A cement company used a 900t silo to store “off specification” cement. This cement was directly from the mill, and until such time as rigid specifications were met, was run into this silo for storage pending recycling through the kiln and milling process.
As it was in constant use for many years, possibly as many as thirty, it had been impossible to clean out, although manual dipping revealed that a build up of product had reduced the silo’s capacity dramatically. In 1998, a dedicated “off spec” bin had been commissioned and Australian Silo Clean was requested to clean out the silo, ready for use for finished products.
During the space of 10 days, 750 tonnes of material was removed, 600 tonnes in powdered form for storage, pending recycling, the balance being dumped on site as being non-reclaimable at that stage. This was achieved with very little dust hazard and with only two operators utilising the Australian Silo Clean System.
The silo was inspected on completion of the work and was suitable for human entry, which was required to inspect and, if necessary, repair the air pads. The walls, cone, and importantly, the underside of the roof, were clear of hazardous build up.
Another cement company utilised a 750 tonne silo purely for bagging. Over a period of time, the available capacity shrunk to only 300 tonnes. Australian Silo Clean were approached to remove 200 tonnes of the build up, enabling the company to utilise the extra capacity and give them a “comfort zone” in case of delivery problems.
The parameters were that loosened product could only be taken away after bagging had ceased, also any product removed had to be of a consistency to pass through the existing air slide system prior to being side lined for recycling. The time allowed was 40 hours.
After 40 hours, the job had progressed with so few problems that the company requested that a full clean be carried out. 79 hours later, the silo was returned to its original 750 tonne capacity. Although not in the original programme, Australian Silo Clean were asked to remain on site and start cleaning the adjacent silo “While you are here!”
Leigh Creek Coal Field
When you have the responsibility of supplying coal to an important facility like a power station, you don’t have the luxury of time when it comes to unblocking the bins and chutes which load trains.
So Leigh Creek Coal Field, which serves the Port Augusta Power Station in South Australia, had to move quickly when its clam shell train loading chutes became choked recently. Not only was the situation causing train loading delays; the resultant buildup in its 9,000t bin itself was reducing capacity to less than 5,000t of flowable product.
Leigh Creek had experienced this type of problem before and had always had difficulty finding a company to clean the chutes and bin without causing major delays. Ideally the clean up operation has to be woven in between train loading operations.
They were justifiably sceptical when Australain Silo Clean undertook to get the job done in the specified time frame. Essentially the contractor needed to clean out the bottom of the bin, open up all the chutes and remove as much product as possible within 14 hours. This 14 hour “window” also included a four hour operation to crane equipment up and down, which left just ten hours for the cleaning and removal operation.
But in fact, by using the Australian Silo Clean System, it took only nine hours to clean the bottom of the bin, open up every chute and remove 2,700t of material.