GEA, the engineering, machinery and equipment manufacturer and solution provider, has delivered a new evaporation plant to Viscofan at its Navarra site in Caséda, Spain.

The upgrade was realized with GEA's Mechanical Vapor Recompression-Technology (MVR). The aim of the project was to increase the evaporation capacity, reduce energy consumption and significantly reduce the CO2 footprint. In addition, since all the measures take effect quickly and efficiently, it is possible to amortize the investment costs after only one year. Viscofan, headquartered in Tajonar, Navarra, Spain, is the world's leading supplier of casings for meat products and distributes them in more than 100 countries.

Viscofan decision for energy conversion in 2021

Viscofan operated for many years a steam-heated evaporation plant to remove water from their liquid process stream from spin bath to keep the required concentration in the process. The growing production required an increased evaporation capacity of 5000 kg/h. Already since 2016 Viscofan started together with GEA to evaluate the implementation of a Mechanical Vapor Recompression solution for this new evaporation plant and finally decided in 2021 to make an energy conversion as part of their commitment to the Sustainable Development Goals and its efforts to achieve the highest possible level of sustainability without compromising its safe and high-quality processes.

Conversion by GEA started in summer 2022

GEA began work on the new MVR system for Viscofan in the summer of 2022. An MVR-heated evaporation plant is a solution that uses the enthalpy of condensation from previously compressed steam streams to heat evaporation processes. The steam is recompressed to the pressure of the corresponding evaporator heating steam temperature, using a small amount of electrical energy compared to the enthalpy recovered in the steam. Said processes substitute the steam generated by fossil fuel heating at a boiler by electrical (green) power allowing for energy costs and CO2, footprint saving.

This MVR solution achieves a reduction of the total costs for energy consumption of the evaporator of up to 90% compared to the old steam heated evaporator system.

GEA uses non-corrosive materials

The GEA expertise on delivering in different materials depending on the process´ requirements is one of the reasons why Viscofan is a longtime customer. For this modernization project, GEA supplied a combination of equipment made of very different materials and special materials. These included heat exchangers made of graphite pumps made of Hastelloy and separators, vessels and pipes made of reinforced plastic, as the product is acidic and would otherwise corrode stainless steel.

Mechanical Vapor Recompression (MVR)

The operating costs for an evaporation plant are largely determined by energy consumption. Mechanical Vapor Recompression (MVR) and Thermal Vapor Recompression (TVR) are technologies that GEA uses based on many years of experience. GEA provides customers with the optimal system tailored to their individual needs.

While thermal vapor recompressors (TVR) compress only a part of the vapor leaving the evaporator, mechanical vapor recompressors (MBV) can recirculate the entire vapor. The vapor is compressed – usually using electric motive power – to the pressure of the corresponding heating vapor temperature of the evaporator. The energy of the vapor condensate is often still used to preheat the incoming product.

Depending on the operating conditions of the plant, a small amount of additional steam or condensation of a small amount of excess vapor may be required to maintain the overall heat balance of the evaporator and ensure stable operating conditions, especially during start-up.

Single-stage centrifugal fans (supplied as high-pressure fans) are used in evaporation plants because of their simplicity and low-maintenance design. These machines operate at high flow rates and therefore handle large throughput volumes at compression ratios of 1:1.2 to 1:2, with typical speeds ranging from about 3,000 to 12,000 rpm. Multiple blowers can be used for higher pressure rise.