Wehr Corporation

John C McNabney

James M Lepper, Jr

James A Haas

Disclosed herein is a method and a digital electronic steam humidifier control for use with a humidifier system including an electrode boiler to provide a normally repetitive fill, boil, fill-on-drain cycle. The humidifier control includes circuitry for providing an analog signal proportional to the electrode current, and a comparator network which receives the analog signal and a reference voltage and scaled voltages provided by additional circuitry to establish predetermined levels of electrode current at which the control responds. The comparator network provides a plurality of digital outputs having a high or low state depending upon the magnitude of the electrode current, which outputs are coupled to logic circuitry including NAND gates and which operates to actuate electrically controlled fill and drain valves to vary the water level so that the electrode current varies between predetermined lower and upper current limits, and which also operates to temporarily cut off the power to the electrodes if the electrode current exceeds a predetermined over-current limit. The logic circuitry also operates in conjunction with high water probes to prevent overfilling of the boiler and to cause boiling of the water without draining during start up so that the water acquires a predetermined higher level of conductivity so that the electrode boiler operates efficiently. An abnormal operation light and high and low current indicators are also provided to inform an operator of the status of operation of the control.

Digital electronic steam humidifier control

The invention provides an air flow control mechanism adapted to be slideably insertable into an air duct without substantial structural modification of the air duct and without requiring shut down of the air system.

Airflow control mechanism insertable into an air duct

The invention provides an airflow control mechanism for use in an air duct for controlling airflow through the duct. The air flow control mechanism includes a frame positionable in the duct, and a plurality of blades supported by the frame and extending transversely to the direction of the air flow through the air duct. At least one of the blades is supported for pivotal movement about its longitudinal axis and has an elongated edge moveable toward and away from an elongated edge of another of the blades to restrict air flow through the duct. A fiber material strip is applied to at least one of those edges, the fiber material strip including a substrate bonded to that edge and a plurality of closely spaced fibers projecting transversely from the substrate, the fiber covering being functional to prevent the generation of a high frequency standing wave between the adjacent surfaces of the blade.

Air control mechanism having noise suppression means

A fluid flow sensor for measuring the conditions of pressure and/or velocity of fluid flow in a passage and which has the capability of averaging measured pressure and/or velocity of flow across the width of the passage.

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Verona, WI, United States of America

John C McNabney