SYSTEM & APPLICATIONS

Quarries

Eurofilter Asia Pacific supplies dust collector
to Australian Dust Solutions for Quarry project

Settling the dust at the quarry

Brisbane CityWorks is one of Queensland's largest civil construction and maintenance organisations. The company has an R2 B1 rating under the Main Roads Classification System and is an approved asphalt manufacturer and laying contractor. As part of the Brisbane City Council, Brisbane CityWorks has behind it Australia's largest local government authority.

Brisbane CityWorks operates three quarries which supply a range of quality products that normally have to be sourced from a number of different suppliers. The company has vast experience in the complete management of quarries and extensive knowledge of quarry products. With a wide variety of natural resources and innovative manufacturing plants, the three quarries manufacture products for all engineering applications including:

• armour/retaining wall rock,
• sized rock spalls,
• road base and crushed rock,
• screenings,
• high quality manufactured sand,
• drainage aggregates,
• bedding sands,
• crusher dust,
• soil products,
• general fill.

Brisbane CityWorks has a mobile crushing unit and can provide NATA Certified (ISO17025) testing and reporting laboratories for asphalt and quarry products. The company also serves business and industry with cement treating, pre-coating, pugmill and rock sizing facilities.

With such a sizeable business quarrying and supplying crushed rock products for Brisbane and South-East Queensland, Brisbane CityWorks has a history of employing the most up-to-date and technologically advanced production systems and equipment at all its sites.

Bracalba Quarry

Brisbane CityWorks operates three sites in south east Queensland: Pine Mountain Road Material Recycling Facility and Mount Coot-tha and Bracalba Quarries.

Bracalba Quarry commenced operations in the early 90's and supplies road base, concrete and asphalt aggregates, and decomposed granite fill from the site. With production exceeding 600,000 tonnes each year, the quarry prides itself on its high productivity and advanced production methods. Regular site surveys and evaluations ensure that quarrying and crushing operations maintain the company's high standards.

Dust: a natural problem

Extracting and crushing 600,000 tonnes of rock each year naturally creates large amounts of dust. As part of the company's regular reviews, the quarry's manager, Peter Harris, together with Project Manager Cameron Braidwood sought input from a number of dust suppression specialists to review the way the crushing plant dealt with dust.

The company assessed the advice received. Whilst the traditional water spray dust suppression system was working well, their assessment indicated that further improvement could be gained from more modern technologies. As a result a scope of works was written around the plant's dust suppression requirements using filtration technology.

"We have looked at water nozzles, water fogging, extractive filtration", says Cameron Braidwood. "All are good systems but we felt that water fogging was an unproven technology, whereas we have filtration systems in other plants. We also felt that standardising on the filtration method with the other plants was a beneficial move for the future."

Other criteria considered included ease and cost of maintenance and the life expectancy of the equipment. "We were looking for equipment that had a reasonable design life and was well built. The maturity of the technology was also an important factor", says Mr Braidwood.

Deciding on the final choice of equipment was the hardest. "There was not much between them", says Mr Braidwood. "All the suppliers put forward very professional submissions, with sound engineering principles and solid construction behind them. After all, it's a competitive business and only the tough are still around."

The final decision was based on a combination of factors: cost vs. value, waterproof, longer lasting filter bags, and sturdy construction. "The Eurofilter 11-11-121 Starjet Collector, installed by Australian Dust Solutions, also came with slightly higher technical specifications", says Mr Braidwood.

The Australian Dust Solutions-designed system extracts 4-5 tonnes of .75 micron dust an hour from the screening and crushing plant. The collector uses 121, 5 metre-long snap cuff-style bags which filter 36,000 m³ an hour. The dust is either returned to the plant's final discharge or gets mixed with products at a metered rate.

The ducting fitted is of heavy wall construction with flanged bends. The ducting was all prefabricated by Australian Dust Solutions and installed with only one Saturday's downtime to the plant.

The system is fitted with a PLC controller that monitors the pressure of the collector and adjusts the pulse to suit the dust loading of the filter bags. This automatic monitoring and continuous adjustment can extend filter life by up to 1-2 years. The information is stored on the controller and is downloaded at each service. Converted to graphs, it shows the dust loading peaks and how many pulses the collector has completed, which enables users to schedule a filter change months in advance.

More Information

Powder Coating

Eurofilter Asia Pacific supplies dust collector to
Australian Dust Solutions for Powder Coating application

Investing in advanced filtration technology resulted in more than just a cleaner working environment for a Brisbane powder coating company.

A powder coating specialist and exporter has made a significant upgrade to its Brisbane workshop which has resulted in enhanced productivity, internal OH&S gains as well as environmental improvements.

Caboolture Powdercoaters services many manufacturers in the Brisbane area, and in any one day can handle up to 70 different jobs. Items range from as small as a hinge to as large as a whole fence panel or large gate, more than seven or eight metres in size.

Until a recent design and fitout of a new filter/collector by Dust Solution, the powder coating workshop for the past seven years had been using a water curtain filtration system to prevent the powder and dust escaping into the atmosphere. But as that equipment began to age, owner Chris Reed began to look around for a more modern system.

"The water curtain was a bit of a dirty job to clean out," says Mr Reed. "Every four weeks we'd have to shut down the workshop for two hours, while three of my men cleaned out the filter. It was a significant disruption to production, and an unpleasant job to do. We weren't looking forward to the end of the month."

Caboolture Powdercoaters has been growing at a steady 14% - 18% each year and now has six employees. The quality of output demanded by customers together with ever-increasing production volumes meant the company could no longer afford the downtime.

Many of the jobs are destined for export markets as far afield as Europe or Canada. The business handles many different metals, from aluminium and stainless steel to wrought iron and everything in-between, which can be powder coated in any one of 250 or so colours. There can be up to twenty colour changes a day.

Mr Reed looked at three alternatives before choosing the Eurofilter Asia-Pacific EFC 4-16 collector from Dust Solution.

"All three suppliers came in at about the same cost", said Mr Reed. "We chose the Eurofilter because it was the most comprehensive package."

"The additional features made it the best value for our business when you consider its performance and its labour-saving low maintenance requirements. The collectors are supplied powder coated as standard and the whole system looks like it was built to last."

"And because we are so busy, it was all installed and commissioned over the two days of a weekend. When we came back to work on the Monday, it was ready and waiting, we just had flick the switch on and start working. The old unit was taken away, too."

The equipment was installed by David Fanning from Dust Solution. The system is highly efficient, removing 16,500m3 per hour and features a computer-controlled, self-cleaning filter system, the Star-Jet PLC pulse controller.

At pre-set intervals the unit starts a reverse pulsing cycle to ensure that the filter does not get clogged up and works at peak efficiency at all times. After using the new filtration system for two months, Mr Reed is satisfied with the result.

"The system does exactly what David Fanning said it would", he said. "We have set the self-cleaning cycle to start every 45 seconds, and it does this automatically while we're working. We don't have to stop production or pay any attention to the filter, which is great for productivity."

Unlike the water curtain's four-weekly maintenance requirement, the Eurofilter system does not need attention for approximately two years between services.

"Instead of three of my men spending two hours every month on a dirty, unpleasant job cleaning the scrubber, we just change the filter every two years - a simple, two-hour job for one man."

By the time he expects to look at his filtration system again in about ten years' time, Chris Reed will have saved more than seven hundred man-hours on maintenance alone.

"That is time I can use to get my customers' work out quicker, get more work in, and grow the business.

"I expect this system to be good for many years, which means that for the next ten years and more, I don't have to worry about filtration - I can concentrate on productive work."