Circulation of gases in furnace is caused by the
(A) Change in volume during a change of temperature
(B) Difference in density between hot and cold gases
(C) Furnace pressure in conjunction with draft in flues
(D) All (A), (B) and (C
(A) Change in volume during a change of temperature
(B) Difference in density between hot and cold gases
(C) Furnace pressure in conjunction with draft in flues
(D) All (A), (B) and (C