Precision weighing & control

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					Digital Re-print - March | April 2009
Feature title: Precision weighing & control
Grain & Feed Milling Technology is published six times a year by Perendale Publishers Ltd of the United Kingdom. All data is published in good faith, based on information received, and while every care is taken to prevent inaccuracies, the publishers accept no liability for any errors or omissions or for the consequences of action taken on the basis of information published. ©Copyright 2009 Perendale Publishers Ltd. All rights reserved. No part of this publication may be reproduced in any form or by any means without prior permission of the copyright owner. Printed by Perendale Publishers Ltd. ISSN: 1466-3872

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Precision weighing control
by Dave Griffiths, Senior Applications Engineer, Chronos Richardson Limited
recision weighing has always been an essential part of most milling plants; providing an accurate record of material movements within the mill and helping to evaluate operating efficiencies.
In the current economic climate the need for optimum weighing accuracies has never been more apparent, especially with the costs associated with some raw materials and the need for maximising operating efficiencies in challenging trading conditions. Couple this with the need to comply with modern regulations relating to things like dust/explosive atmospheres and the need to select the right weighing equipment becomes ever more important. As mills have closed there has been an increase in the availability of second-hand equipment. Special consideration should be given to the suitability and reliability of this type of equipment, before it is incorporated into any mill.


allow for the continued use of existing equipment if you can prove: •	 •	 •	 •	 Previous	safe	working experience Comprehensive	maintenance records Manufacturer’s	data	that	 the equipment is safe Comparison	of	plant	 to recent standards

ATEX-compliant weighers
In recent years two European Directives the Explosive Atmospheres Directives [ATEX] have been enacted, which may have an implication on the continued operation of in-process weighers and other bagging weighers. Two of these regulations: ATEX – Directive 94/9/EC [ATEX 95] (the Equipment and Protective Systems Intended for Use in potentially Explosive Atmospheres Regulations 1996) and DSEAR – Directive 99/92/EC [ATEX 137] (the Dangerous Substances and Explosive Atmospheres Regulations 2001),
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In order to help millers to comply with these directives, Chronos Richardson has developed upgrade solutions and part kits for its APW inprocess weighers and bagging weighers, which fulfil the manufacturer’s data obligation for equipment safety. As a minimum these upgrade solutions comprise of ATEX certified loadcell(s), solenoid valves, sensors, mounting plates and/or brackets associated with their integration into the existing weighers. To ensure that a specific site fully complies with the Directives you may require to be externally audited to ensure where and what zones apply to the equipment in question. When this has been established Chronos engineers can assess the removal of such things as in-built controllers and their repositioning to a safe location to ensure the site meets with the site assessment of individual ATEX Zone requirements. Company trained service engineers can work with mill engineers to ensure that weighers comply with the ATEX Directives.

Above: CHRONO-WEIGHTM E55 NXT Precision Weighing System Below: CHRONO-WEIGHTM E55 F1 High-Capacity Nett Weigher

ATEX version of the APW
Chronos has introduced ATEX-compliant weighers into its APW in-process and bagGrain

ging weigher ranges. These weighers are compact and versatile and have been specifically designed for installation in those mills where dusty materials are weighed and packed on a daily basis. The ATEX version of the APW is designed for simple integration into new or existing mills FIBC weigh filling system at McCreath Chronos Richardson AW301 and is capable Simpson & Prentice bulk weigher of freestanding operation or integration into an overall system. ing system, which was filling FIBCs using ensure optimum filling outputs are mainThe latest generation of the Chronos a multi-tipping configuration. tained, the system incorporates a bag inflation E-series nett weighers meets the highest The new high-speed weigh-filling sys- system and an indexing takeaway conveyor to demands for accuracy and performance tem was across a range of bagging applications ordered in and industries. These precision weighing March 2008 systems are available in single weigher and as part of a double weigher combinations for bagging major plant lines with a weighing range from five to upgrade that 50kg. A recent form fill and seal packing involved a application is packing rice into 20kg bags major recon60 YEARS ENGINEERING EXPERIENCE at 1500 bags/hour; 10kg bags at 1740 figuration bags/hour; 8kg bags at 1800 bags/hour of the filling Bulk handling with and 5kg bags at 1800 bags/hour. area and the In recent trials a single E55 F1 weigher installation complete confidence packed 18kg weighments of Biofuel wood of new bulk pellets [similar to many feed pellets; approx. intake silos. Designers and UK 5mm x 32mm] at 1200 bags/hour. At the manufacturers of: heart of the • Bucket elevators new system FIBC Weigh filling With the desire for increased filling speed is a Chronos • Chain & flight conveyors and accuracies, larger capacity nett weighers Richardson • Screw conveyors & are being used for filling Flexible Intermediate AW301 bulk weigher that bin dischargers Bulk Containers [FIBCs] or ‘Big Bags’. A recent application in the grain/seed is controlled • Belt conveyors sector illustrates the benefits of this type of by a SpeedAC NXT controlsystem. According to Berwick upon Tweed-based ler. Multiple grain and seed merchant McCreath Simpson high capacity & Prentice [MSP] their new Chronos weighments treated Richardson FIBC filling system has provided of them with “easier bag handling and better seeds are discharged into plant logistics”. MSP supplies grains to more than single loop 2000 farms in northeast England, south- FIBCs, which have capaciern Scotland and the borders region, Dunkeswell Airfield, Honiton many of who provide malting barley to ties ranging Devon, EX14 4LF Simpsons Malt. MSP were also a long- from 500 to Tel: 01404 891400 term user of a Chronos E55 nett weigh- 1200kg. To Fax: 01404 891402

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march-april 2009 | 41



“The quality of the machinery we
are bulk throughput weighers, which provide a more accurate recording and performance monitoring.

manufacture is only as good as the buckets in them – which is why we choose Tapco.


Chronos Richardson offer a range of loadcell bulk throughput weighers, designed to meet the handling requirements of free-flowing bulk materials. These weighers are available in a variety of sizes with hopper capacities from 50kg to 10 tonnes, which can provide throughput rates of more than 1,000 tonnes/hour. Their proven robust design ensures reliable long-term operation even in harsh operating environments. A range of electronic weighing modules BULK 3000, BULK 8000 and the high-capacity BULK 9000 were recently introduced. Each of these bulk weighing controllers meets the accuracy classes 0.2, 0.5, 1 and 2 pursuant to OIML R 107, high interference resistance according to OIML R 51, PTB approval in line with MID Directive. The userfriendly modules feature multilingual menus for simple operation, with error and status messages in plain text. The BULK 8000 and 9000 modules provide: •	 Optional	PC	keyboard connectivity Can	store	up	to	250	 customer files 150	product	data	files Up	to	100	silos	can	be	addressed

Gustaaf Zeeman, Managing Director EUROPEAN MACHINE TRADING ’t Zand, Noord-Holland, The Netherlands

Janco Zeeman, Technical Director EUROPEAN MACHINE TRADING ’t Zand, Noord-Holland, The Netherlands

efficiently remove filled bags from the weighing station. “The weighing equipment and other new upgrade machines have really settled down and have helped streamline our packing process,” commented Steve Park at MSP. “This has in turn given us a 15 to 20 percent increase in daily production, which was the target area we wanted to achieve,” he added.

The importance of weigher control
Weigher control is important to maintain high accuracy operation and the SpeedAC NXT weighing controller is an advanced controller that provides preci-

sion bag filling weights across the Chronos bagging weigher portfolio. This was featured in an article in the July/August 2008 edition of GFMT. SpeedAC NXT provides high precision weighing with dynamic weighment accuracies, which conform to OIML R61; and static accuracies that comply with class III as per OIML R76 or EN45501. A further enhancement to SpeedAC NXT was secured 12 months ago when the controller was awarded the Measuring Instrument Directive (MID) certificate. A cost-effective alternative to traditional weighbridges/silo weighing systems

•	 •	 •	

For more than 90 years, European Machine Trading has maintained their reputation as a high quality, family-owned business. In 1988, the former feed mill decided to manufacture elevators, transport conveyors, bagging machines and other equipment for feed mills, fertilizer plants and dealers. However, one thing stayed the ® same...quality. “Our company has been built on quality,” Gustaaf Zeeman of European Machine Trading says. “And quality is what we want in our products. When you make a machine, the components you select must be the same quality, which is why we chose Tapco buckets.”
HEAVY DUTY Polyethylene Elevator Bucket
Polyurethane • Nylon

How Tapco Buckets Help Maintain a Family Tradition of Quality

“The polyethylene Tapco Super EuroBuckets are strong, which is important to fertilizer plant managers. They are tough enough to handle heavy loads, yet flexible, so they absorb impact from elevator legs, bypass obstructions and return to their original shape. And, they don’t rust!” With 900,000 buckets in 60 sizes, stocked throughout the world, Tapco can help take a load off of your mind – and elevators, too. Call us at +1-314-739-9191 or visit to find out why 75% design engineers, contractors and FANGED HEAD bucket elevator manufacturers in the Elevator Bolt U.S.A. specify Tapco* with no equal.


The standard version features up to 150 weighing parameter files for pre-setting of accurate designation of weighing goods. The systems are equipped with a printer and PC interface for data storage and actual value recording. Depending on the module, optional interfaces enable remote display, networking to Profibus, DeviceNet, and Ethernet as well as to workstations with PC COM+. Power failure data protection and integrated password protection ensure increased data safety.


Tel.: +1 314 739 9191


+1 800 288 2726

St. Louis, Missouri U.S.A. • Fax: +1 314 739 5880


*Grain Journal, Country Journal Publishing Co., Inc., Decatur, Illinois, U.S.A.

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The color blue, when used in connection with elevator buckets, is a U.S. registered trademark owned by Tapco Inc. © 2009 Tapco Inc.® All rights reserved.



Above: precision weighing controller Right: BULK 9000 weighing control system Below: APW: ATEX version of the APW in process weigher

Retrofit & Refurbish
Affordable improvements – at a fraction of the cost of new equipment In the current economic climate new capital equipment spend is becoming more difficult to justify; but when a plant needs upgrading mills can make the most of their existing weighing equipment. In some cases there might be an old weigher in store that was believed to be beyond repair; or a second-hand weigher has been purchased that needs repairing. Cost-effective upgrade/refurbishment solutions can be implemented with minimum impact on operation thereby modernising your plant. These refurbishment programmes allow the mill to benefit from renewal and improvements whatever the equipment supply. This has been applied to: •	 Upgrades	 allowing old equipment to meet today’s operating standards •	 Costeffective adaptations for your

changing production requirements Allowing	old	equipment	to	 regain its functionality In April 2002 Richard Simon Limited became part of the Premier Tech Group of companies and Richard Simon engineers and personnel were integrated into Chronos Richardson. Since then genuine spare parts matched to the original Richard Simon design authority documentation and drawings have been supplied by fellow Premier Tech company Chronos Richardson. A recent refurbishment example was a Richard Simon Weigh-Belt Feeder, which was previously surplus to requirements and when removed from operation it had not been cleaned down. Congealed product had jammed most of the belt drive mechanisms and had started to rot away some of the electrical control boxes. Whilst appearing to be in a poor condition a survey revealed that the structural framework and major components were repairable; it was therefore economically viable for refurbishment. The unit was carefully stripped down and those structural items to be reused [feeder casing, weigh frame and belt carriage] were shot blasted and re-sprayed. The feeder was reassembled and where appropriate new parts were incorporated into the rebuild, this included: belt, scrapers, bearings, springs, loadcell, terminal boxes and wiring. •	

Once the feeder had been reassembled it was retested and recalibrated prior to dispatch back to the customer.

Improve your plant performance
Your mill’s output and performance can be improved by installing new or upgrading old weighing equipment. Our engineers can visit your mill and provide you with a preliminary evaluation to advise on how best to upgrade your weighing equipment. Chronos Richardson Limited is a Business Unit of Premier Tech a word leading manufacturer weighing bagging and palletising systems. More

Chronos Richardson


reLateD CoMPanieS:

Precia Molen Contact: Monique heessels
Tel: +31 76 5242503 Email: Website:

Looking for Weighing equipment?
The IMD has companies listed under thousands of products and services What ever you are looking for find it with IMD

44 | march-april 2009




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This digital Re-print is part of the March | April 2009 edition of Grain & Feed Milling Technology magazine. Content from the magazine is available to view free-of-charge, both as a full online magazine on our website, and as an archive of individual features on the docstoc website. Please click here to view our other publications on




• See the full issue
In this issue:
• Safety monitoring for conveyors, bucket conveyors and conveyor belts Precision weighing & control Fast quantitative detection of mycotoxin residues

• Rollermills sieves & flaking

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• Can we keep up with mycotoxins?


• Maximum Bulk Storage


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Description: Precision weighing has always been an essential part of most milling plants; providing an accurate record of material movements within the mill and helping to evaluate operating efficiencies.