Veco, a company from the SPGPrints Group and the largest global manufacturer of high quality screens for application in continuous centrifuges, carried out a comparative performance study between their special sieves and standard sieves in a sugar mill in Sao Paulo State, in the summer of 2015. The results were expressive in regard to the product’s cost/benefit ratio. The use of VecoFlux in the sugar production of 1.6 million tons of raw material would bring savings of R$ 190 thousand for the plant during the year/harvest.
In this result, the cost/benefit ratio for the mill using VecoFlux was undeniable. The savings brought in the plant recovery during the test ensures, for example, that the company may acquire new special screens for all centrifuges and still is able to perform the required maintenance to run the sugar production process.
According to the consultant Achiles Mollon, industrial chemist with more than 35 years of market experience followed the test and owner of A2M Consultoria Laboratorial. Savings in that order in the manufacturing process have a large impact. Given that the sugar-ethanol sector has been operating with a low cash flow for some years and, eventually, plant maintenance ends up being impaired.
According to Paulo Ruffini, manager at SPGPrints, the results confirm the quality of VecoFlux and its importance in bringing savings within the productive process. “We have special screens that can ensure significant improvement in the production process and we showed that during the test. The result is the efficiency of the plant and the demonstration of our products’ benefits”, he elaborated.
Due to the type of assembly and the patented process, the VecoFlux special screen has totally different electroforming behaviors than the standard screen. “With a larger open area, as a result of its structural build, enabling a larger number of holes per surface. The product ensures an efficient syrup flow, higher retention and productivity of sugar crystals, lower purity of the final molasses, lower breakage of sugar crystals and clogging reduction in the centrifuge process. Providing high performance and savings at the end of the process, as proven in the test”, according Ruffini.
SPGPrints performed the test between November 21st and December 25th, 2015. With some plant interruptions due to rains registered in the period, resulting in 14 days of assessments. The objective was technically comparing VecoFlux with standard screens. Taking into account the quality in the sugar production process, the variation of the final molasses purity and the financial return by only replacing the conventional screen by the special screen.
The test was made in three centrifuges, two with the standard screens and one with the special screens. “While performing the test we compared the screens in equal conditions. In this case they were new screens. The raw material used in the process was also the same to maintain the same process conditions”, explained Mollon, adding that he followed the assembly of the screens in the centrifuges.
In order to quantify the test results reaching the savings value in Real, Mollon used the final syrup purity as a parameter. “I used the SJM recovery formula – which is based on the sugar purity, broth purity and syrup purity, resulting in the plant recovery – and the TRS balance (Total Reducing Sugars). In the methodology, I determined the brix and the polarization. With this calculation I obtained the purities. These are the numbers that will go into the plant recovery”, he explained.
According to Mollon, water wasn’t used in the mass that supplied the centrifuges, neither was syrup. “The performance difference between the screens during the assessments was 0.65, which is the SJM recovery in favor of the special screen. Thus we were able to determine the variation in the quantity of the sugar produced. With the special screen during the year/harvest, 1,329 extra tons could have been produced in comparison to the standard screen”.
To obtain the final value in Real of the savings by the use of the special screen for the mill during the crop, the consultant used the price data that ethanol and sugar had on the market on January 22nd. “After this result, the gain in Real in the production of sugar, would be approximately R$ 190 thousand. By the increment produced in the factory recovery. Therefore, in a crop for those testing conditions, we would practically gain R$ 190 thousand for the mill per 1.6 million ton”, concluded Mollon.
In the chart below, SPGPrints/Veco outlines the savings brought in Real according to the tons per year/harvest with the use of VecoFlux screens:
| Milling (t) | 1.500.000 | 3.000.000 | 4.000.000 | 6.000.000 | 8.000.000 |
| Gain | R$ 174.593 | R$ 349.173 | R$ 465.564 | R$ 698.347 | R$ 931.128 |
Source: SPGPrints/Veco
In the last few years, several mills closed down in Brazil, most of them in Sao Paulo. The state is responsible for more than half of the national sugarcane production and the mills’ closure reflects the crisis the sector has been facing for at least six years. Despite the price recovery both for sugar and ethanol in the market, the sector’s resumption may take another couple of years and this setting primarily impairs the maintenance of the factory in the entire productive process.
Mollon explained that some mills already deal with major cash flow problems. “The outlook for the next couple of years is not good, because there are no investments. The maintenance being performed on the equipment is very basic, particularly this year in which the harvest delayed and the mills shut down practically in December, and have now started milling in March. Hence, maintenance was short and done only on the essential equipment”.
According to Ruffini, in the last couple of years, sugar prices were among the lowest for the last ten years. “However, Brazil is producing less, India is producing less and consumption has increased. The demand can be part of a growth upturn. However, the best results expected for the next years will only take place when the entrepreneurs consider production line details, such as frequent maintenance, to improve the mill operation performance”, argued Ruffini.
One of the important points within the sugar production process focusses the continuous centrifuges. Its maintenance, regular screen replacements, and the option for the special screens are important factors to obtain positive results, such as those demonstrated in the study made by SPGPrints.
Lack of screen replacements, for example, may influence in sugar loss for the final molasses. This loss may be a result of screens having a lot of usage time, with dilation of screen openings and wear. Improper screen replacement – even special ones that have longer work lives compared to the standard ones – may compromise the centrifuge’s performance and, in result, cause major losses in the factory’s recovery.