US 6,408,702 B1Granted

Wood processing drier sensor

AssigneeAutomated Control Engineering Inc.

InventorsLum C. Gaither, Wesley Harbour

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Abstract

A particle sampling system reads the moisture content of particulates (i.e., wood flakes) travelling through a pneumatically-driven conduit to control the remote drier. A rotatable hood penetrating an opening in the conduit is secured by a suitable mounting flange. When the hood is aimed upstream, facing the particle flow, a captivated sample drops through the apparatus into a special sampling compartment. After a reading the hood is rotated into a position facing downstream. Moisture-reading apparatus transmits light through the sampling window to determine moisture content. Readings may be relayed back to the drier for operating parameter correction. A suitable drive motor activates the hood assembly through a friction drive ring. A valve plate within a special housing may be switched between a closed position, defining the sampling compartment within its enclosure, and an open position, venting the apparatus to atmosphere. When the hood faces downstream, the valve plate is opened, and the sample is suctioned back into the particulate stream within the conduit to recycle raw materials. After the sample is returned, the valve closes and the hood is rotated back into a sampling position, enabling the cycle to repeat.

Claims16

Dependent claims

A device for sampling a stream of particulate material moving in a flow path through a tubular conduit, said device comprising:

hood means penetrating said conduit, the hood means comprising an open ended sample-intake spout and an opposite end in fluid flow communication through the device;
means for rotating said hood means between an upstream position with the spout facing the flow path to captivate samples and a downstream position for returning said samples into the flow path;
valve means for selectively closing said device when said hood means faces upstream and for venting said device when said hood means faces downstream;
valve housing means in fluid flow communication with said hood means for mounting said valve means;
means for selectively displacing said valve means between a closed position for obtaining said samples and an open position for returning the samples to the flow path within the conduit;
a sample collection compartment formed within said valve housing means by the closed valve means for temporarily holding samples of materials to be monitored;
moisture determining means for testing samples captivated within said collection compartment;
wherein said valve housing means comprises an inspection window adjacent said sample collection compartment, and said moisture determining means comprises means for reading sample moisture through said inspection window;
and,
circuit means for activating said means for rotating said hood means to rotate said hood means between operative positions and for opening said valve means so that samples that have been tested are returned via suction to the conduit flow path, and wherein, after tested samples have been returned to the conduit flow path, said circuit means closes said valve means and causes said means for rotating said hood means to return the hood means into a position to again take a sample so the sequence may repeat.

7 more elements

Dependencies are inferred from the claim text.