ELETTRA, the perfect combination of performance, flexibility and sustainability: how the first evaporator to eliminate steam consumption in hot and cold break tomato concentrate production was born

For more than seventy years, Rossi Ingegneria Alimentare has been developing technologically advanced solutions for the food processing and packaging sectors. Since the early 2000s, Rossi has focused on developing energy-saving technologies, with the aim of promoting a business model that is sustainable for both the environment and the community.

Now more than ever, sustainability is an urgent issue. We are in the midst of the ecological transition, and the key factors in this process are:

• Energy efficiency
• Decarbonisation
• Waste re-use

Pursuing these objectives - depending on the country in which you operate - also opens up significant business opportunities, including:

• Direct cost reduction
• Tax avoidance
• Investment incentives

ECOLOGICAL TRANSITION: what are the opportunities for tomato processors?

We at Rossi are dedicated to supporting our clients on this journey with our solutions. This mission has led us to create our most recent innovation, ELETTRA: the first evaporator capable of producing hot and cold break tomato concentrate without consuming boiler steam.

We talked about it with our Sales Director, Francesco Rossi.

ELETTRA is a completely new concept in the evaporator sector. How did the idea of developing an all-electric solution come about?

The fresh tomato processing industry has a non-negligible ecological footprint, and to understand what the areas for improvement were, we analysed the impact of each stage of the process for different products: hot and cold break concentrate, diced products and pulps, purée and other intermediate Brix products. We analysed a weighted average based on the volumes of these products worldwide, and found that 93% of energy consumption is due to two phases: evaporation and enzymatic deactivation. Most of this energy is used to generate boiler steam, so 94% of emissions come from these same phases. This led us directly to the idea of creating a fully electric evaporator.

Ecological footprint of each process step

However, just building a tomato processing machine which does not use steam is not enough to significantly reduce energy consumption and emissions. In addition, our customers need solutions that also guarantee high product quality, reliability, maximum operational efficiency, and flexibility in use and configuration, to ensure the best return on investment.

ELETTRA’s answer to these requirements?

Thanks to its innovative design, consisting of pre-engineered modules, ELETTRA enables us to configure the most suitable solution for the client's needs - whether for a new plant or an upgrade or replacement of existing lines - depending on the type of production, up to 38 °Bx in concentration. Indeed, ELETTRA makes it possible to integrate multiple product circulation technologies - falling film, hybrid flow circulation and forced circulation – into a single evaporation system, thus combining their respective structural advantages with the benefits offered by optimising the mechanical recompression of the vapours in the various sections of the plant.
Suppose that a client is producing both purée and concentrate - even simultaneously - and is not equipped with high-efficiency technologies: in this case, we can provide an ELETTRA solution with a falling film pre-concentration module that simultaneously feeds both a hybrid flow circulation module (for intermediate Brix purée) and a forced circulation section (for concentrate at 28-30 °Bx). The entire evaporation section would share two mechanical compressors rated for the operation of the entire system, thus taking steam out of the equation and reducing energy consumption by up to 80%.

What about product quality?

The quality of the product is preserved thanks to a design that accounts for the parameters that risk thermally damaging the product: time and temperature. With ELETTRA, you no longer need a finisher evaporator after the pre-concentration phase, so the total residence time of the process (the first parameter) is greatly reduced. If the product being processed allows it, this can be further optimised by combining falling film and hybrid flow circulation evaporative modules. Using MVR (Mechanical Vapour Recompression) technology even on stages with product at higher concentrations enables us to drastically reduce the wall temperature of the exchanger, thus controlling the second of these parameters, temperature.
Like our THOR and HERCULES evaporators, ELETTRA can also be equipped with particularly delicate pumping solutions, ideal for preserving the pulp and texture of special products like rustic purées.

One might think that such an innovative and versatile solution would involve a significant investment and very long delivery times. Is that true?

The project was developed from the very start with a view to short payback and time to market in line with customer needs: the technologies implemented in each module are widely established and have been part of our range for years, so that each section has already been optimised in terms of exchange surface, product processing and energy consumption. We have over ten years of experience in MVR technology applied to concentrations up to 16 °Bx, and ELETTRA now allows us to integrate the last product concentration stage in a single plant, thus offering the same benefits.

Market Needs

Optimising water consumption is an equally important issue in terms of cost savings and sustainability: is ELETTRA a winning solution in this area too?

The main source of water consumption is the tomato washing stage, followed by the need to replenish water in boilers and other services. By combining ELETTRA with METIS, our high-efficiency enzyme deactivator, we have been able to achieve reductions in water consumption running from 40% up to almost 100%, depending on system configuration.
METIS optimises the reuse of process condensates, thus reducing the consumption of steam for enzymatic deactivation and providing room temperature water for other processing stages at no additional cost. We call this the “Virtuous Circle of Recovery”.

So business and sustainability can really work together?

For us at Rossi, the answer is yes, without a doubt. We have always aimed to develop efficient technologies that create value for our clients, respect the environment and improve the lives of consumers around the world.
ELETTRA is a major step forward in achieving this aim, and we are very proud of it.