If you own a food and beverage or pharmaceutical processing company, a heat exchanger will add value to your operations. Among other properties, these systems provide constant temperatures for pasteurization without the risk of contaminating the heated fluids. In the same way, they provide adequate heat levels for the fluids used in cleaning in place.

We invite you to learn the basics about heat exchangers and their most common applications.

 

First of all, what is a heat exchanger?

Basically, a heat exchanger is a piece of equipment that is responsible for transferring heat continuously from one medium to another. These exchangers allow us to regulate the temperatures of the different liquids during the processing of beverages, food and pharmaceutical products destined for pasteurization, sterilization and cleaning in situ, among other hygienic procedures. There are two types of heat exchangers: direct and indirect.

 

Direct heat exchanger

In essence, it is when both media are in direct contact with each other. Furthermore, it is assumed that they do not mix. A cooling tower would be a clear example of this type of exchanger since the water is cooled through direct contact with the air.

 

Indirect heat exchangers

On the contrary, in an indirect heat exchanger, both media are separated by a barrier through which heat transfer takes place. We can find three main types of indirect heat exchangers: plate and frame, shell and tube and scratched surface. In general terms, this latest temperature exchanger offers a more efficient solution to thermal problems, since it provides broader limits, both in pressure and temperature, within the restrictions that current equipment may have.

 

Uses of a heat exchanger and how they work at an industrial level

For the food and beverage industry, a heat exchanger makes products completely safe for consumption. In the same way, it can prolong its useful life of it, preventing the growth of harmful microbes. In the case of milk processing, these exchangers have the function of pasteurizing said beverage, by increasing its temperature.

In pharmaceutical processing, the ingredients used in the manufacture of cosmetics and pharmaceutical products must be mixed at specific temperatures. This procedure ensures both its use and its quality. In this case, the heat exchanger can vary depending on the qualities of the processed fluids. Specifically, by the size of the particles, the viscosity, the temperature and the flow.

 

How does a plate and frame heat exchanger work?

It should be noted that plate heat exchangers and frame heat exchangers are among the most efficient designs. Apart from that, it is one of the most common models in processing systems. The joints between the plates direct the flow of the product, as well as that of the heating and cooling fluids, through alternative paths. For its part, the hot fluids advance through the plates, the heat is transferred from the hot to the cold side. This indicates a temperature decrease in the hot area and an increase in the cold area.

To function optimally, heat exchangers must maintain sufficient fluid velocity through the plates. In such a way that the heat can be transferred, controlling, in turn, the pressure drops that can stop the optimal operation.

In general, we can find a plate and frame heat exchanger intervening in the pasteurization and refrigeration processes of raw milk. It is also ideal for CIP heating or “clean in place”. In the same way, this type of temperature exchanger are common in the processing of beverages, such as beer, must, sauces and eggs. As well, they are involved in the production of most dairy products. This is because the aforementioned systems are suitable for products with low or medium viscosity and with few or no particles present.

 

How shell and tube heat exchangers work

Unlike the previous system, which sends heat through parallel plates, shell and tube exchangers transfer heat between a set of tubes surrounded by a huge container of the shell. In short, the fluids that circulate through the tubes exchange heat with the other fluids that pass over the tubes contained in the shell. The basic principle of this heat exchanger allows the product to be moved through a bundle of tubes in parallel, with heating fluid around and between the tubes.

A concentric tubular heat exchanger exhibits tubes having different diameters, placed concentrically one inside the other. This generates an optimal result for both heating and cooling, since the fluids of both processes pass through both sides of the product tubes. These tubes can have the ideal size, to meet the established requirements of viscosity and particles. A concentric tube is ideal for high-viscosity, non-Newtonian fluids that change under pressure. Some examples are tomato sauce or ketchup, shampoo, or nail polish.

In the pharmaceutical industry, shell and tube heat exchangers are particularly effective. In fact, in this field, the hygiene levels and the demand for insulation from heating and cooling fluids are too high. To meet the demanding requirements of the industry, heat exchangers of this type restrict the growth of microbes and prevent cross-contamination.

 

Operation of scratched surface heat exchangers

All those processes associated with the production of food and pharmaceutical, chemical, cosmetic and health and beauty products require safe heat transfer. In parallel, this heat must prevent fouling of sticky and viscous products. For this kind of procedure, an ideal option is to have heat exchangers with scratched surfaces. This system is characterized by its optimal capacity for processing fluids with high viscosity or with a large number of particles.

To tell the truth, this heat exchanger is usually more expensive, but it works effectively when other heat exchangers are useless.

In general, the operation of this system begins with the entry of the product into a cylinder located in the lower part. From there, it flows up. The heating or cooling medium circulates through a reduced, ring-shaped channel. Also, this device is provided with rotating blades whose purpose is to remove the product from the cylinder wall. In such a way, it allows the constant transfer of heat. It is relevant to note that, due to their design, these devices are ideal for extremely careful handling of the product. It is also applicable to avoid as much as possible variables that interfere with its consistency and quality.

In fact, the scratched surface heat exchangers are used in the production of food products such as ketchup, mayonnaise and other sauces. And also in cosmetic products such as shampoos and skin lotions.

 

Do you need a heat exchanger for your company?

At Intersam we have been manufacturing heat exchangers tailored to the needs of our customers since 1995. Therefore, we have the experience and capacity to supply this and other industrial refrigeration and air conditioning systems, made with the most advanced technology.

In fact, we develop all kinds of refrigeration and air conditioning systems: air-water, water-air and air-refrigerants, which provide maximum efficiency and energy savings. As if that were not enough, we transport this equipment to the place where your business is. Our service includes installation and our own software to facilitate the operation of our products.

And remember: if what you need is a heat exchanger, do not hesitate to contact us. Refrigeration is our business! Contact us now!