The CHU goes beyond the recycling of cutting fluid as it can also clean the sump of the machine tool, removing stubborn residue and swarf. Unlike previous fluid extraction and recycling units, the Freddy CHU has the ability to continuously recycle coolant at the machine, unmanned. For machine tools with relatively large coolant sumps, the CHU can recycle the coolant while the machine is operational, keeping spindles turning during coolant and sump cleaning.

Recycling fluid at the machine during operation is what sets the unit apart. This functionality is credit to the addition of a secondary filter bag that allows the CHU to retain its consistently high coolant flow rate without ‘blinding’ or blocking-up filtration bags. As a result, there is no need to extract coolant to an external IBC and then transfer the clean fluid back to the machine.

The mobility of the CHU is derived from its compact design, with respective length, width and height dimensions of just 1,260 by 880 by 610 mm. Furthermore, the 151 kg (365 kg when full) CHU can be easily moved around the workshop on its castors, while the 2 kW motor runs off a single-phase 110 V power supply.

Freddy’s CHU reduces the time to clean cutting fluid in machine tools: recycling 2,500 litres of coolant takes place in less than one hour. This cleaning rate allows manufacturers to clean fluid rapidly and efficiently, reducing the need for coolant changes, lowering fluid costs and disposal, and improving environmental credentials for the end user.

Hugely significant to the development of the CHU is the magnetic suction and return nozzles that can be placed in the machine tank to provide completely hands-free operation. This capability is complemented by a fully automated ‘fill’ and ‘empty’ function that allows the transition of fluid through the CHU and back to the machine without operator intervention.

Development of the CHU is the result of a 12-month joint project with Rolls-Royce that targeted ‘at-machine’ fluid recycling. The aim was to recycle machine coolant, reduce waste, and improve operator health and working conditions – in the most efficient way. This collaborative effort resulted in the integration of a second filtration unit, whereby fluid passes through a primary filter that catches large chips and swarf prior to passing through a secondary filter bag for capturing small fines and oil residue.

Choosing the filter bag combination is dependent upon the application, but in many machine shops, the configuration of a 100 micron bag for catching larger chips with a 25 micron secondary filter bag is sufficient for most. However, grinding centres, specialist machines and particularly dirty machine tools may require different filtration options. Experts at Freddy Products can supply filtration bags from 1 micron up to 1,000 micron. Filtration bags from 100 micron upwards can be cleaned by hand to reduce the maintenance and running costs of the CHU.

As well as having the facility to run unmanned, the Freddy CHU is available with a host of optional tools such as a Y-shaped outlet for connection to a standard discharge gun, extended length (800 mm) discharge guns and a fishtail nozzle with additional extenders in 1 m lengths. The optional additions enable manufacturers to use the CHU as a jet-wash inside the machine while recycling the coolant. Furthermore, the ability to extend lance lengths up to 3 m allows operators to loosen and unblock stubborn stains, and provides access to difficult-to-reach areas where dirt and debris may be resting.

Managing director at Freddy, Simon Hanmer, says: “The big thing for us is the extra filtration, which is credit to an additional basket placed at the top of the machine. This allows us to speed up the operation and, by putting two different filters in the machine, it becomes twice as effective.

“Very early in the development stage, we knew we were getting great results with the CHU,” he continues. “A CHU delivered to Rolls-Royce back in August 2019 saved 24,000 litres of coolant in just four weeks. That was achieved by cleaning coolant and recycling it back to the machines, avoiding the financial and environmental cost of disposal. In terms of financial numbers, the oil that is not being taken off-site and replaced is equating to a £9,000 saving in a short period of time. Furthermore, we can refurbish some existing Freddy vacuums to integrate this technology.”