Re: How To Stop Vibro Screens / Feeders
Dear Shri S Ganesh,
Your query states that when the cardon shaft or V belt drive of a vibrating feeder or vibrating screen fails / breaks, how to get it identified by automatic control system so that it will trip the feeding conveyor and system. You have already mentioned certain ideas. When the cardon shaft or V belt drive of such equipment fails, then as you have said motor will be running but there will not be flow of the material through the vibrating feeder or vibrating screen. It seems following are the options (and may be more also) :
1) Put a material level switch in the feeding chute of this item. The switch should be located such that material build up will deflect it or sense it and the instrumentation system will interpret that this particular item is not functioning (or faulty) and will trip the feeding conveyor.
2) You can contact with the supplier of such item and enquire whether they can give speed sensor on the shaft fitted with the tray or screen deck. In case its speed falls below certain limit, it should trip the incoming feeding conveyor. Such switch or sensor needs to be vibration proof. It is similar to zero speed switch but amended to suit the place of installation.
3) Sensing the ampere to identify the fault needs to be thought properly. Possibly even if there is no failure but if the equipment is running without any feed, it might be consuming less power. Refer electrical engineer when the motor is running at very less load then whether ampere will diminish or power factor will be poor. kW consumed will certainly drop but may not be ampere. Well the electrical engineer will be able to clarify on this point very easily because I would not prefer to investigate into electrical book. Your idea is more relevant to kW sensor rather than ampere. But as I said even empty running of the equipment might also consume less kW.
4) Interact with your supplier of such item. They may already have the solution for this kind of problem.
Regards,
Ishwar Mulani
Author book - Engineering Science and Appication Design for Belt Conveyors
Author book - Belt Feeder Design and Hopper Bin Silo
Tel. No. : 0091 (0)20 2587 1916
Email : parimul@pn2.vsnl.net.in ■
Re: How To Stop Vibro Screens / Feeders
We use the Power Cells from Load Controls Incorporated http://www.loadcontrols.com/. They have a unit typically specified for pumps, however it has a settable relay trip that you can interlock upstream process equipment.
Additionally it has a 4-20mA output that you can monitor with your PLC and take corrective action before a plug occurs.
Click below for a link.
http://www.loadcontrols.com/products...01datash.pdf
Regards, Delmar Schmidt
Melfi Technologies Houston
www.melfitechnologies.com ■
Re: How To Stop Vibro Screens / Feeders
we are using zero speed sensors on counterweight covers on our double deck circle throw screens.& it works ■
How to Stop Vibro Screens / Feeders
Dear all,
There are many vibrating equipments in material handling system installed between conveyors.
Many of these vibrating equipments are operted through cardon shafts or V belts.
I have seen , if the cardon shafts or V belts snaps, the receiving chutes of these equipments getting clogged and creates lot of house keeping problems. The feeding conveyors are also getting damaged since only the motors of these vibroscreens / motors are running.
When the mechanical transmission cuts off due to cardon shaft failure or v-belts snapping, then the ampere of the motors will suddenly come down drastically.
I am wondering is there any electrical relay / contact observes this sudden drop in running ampere and stops the machine so that system will become safe.
Having chute plug may be another solution, but if my above idea is possible , I think it may eliminate the correct installation & labourious issues related to chute plugs. I do not know it is being followed in industries.
Request to share your comment.
Thank you & regards
S.Ganesh ■