Abb Inc.

Transphase Technology, Ltd.

Robert G Hamel

Shizhong Duan

Geoffrey Arthur Jones

There is described a method and apparatus for applying steam from a steam source to a moving web to thereby improve the smoothness and gloss of the web. A housing has at least one cooling chamber upstream and at least one steam chamber downstream. The cooling air in the cooling chamber is used to cool the web before steam is applied to the web from the steam chamber. This allows a sufficient volume of steam to be delivered to the web to thereby raise its moisture content to a desired level to thus achieve optimized calendering of the web.

Supercalendering optimization using a steam shower

A steam box for applying steam to a moving web comprising a housing having a leading end and a trailing end positionable above and proximate to a moving web; a supply header within the housing, said supply header in communication with a steam source; at least first and second steam chambers aligned with said leading edge in the direction of movement of said web, said first and second steam chambers able to receive steam from the said supply header to apply steam through respective first and second steam discharge points to the moving web, and a screen plate securable to said housing, said screen plate including a horizontal plate; and a first descending barrier positioned between said first and second steam discharge points, said descending barrier having a first trailing side adjacent to said-second steam discharge point to protect said second steam discharge point from stock flung from the web.

Steam box

An apparatus and method to use steam to atomize water to produce a mixture of moisture and heat for application to the web of a paper machine for both production improvement and paper quality control. The method allows independent droplet size and heat control in the mixture, resulting in flexibility that can not be offered by conventional steam showers or water spray systems individually. In one embodiment the apparatus consists of a plurality of actuator nozzle modules which control the water volume flow feeding the nozzle through a pneumatic pressure signal. Pressurized steam feeding the nozzle is used to break the water into fine droplets. The resulting nozzle spray is a mixture of moisture in fine water droplets and steam vapor, and heat stored in the steam. Alternatively, a plurality of steam valves can be used to regulate the steam volume flow feeding each atomizing nozzle.

Steam water spray systems

Apparatus and method for applying steam from a steam source to a moving web are provided. The preferred apparatus for carrying out the method comprises a housing having a leading edge and a trailing edge positionable adjacent the moving web. A main supply header within the housing communicates with the steam source. There is at least one steam chamber formed adjacent the leading edge of the housing to receive steam from the main supply header to apply heat and moisture to the web. A steam flow valve associated with the steam chamber controls the flow of steam from the main supply header to the steam chamber. There is at least one cooling chamber adjacent the trailing edge of the housing to lower the temperature of the web to a level sufficient to perform calendering. The method involves delivering steam to the web in sufficient volume to raise the moisture content to a desired level with a concomitant rise in the temperature of the web and then cooling the web to lower the temperature to a desired level to permit subsequent calendering of the web. By providing cooling of the web after adding steam, it is possible to deliver a greater volume of steam to the web than is conventional. The greater volume of steam causes increased condensation which raises the moisture content of the web. At the same time, the greater volume of steam raises the web temperature outside normal production limits, however, cooling of the web to its maximum allowable temperature leaves additional moisture on the web for improved calendering.

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Bowen Island, Canada

Robert G Hamel