works fine to spread the load, relatively cheap and easy to install and operate. ■

Conceptually, you are trying to build a flow stream regulator that treats the ore stream as a fluid to unify the hydraulic head.

The chute spreader can be regulated as proposed with rockbox and spreader chute. You can also fix the feeding conveyor loading chute to center the load prior to placing it on the feeding conveyor.

DEM can show this process and fine tune any "what if" questions regarding the feed irregularities and their consequences.

The spreader can be further enhanced at the entry to the vibrating screen.

Again, philosophically, you are trying to treat the ore stream like a water stream to unify the hydraulic head as the ore flows in any of the beds proposed. ■

the rock box will slow the material drop height but, the spreading arrangement actually looks pretty good. ■

Rockbox Chute will not spread the material the way you want but will reduce the velocity and therefore impact to the jig.

Spreading impact plate could give the width but you still need to have a rockbox to slow the material down.

Another option is a hopper and diverging vibrating feeder - the advantage is uniform continous feed to the jig.

Regards

Ziggy Gregory ■

Spreading impact plate with a rockbox just above the jig surface could work pretty well. Honl about redesigning the spreading plate to also make it working as a rockbox to minimise wear. Current arrangement and iron ore will make your maintenance department busy.

Regards

Ziggy Gregory ■

The sketches capture the basic principle of gravity spreading described earlier by designer and Mr. Mulani, but the most effective gravity flow method seems to be to combine two stage geometric rock boxes that exploits conical repose flow to distribute the feed sideways in a quadrant of a pile from the fill point, onto a plane flow repose pile to produces the requried linear discharge. The clever part is to extend the length of the sides for the bed of the initial repose cone to compensate for the sinusoidal gain of direct linear transfer and the transverse inertia of the material, so that the material is evenly distributed across the final emerging ‘waterfall’. Gravity is free, dependable and the flow of material on a dead bed of product, which can be a conical pile or a flat plane, eliminates a wear problem. The only requirement is headroom. whish is said to be available. Some of the saving on capital equiment and maintenance should be put into good design.

lyn ■