1957 G60 Probat Coffee Roaster Restoration

Coffee Roaster Refurbishment

In 2015 Coffee Roasters Australia commenced a coffee roaster restoration service. This initiative stemmed mostly from customer requests to upgrade various brands and makes of roasters with our Coffee Sweet control system that we were already fitting to the Has Garanti and Proaster brands we sell. We have been modifying the brands we sell for quite a while with the in-house control system we developed to cater for the trend of Australian roasters wanting finite control and visual feedback during the roasting process. I am proud to say that the Coffee Sweet control system has continued to develop into one of the market leading coffee roasting interfaces thanks to the input and recommendations of the many users out in the market. We decided to take things a step further and offer this system as well as a full refurbishing service to other brands out in the market both new and used.

One of things that I have noticed over the years in dealing with coffee roasters and the people using them is that there is no perfect system. If you ask a coffee roaster they will always highlight a few things about their equipment that they don’t like or think can be improved. It doesn’t matter how much money you spend there will always be some limitations on the equipment. Customers are always looking for an edge or a feature that they believe will help them develop a raw coffee bean into something magical. From my experience this is rarely delivered by the equipment but more so by the skill of the person operating it. I would like to think though that we at Coffee Roasters Australia are better positioned to be able to give the roaster what they want when it comes to equipment features. We are constantly improving our technology based on user feedback. We always do our best to try to give the consumer what they want and where it is not possible we try to educate them as to why.

The Restoration Project

I have a passion for equipment and a deep appreciation for the relics of the past. What you will notice is that roasting equipment structure and design has not really changed all that much over the last 70 years. Sure there are improvements in manufacturing processes and vast improvements in the operating systems but the structural design and integrity of the machines is not all that different. To give you an example; we took on a full refurbishment of a 1957 G60 Probat Coffee Roaster. The brief from the customer was to refurbish the machine and install a new modern operating system. The roaster was in a very bad state of disrepair but structurally it was still sound. What I mean by that is the drum and housing was still in working condition. The drum is basically the heart of the machine. The machine also came with a green bean loader, separate cyclone with rotator valve, afterburner and a destoner. The roaster originally would have had an atmospheric heating system but this one had been converted at some point to use a package burner. This was probably as big as refurbishments of roasters go due to the amount of restoration work as well as a new electrical and gas system. The G series Probats were built to last though and are an important part of roasting equipment history. We really wanted to see this old girl working again and were excited that the brief went beyond just the restoration but to also incorporate a new control system offering full automation of the process.

We started by disassembling and cataloging all the parts. Most of the metal work was structurally sound but was either caked in scale, paintwork faded or peeled or fire damaged. We decided to get most components sand blasted to strip them bare so we would have a clean surface to work off. Unfortunately one of the downsides to the very old roasters is they didn’t use stainless steel but mainly plated metal. So after sandblasting we had to re-plate the metal where required or use special sealers and paint for food areas. The cleaning alone of just the internal parts of the system was a mammoth effort. All motors and gearboxes were stripped, cleaned and lubricated. We had buckets full of scale from under the cooling tray and in the fans and pipes. Once the parts came back from the sandblasters the next step was to prep the surfaces for painting. You have to use special paint and primer for roasters due to the high operating temperatures. We decided on a colour scheme in keeping with the style of Probat with black and silver. We do painting in house and the colour scheme we used on the Probat really stood out.

There were quite a few parts that were damaged beyond repair. This meant identifying the parts and then drawing the CAD plans for manufacturing. All the CAD design work we do in house at Coffee Roasters Australia. The cooling tray except for the structural components was basically re-made and looks as new. A completely new combustion chamber was designed and manufactured. The afterburner supplied was poorly made and falling apart so we designed and made a new afterburner system with modulating control. Some other parts remade were: the bean sampler, all site glasses, destoner frame, some of the pneumatic gates, 3 way diverter valve for the cooling and destoner.

Whilst all this was going on, the other part of the brief of developing a new control system was also underway. At this stage we didn’t have a control system for package burner systems greater than 300Mj/hr.  Our standard Coffee Sweet system is more for an atmospheric burner system or smaller package burner roasters up to 30kg batch size. For this project a completely new control system was designed. We used the framework of Coffee Sweet to write the program but took it a step further by incorporating all the control parameters required for automating a larger industrial plant. The system had to incorporate a number of actuators that control the opening and closing of gates and all the additional motors, plus the heating of the roaster and afterburner. All the previous electrics of the roaster were removed and the wiring was started from scratch. A new control panel was built with large touchscreen to handle all the operations. The system also has a completely new burner and valve train with the burner system we use offering an extremely low turn down ratio allowing the user a much greater range of modulation than a standard modulating package burner which you see on all industrial roasters.

Like the standard Coffee Sweet systems it was chosen to write the software interface in a Windows based format. The PLC based operating systems have too many limitations in regards to profiling and visual display as well as future functionality. It is also easier to provide updates and support for this system as they can be made available automatically through WIFI. That being said the software was written to communicate with a PLC for the switching and motor control functionality. The software system includes many features as well as controlling the burners and all motor speeds in 1% increments. You can roast fully manual or you can automate all or various parts of the process. The burner range of control on this system is far superior to what is out there in the market. Four thermocouples can be graphed and monitored with ROR and there are infinite profile saves. The system has a lot of safety features built into it and is made to comply with Australia’s strict gas and electrical standards. One of the advantages of this system is that we can customize it for any project and future updates and improvements are made available to users through WIFI. If you wanted something specific for your application then we could do it.

At the time of writing this the plant was fully operational and the focus was now more on improving cosmetic graphics on the control system. To date we have completed a number of restorations and are currently refurbishing a Diedrich IR24, Petroncini 30kg, Vitorria 25kg and Has Garanti 30kg.

1957 G60 Probat Coffee Roaster Restoration Before & After
1957 G60 Probat Coffee Roaster Restoration Before & After

Helping growing coffee companies

One of our key focus points at Coffee Roasters Australia is helping customers through their growing pains when it comes to taking their business to then next level. It can be a very large jump in capital expenditure required to invest to increase production output and efficiencies. We understand that this is a very difficult decision for growing coffee companies so we have a range of options available in many different budgets from new to used. We already are supplying destoners and afterburners for many different market brands with a quick cost effective turnaround that are Australian compliant. Importing from overseas whether direct or through a distributor can take a very long time, is expensive, can be non-compliant and a less flexible option. We also offer trade-ins, purchase of old machines, sourcing of second hand machines and custom made plant options as well as new equipment from Has Garanti, Proaster and Coffee Tech Engineering. We are lucky to have a very close relationship with our suppliers who are very accommodating in design flexibility when it comes to the Australian market.

In the future we plan to innovate, develop and continually improve our technology. I would like to see Australia recognised for coffee equipment as much as we are for barista and roasting skills.

Article by Mark Beattie