It is hereby declared to be a nuisance and unlawful for any person having a restaurant, tavern, hotel, inn or other eating establishment within the police limits of the city to discharge through exhaust fans, vents or other manners of exit from the premises where such restaurant, tavern, hotel, inn or other eating establishment is conducted, any grease, fats or other combustible materials which constitute fire hazards. The city engineer is hereby authorized to notify the owner or tenant of the restaurant, tavern, hotel, inn or other eating establishment that grease, fats or other combustible materials are being discharged from the premises which constitute a fire hazard, and that unless such condition is remedied within a period of twenty (20) days from the date of notification by the city engineer or such time as may be allowed, not less than twenty (20) days, then such owner or tenant, shall be guilty of a violation of this section. (Code 1953, § 11.4)