Abstract: A convective dryer for drying a moving coated web has at least one module arranged on one side of the path of web travel. The module includes a housing subdivided into a first chamber opening towards the path of web travel and a second adjacent enclosed chamber. Mutually spaced nozzle assemblies extend laterally across the path of web travel within the first chamber. The nozzle assemblies are connected by a supply duct to air heating and recirculating components in the second chamber. The supply duct gradually diverges in width from a narrow inlet section communicating with the second chamber to a widened delivery end communicating with the nozzle assemblies at the approximate center of the path of web travel.

Abstract: In a doctoring apparatus, blade edge loading is controlled along the sides of the surface being doctored.

Abstract: Method and system for applying steam to a paper forming web for the purpose of heating the web to improve the quality of the paper, and withdrawing steam through the use of a vacuum opposite the steam shower, by the simultaneously controlled removal of steam at equally spaced increments by the use of a computer based control system. The computer based control system includes a selectively actuable stepper motor, to effectuate the simultaneous opening of both the steam valve and opposing withdrawal means valve. The system includes a coanda nozzle to cause steam to travel between the sheet and the adjacent surface of the apparatus in a direction opposite to the direction of travel of the sheet and also includes steam impingement nozzles. The apparatus includes devices for creating, housing and providing a supply of steam and a supply of vacuum.

Abstract: In a pull through doctor blade transfer system, the blade ends are slotted at their working edges. The slots are arranged and configured to accept complimentarily shaped portions of a connecting link used to detachably connect the trailing end of a spent or worn blade to the leading end of a fresh blade.

Abstract: A method and apparatus for drying a continuously moving web carrying a liquid, wherein the web is passed through a dryer in which the web is exposed to a recirculating flow of heated drying gas. Exhaust gas is diverted and discharged from the recirculating gas flow at a flow rate which is variable between maximum and minimum levels, and makeup gas is added to the recirculating gas flow at a flow rate which is also variable between maximum and minimum levels. A process variable is sensed and compared to a selected set point. A first of the aforesaid flow rates is adjusted to maintain the process variable at the selected set point, and a second of the aforesaid flow rates is adjusted in response to adjustments to the first flow rate in order to insure that the first flow rate remains between its maximum and minimum levels.

Abstract: A steam shower apparatus and method including a supply of steam which is fed through a Coanda nozzle and along a path running adjacent one surface of the apparatus which is heated to a temperature in excess of 175-180 degrees Fahrenheit. The sheet to which the steam is to be applied runs adjacent this same surface of the machine, but in a direction opposite to the direction of the flow of steam. In one embodiment, the heated surface is located relative to the sheet so that an upstream edge of the apparatus is spaced from said sheet by a greater distance than is the downstream edge of the apparatus which preferably contacts the sheet to back pressure the steam between the apparatus and sheet. The flow of steam runs the entire length of this surface heating the sheet as it flows in the opposite direction. The apparatus may be divided into several sections so that the sheet may be profiled along certain regions which are defined by these sections.

Abstract: In a pull through doctor blade transfer system, blade edge loading is controlled along the sides of the surface being doctored to relieve loading forces and to achieve a gradual feathering of the blade during its initial application.

Abstract: An apparatus for removing excess steam from an area around a web, such as paper, the apparatus having a stationary vacuum pick-up slot positioned adjacent the web, a steam exhaust pipe leading from the pick-up slot to a vacuum header, an adjustable opening in the exhaust pipe in the vacuum header, facilitating control of the vacuum across the pick-up slot, and a chamber adapted to be heated, the chamber being configured so as to form one wall of the pick-up slot, and means for maintaining a vacuum on the header and the pick-up slot.

Abstract: A modified double slot impingement nozzle for floater dryers is used to maximum advantage by optimizing the relationships of the spacing between the nozzles and the nozzle lengths for each row of nozzles along the web. The nozzle is also used to advantage by optimizing the slot width of the secondary jet of the nozzle in relation to the slot width of the primary jet.

Abstract: In a pull through doctor blade transfer system wherein a coiled blade is payed off one rotatable reel while simultaneously being taken up on another rotatable reel, with an intermediate portion of the blade between the reels being supported in a blade holder arranged to apply the blade to a moving surface to be doctored, each reel is driven by a hydraulic motor. In operation, hydraulic fluid discharged from the motor driving the take up reel is fed to the motor connected to the pay off reel. This fluid is pumped to a high pressure by blade induced rotation of the pay off motor, thus creating a braking torque.

Abstract: An apparatus for doctoring a cylindrical rotating surface, comprising a doctor back mounted for rotation about a first axis, and a blade carrier assembly mounted on the doctor back for rotation about a second parallel axis. A doctor blade is removably supported by the blade carrier assembly and is loaded against the rotating surface by a force applied to rotate the doctor back about the first axis. A liquid filled flexible walled tube extends along the second axis between the doctor back and the blade carrier assembly. The blade angle is adjusted by expanding and contracting the liquid filled tube to rotate the blade carrier about the second axis.

Abstract: A fluid pressure oscillator is provided with a cylinder containing a piston assembly. Fluid actuated reciprocation of the piston assembly is controlled by a valve mounted externally of the cylinder. The valve is alternately shifted between "advance" and "retract" settings by a reciprocating actuating rod removably received in the cylinder. A magnet on the piston assembly cooperates with magnetic elements on the actuating rod to automatically reciprocate the latter.

Abstract: A caliper control system for controlling the thickness and sheet quality of paper passing between calender rolls of a calender stack includes a distribution chamber which houses a supply of heat transfer fluid. A series of nozzles extends across the width of the unit in the cross machine direction, and each of these nozzles are selectively actuable. An actuating means, which may be a piston connected to a solenoid, opens and closes an opening in the wall between the distribution chamber and the nozzle for each nozzle of the unit. In a preferred embodiment, the caliper control system includes two such units. One of these units will supply hot air to the roll surface, and the roll to which the hot air is applied to an unheated roll. The second unit will supply cold air to a heated roll. Each of the nozzles is covered with a plate which includes a large number of apertures for expelling the heat-transfer fluid from the nozzle.

Abstract: Disclosed is an apparatus for transporting a web about a nonlinear path without allowing the apparatus to contact the web. The apparatus includes a series of positive pressure nozzles which emit a primary jet flow of fluid in a single direction, and a secondary jet flow of fluid in a direction perpendicular to the primary flow. The two flows merge and transport the web on a cushion of air along the nonlinear path. The magnitude of the cushioned pad is controlled by a series of slide dampers which are positioned between adjacent nozzles, and the opening of these slide dampers controls the amount of exhaust from the merged flow so as to control the cushioned path. The last nozzle in the series will direct its primary flow in a direction opposite to that of the other nozzles in the series in order to maintain the overall pressure pad under the web.

Abstract: A doctor blade assembly has a doctor blade supported in a blade holder. The blade has a projecting front edge adapted to be placed in contact with a moving surface to be doctored, and a rear edge adapted to be received in the blade holder. The blade is preloaded in a manner such that tensile stresses are induced in the front edge thereof. The level of such tensile stresses is below the yield strength of the blade material, yet high enough to prevent compressive stresses from developing at the blade front edge as a result of heat being generated by frictional contact between the blade and the moving surface being doctored.

Abstract: An apparatus for doctoring a cylindrical rotating surface, comprising a doctor back mounted for rotation about a first axis, and a blade carrier assembly mounted on the doctor back for rotation about a second parallel axis. A doctor blade is removably supported by the blade carrier assembly and is loaded against the rotating surface by a force applied to rotate the doctor back about the first axis. A liquid filled flexible walled tube extends along the second axis between the doctor back and the blade carrier assembly. The blade angle is adjusted by expanding and contracting the liquid filled tube to rotate the blade carrier about the second axis.

Abstract: A nozzle assembly for a web drying apparatus that can be quickly assembled and disassembled from the front or tending side of the web drying apparatus. At the rear of the web drying apparatus, instead of the normal bolt fastening system, a slidable connection is provided between the nozzle housing and the bulkhead. By manipulating the front end of the nozzle housing, nozzle mounting flanges secured to the rear end of the nozzle housing are slid under nozzle support clips on the bulkhead to secure the rear end of the nozzle housing to the bulkhead. Conventional systems are used to secure the front end of the nozzle housing. There may be one or two bulkheads in the nozzle assembly of the present invention.

Abstract: A flotation drying system utilizing a nozzle assembly having a mounting system that enables quick assembly and disassembly of the system. The nozzle assembly comprises one or more high pressure supply headers or bulkheads, a nozzle housing extending across the grooved face of the one or more bulkheads in a perpendicular direction to the direction of the bulkhead, the nozzle housing having a port connecting it to the bulkhead so that a stream of air goes through the nozzle housing and is applied to the web for drying. The nozzle assembly comprises sealing plates removably supported by the groove face of the bulkhead adjacent each of the nozzle housings to seal the area between the nozzle housings. A flange extends from each of the nozzle housings over the sealing plates as a means to seal the nozzle housings to the grooved face of the bulkhead.

Abstract: Disclosed is a steam-shower apparatus and method including a supply of steam which is fed through a Coanda nozzle and along a path running adjacent one surface of the apparatus which is heated to a temperature in excess of 212 degrees Fahrenheit. The sheet to which the steam is to be applied runs adjacent this same surface of the machine, but in a direction opposite to the direction of the flow of steam. In one embodiment, the heated surface is located relative to the sheet so that an upstream edge of the apparatus is spaced from said sheet by a greater distance than is the downstream edge of the apparatus which preferably contacts the sheet to back pressure the steam between the apparatus and sheet. The flow of steam runs the entire length of this surface heating the sheet as it flows in the opposite direction. The apparatus may be divided into several sections so that the sheet may be profiled along certain regions which are defined by these sections.

Abstract: Disclosed is an apparatus and method for providing a shower of fog onto a web or a machine component in contact with a web or for applying a layer of moisture to a web. The fog, which as a temperature lower than the temperature of the surface of the web or the machine component to be cooled, is applied to the surface and is caused to evaporate by the difference in the temperatures. A supply of dry air is supplied to transport the evaporated fog from the region adjacent the surface to be cooled. Fog may be generated through the use of an air-atomizing nozzle which propels water and compressed air through a small orifice under pressure to create an atomized mist or fog. To achieve localized control of the application of fog, a plurality of air atomizing nozzles is mounted in a row extending in the cross machine direction of the apparatus. An air plenum extending parallel to the row of air atomizing nozzles is mounted on at least one side of the row.