Re: Bunker Level Indicator
Dear Shri Rekhawar,
It is difficult to understand how the rotating belt conveyor is positioned and how it is discharging in to the bunkers. Some sketch (plan view) will enable the readers to understand the arrangement for appropriate response.
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 ■
Bunker Level Indicator
Dear all,
The bunker drawings are attached in zip file (pdf format).
Reagrds
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Dear Rekhawar,
What I guess from your post is that the ultrasonics must be installed at an angle based on the profile of filling.
Anyway, we earlier had supplied an ultrasonic sensor with a similar bunker with 2 prismatic openings/discharges which stored woodchips of 20-100 mm size. We had a similar problem of erratic readings.
It should be mounted on the side walls of the bunker and should see the product on the lower side of the heap (if product overfilling is critical for the turn table). What is required is a coupling welded to the side walls of M30 bore.
We finally used a simple capacitive proximity switch by IFM. Size of this sensor is M30 which is good enough for your application. We also have 2 of them in stock with us and can be supplied if you wish to install them with our support. Let me not forget to suggest you that on the inside of the hopper wall, a small 'C' shaped umbrella could be provided so that direct falling coke doesn't damage the sensor.
Also the sensitivity of these PNP switches are adjustable ( you just need a small screw driver). These switches are available in metalic as well as PBTP housings. They are IP67 quality and the most attractive part of it is "IFM gives a LIFE TIME GUARANTEE or REPLACEMENT AGAINST ANY DEFECT/MALFUNCTION on all of their products". Apporox. price idea will be 120 USD/switch. Installation charges as extra.
I am attaching a file , for you to read through the specifications and other details.
Please let me know your feedback.
Regards,
Amresh Mehta
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Bunker Level Indicator
Dear Mr. Mehta,
Proximity switch won't work in our case, as Coke Fines is a sticky material. There are always build up of Coke Fines on sidewalls, hence putting sensors on sidewalls won't work.
We are looking for continuous measurement of levels in %age of fill or quantity in MT, the proximity switches at best will give levels at certain intervals only (i.e. Low-Low, Low, Middle, High, High-High etc. depending on number of switches installed in bunker walls).
Let us know, if you have installed the switches proposed by you, in any of the steel plant?
Radar levels as discussed in some other threads appears to be a promising solution, as it will cover the top area instead of only a point.
Awaiting more responses from members. ■
Re: Bunker Level Indicator
Mr Rekhawar
I work with an ultrasonic level measurement company that has had success with this application in quarry stone. The best you will achieve is an indication of the level rather than an accurate measurement, but a reliable result should be obtainable. The difficulty often is that the echo bounces around the inside of the quarter silo and gives a very variable echo profile back at the transducer. It will also be an acoustically noisy environment. The quality of the digital echo processing is key and there are only one or two companies who produce equipment suitable for this type of application. I hope it is acceptable for me to invite you to look at the company's website http://www.pulsar-pm.com for more information on this particular company. Incidentally, I believe the sales director of Pulsar is in Mumbai today (4th November) ■
Re: Bunker Level Indicator
following on from other comments, Ultrasound will be erratic and at best a crude indication of level only. Load cells would have been the preffered option. Capacitance probes have been mentioned and we have had success using them on fines where the probe is contaminated by the dust ( We call this **/C for coal dust applications). We also offer a cable type with suspended stainless wire and a protective shroud to stop physical damage to the probe.
john.slevin@hawker-electronics.co.uk ■
Bunker Level Indicator
Dear all,
We have six bunkers for Met. Coke (Bulk density - 0.6 T/m3, particle size -10- 80 mm) in Stock house. The top portion is rectangular (L - 7500 mm x B- 10500 mm and 6230 mm Ht.) where as bottom portion is asymmetric prism frustum (bottom opening 800 mm sq. x 11200 mm ht).
The feeding conveyor is on rotating platform at top, hence feeding point varies for all the bunkers.
The discharge point & feeding point do not fall on the same line. This causes the profile of material inside the bunker uneven. The problem gets aggravated by asymmetric section of the bunkers.
We have ultrasonic type sensors installed in each of these bunkers. The sensors have been positioned after studying the expected profile of cargo inside the bunkers. But the level readings being shown by the level sensors are not correct.
Can somebody suggest a better Level sensors for such bunkers?
Regards ■