HEATING SYSTEM FOR CERAMIC

TILE FACTORY IN VIETNAM

USING FURNACE OIL

Devon Guile

Jean-Marc Guindon

Andreas Hart

Emerson Hawkins

Alex Higgs

Jono Horne

OUTLINE

• Background

• Process Flow

• Engineering

• Plant layout

• Economics

• Conclusion

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Roller Hearth Kiln. (February 2014). Retrieved from http://www.ngk.co.jp/english/products/ceramic/heating/

INTRO

• Vietnam has a very successful tiling industry

• In 2013 a total of 199 million m2 of tile was manufactured

• That’s a 27% share of the global market output

• Runs 24 hours per day

• Regenerative heating

• Fuel Oil

• Proper design of tiles factories maximized the profit/output

• This factory is capable of outputting 25,700 tiles per hour

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BACKGROUND

• Process followed for manufacture

• Raw materials are crushed

• Wet milled into a paste

• Mixed, formed and dried into 12” by 12” by 1/2 “ blocks

• Glazed to add color and protective coating

• Fired in a continuous kiln to save time

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Ceramic material properties. (2014, February). Retrieved from http://www.engineeringtoolbox.com/ceramics-properties-d_1227.html

PROCESS FLOW

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ENGINEERING ANALYSIS

The following factory properties were assumed during the design stage:

• The factory will operate 24 hours per day, 365 days per year.

• The material will be formed into 12” x 12” x 1/2” floor tiles.

• The average temperature of the kiln will be 2500 °F [3].

• The total firing time will be 60 minutes.

• The factory will produce 2000 tons of tiles per day [3].

• To fire 1 kg of ceramic tiles, 1000 kCal of energy is required [3].

• Typical efficiencies of ceramic tile kilns are approximately 50% [3].

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KILN DESIGN

Based on the previous assumptions, the kiln was designed yielding the following results:

• 8.4 GJ/day energy requirement.

• This energy will be supplied by burning furnace oil number 4.

• Furnace oil number 4 is often used in industrial boilers; with a heating value of 34.4 MJ/l [9].

• The total fuel flow required to fire the tiles is then calculated as 2.82 l/s.

• Due to the 50% efficiency, the total fuel flow rate required is increased to 5.64 l/s.

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KILN DETAILS

To determine the dimensions of the kiln, the following assumptions were used:

• The density of ceramic tile is 2900 kg/m3 [5].

• The horizontal and vertical distance between the tiles in the kiln is ½”.

The kiln details are then given as:

• The number of tiles manufactured is 25,700/hr.

• The overall size of the kiln will be 10.4’ wide, 2’ tall and 104’ long.

• Tiles arranged 10 horizontally and 24 vertically.

• Require using racks to transport the tiles from one end of the kiln to the other.

• Ceramic rollers will be driven by an electric motor at 1.73 ft/min.

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REGENERATIVE AIR HEATER

• Used to capture the waste heat in the exhaust from the kiln.

• Heat exchanger that uses the flue gas from the kiln to preheat metal plates.

• These metal plates then transfer the heat to incoming kiln air.

• Require less fuel to achieve an average kiln temperature of 2500 °F.

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Preheated combustion air. (2007, November). Retrieved from http://www1.eere.energy.gov/manufacturing/tech_assistance/pdfs/et_preheated.pdf

AIR HEATER DESIGN

Several assumptions were made to perform the air heater design:

• All heat transfer takes place between the flue gas and the entering air.

• The mass flow rate of the inlet air is the same as the mass flow rate of the flue gas.

• cp of flue gas = 0.96 kJ/kg [2] and cp of air = 1.05 kJ/kg[1].

• Flue gas entrance temperature is 2500 °F and outlet temperature is 1500 °F.

• Inlet air temperature to the heat exchanger is 86 °F.

• Outlet air temperature of the heat exchanger can be calculated as 1000 °F.

• This level of heat transfer is possible with most modern regenerative air heaters.

• Estimated 38% fuel savings can be achieved [10].

• Total fuel rate required is decreased to 3.5 l/s from 5.64 l/s. 10

BURNERS

• Our design will utilize 40 burners; 20 on each side of the kiln, spaced 5 feet apart.

• The fuel flow rate for each burner is calculated as 0.0875 l/s.

• This flow rate is attainable for a typical industrial burner [4].

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FINAL KILN DESIGN

Parameter Value

Material processed 2000 tons/day

Energy requirement 1000 kCal/kg

Tiles manufactured 25700 tiles/hr

Fuel flow rate 3.5 l/s

Kiln dimensions 10.4’ x 2’ x 104’

Number of burners 40

Conveyor speed 1.73 ft/min

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PLANT LAYOUT

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ECONOMIC ANALYSISINITIAL COST

Item Qty. UnitsKiln[17] 178,000.00 $

Burners 40 units

Retail Price 160.00 $/unit

Air-Air Heat Exchanger[11] 50,000.00 $

Property[18] 1800 m2

Land rate in Vietnam 5.37 $/m2

Infrastructure[18] 220,000.00 $

Contingency 10 %

Total Capital Expense 488,472.60 $

• All figures are in USD• Equipment:

• Kiln, burners, heat exchanger• Install & commission

• Property• Infrastructure:

• Facilities, utilities14

• Operations Cost = 4 x Fuel Cost• Max revenue based on individual tile sales

PERFORMANCE PARAMETER:

• Net Present Value• 8%, 10 years

• NPV of +452.7 million USD

ECONOMIC ANALYSISREVENUE & EXPENSES

Item Qty. UnitsFuel 3.5 litre/s

Market Price [7,8] 1.03 $/US gallon

Total 30,022,272.00 $/yr

Raw Clay 2000 tons/day

Market Price[15] 40.00 $/ton

Total 29,200,000.00 $/yr

Operations 4*Fuel Cost

Estimated Total 120,089,088.00 $/yr

Total Expenses 149,289,088.00 $/yr

Item Qty. UnitsRetail price 0.929 $/ft2

Tiles manufactured 25700 units/hr

Total Revenue 209,147,628.00 $/yr

CONCLUSION

• Ceramic tile factory located in Vietnam

• 2000 tonnes of tiles per day

• 1000 kCal per kilogram of tile

• High Efficiency Kiln

• 40 Burners

• Inlet Air Reheater (38% fuel savings)

• Valued at $450 Million US

• Annual Revenue $209 Million US

• Construction is recommended

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http://myatlantaflooring.com/wp-content/uploads/2011/03/Atlanta-Ceramic-Tile-Flooring-1.jpg

REFERENCES

1. Air properties. (2014, February). Retrieved from http://www.engineeringtoolbox.com/air-properties-d_156.html 2. Assessment of boilers and thermic fluid heaters. (2006, September). Retrieved from

http://www.energyefficiencyasia.org/energyequipment/assessment_boiler_indirectmethod.html 3. Basu, Pabir, Dr. "Kiln Design." Telephone interview. Feb. 2014.4. Bussman, W., Venizelos, D., & Hayes, R. (2003). Fluid flow. Retrieved from

ftp://ftp.demec.ufmg.br/ema867j/Livros%20selecionados/QueimadoresInd/1386_C03.pdf5. Ceramic material properties. (2014, February). Retrieved from http://www.engineeringtoolbox.com/ceramics-properties-

d_1227.html 6. "Fuel Cost." Fuel Cost. Vietnam Online, 2011. Web. 10 Feb. 2014. <http://www.vietnamonline.com/az/fuel-cost.html>.7. “Fuel Cost." In Vietnam. Energypedia, 15 Apr. 2013. Web. 11 Feb. 2014. <http://www.vietnamonline.com/az/fuel-cost.html>.8. "Basu, Pabir, Dr. "Kiln Design." Telephone interview. Feb. 2014.9. Fuel oil and combustion values. (2014, February). Retrieved from http://www.engineeringtoolbox.com/fuel-oil-combustion-

values-d_509.html10. Preheated combustion air. (2007, November). Retrieved from

http://www1.eere.energy.gov/manufacturing/tech_assistance/pdfs/et_preheated.pdf

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QUESTIONS?

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