Ovens: Energy Saving, Top of Priorities

One of the most important requirements when talking about equipment upgrade is resource saving. Because of the costs and effects on the environment, energy is maybe the first things coming in mind of any manufacturer.

We asked Enrico Pevarello, manager at Laser, what are the important factors to consider when purchasing a tunnel oven for a biscuit plant in order to save energy. Easy access to the inside of the oven for cleaning, the baking chamber volume, the possibility to pre-heat the air before utilization, a light wire mesh, insulation of the wire mesh return (if process permits) or control of negative pressure on the baking chamber are measures that can be taken into consideration to save energy in biscuit plant, explains the engineer at Laser.

For biscuits, crackers, sponge cakes and even bread or pizza, there is a wide range of tunnel ovens such as electric ones, direct gas, cyclothermic, hybrid or convection. The hybrid oven is the recommended for biscuits and crackers lines, with its high temperature during the starting phase (direct gas) and the following stabilization within the normal baking parameters (cyclothermic).
A good insulation, a low baking temperature, but higher volumes of air, stoichiometric combustion with modulant burners are the parameters that helps a factory reduce energy consumption during the baking process, explains the expert.

As breakthroughs in terms of oven technology, direct heating with gas or LPG utilization will become more and more popular as well re-utilization of part of the smokes of combustion to pre-heat air or water used in the process or in the factory.

In case of power outage

The best way to minimize the product wastage when a power outage happens is to install a UPS able to fully operate oven and post oven section until the generator comes to function. Usually cuts of one to three minutes can occur and, in this case, having a back up of five minutes on oven and post oven section allows to not stop production and not throw the continent of the oven, Pevarello explains.

When to renew

Every 15-20 years, the electrical components and those related to gas handling go out of production so it is usually time to change them since you don’t find spare parts.

The energy goes into baking the product

British equipment manufacturer Baker Perkins has been paying a particular attention to ensuring that as much as possible of the energy goes into baking the product. Efficient turbulence and convection systems reduce temperatures and bake times, while precise control of extraction rates minimizes losses. Generous amounts of high density insulation and good sealing of joints and doors also contribute to minimizing energy loss.

Baker Perkins also offers a wide range of ovens. Direct Gas Fired Oven is the most flexible oven of the company and also very appropriate for biscuit and cracker production. Operators appreciate visibility into the baking chamber, which simplifies understanding the process and also translates into ease of control. Heat transfer method is radiation plus turbulence, but turbulence may be turned off if a radiant-only bake is required.

Flexiflame ribbon burners are divided into separate flame sections that can be individually adjusted to precisely balance the heat input into the oven.

TruBake convection oven offers high throughput and low operating costs across a full range of hard and soft biscuits, cookies and bars. Precision control of temperature and airflow creates a stable, predictable and controllable environment for consistent baking with minimum fuel consumption. TrueBake uses higher volumes of air at lower temperature and more nozzles to achieve a faster, more stable bake than conventional ovens. High pressure ducts improve bake stability and ensure even heating across the band.  Lower bake chamber and exhaust temperatures significantly reduce energy consumption.

Energy-saving measures and features that can be applied in biscuit plants:

• Easy access to the inside of the oven for cleaning,
• The baking chamber volume,
• The possibility to pre-heat the air before utilization,
• A light wire mesh,
• Insulation of the wire mesh return (if process permits)
• Control of negative pressure on the baking chamber

The hybrid oven is the recommended for biscuits and crackers lines, with its high temperature during the starting phase (direct gas) and the following stabilization within the normal baking parameters (cyclothermic).

“Direct heating with gas or LPG utilization will become more and more popular as well re-utilization of part of the smokes of combustion to pre-heat air or water used in the process or in the factory” – Enrico Pevarello (Laser).