Method of and apparatus for heating circulating air in drying equipment

In an apparatus for heating air, parituclarly circulation air in drying equipment or the like, particularly combination comprising a drying chamber containing circulation air, a combustion chamber separate from said drying chamber;

• first passage path means for circulating a portion of the air from said drying chamber in a first path and into said combustion chamber;
• second passage path means for circulating incinerated gases from said combustion chamber in a second path in which said incinerated gases exchange heat with said air in said first path, so as to preheat said air in said first path prior to entry thereof into said combustion chamber, said second passage path means comprising a heat-exchanger, said heat-exchanger having at least two sections, one of said sections surrounding a portion of said first path, and the other of said sections surrounding a portion of said second path and being in heat-exchanging relationship with said one section;
• and third passage path means for circulating said incinerated gases from said other section of said heat-exchanger in a third path, so as to heat said remaining circulating air in said drying chamber, said third passage path means comprising means defining a conduit, pumping means, and a flow control means, said means defining a conduit forming a portion of said third path and conveying a portion of said incinerated gases to said drying chamber by operation of said flow control means cooperating with said pumping means.

In an apparatus for heating air, particularly circulation air in drying equipment or the like, a combination comprising a drying chamber containing circulation air;

• a combustion chamber separate from said drying chamber;
• first passage path means for circulating a portion of the air from said drying chamber in a first path and into said combustion chamber;
• second passage path means including a heat-exchanger for circulating incinerated gases from said combustion chamber in a second path to said heat-exchanger in which said incinerated gases exchange heat with said air in said first path so as to preheat said air in said first path prior to entry thereof into said combustion chamber;
• and third passage path means for circulating said incinerated gases from said heat-exchanger in a third path, so as to heat said remaining circulating air in said drying chamber, said third passage path means comprising means defining a conduit, and air lock, and a flow control means, said means defining a conduit forming a portion of said third path and conveying a portion of said incinerated gases to said air lock to heat the same by cooperation with said flow control means, and said air lock being separate from said drying chamber and being in heat-exchanging relationship with said remaining circulating air in said drying chamber.

In an apparatus for heating air, particularly circulation air in drying equipment or the like, a combination comprising a drying chamber containing circulation air;

• a combustion chamber separate from said drying chamber;
• first passage path means for circulating a portion or the air from said drying chamber in a first path and into said combustion chamber;
• second passage path means for circulating incinerated gases from said combustion chamber in a second path in which said incinerated gases exchange heat with said air in said first path so as to preheat said air in said first path prior to entry into said combustion chamber, said second passage path means comprising a heat-exchanger, said heat-exchanger having at least two sections, one of said sections surrounding a portion of said first path, and the other of said sections surrounding a portion of said second path and being in heat-exchanging relationship with said one section;
• and third passage path means for circulating said incinerated gases from said other section of said heat-exchanger in a third path, so as to heat said remaining circulating air in said drying chamber, said third passage path means comprising means defining a conduit, an air lock, and a flow control means, said means defining a conduit forming a portion of said third path and conveying a portion of said incinerated gases to said air lock to heat the same by cooperation with said flow control means, and said air lock being separate from said drying chamber and being in heat-exchanging relationship with said remaining circulating air in said drying chamber.

In an apparatus for heating air, particularly circulation air in drying equipment or the like, a combination comprising a drying chamber containing circulation air;

• a combustion chamber separate from said drying chamber;
• first passage path means for circulating a portion of the air from said drying chamber in a first path and into said combustion chamber, said first passage path means comprising exhaust means, a bypass conduit, and a flow regulation means, said exhaust means removing a portion of said circulating air from said drying chamber and directing said portion of exhaust air along said first path, and said flow regulation means comprising sensors and flow control means, said temperature sensors being located in said drying chamber and detecting the temperature of the remaining circulating air in said drying chamber, and said flow control means located in said first path and being valves regulating the flow of said portion of exhaust air to said combustion chamber by cooperating with said temperature sensors;
• and second passage path means for circulating incinerated gases from said combustion chamber in a second path in which said incinerated gases exchange heat with said air in said first path, so as to preheat said air in said first path prior to entry thereof into said combustion chamber, said second passage path means comprising a heat-exchanger, said heat-exchanger having at least two sections, one of said sections surrounding a portion of said first path, and the other of said sections surrounding a portion of said second path and being in heat-exchanging relationship with said one section, said bypass conduit defining a portion of said first path and providing an alternate parallel path so as to bypass said one section of said heat-exchanger.

In an apparatus for heating air, particularly circulation air in drying equipment or the like, a combination comprising a drying chamber containing circulation air;

• a combustion chamber separate from said drying chamber;
• first passage path means for circulating a portion of the air from said drying chamber in a first path and into said combustion chamber;
• and second passage path means for circulating incinerated gases from said combustion chamber in a second path in which said incinerated gases exchange heat with said air in said first path, so as to preheat said air in said first path prior to entry thereof into said combustion chamber, said second passage path means comprising a heat-exchanger, said heat-exchanger having at least two sections, one of said sections surrounding a portion of said first path, and the other of said sections surrounding a portion of said second path and being in heat-exchanging relationship with said one section, said second passage path means further comprising means defining a bypass path and a flow regulation means, said means defining said bypass path forming a portion of said second path and providing an alternate parallel path so as to bypass said other section of said heat-exchanger, and said flow regulation means having temperature sensors to detect the temperature of said incinerated gases and flow control means located in said means defining a bypass path which cooperates with said temperature sensors to regulate the flow of said incinerated gases past said other section of said heat-exchanger.