Crop dehydrator

Claim 2

In a dehydrator including an elongated drum having a material inlet at one end of the drum and an outlet at the other end thereof, and means mounting the drum for rotation about its longitudinal axis, the combination with said drum of a furnace for providing hot gases to the drum, said furnace comprising: a frustoconical, tubular combustion chamber communicating with the inlet end of the drum, said chamber being disposed with the end thereof having the greatest diameter adjacent said drum inlet; and a ring burner in the combustion chamber at the end thereof remote from said drum inlet, the sidewall of said chamber having a uniform, substantially continuous taper in a direction toward the drum inlet to reflect a portion of the heat from said combustion out of the chamber and into the drum through said inlet.

Claim 3

The invention of claim 1, wherein said burner includes an elongated tube shaped into a ring, the axis of said ring being in general alignment with the longitudinal axis of said combustion chamber, and a plurality of ports in the tube for egress of fuel for combustion.

Claim 4

The invention of claim 2, wherein is provided an annular offset in the inner surface of said sidewall downstream of said burner for retaining the zone of initiation of the flame of said combustion in the region of said annular offset during operation of said furnace means.

Claim 5

The invention of claim 1, wherein is included inlet means for providing air to said combustion chamber, said air inlet means including a tubular shroud extending around the sidewall of said chamber in outwardly spaced relationship from the latter and communicating with the chamber, the inlet end of said shroud being remote from the zone of communication between the shroud and the chamber whereby heat emanating through the sidewall may preheat the air traveling through the shroud.

Claim 6

The invention of claim 4, wherein said air inlet means includes a Closed vessel having a pair of spaced-apart end walls and an annular sidewall, there being an opening in one of said end walls communicating the vessel with the chamber, and conduit means extending between the shroud and the vessel and including an inlet for the vessel extending tangentially to said annular sidewall to impart a swirling of the air in the vessel to enhance turbulence of the air as the latter enters the combustion chamber.

Claim 7

The invention of claim 5, wherein is provided blower means interposed in said conduit means, and wherein is provided a discharge for said air from the shroud and upstream of the blower means, said discharge extending generally tangentially from said shroud to enhance the swirling of the air around the sidewall of the combustion chamber as the air is drawn through the shroud.

Claim 8

In a dehydrator including an elongated drum having an inlet end and an outlet, a furnace for providing hot gases to the inlet end of said drum, said furnace including an inlet damper means interposed in the furnace air supply structure, and a fuel supply line coupled with the furnace and adapted to be coupled with a source of fuel under pressure, a control for said dehydrator comprising: a conduit in fluid communication with said supply line and vented to atmosphere; temperature controlled valve means interposed in said conduit and including temperature responsive actuator means for the valve means and disposed to control the valve means for regulating the fluid pressure in the conduit responsive to the temperature at the outlet end of said drum; a valve interposed in said fuel supply line for regulating the flow of fuel to the furnace; means responsive to the pressure of fluid in the conduit and operably coupled with said valve and with the inlet damper means for automatically operating the valve and inlet damper to regulate the fuel and air supply responsive to the temperature at said outlet end, fan means operably coupled with the outlet end of said drum for creating artificial currents of gases through the drum to convey the material to said outlet; outlet damper means operably associated with the fan means for regulating the velocity of said currents; and actuator means operably coupled with the outlet damper means and said fuel supply line and responsive to the fuel flow in the latter to automatically regulate said outlet damper to control the rate of conveying of the material through the drum responsive to the fuel supply to said furnace, said actuator means including time delay means to permit movement of said outlet damper means only after a predetermined time increment following a change in the flow of fuel through said line, whereby to effect uniform drying of the product.

Claim 9

In a dehydrator including an elongated drum having an inlet end and an outlet, a furnace for providing hot gases to the inlet end of said drum, said furnace including an inlet damper means interposed in the furnace air supply structure, and a fuel supply line coupled with the furnace and adapted to be coupled with a source of fuel under pressure, a control for said dehydrator comprising: a conduit in fluid communication with said supply line and vented to atmosphere; temperature controlled valve means interposed in said conduit and including temperature responsive actuator means for the valve means and disposed to control the valve means for regulating the fluid pressure in the conduit responsive to the temperature at the outlet end of said drum; a valve interposed in said fuel supply line for regulating the flow of fuel to the furnace; means responsive to the pressure of fluid in the conduit and operably coupled with said valve and with the inlet damper means for automatically operating the valve and inlet damper to regulate the fuel and air supply responsive to the temperature at said outlet end, fan means operably coupled with the outlet end of said drum for creating artificial currents of gases through the drum to convey the material to said outlet; outlet damper means operably associated with the fan means for regulating the velocity of said currents; and actuator means operably coupled with the outlet damper means and said fuel supply line and responsive to the fuel flow in the latter to automatically regulate said outlet damper to control the rate of conveying of the material through the drum responsive to the fuel supply to said furnace, said actuator means including time delay means to permit movement of said outlet damper means only after a predetermined time increment following a change in the flow of fuel through said line, whereby to effect uniform drying of the product.

Claim 10

In a furnace for use in providing a stream of combustion gases, structure for providing air for combustion to the chamber, said structure comprising: a closed, cylindrical vessel having a pair of spaced apart end walls and an annular sidewall, the vessel being disposed at the inlet end of said chamber, there being an opening in the endwall adjacent the chamber communicating the vessel with the chamber; a tubular shroud extending around the sidewall of the chamber in outwardly spaced relationship from the latter and having an outlet opening through the shroud at the end thereof proximal the vessel, the spacing between the shroud and the outer surface of the chamber permitting flow of air between said chamber surface and the shroud to preheat the air; a discharge conduit communicating with the shroud opening and extending generally tangentially outwardly therefrom; inlet structure for the vessel including an inlet conduit extending generally tangentially from the annular sidewall and communicating therethrough; and blower means interposed between the discharge and inlet conduits whereby air is drawn in a swirling path around the chamber and is discharged in a swirling path into the vessel for swirling flow through thE opening into the combustion chamber.

Claim 11

In a furnace for use in providing a stream of combustion gases, structure for providing air for combustion to the chamber, said structure comprising: a closed, cylindrical vessel having a pair of spaced apart end walls and an annular sidewall, the vessel being disposed at the inlet end of said chamber, there being an opening in the endwall adjacent the chamber communicating the vessel with the chamber; a tubular shroud extending around the sidewall of the chamber in outwardly spaced relationship from the latter and having an outlet opening through the shroud at the end thereof proximal the vessel, the spacing between the shroud and the outer surface of the chamber permitting flow of air between said chamber surface and the shroud to preheat the air; a discharge conduit communicating with the shroud opening and extending generally tangentially outwardly therefrom; inlet structure for the vessel including an inlet conduit extending generally tangentially from the annular sidewall and communicating therethrough; and blower means interposed between the discharge and inlet conduits whereby air is drawn in a swirling path around the chamber and is discharged in a swirling path into the vessel for swirling flow through thE opening into the combustion chamber.