Dual drum spiral oven

摘要

In one aspect, an oven is provided and includes a drum oriented with a vertical axis and a motor for rotating the drum about the axis, a conveyor belt having a length helically surrounding the drum, and having an infeed end and outlet end, a chamber defined by walls surrounding the drum and the length of the conveyor belt, and a plenum within the chamber and being curved substantially concentrically with the drum. The plenum forms a substantially closed air pathway having an inlet at one end and an outlet at an opposite end passing air into the chamber. The oven also includes a fan arranged to circulate air within the chamber and force air into the plenum inlet, through the plenum and out of the plenum outlet, and a heat exchanger arranged in the plenum.

主权项

1. An oven comprising:
a first drum oriented with a first vertical axis and a first motor for rotating the first drum about the axis; a conveyor belt having a first length helically surrounding the first drum, and having an infeed end and outlet end; a first chamber defined by walls surrounding the first drum and the first length of the conveyor belt; a first plenum positioned within the first chamber, curved substantially concentrically with the first drum, and surrounding at least a portion of the first length of the conveyor belt, the first plenum forming a substantially closed air pathway having an inlet at one end and an outlet at an opposite end passing air into the first chamber; a first fan arranged to circulate air within the first chamber and force air into the first plenum inlet, through the first plenum and out of the first plenum outlet; a first heat exchanger arranged in the first plenum; a second drum oriented with a second vertical axis and a second motor for rotating the second drum about the axis; a conveyor belt having a second length helically surrounding the second drum, and having an inlet end to receive products from the outlet end of the first length and a discharge end; a second chamber defined by walls surrounding the second drum and the second length of the conveyor belt; a second plenum within the second chamber and being curved substantially concentrically with the second drum, the second plenum forming a substantially closed air pathway having an inlet and an outlet passing air into the second chamber; a second fan arranged to circulate air within the second chamber and force air into the second plenum inlet, through the second plenum and out of the second plenum outlet; and a second heat exchanger arranged in the second plenum; wherein the first fan is arranged in a fan chamber that has a radially oriented inlet with respect to the first drum and a tangentially oriented outlet with respect to the first drum that is in substantially enclosed air flow communication with the inlet of the first plenum; wherein the outlet of the first plenum and the fan chamber inlet are arranged to cause air circulated in the first chamber to substantially circulate in a first circular direction around the drum from the first plenum outlet to the fan chamber inlet; wherein the second fan is arranged in a fan chamber that has a radially oriented inlet with respect to the second drum and a tangentially oriented outlet with respect to the second drum that is in substantially enclosed air flow communication with the inlet of the second plenum; and wherein the outlet of the second plenum and the fan chamber inlet are arranged to cause air circulated in the second chamber to substantially circulate in a second circular direction around the drum from the second plenum outlet to the fan chamber inlet; wherein the first and second circular directions are opposite circular directions.