Satake has installed a “bottomless” bucket elevator system for a major manufacturer to improve conveyor capacity and safety in hazardous areas.
A major multinational food manufacturer had a problem at one of its Australian sites.
The area where trucks would unload grain near the intake of its bulk elevators. An audit of the plant revealed the density of the dust posed an explosion risk, which would need to be minimised.
Gajan Illankovan, a senior project engineer at Satake Australia, said the company reached out, in search of bulk handling specialist that could supply and install a solution.
“We went down to the site and knew we would need to explosion-proof the conveyors,” he said.
“They provided us with a hazard and operability analysis report. We used that report and sat down with our suppliers to do a design review, looking at the bearings, motor, belts – anything that could cause a spark.
“What we found was the elevators themselves were the most important thing to explosion proof.”
Satake’s team worked closely with its supplier, 4B and Fike to install sensors and monitoring equipment around the elevators. These would track the temperature, belt alignment, belt speed, and more to ensure the client knew exactly what was happening in the elevator. For example, they could tell if the belt was too hot, or if the buckets were knocking on the walls of the elevator, creating the potential for a spark.
These sensors were connected to a monitoring system called Watchdog, allowing the site to keep track of all the relevant data in come place.
Illankovan said the client was happy with the results. So happy, that a few years later Satake was brought on board to help with a similar issue.
“This time, the elevator was inside a building,” he said. “When auditors had examined the plant, they found the elevator needed to be dust explosion proof, but the building had concrete floors, so it was difficult to get the machine in or out.
“There were also other challenges we needed to work around. The elevator for the site had proven to be inadequate, and the client wanted a higher capacity elevator. We looked at different designed but couldn’t go bigger because we would need to cut through the concrete floors.
“On top of that, we could only work on the weekends, while the mill wasn’t running.”
The solution Satake found was 4B’s “bottomless” elevator buckets. The bucket’s design is unique and somewhat counter-intuitive, consisting of a series of open buckets without a bottom followed by a closed bucket with a bottom.
The buckets are placed on very close vertical spacing so that the bottom of the top bucket rides just above the top of the bucket beneath it.
When material is loaded into the series of buckets, it flows into a continuous column so that the carrying space between the buckets is completely filled. The material from the first bottomless bucket rests on top of the material in the bucket below but does not displace it.
Tension is created both by the sloped sides of the buckets and the relatively small opening in the bottom of the bucket. The material footprint holds the mound beneath it in place without disrupting the materials angle of repose.
As the buckets rotate around the head or tail pulley, they fan out to increase the space necessary for proper discharge and filling.
The momentum of centrifugal force does the rest.
The system maximises bucket elevator capacity, helps to reduce materials from collecting in the buckets, and efficiently elevates dusty materials that require extreme venting.
Illankovan said the bucket had been proven to work elsewhere, but it was one of the first times it was implemented in Australia.
“The system worked well, it increased capacity and achieved the target of reducing dust,” he said.
Throughout the project, Satake highlighted safety at every step. Its safety officer undertook a full analysis of the jobsite, and its teams would go through briefings every morning.
It also provided the client with a full spare parts list, along with disabilities and expected lifespan. Satake can supply all the parts involved in both projects, removing the logistical headaches of dealing with multiple suppliers.
“The client said they liked working with Satake because we are flexible,” Illankovan said.
“We don’t just bring a solution; we can make sure the customer understands every step we do.”