Metal heat treating methods and devices

A device for the heating of a directly- or indirectly-fired furnace comprising a heated space, two burners for the burning of gas or liquid fuel mixed with heated air at a certain fuel to heated air ratio characterized by a relevant value of the air excess factor, a duct for the supply of gas or liquid fuel, a duct for the discharge of cooled combustion products, a system for the heating of air and its supply to each of burners including a duct for the supply of air from outside and two regenerating headpieces;

• wherein, each of the headpieces has an interior space with two input-output windows filled with a layer of heat-transfer elements in a certain amount and a system for the control and exchange of specified ducts, burners and regenerating headpieces, and designed with a performance ability involving the cyclical changing of functions between burners and regenerating headpieces;
• wherein, each of regenerating headpieces is used for the heating of the heat-transfer elements using hot combustion products during one operation cycle of the unit for the heating of the combustion furnace, in particular, it is used for the heating of air using the heat-transfer elements heated during the previous cycle;
• wherein, each of the burners function as burners during one operation cycle of the unit for the heating of the combustion furnace and as a window for the removal of combustion products from the heated space during the other operation cycle;
• said device is characterized in that, that the interior space of each of regenerating headpieces is filled with a layer of heat-transfer elements volume corresponding with the following formula:
• V=K·α·B1,
• where V stands for the volume of the layer of heat-transfer elements filling the interior space of the regenerating headpiece, m3;
• K stands for the proportionality factor depending on the type of fuel, the type and size of the heat-transfer elements, the temperature of air and combustion products in the input-output windows of the regenerating headpiece, and the duration of the operation cycle of the unit for the heating of the combustion furnace, h;
• α stands for the air excess factor chosen depending on the required mode of heat treatment in the combustion furnace that exceeds 2.0 and falls primarily within a range of up to 6.0, a non-dimensional value;
• and B1 stands for fuel consumption (gas or liquid fuel) per burner where α=1, m3/h.

A device for the heating of a directly- or indirectly-fired furnace comprising a heated space, two burners for the burning of gas or liquid fuel mixed with heated air at a certain fuel to heated air ratio characterized by a relevant value of the air excess factor, and two regenerating headpieces;

• wherein each of headpieces has an interior space with two input-output windows filled with a layer of heat-transfer elements in a certain amount;
• wherein each of the burners is connected to a duct for the supply of gas or liquid fuel through a rectifier and is also connected to one of the input-output windows of one of the regenerating headpieces;
• wherein, the other input-output window of each of the headpieces is connected to a duct for the supply of air, and to a duct for the removal of the combustion products through each of the headpieces individually, a three-input reversing valve, or through both of the headpieces in combination, a four-input reversing valve;
• said device is characterized in that the interior space of each of the regenerating headpieces is filled with a layer of heat-transfer elements volume that corresponds with the following formula:
• V=K·α·B1,
• where V stands for volume of the layer of heat-transfer elements filling the interior space of the regenerating headpiece, m3;
• K stands for the the proportionality factor depending on the type of fuel, the type and size of heat-transfer elements, the temperature of air and combustion products in the input-output windows of the regenerating headpiece, and the duration of the operation cycle of the unit for the heating of the combustion furnace, h;
• α stands for the air excess factor chosen depending on the required mode of heat treatment in the combustion furnace that exceeds 2.0 and falls primarily within a range of up to 6.0, a non-dimensional value;
• B1 stands for the fuel consumption (gas or liquid fuel) per burner where α=1, m3/h.

A regenerating headpiece of a directly- or indirectly-fired furnace heated with a burned mixture of liquid or gas fuel and heated air at a certain fuel to heated air ratio characterized by a relevant value of the air excess factor comprising an interior space with two input-output windows filled with a layer of heat-transfer elements in a certain amount;

• characterized in that, that the interior space of the regenerating headpiece is filled with a layer of heat-transfer elements volume that corresponds with the following formula:
• V=K·α·B1,
• where V stands for the volume of the layer of heat-transfer elements filling the interior space of the regenerating headpiece, m3;
• K stands for the proportionality factor depending on the type of fuel, the type and size of the heat-transfer elements, the temperature of air and combustion products in the input-output windows of the regenerating headpiece, and the duration of the operation cycle of the unit for heating of the combustion furnace, h;
• a stands for the air excess factor chosen depending on the required mode of heat treatment in the combustion furnace that exceeds 2.0 and falls primarily within a range of up to 6.0, a non-dimensional value;
• B1 stands for the fuel consumption (gas or liquid fuel) per regenerating headpiece where α=1, m3/h.

A regenerating headpiece of a directly- or indirectly-fired furnace heated with a burned mixture of liquid or gas fuel and heated air at a certain fuel to heated air ratio characterized by a relevant value of the air excess factor comprising an interior space filled with heat-transfer elements and connected with an under-headpiece space located under it;

• wherein, the interior space has an input-output window in the upper part and the under-headpiece space has another input-output window with a shut-off valve;
• wherein, the headpiece is characterized in that the interior space filled with heat-transfer elements is designed in the form of several—at least two—sections located one under the other, each of which, with the exception of the bottommost section, is connected with an underlying section with the help of an additional under-headpiece space located between these sections;
• wherein, each of these additional spaces has an additional input-output window with an additional shut-off valve;
• wherein, each section of the interior space is filled with a layer of heat-transfer elements of a certain volume, with the total volume corresponding with the following formula:
• Vmax=K·αmax·B1,
• where Vmax stands for the total volume of layers of the heat-transfer elements of all sections of the interior space of the regenerating headpiece, m3;
• K stands for the proportionality factor depending on the type of fuel, the type and size of heat-transfer elements, the temperature of air and the combustion products in the input-output windows of the regenerating headpiece, and the duration of the operation cycle of the unit for the heating of a combustion furnace, h;
• αmax stands for the maximum air excess factor of the regenerating headpiece chosen depending on the required mode of heat treatment in the combustion furnace that exceeds 2.0 and falls primarily within a range of up to 6.0, a non-dimensional value;
• B1 stands for the fuel consumption (gas or liquid fuel) per regenerating headpiece where α=1, m3/h;
• wherein, the, maximum air excess factor of the regenerating headpiece and the air excess factors for each section of the interior space of the regenerating headpiece are related to each other by the formula:
• αmax=Σ αi,
• where αi stands for the chosen value of the air excess factor of section i of the interior space of the regenerating headpiece, a non-dimensional value;
• i stands for the ordinal section number of the interior space of the regenerating headpiece, varying from 1 to n where n equals the number of sections of the interior space of the regenerating headpiece;
• and wherein, the volume of the layer of heat-transfer elements filling each section of the interior space corresponds with the formula:
• Vi=K·αi·B1,
• where Vi stands for volume of the layer of heat-transfer elements of section i of the interior space of the regenerating headpiece, m3 (variable i and members K, B1 are defined above).

A regenerating headpiece of a directly- or indirectly-fired furnace heated with a burned mixture of liquid or gas fuel and heated air at a certain fuel to heated air ratio characterized by a relevant value of the air excess factor comprising a first interior space filled with a layer of heat-transfer elements of a certain volume with two input-output windows, where the upper window is connected with the upper input-output window of the regenerating headpiece and the bottom window has the first shut-off valve;

• wherein, the headpiece is characterized in that the regenerating headpiece is fitted with at least one additional interior space filled with a layer of heat-transfer elements of a certain volume;
• wherein, the additional space has its own under-headpiece space and upper and bottom input-output windows, where the upper window is connected with the upper input-output window of the regenerating headpiece and the bottom window is fitted with an additional shut-off valve;
• wherein, the total volume of layers of heat-transfer elements in all interior spaces of the regenerating headpiece corresponds with the formula:
• Vmax=K·αmax·B1r,
• where Vmax stands for the total volume of layers of heat-transfer elements of all interior spaces of the regenerating headpiece, m3;
• K stands for the proportionality factor depending on the type of fuel, the type and size of heat-transfer elements, the temperature of air and the combustion products in the input-output windows of the regenerating headpiece, and duration of the operation cycle of the unit for the heating of the combustion furnace, h;
• αmax stands for the maximum air excess factor of the regenerating headpiece chosen depending on the required mode of heat treatment in the combustion furnace that exceeds 2.0 and falls primarily within a range of up to 6.0,
• a non-dimensional value;
• B1 stands for fuel consumption (gas or liquid fuel) per regenerating headpiece where α=1, m3/h;
• wherein, the maximum air excess factor of the regenerating headpiece and the air excess factors for each interior space of the regenerating headpiece are related to each other by the formula:
• αmax=Σ αi,
• where αi stands for the chosen value of the air excess factor of interior space i of the regenerating headpiece, a non-dimensional value;
• i stands for ordinal number of the interior space of the regenerating headpiece, varying from 1 to n where n equals the number of interior spaces of the regenerating headpiece;
• and wherein, the volume of the layer of heat-transfer elements filling each of interior spaces corresponds with the formula:
• Vi=K·αi·B1,
• where Vi stands for the volume of the layer of heat-transfer elements of interior space i of the regenerating headpiece, m3 (variable i and members K, B1 are defined above).