Molten metal plating furnace, system for producing and method for producing plated product, and metal plated steel tube obtained by means of said method for producing

A system for producing a metal-plated product comprising at least one plating performing part that performs molten metal plating on an object to be plated, wherein

• at least one of the plating performing part includes a plating bath, an inner wall in a substantially rectangular shape disposed outside of the plating bath and made of side wall portions and end wall portions shorter than the side wall portions, a heat-resistant outer wall in a substantially rectangular shape made of side wall portions and end wall portions shorter than the side wall portions, the side and end wall portions of the inner wall facing the side and end wall portions, respectively, of the heat-resistant outer wall, thereby forming an annular heating chamber surrounding the plating bath, a heating device, the heating device being disposed on one end wall portion of the heat-resistant outer wall and configured to completely combust fuel within the heating device and situated so as to inject combustion gas molecules generated by the combustion in the heating device into the heating chamber at a site laterally offset from the end wall portion of the inner wall facing the end wall portion of the outer wall on which the heating device is disposed, to circulate inside the heating chamber;
• and
• an exhaust port configured to exhaust part of the combustion gas molecules circulating inside the heating chamber, the exhaust port being disposed on the end wall portion of the outer wall on which the heating device is disposed, the exhaust port being situated so as to exhaust combustion gas molecules from the heating chamber at a site directly facing the end wall portion of the inner wall and laterally offset from the site at which combustion gas molecules are injected into the heating chamber by the heating device,
• wherein the heating device is a combustor including a combustion chamber having a wall extending about a center axis of which at least part of the axially extending wall is formed with an array of fuel charging orifices and an array of air charging orifices facing a common combustion zone along the combustion chamber to discharge fuel and air into the common combustion zone with sizes of the fuel charging orifices relative to those of the air charging orifices being predetermined to achieve an effective combustion reaction to produce the combustion gas molecules to be injected into the heating chamber, a progressively constricted combusted medium discharge nozzle for accelerating discharge velocity of combustion gas molecules is provided, and fuel and air supply chambers opening respectively into the fuel charging orifice array and the air charging orifice array are provided, each array being connectable to a supply of fuel or air respectively, an igniter configured to ignite a combustible mixture in the combustion chamber is provided;
• wherein the combustor includes an adjustment device configured to adjust an effective cross sectional orifice size of at least a majority of orifices of at least one of the orifice arrays, and wherein the adjustment device is configured to independently adjust the fuel charging orifice arrays and the air charging orifice arrays to adjust the flow of fuel and air, respectively.