The wool scour industry - the sector responsible for removing grease and other foreign substances from raw, greasy wool - is under pressure, as the fibre faces increasing competition from synthetic textiles and cotton. Leading wool scour technology OEM, New Zealand-based ANDAR (ADM Group), believes a strategic approach to wool scour technology plays an important part in meeting this industry challenge. The ANDAR wool scour solution comprises many elements including technical leadership, improved operating cost efficiencies, reliability and flexibility. Advanced automation plays a central role in the ANDAR solution. Working in conjunction with Rockwell Automation system integrator Streat Automation, ANDAR has developed new automated scour technologies, in an industry traditionally encumbered with laborious, manual operation and supervisory techniques. The approach has paid dividends - the ANDAR/Streat team is a world leader in wool scour technology, with exports to Asia, Europe and Australia making up the majority of both companies' business.
Scour performance is largely judged on wool throughput and the washing quality. Precise control of the wool mat flow rate, bowl liquor concentrations and dryer operation is crucial to this performance. The challenge to scour designers, according to ANDAR Technical Manager, Mark Cunliffe, is to minimise energy, labour, water and detergent costs, while ensuring optimal throughput and reliability. "These are typically 24 h, 6 1/2 day per week pro-cesses," explains Cunliffe. "Reliability is a key, as is control of the wool motion and liquor concentrations." Correct wool speed regulation is critical. Bunching may result from the wool mat moving too slowly, jamming the scour - whereas poor washing is often the result of too high a speed. Incorrect pump speeds can lead to disturbances in the liquor equilibriums.
These problems are particularly evident after wool-type changeovers, when drive speeds and drying parameters must be 're-tuned' to suit the new fibre. The Streat team has developed an ingenious solution called 'Scourcom' - a PLC-based control system, designed to control the Scour's numerous operating parameters, according to a predetermined wool-type recipe selection. Scourcom features in the ANDAR/Streat team's current project, the massive Jandakot wool scour. The team's largest scour project to date, the Jandakot scour was installed in Rockingham, Western Australia in June this year.
The A$45 million scour expansion project will include dual 90 m long, 3 m wide scours, featuring a totally sealed wash-water re-circulation system and advanced dryer fan and burner energy optimisation. The Jandakot scour control system is a truly total Rockwell Automation solution package. The control system comprises SLC-5/05 controllers, Bulletin 160, 1305 and 1336 Plus II drives linked via a DeviceNet device-level communication network, plus Rockwell Software's RSView32 human-machine interface (HMI) package.
The total solutions approach is crucial in the OEM export market, according to Streat Automation's Automation Manager Rodney McKay. "We've designed and installed Scourcom systems all over the world," explains McKay. "Using Allen-Bradley and Rockwell Software equipment end-to-end provides important advantages, because it makes site support of the system so much easier. All we have to do is locate the Allen-Bradley office local to the site!" The Jandakot control system's 'front end' will be developed on the 32,000 point RSView32 package, with around 2000 tags and 10 to 12 screens per scour line.
For the Jandakot scours, approximately 100 recipe parameters are required per wool type, with typically ten different wool types. A recipe parameter 'library' is stored in the RSView32 system, with the selected control parameters downloaded to the SLC-5/05 controllers as each new wool type is selected. Scour control parameters include bowl discharge times, temperature setpoints, drive speeds, faults, alarm limits, liquor flowrates and chemical additions. With experience in a wide range of HMI systems, McKay describes the RSView32 system as Streat's 'product of choice'. "A feature we particularly like is its hierarchical database," he explains. "A lot of other products provide only a single tag file; RSView32 allows you to develop a tag directory structure, which simplifies tag list development."
Additional RSView32 features:
* VBA supports code with conditional branching, RSView32 data can be tied to other third-party applications, and allows control of RSView32 from within a VBA sub-routine by issuing RSView32 commands.
* The RSView32 ActiveX and OLE container capabilities can be used to take advantage of advanced technology. For example, use RSTools and other ActiveX components to enhance and extend RSView32 functionality. OLE automation facilitates integration with products like Microsoft Office and Back Office.
* Easy integration of RSView32 with other Rockwell Software products - including RSLogix 500, RSLogix 5, RSSql, and RSWire - makes for a complete automation solution.
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