System for reheating air in dryers
AssigneesCmpc Tissue S.A., Andritz Inc.
InventorsReinaldo Augusto Uribe Arancibia, George Z. Nowakowski
Life of this patent
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Abstract
An exemplary process air recirculation system, and an electric heater mixing apparatus is disclosed herein. Exemplary process air recirculation systems comprise the electric heating mixing apparatus. An exemplary electric heating mixing apparatus comprises: walls defining a first chamber having a first upstream opening and a first downstream opening, and a second chamber having a first upstream opening and a first downstream opening, wherein the second chamber is adjacently disposed to the first chamber, a first inlet damper disposed at the first upstream opening, a second inlet damper disposed at the second upstream opening, and a resistance-type electric air heater disposed in the first chamber.
Claims19
A method of controlling air flow through an electric heater mixing plenum, wherein the electric heater mixing plenum includes an upstream end, a downstream end, a first chamber, a second chamber adjacently disposed to the first chamber, and a mixing chamber located at the downstream end of the electric heater mixing plenum, comprising:
- controlling a first inlet damper and a first outlet damper of a first chamber of the electric heater mixing plenum to open positions to allow air flow through the first chamber, wherein the first chamber includes a resistance-type electric air heater;
- controlling a second inlet damper of a second chamber of the electric heater mixing plenum to an open position to allow air flow through the second chamber;
- monitoring a property of process air as it exits the mixing chamber of the electric heater mixing plenum;
- adjusting the open position of the first inlet damper based on the monitored property;
- and
- adjusting the open position of the second inlet damper based on the monitored property.
A method for controlling an electric heater mixing plenum used in an air recirculation system, comprising:
- controlling a first inlet damper and a first outlet damper of a first chamber of the electric heater mixing plenum to open positions to allow air flow through the first chamber, wherein the first chamber includes a resistance-type electric air heater;
- controlling a second inlet damper of a second chamber of the electric heater mixing plenum to an open position to allow air flow through the second chamber, wherein the second chamber is adjacently disposed to the first chamber within the electric heater mixing plenum;
- and
- closing the first inlet damper and the first outlet damper of the first chamber to prevent air flow through the first chamber,
- wherein when the first inlet damper and the first outlet damper are in closed positions and the second inlet damper is in the open position, air flow through the electric heater mixing plenum flows from an upstream end of the electric heater mixing plenum through the second inlet damper into the second chamber, through the second chamber into a mixing chamber, and through the mixing chamber to a downstream end of the electric heater mixing plenum, and
- when the first inlet damper and the first outlet damper are in open positions and the second inlet damper is in a closed position, air flow through the electric heater mixing plenum flows from the upstream end of the electric heater mixing plenum through the first inlet damper into the first chamber, through the first outlet damper into the mixing chamber, and through the mixing chamber to the downstream end of the electric heater mixing plenum.
A method for controlling an electric heater mixing plenum used in a drying system, comprising:
- controlling a first inlet damper and a first outlet damper of a first chamber of the electric heater mixing plenum to open positions to allow air flow through the first chamber into a mixing chamber of the electric heater mixing plenum, wherein the first chamber includes a resistance-type electric air heater;
- controlling a second inlet damper of a second chamber of the electric heater mixing plenum to an open position to allow air flow through the second chamber into the mixing chamber, wherein the second chamber is adjacently disposed to the first chamber within the electric heater mixing plenum;
- monitoring a temperature of process air at an upstream end of the electric heater mixing plenum, a temperature of electrically reheated air from the first chamber, and a temperature of reheated air from the mixing chamber;
- and
- comparing the monitored temperatures to preselected temperatures;
- and
- based on the comparison, controlling the positions of the first inlet damper, and the second inlet damper to adjust air flow through the first chamber and the second chamber,
- wherein the first inlet damper and the second inlet damper are positioned at the upstream end of the electric heater mixing plenum and the mixing chamber is positioned at a downstream end of the electric heater mixing plenum.
Dependencies are inferred from the claim text.