Cost Effective Use of Heat Recovery Tony Cotton

Johnson Tiles Formed in 1901Formed in 1901 One of the UK’s largest tile manufacturersOne of the UK’s largest tile manufacturers Up to late 1990’s – 3 sites in the Tunstall areaUp to late 1990’s – 3 sites in the Tunstall area Operations consolidated onto one site in 2001 with £35m investmentOperations consolidated onto one site in 2001 with £35m investment Highly automated process consuming ~1,500 tonnes of raw materials per weekHighly automated process consuming ~1,500 tonnes of raw materials per week 4,500,000 m 2 of tiles per annum4,500,000 m 2 of tiles per annum

Why Save Energy? Reduce the environmental impact of energy usageReduce the environmental impact of energy usage Protect the world’s resources:Protect the world’s resources: –the UK consumes 8% of oil resources & 4% gas resources every year To reduce our carbon footprintTo reduce our carbon footprint To meet legal obligations of climate change legislationTo meet legal obligations of climate change legislation Good business sense - to save money & improve profitabilityGood business sense - to save money & improve profitability

Energy Use 126 GWh of gas per annum 126 GWh of gas per annum 21.5 GWh of electricity per annum 21.5 GWh of electricity per annum All firing by continuous gas roller-hearth kilns All firing by continuous gas roller-hearth kilns All production is fast once-fired using gas All production is fast once-fired using gas Slowest firing cycle is 1 hour & fastest ½ hour Slowest firing cycle is 1 hour & fastest ½ hour

The problem of waste heat “Surplus industrial heat should be better exploited. Industrial plants often generate large amounts of high quality heat as a by- product. A comprehensive heat strategy must include ways to ensure this heat is reused wherever possible. In some cases industrial firms can reuse heat in their own processes.” “The Heat is On”: CBI

Nothing new! Waste heat has been used for decades!Waste heat has been used for decades! Heat exchangers on tunnel kilns provided space heatingHeat exchangers on tunnel kilns provided space heating Exhaust gases preheated spray driers to save gasExhaust gases preheated spray driers to save gas

Kiln Heat Recovery System Retrofit on existing roller kiln in 2008Retrofit on existing roller kiln in 2008 Applicable to any continuous kilnApplicable to any continuous kiln Heat exchanger in rapid cooling zoneHeat exchanger in rapid cooling zone Combined with heat extracted from slow & final cooling zonesCombined with heat extracted from slow & final cooling zones Recovered heat ~200°C into gas burners as combustion airRecovered heat ~200°C into gas burners as combustion air

Energy Savings Since installation Since installation –Saved: >£83K of gas >4,000,000 kWh of gas (9% of the kiln’s gas) >750 tonnes of CO 2 emissions Payback estimated ~3 years

Current Site Innovative use of waste heat: –Excess heat from kiln fan platform used for space heating –Warm cooling air used for two process driers –Ducted hot air to replace electric heating in canteen

Important Considerations Use for heating is seasonal Use for heating is seasonal New buildings require little space heating New buildings require little space heating Old buildings have high heat loss & need to consider insulation Old buildings have high heat loss & need to consider insulation Target heat recovery for use in 24/7 process Target heat recovery for use in 24/7 process Minimise creation of airborne dust Minimise creation of airborne dust

Training & Communication Involve the workforce Involve the workforce Continuous Improvement Teams Continuous Improvement Teams Energy CIT Energy CIT Departmental Energy Champions Departmental Energy Champions Encourage suggestions Encourage suggestions Regular bulletins & posters Regular bulletins & posters Newsletter to inform of improvements Newsletter to inform of improvements Home energy-saving tips Home energy-saving tips

Energy Performance

Carbon Footprint 2009 Down 7.8% on % from gas consumption 33% from electricity consumption 1% from company road vehicles Note: Excludes deliveries & distribution of CO 2 reduction in 2009 Specific Energy Consumption 20004,519 kWh/tonne 20103,143 kWh/tonne 30% Reduction of SEC in CCA

Future Opportunities Evaluate CHP systems Evaluate CHP systems Heat recovery as standard on kilns Heat recovery as standard on kilns Heat exchangers on kilns for space heating Heat exchangers on kilns for space heating Main kiln exhaust scrubbing to use heat in spray drier Main kiln exhaust scrubbing to use heat in spray drier New concept of kiln exhaust control New concept of kiln exhaust control

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