Buyer’s guide: heating industrial cooking kettles

November 16, 2021
Home » Buyer’s guide: heating industrial cooking kettles

Why does the right heating source matter?

Customers often ask how they should heat up their industrial cooking kettles. There is no easy answer, as every heating source has its advantages and disadvantages. The right heating source depends on the cooking process and desired outcome

Each heating source differs in energy consumption, efficiency, maintenance, peak temperature and warm-up time. You should carefully consider what you exactly wish to cook and how much you wish to cook.

 

How are industrial cooking kettles best heated?

  • High-pressure steam
  • Electrical resistors and thermal oil
  • Thermal oil circuit

Heating industrial cooking kettles using steam

Steam is the most energy-efficient and flexible heating source for industrial cooking appliances. For that reason, it is the optimal choice for industrial kitchens equipped with several kettles and other installations.

Double jacketed steam kettles

Steam heated kettles are fitted with a double jacket. High-pressure steam flows through the double jacket and evenly heats up the kettle. Steam is immediatley at the right temperature, meaning you can start cooking almost right away.

A kettle filled with 500 liters of water and heated with 3 bar of high-pressure steam, is at boiling point after merely 28 minutes.

The maximum temperature depends of the maximum pressure in the double jacket. The higher the pressure, the higher the temperature. A proportional steam valve can regulate pressure to set the temperature to the degree.

For applications like cooking sauces, soups, vegetables, potatoes and meats, 3 bar steam pressure should suffice. With 3 bar, you can reach a jacket temperature of 140°C. If you wish to roast meat, it is recommended to increase the pressure to at least 8 bar and roast at at least 175°C.

The main advantage of steam heated kettles is the flexibility they offer. You can easily adjust the temperature but also prevent burnt dishes. Once the steam supply is cut off, the double jacket immediately stops heating up. It is then possible to cool down the kettle with tap or ice water in the double jacket.

 

Direct steam injection

Direct steam injection is the fastest way to heat up your kettle and your products. The dry, culinary steam directly heats your products. This means you no longer need to wait for your kettle to get up to temperature to add your products.

Voor directe stoominjectie is culinaire stoom nodig. Deze stoom wordt ook gefilterde stoom genoemd. De stoom stroomt door een roestvrij stalen filter van doorgaans 5 micron. Deze filter houdt 95% van alle onzuiverheden tot 2 micron tegen en wordt aanvaard als een veilig niveau voor voedselproductie.

Direct steam injection requires culinary steam, also called filtered steam. This article explains in detail how culinary steam works. Here’s a quick recap:

    • Food-suitable steam needs to be free of rust and other dirt particles.
    • The steam flows through 2 filters before it is food safe.
    • Firstly, it flows through a pre-filter, eliminating all particles at 10 micron or larger.
    • Secondly, it flows through the actual filter, eliminating 95% of all particles at 2 micron or larger.
    • After this process, the steam is considered food safe and adequate for direct steam injection.

     

    Advantages of steam-heated kettles

    • Energy efficiency
    • Flexibility
    • Quick heating

    Heating industrial kettles using electricity

    Electrical heating is recommended for preparations that require roasted meat. By heating with electricity, you can reach up to 230°C.

    These kettles are also equipped with a double jacket. The jacket is filled with thermal oil and electrical resistors. The oil is heated by the resistors which heats up the walls and bottom. These walls and bottom indirectly heat up your products.

    Temperature control is not as flexible as with steam heated kettles. Once your preparation is finished, the kettle stays at temperature for longer. The thermal oil needs time to cool off, which can cause burnt or overcooked dishes.

     

    Advantages of electrically heated kettles

    • High maximum temperature
    • Suitable for roasted meat
    • No steam generator or other installation needed

    Industrial cooking kettle heated with thermal oil

    Met verwarming op thermische olie kan u ook temperaturen tot 230°C bereiken. Hiervoor is een extra installatie nodig die de thermische olie opwarmt en door een cicruit pompt. Dit vergt een extra investering maar is rendabel voor bedrijven met veel ketels en andere apparatuur. Omdat de thermische olie-installaties op gas kunnen werken, zijn ze efficiënter dan zuiver elektrisch verwarmde installaties.

    Heating with thermal oil also allows you to cook and roast at 230°C. This setup required additional equipment because you need a thermal oil heater and circuit. Hot thermal oil enters the double jacket and flows out, back to the heater for a constant warm oil supply and even heating.

    This requires additional investments but can be a more cost-effective long-term solution. The thermal oil heater can be powered not only with electricity but also with natural gas. This drastically increases performance and reduces electricity usage.

     

    Advantages of thermal oil

    • More cost-effective than electricity
    • High maximum temperature
    • Suitable for roasting meat

    In a nutshell

    There is no easy answer to the question “how should I heat up my industrial kettle”. There are however some basics to help you make an informed decision.

     

    • Do you need a flexible and energy efficient kettle and is 180°C sufficient for your processes? Pick a steam heated kettle.
    • Do you need to cook and roast at high temperatures? Pick an electrically heated kettle.
    • Do you need to cook and roast at high temperatures and do you need multiple kettles? Get a thermal oil heater and thermal oil kettles.

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