New dribble chutes have been launched to prevent buildup in conveyor discharge chutes.
Martin, a global bulk materials handling business, has developed a new solution to prevent carryback released by secondary conveyor belt conveyors from sticking to the rear slope of the discharge chute.
Typically, if left to build up, material can compress on secondary cleaners and deposit carryback on the return side of the belt, fouling and causing accelerate wear on idlers and pulleys, as well as mistracking and belt slippage.
This not only caused a productivity issue, but also created a safety one, as it often required workers to reach into – or even enter – the chute to clear the blockage.
Martin has created a vibrating dribble chute which uses material disruption to cause tacky sludge and fines to fall from the chute wall and back into the main discharge flow.
“By addressing these issues, operators can experience a reduction in maintenance house, equipment replacement, and downtime, lowering the overall cost of operation,” Martin stated.
It was developed after engineers noted that majority of the buildup released by secondary cleaners collected at the rear of the chute mouth, where a sloped surface could trap carryback.
“We discovered this could happen with nearly every discharge chute conveying adherent material,” Martin Engineering product engineer Dan Marshall said.
“In some cases, even chutes treated with a low friction coating can experience buildup,” he said,” it’s only with the persistent disruption from vibration that we found materials flowed consistently.”
The equipment itself comprises three parts, a low friction polyurethane dribble sheet, a steel mounting bracket, and a powerful vibrator, while the machine’s mechanical disruption combined with the slick surface prevents sticky material from adhering to the conveyor, ultimately feeding it back into the main discharge flow.
When the unit is mounted onto pre-existing chute work, it also often extends the rear configuration closer to the belt, increasing the overall amount of material captured and further reducing spillage.
The dribble chute is also designed for easy installation, with operators creating a slot in the rear sloped wall top accommodate a steel hook bracket that secures the entire unit to the chute.
Lined with a soft thick rubber on the inside arch to protect the chute from structural abrasion caused by the equipment’s constant vibration, as a J-shaped bracket holds the dribble sheet secure with four bolts.
Importantly, the equipment can be field modified to fit with the width and length of any chute with the necessary belt clearance.
A thick rigid sheet of abrasion resistant ultra-high molecular weight polyethylene material is also installed in an elevated position parallel to the chute floor so the sheet can vibrate free.
It is driven by an electric motor that can be as large as 230-460 volts, three phase,50/60 Hz and runs as fast as 3450 RPM at a centrifugal force output of 7484 kilograms.
Its internal H class windings are tripled dipped, shock resistant, and able to operate under sustained internal temperatures as high as 180 degrees Celsius.
“We sought to design a simple and effective solution that only needs periodic pressure washing and is safer and more economical than the alternative: digging out equipment with shovels,” Marshall said.
“Less downtime and fewer maintenance hours results in a lower cost of operation, and over the long run, creates a safer workplace.”