The unloading and pneumatic conveying of fluorinated derivatives

Processed powders: fluorinated derivatives: ammonium bifluoride, sodium fluoride, potassium fluoride, magnesia

Ethanol production

Our customer is a specialist in the processing of oil seeds for biofuel processes. The new plant had a need to introduce fluorine derivatives into its production process. They were required to design a dedicated production skid to meet the delivery method of ingredients contained in bags.

Objectives of the project

Production requirements: Once a week a 3,000-liter buffer hopper is filled with the dry bulk materials. The buffer hopper then feeds a 1,200-liter dilution tank, which retains a high concentration of this bulk material in the water.
In the final phase, the concentrate is diluted in a 10,000-liter tank with a simple suspension of the dissolved solution.
Due to the small size of the first tank, the batch manufacturing process makes it easier to dilute fluorinated derivatives and avoid investing in a powerful and therefore expensive industrial mixing system.
The major imperative was to minimize the dimensions of the system, risks for operators and respect the process demands.

In order to limit operator fatigue and bad posture, Palamatic Process has installed a bag manipulator to assist in the lifting of bags from 25 to 50 kg, without any effort (weightlessness), up to the discharge point.
Once the bag is placed on the screen of the semi-auto bag emptying station, the operator closes the station’s door. A blade operated by a pneumatic cylinder cuts the bag along its width. An operator then opens the door and finishes emptying the bag manually, without having to use a cutting tool. Once the bag is emptied, the operator discards it directly into the adjacent bag compactor. This method prevents the release of potentially polluting dust into the atmosphere, because the residual fines tend to cling to the bag material and get into the air when tossing into an open top waste receptacle.
The empty bags are extruded directly into a polyethylene sheath that ensures containment and compaction.

The bottom of the sack tip tray station is equipped with a flat-bottomed anti-bridging system that feeds a pneumatic vacuum conveying line. The advantage of this technology allows the bulk material to be elevated at a lower cost and lower speed (limiting degradation).
The pneumatic conveying system is supplied by an air/material separation cyclone, which is installed directly with a flexible connector on the first 3,000 liters buffer hopper. The hopper, mounted on load cells, is provided with a dehumidifying system to limit the material's exposure to moisture.

In the lower part of this hopper, a flat-bottomed anti-bridging device is used to feed a screw conveyor that transfers the material to a dispersion tank used to produce the concentrate. The dosing is carried out by the servo control of the screw and the anti-bridging device on load cells. Dispersion is carried out by a profiled helix shaft which allows the dry bulk material to dissolve rapidly at room temperature. The HDPE manufacturing tank (avoiding any risk of corrosion) is supplied with an anti-vortex system.
The resulting concentrate, obtained in masked time, is vacuum conveyed on demand of the final liquid storage tank.

Results

By its design, the system allows the production of a long-lasting buffer before a dilution phase and therefore avoids a disproportionate investment of the small daily quantities of mixture used.