answer caret-left caret-right close-large facebook hamburger linkedin mail password question repeat-password thumb triangle twitter username youtube circle-right trending search checkmark pin alert

Energy Saving for Biscuit Baking

Energy Saving for Biscuit Baking

Energy saving for biscuit baking with heat recovery system

The Heat Recovery System (HRS) uses the waste heat from the burner flues. This may be used to heat one or two final zones of the oven. These zones would not require burners, giving a saving in capital and running costs.

All gas burners draw in a large amount of air for combustion. 1.0m3 of gas requires 3.0m3 of oxygen, (approximately 15m3 of air) for complete combustion. This air is exhausted through the extraction system of a direct gas fired oven and through the natural draught burner flue of an indirect oven.

The hot air and burnt gas in the burner flues of an Indirect Radiant oven are at a high temperature, typically up to 200oC in the first zones and this hot air can be recovered and used for baking in a Heat Recovery System.

A proportion of the hot gases in the burner flues are diverted to an HRS collection pipe which runs along the top of the oven. Hot gases are collected from each zone with a burner. The hot gases are drawn along the collection pipe by a fan and blown into radiant ducts in the final oven zone.

Baker Pacific Heat Recovery Zone
Image 1: Baker Pacific Heat Recovery Zone


The HRS zone is constructed with radiant ducts above and below the oven band. The hot gases recovered from the burner flues are fed by the fan to the ducts. The fan is located on top of the oven at the end of the collection pipe.

Heat Recovery Zone
Image 2: Heat Recovery Zone

Heat Recovery Zone


The final zone of the oven has radiant ducts above and below the oven band. These ducts are divided along their length into 3 sections (control side, centre and non-control side).  The flow of hot air into each section is controlled by a damper. These dampers may be adjusted to ensure the optimum heat balance top to bottom and across the width of the oven.

Energy saving

The following data is from a multi-national biscuit manufacturer comparing several ovens baking short dough biscuits

Product Oven type Oven size kWh/kg of biscuits
Rotary moulded Indirect Radiant with Heat Recovery Zone 1.2 x 100m 0.404
Rotary moulded DGF/Convection 1.2 x 60m 0.430
Rotary moulded DGF/Convection 1.5 x 100m 0.441
Rotary moulded Cyclotherm 1.2 x 100m 0.475
Rotary moulded DGF/Convection 1.2 x 60m 0.492

Technology transfer

Baker Pacific are now able to offer a complete Technology Transfer for the design of the Heat Recovery Zone with manufacturing drawings from S.Eldridge Design Ltd.

The Technology Transfer includes:

  • Heat recovery design and performance data
  • Assembly and detail manufacturing drawings
  • Parts lists
  • Material specifications
  • Key component specifications
  • Control system
  • Operation and maintenance manual

Leading image: rudall30/

Want to know more?
Ask industry experts in Biscuit People TechTalks section.
Read more from Our experts
Read all
Biscuits as Vehicle for Delivering Therapeutic Agents: Diabetes Mellitus Management as A Case Study
Biscuits as Vehicle for Delivering Therapeutic Agents: Diabetes Mellitus Management as A Case Study
Our experts
Delivering therapeutic agents through biscuits as a vehicle is an important emerging technology which offers a promising outcome for disease managemen...
Maintenance of Biscuit Baking Ovens
Maintenance of Biscuit Baking Ovens
Our experts
Maintenance of biscuit baking ovens, what to check in the oven band, baking chamber, burners, controls and electrical panels and explanation for energ...
Baking ovens: Types of Heat Transfer
Baking ovens: Types of Heat Transfer
Our experts
There are three modes of heat transfer: radiation, conduction and convection. However they differ in importance and effect on the product, and their a...
Looks like you don’t have a subscription to do that. Want to upgrade?
Upgrade subscription