We want to reduce the moisture content! We want to migrate from other filtration machines (Nutsche) to centrifuges! Bottom-discharge DMN β
N Corporation, an agricultural chemicals manufacturer, contacted us about “lowering the moisture content before putting the product into a dryer by migrating from the existing Nutsche to a centrifuge. “
However, if the centrifuge were not airtight, as a flammable solvent (which might explode if the oxygen concentration were not lowered) would be used it would be dangerous, but they requested that a test be conducted once.
So, we suggested that the test be conducted on a HERVA 24 + M (bottom-discharge centrifuge) test rig.
The machine itself is airtight, so there is no problem with the machine itself. However, the piping and outlet sections were open for the test machine. So, we had the user make them closed at our suggestion and conducted the test while checking the oxygen concentration.
The results were positive, and we were able to reduce the water content, which was our goal, so the customer installed the DMN type.
The moisture target was between 10 and 15% and the test result was 10.7%. Nutsche, the currently installed filtration machine used until now, had a water content of about 30%, so the target water content was achieved, and the water content was significantly lower than that for the Nutsche.
The main reason for selecting the DMN was that it was easier than for the MARKIII model to visually check the interior of the basket when the casing opening and closing device was activated.
(1) Conducting the test with the actual machine
We made several suggestions from the testing stage, actually cleared the high hurdle of the test, and confirmed that the centrifuge could be used.
(2) Casing Opening and Closing Mechanism
By using the casing opening and closing mechanism, the wetted parts’ visual confirmation and cleanability are significantly improved.
In the absence of an opening and closing mechanism, heavy lifting is required to check the wetted parts, but with this mechanism it is no longer necessary and opening and closing can be performed at the touch of a button.
If an oilless machine is desired, electric cylinders can be used to open and close without oil. (Usually, a hydraulic cylinder is used. Depending on the model and size, this may or may not be acceptable.)
(3) Screw, Nitrogen Blow
・Screw (residual crystal detachment device)
->During scraping, a clearance of 12.5 mm or more is provided to prevent the scraper device from coming into contact with the basket, but the adoption of a screw makes it possible to narrow the clearance to a standard of 6 mm or more.
The quantity of residual crystals recovered is increased, and the recovery speed is also faster, thus shortening the production process time.
->As above, it is attached to the cutting edge of the scraper device for residual crystal detachment.
Residual crystals can be detached from the filter cloth by ejecting nitrogen from the cutting edge.
If the crystals come off easily, the entire amount can be recovered.
N Corporation, a manufacturer that produces agricultural chemicals