Sodium Silicofluoride Packages
ProMinent offer sodium silicofluoride packages designed in accordance with the NSW Fluoride Act. A typical sodium silicofluoride package might operate as follows:
From the storage hopper the powder is fed via a ProMinent dry chemical feeder into the mixing tank. The mixing tank is equipped with a high speed stirrer, overflow and drain pipework and has a retention time of 10 minutes. The solution is then transferred to the injection point by a Spectra positive displacement pump all controlled by an Allen Bradley PLC.
The loading of the hopper is normally carried out by one of three ways.
By unloading from 25 kg bags via vacuum loader
By unloading from the top of a bulk bag via vacuum loader
By using a crane and hoist bulk bag unloader
Our loss of weight system includes 3 load cells that are mounted on a galvanised support frame. A 4-20 mA signal is available for retransmission to the main WTP or to a circular chart recorder. Electrical panels would include for all interlocks as required, together with all necessary sequencing that we normally build into a fluoridation system to comply with the Health Commission and other statutory requirements of NSW.
Vacuum Loader (25 kg bags)
The ProMinent vacuum transfer system is designed to transfer powder from 25 kg bags to the hopper. The suction wand is inserted in the bag and the air is drawn upwards through a filter to remove any powder particles that are still airborne, before leaving the unit via the vacuum motor.
As the powder enters the collection unit, the large volume inside the unit causes the air velocity to drop, allowing the powder to fall to the bottom of the unit.
A pneumatically actuated valve at the bottom of the collection unit is used to dump the collected powder into the hopper. A second valve on the suction side prevents powder from blowing out of the wand during the cleaning cycle.
Vacuum Loader from top of Bulk Bag
A bulk bag vacuum system safely transfers the fluoride powder to the day hopper by unloading from the top of a bulk bag. System operates as follows:
A bulk bag is loaded by the operator into the bulk bag trolley via a forklift. The vacuum blower is started and the outlet of the bag is clamped by the operator to the inner connection and the bag tie is then removed.
Fluoride powder is then drawn from the bulk bag by the vacuum transfer system through the suction wand to one of the 2 vacuum chambers mounted on top of the storage hopper.
After a preset time, operation is switched to the second vacuum chamber for vacuuming and the powder collected allowed to fall into the hopper. After a short dwell time, the first vacuum chamber is purged with compressed air to clean the internal filter screen.
When the second chamber is finished, same happens and operation switches back to the first. Operation will continue to swap between each of the vacuum chambers until vacuuming is stopped.
Crane and Hoist Bulk Bag Unloader
A bag is placed on the lifting frame by attaching all 4 hooks to the top of the bag. The over-head crane is then used to lift the bulk bag over the intermediate "floor" hopper for transferring to the storage hopper ready for metering into the water supply