Overcoming excessive machine wear in sugar processing

Castolin Eutectic’s technical lead, Raul Amor explains how excessive wear can be avoided to ensure that critical sugar processing machines will remain in service throughout the harvest

Sugar cane processors face the challenge that cane is extremely tough and can damage processing equipment. Components in harvesters, feed systems, knives and hammers in defibering units and crushers can all wear out quickly and even break down. But there is a solution: wearfacing coatings protect equipment from the damage caused by sugar cane. The benefits are that equipment will extract sugar more efficiently, last longer and need fewer repairs.

Sugar is big business and it is growing bigger. According to Fortune Business Insights, the worldwide sugar market is expected to grow to US$46.56bn by 2029, with operators in Asia Pacific having the biggest share of the market. Typically, mills process between 10,000 to 45,000 tons of sugar cane per day. They need heavy industrial machinery – and a lot of it – to do this. However, excess wear and breakages can stop production. This can be expensive due to repair costs, downtime and lower yields. 

Overcoming abrasion at every processing step

Abrasion from sugar cane, stones and earth can cause excess wear on washing, chopping, defibering and crushing systems. Wearfacing coatings can overcome this to enable operators to extract more sugar cane with less downtime. One particularly vulnerable area is rollers in cane crushers, which experience wear and breakages on their teeth. Being made of cast iron, the rolls need particular care. To prevent cracks forming, specialist welding electrodes for cast iron should be used.

It is important for the electrode material to have high hardness and corrosion resistance, which will provide additional wear resistance and ensure a long service life for the rollers. For rollers that experience a lot of damage from rocks and soil, some wearfacing materials offer better resistance to impact.

Wearfacing coatings can build the teeth sides and tips to their original shape so that the crusher will work more efficiently for higher yield. Several passes can be applied to rebuild the teeth with a serrated teardrop profile. This can even be done with an automated welding system to ensure uniform size and spacing between teardrops. It is also possible to apply a top layer of dots onto the sides of teeth while a roller is turning. This creates a rough surface that maximises juice extraction.

Case study: cost savings in action

Burning bagasse can also cause excess wear on fans, tubes and ducts. At one sugar cane mill, a boiler induced draft fan was suffering severe erosion caused by unburned bagasse and soil. These had begun to wear down important sections of the blades until, gradually, the entire rotor wore down. For an idea of the potential impact on production, the plant had four boilers, and each one with a fan.

In a previous attempt to repair the fan, a wearfacing had been applied by electrode welding in one area of the blade where wear had begun to affect the fan. However, this did not last. As an alternative, a Castolin Eutectic engineer applied an arc spray coating based on a 10 mil Arc 500 wire and 20 mil Arc 595 wire. This doubled the rotor lifespan without increasing the weight of the rotor or affecting its balance. 

The result: a more profitable production line

By installing wear-resistant coatings, processing equipment will withstand abrasion from the coarse sugar cane. By avoiding such wear and tear, equipment can last a whole milling season without downtime for repairs. Uninterrupted, each milling season will be more productive, and ultimately more profitable.

To find out more about wear resistant coatings, visit: https://www.castolin.com/sugar