When Brick Orders Fall, Every Unit of Kiln Gas Has to Work Harder: Practical Brick Kiln Gas Savings
- Rapidflame Ltd
- Aug 12
- 5 min read
British brick manufacturers are operating under sustained commercial pressure. Energy remains a major production cost, while weak construction demand is limiting orders and reducing output across the sector. For works managers, energy managers and operations directors, the challenge is not simply to consume less gas. It is to obtain more useful thermal work from every unit purchased without compromising firing quality, product consistency or kiln reliability.
Lower production can make brick manufacturing energy costs particularly painful. Kilns, combustion systems and associated equipment do not always scale down efficiently when throughput falls. If a kiln operates below its preferred utilisation, the gas consumed per tonne or per thousand bricks may rise even when total site consumption declines.
Manufacturers cannot control market demand or wholesale energy prices. They can, however, examine how effectively fuel energy is transferred into the product and whether heat already present within the kiln system can be used more productively.
Brick Kiln Gas Savings When Production and Utilisation Fall
A continuous kiln normally performs best within an established operating window. When production schedules become intermittent, kiln cars are less densely loaded or throughput is reduced, the relationship between gas consumption and saleable output can deteriorate.
Heat is still required to maintain kiln structure temperatures, compensate for casing and exhaust losses, and support stable firing conditions. Fans, burners and control systems must also continue operating, even though fewer bricks are moving through the process.
This makes brick kiln gas savings commercially important during periods of weak demand. The relevant question is not whether gas can simply be turned down. Excessive or poorly controlled reductions may affect temperature uniformity, atmosphere control and product quality. The better question is whether combustion and heat transfer can be improved while retaining the thermal conditions required by the firing curve.
Industrial Burner Efficiency, Air Management and Heat Transfer
Burner condition has a direct influence on combustion stability and the way heat enters the kiln. Worn components, incorrect settings, unsuitable velocities or restricted turndown can make it difficult to maintain efficient operation across a changing production range.
Air management matters as well. Too little combustion air can lead to incomplete combustion and elevated carbon monoxide. Too much air can increase the volume of gas being heated and discharged through the flue, carrying useful energy out of the process. Air leakage and poorly balanced kiln pressure can add further losses.
Effective industrial burner efficiency therefore depends on more than the burner’s nominal rating. Burner selection, air-to-gas ratio control, flame velocity, positioning, maintenance condition and interaction with the kiln atmosphere all need to be considered.
For senior teams assessing energy efficiency for brick manufacturers, these factors have commercial consequences. Stable combustion can support firing consistency, while appropriate flame characteristics can improve heat transfer and reduce avoidable fuel use. The opportunity is site-specific and must be evaluated against product requirements, kiln design and operating conditions.
Cooling Air Is a Source of Heat That Has Already Been Paid For
Brick cooling requires substantial airflow. As this air passes over hot ware, it collects heat from the fired product. Depending on the kiln arrangement, some of that heated air may be exhausted or used only partially elsewhere in the process.
This heat is not free: gas was originally consumed to raise the bricks to firing temperature. It is therefore worth examining whether the warm cooling air represents recoverable energy that has already been paid for.
Where suitable, recovered heat may be reused as preheated combustion air. Supplying burners with warmer combustion-supporting air can reduce the fuel required to deliver the same thermal duty because less energy is needed to raise the incoming air to the process temperature.
That does not mean every cooling-air stream should be connected directly to a burner system. Temperature, pressure, air cleanliness, moisture, flow stability, duct losses, control philosophy and operating schedules all require assessment. The available heat must also coincide with the kiln zones and production periods in which it can be used effectively.
Extflame for Preheated Combustion Air Applications
Rapidflame’s Extflame Burner is designed for medium- and high-temperature industrial applications. It is relevant to heat recovery projects because it can operate with preheated combustion-supporting air at temperatures of up to 300°C. The burner does not recover cooling air itself; it can form part of a correctly designed system that makes productive use of recovered heat.
The Extflame range offers:
Heat inputs from 2 to 400 kW
Turndown of up to 50:1
Medium- and high-velocity versions
Operation with natural gas or LPG
Maximum flame or flue velocity of 150 m/s
Combustion-air preheat capability up to 300°C
Customisable flame-tube length
Low CO and NOx performance
Direct spark ignition
The 50:1 turndown can be useful where the required heat input changes through the firing cycle or as production conditions vary. Medium- and high-velocity options allow the burner arrangement to be selected around the required circulation, penetration and heat-transfer characteristics. Customisable flame-tube lengths can also assist integration with different kiln-wall and refractory arrangements.
These capabilities do not guarantee a fixed fuel saving. Potential savings depend on the temperature and volume of recovered air, existing burner performance, kiln balance, control accuracy, production profile and the cost of the required modifications.
Assess the Whole System, Not One Component
A credible efficiency project should start with measured operating information. Useful areas for review include current gas consumption per unit of saleable production, kiln loading and utilisation, burner condition, excess-air levels, flue-gas composition, cooling-air temperatures and available airflow.
The assessment should then consider whether recovered heat can be transported and controlled economically, whether existing burners can accept preheated air, and whether a burner upgrade could improve turndown, heat transfer or combustion control. Capital cost, maintenance requirements, production disruption and expected payback should all be included.
The practical next step is a site-specific assessment rather than a headline savings assumption. Speak with Rapidflame about reviewing your existing kiln, burner arrangement, gas use and available recovered heat to establish whether they could support a fuel-efficiency improvement project—and whether the potential savings justify the investment.
Frequently Asked Questions (FAQs)
Can cooling air from a brick kiln be reused for combustion?
Where suitable, warm cooling air may be reused as preheated combustion air. Feasibility depends on its temperature, pressure, cleanliness, availability and compatibility with the burner and control system.
Does the Extflame Burner recover cooling air?
No. The Extflame Burner does not recover cooling air. It can work with preheated combustion-supporting air up to 300°C, making it relevant to appropriately designed heat recovery projects.
Will preheated combustion air always reduce kiln gas consumption?
Warmer combustion air can reduce the fuel required for the same thermal duty, but actual results depend on kiln design and operating conditions. A site-specific assessment is necessary.
What should a brickworks review before considering a burner upgrade?
The review should cover gas use, kiln utilisation, burner condition, combustion settings, available recovered heat, firing requirements, integration costs and potential payback.
