Launching January 2023
ABC Hansen Africa has developed a range of dust free hammermills – based on our tried and tested Hippo Hammer mill platform.
While Hippo Hammer mills have in the past nearly 100 years always been manufactured with a positive pressure cyclone system (where the product is extracted from the milling chamber with the integrated fan, and the product then passes through the fan, and is blown into the cyclone – so the cyclone is under positive pressure – hence a positive pressure system) – ABC Hansen has now developed a system where the product is handled in a negative pressure manner in the cyclone.
What is meant by a negative air manner – is that the product is still extracted by air from the milling chamber, but the fan actually sucks the product through the cyclone, instead of pushing the material through the cyclone – hence the cyclone is under negative pressure – instead of being under positive pressure where it is blown into the cyclone.
The advantages of this in the use of air in the cyclone are as follows:
1) The Hippo Hammer mill will now create even less dust. The standard positive pressure mill is probably the least dusty of all the mills in the South African market at the moment – but this improvement will virtually eliminate dust from your milling experience
2) It is possible to fit more efficient fan impellers – as the fans are no longer material handling fans – they are now purely air fans – which could increase capacities of the mills, due to higher airflows.
3) It is possible to run a higher range of rotor speeds – as the more efficient fan allows for higher airflow at lower rotor speeds – allowing for greater particle size distribution control.
To prevent air from getting sucked in from the outlet of the cyclone, ABC Hansen has developed a gravity controlled air valve, which is opened by the weight of product laying on top of the valve – and then discharges the product, till the weight is low enough to close the valve again. In cases of very light product being milled – that doesn’t have sufficient weight to press down on the gravity valve, a normal airlock/rotary valve can be installed.
The excess air from the system – will still be discharged to a 1/4/8 sock dust bank – as in standard variations.
As is standard on all Hippo Mills – an automatically adjusted inlet is installed, that controls the inlet size of the mill – by using airflow. When the milling chamber is empty, the airflow will be high, and the adjustable inlet will open completely, allowing maximum inflow into the milling chamber. Once the milling chamber starts filling up, the airflow will decrease, which will then cause the inlet to move to a smaller opening position – allowing the mill to grind down the product in the chamber – once the milling chamber is cleared out again, the airflow will increase – allowing more product in – thus automatically regulating the feed into the mill – eliminating overfeeding and clogging of the mill, while keeping the capacity at maximum, by allowing a steady, regulated flow of raw material into the mill.