Indirect fired oven system for curing coated metal products

An indirect fired oven system for curing coated product which is moved in a continuing manner through said oven and is coated with a heat-curable, solvent releasing coating material, comprising:

• an oven line having at least one oven zone through which the coated product is arranged to travel, which zone is operated at elevated temperatures;
• the entrance and exit ends of said oven line each having means to exhaust substantially all indraft air entering said entrance and exit ends at a position near each respective end;
• a balance air fan connected to said means to exhaust, and adapted to direct its output flow in a first volume flow to a heat exchanger for heating, and thence back to said oven line for distribution to said at least one oven zone, and in a second unheated volume flow to said oven line for distribution to said at least one oven zone;
• an exhaust fan adapted to withdraw air from said oven and to direct its output in a third volume flow to an afterburner and thence past said heat exchanger and to an exhaust stack;
• where the principal fuel source for said afterburner is the volatile solvent released from said coating material on said coated product as it travels through said oven;
• and where the sum of said first and second volume flows drawn by said balance air fan from said oven line substantially equals said third volume flow drawn by said exhaust fan from said oven line.

An indirect fired oven system for curing coated product which is moved in a continuing manner through said oven and is coated with a heat-curable, solvent releasing coating material, comprising:

• an oven line having at least two oven zones arranged in line, through which the coated product is arranged to travel, which zones are operated at elevated temperatures;
• the entrance and exit ends of the first and last of said at least two zones, respectively each having means to exhaust substantially all indraft air entering said entrance and exit ends at a position near each respective end;
• a balance air fan connected to said means to exhaust, and adapted to direct its output flow in a first volume flow to a heat exchanger for heating, and thence back to said oven line for distribution to said oven zones, and in a second unheated volume flow to said oven line for distribution to said oven zones;
• an exhaust fan adapted to withdraw air from said oven and to direct its output in a third volume flow to an afterburner and thence past said heat exchanger and to an exhaust stack;
• where the principal fuel source for said afterburner is the volatile solvent released from said coating material on said coated product as it travels through said oven zones;
• and where the sum of said first and second volume flows drawn by said balance air fan from said oven line substantially equals said third volume flow drawn by said exhaust fan from said oven line.