Abstract: A screen panel for a wood-chip digester, comprises a screen plate having a plurality of slots therein that are curved in the form of an arc. Each slot has a generally parallel-sided middle portion in the middle of the thickness of the screen plate, which middle portion has a width in the range of from 3 mm to 10 mm, and a portion that tapers out at an angle on each side of the middle portion, at a half-angle in the range of from 10° to 20°, for approximately one quarter of the thickness of the plate. All of the slots have their concave sides facing in the upstream direction of chip flow in the digester.

Abstract: A screen panel for a wood-chip digester comprises a screen plate having a plurality of slots therein that are curved in the form of an arc. Each slot has a width in the range of from 3 mm to 10 mm. One form of slot has a generally parallel-sided middle portion in the middle of the thickness of the screen plate, which middle portion has a width in the range of from 3 mm to 10 mm, and a portion that tapers out at an angle on each side of the middle portion, at a half-angle in the range of from 5° to 20°, for approximately one quarter of the thickness of the plate. Another form of slot tapers out from one side of the plate to the other side. All of the slots have their concave sides facing in the upstream direction of chip flow in the digester.

Abstract: A chip bin for a digester has an upper part through which chips fall freely from an inlet and a lower part within which the chips remain until they are fed to a digester. Steam orifices strike falling chips with steam and disperses the chips over the interior of the chip bin. Further steam heats the chips and drives out non-condensable gas. The lower part of the chip bin is conical. Steam jets aimed down the conical walls propel the chips to an outlet at the bottom and prevent bridging.

Abstract: A screen panel for a wood-chip digester comprises a screen plate having a plurality of slots therein that are curved in the form of an arc. Each slot has a width in the range of from 3 mm to 10 mm. One form of slot has a generally parallel-sided middle portion in the middle of the thickness of the screen plate, which middle portion has a width in the range of from 3 mm to 10 mm, and a portion that tapers out at an angle on each side of the middle portion, at a half-angle in the range of from 5° to 20°, for approximately one quarter of the thickness of the plate. Another form of slot tapers out from one side of the plate to the other side. All of the slots have their concave sides facing in the upstream direction of chip flow in the digester.

Abstract: A screen panel for a wood-chip digester, comprises a screen plate having a plurality of slots therein that are curved in the form of an arc. Each slot has a generally parallel-sided middle portion in the middle of the thickness of the screen plate, which middle portion has a width in the range of from 3 mm to 10 mm, and a portion that tapers out at an angle on each side of the middle portion, at a half-angle in the range of from 10° to 20°, for approximately one quarter of the thickness of the plate. All of the slots have their concave sides facing in the upstream direction of chip flow in the digester.

Abstract: A pre-treatment device for wood chips for pulping comprises a tube through which the wood chips fall into a digester. Steam is injected into the tube through rings of nozzles, which are angled circumferentially to impart a rotary and turbulent motion to the falling chips. Some nozzles are angled downwardly to encourage the chips to flow freely through the tube, some are horizontal to encourage a longer dwell time near the nozzles. Digesting liquor is also sprayed onto the chips from spray nozzles after the first ring of steam nozzles. The heat and steam expel air and other non-condensable gases and volatiles from the chips, allowing them to absorb the liquor. At the bottom of the tube, the chips are propelled down and outwards by jets of higher-pressure steam, spreading and packing them into the digester.

Abstract: A pre-treatment device for wood chips for pulping comprises a tube through which the wood chips fall into a digester. Steam is injected into the tube through rings of nozzles, which are angled circumferentially to impart a rotary and turbulent motion to the falling chips. Some nozzles are angled downwardly to encourage the chips to flow freely through the tube, some are horizontal to encourage a longer dwell time near the nozzles. Digesting liquor is also sprayed onto the chips from spray nozzles after the first ring of steam nozzles. The heat and steam expel air and other non-condensable gases and volatiles from the chips, allowing them to absorb the liquor. At the bottom of the tube, the chips are propelled down and outwards by jets of higher-pressure steam, spreading and packing them into the digester.

Abstract: A pre-treatment device for wood chips for pulping comprises a tube through which the wood chips fall into a digester. Steam is injected into the tube through rings of nozzles, which are angled circumferentially to impart a rotary and turbulent motion to the falling chips. Some nozzles are angled downwardly to encourage the chips to flow freely through the tube, some are horizontal to encourage a longer dwell time near the nozzles. Digesting liquor is also sprayed onto the chips from spray nozzles after the first ring of steam nozzles. The heat and steam expel air and other non-condensable gases and volatiles from the chips, allowing them to absorb the liquor. At the bottom of the tube, the chips are propelled down and outwards by jets of higher-pressure steam, spreading and packing them into the digester.

Abstract: A robotic sampling device has a maneuverable, telescoping sample collector comprising a sample collecting arm and a propulsion module containing means for supporting and facilitating movement. Most preferably, the means for supporting and facilitating movement are wheels. The robotic sampling device also contains means for increasing traction for the propulsion module. The sampling device is remotely controlled. The sampling device contains at least one light source and a viewer that provides information for navigation and sample collection. The wheels of the propulsion module contain extendable pins which promote increased traction. The telescoping sample collector may also be rotated or tilted through a 180 degree arc relative to the axis of the pipe. The robotic sampling device also provides a means for collecting, labelling, and storing a sample, as well as cleaning the sample collector in preparation of another sampling event.

Abstract: A heat exchanger that is universally usable in the flue stack of a heating appliance and yet is efficient and capable of properly matching the rate of heat exchange to the heat rating of the heating appliance. The basic elements of the heat exchanger which affect heat transfer, include the length and diameter of the flue gas tubes, the tube support structure defining the tube spacing, air flow baffles, air openings and the size of the blower are held constant. To match the amount of heat recovery from the flue gas to the heat rating of heating appliance, only the amount of heat exchange surface area (finning) is varied from heat exchanger to heat exchanger. Further, the heat exchanger includes a heat transfer section which is readily separable from the flue gas inlet and outlet assemblies for cleaning or repair without the need for complete removal of the entire heat exchanger from the flue stack.