Marquip, LLC

Larry M Krznarich

Carl R Marschke

Paul T Melby

Light weight fabricated metal hot plates in a double backer are initially leveled and maintained flat and coplanar against the forces of thermal distortion by utilizing a dense array of adjustable spring biased support assemblies attached to the underside of the hot plate and securing the plate to an underlying supporting framework. The support assemblies allow horizontal thermal deflection of the hot plate but hold the hot plate heating surfaces firmly against vertical deflection.

Apparatus for leveling and supporting the hot plates in a double backer

A system for controlling the rate of heat transfer between the heating surfaces and a corrugated web in a double backer includes an air flow system operable to selectively apply a vacuum to the underside of the web via chambers formed in the spaces between the heating units or to apply pressurized air to the chambers to cool and lift the web, as necessary. A complementary system controls bowing in the surfaces of the heating units by supporting the undersides of the heating units with columns which include a thermally responsive metal member having an known coefficient of thermal expansion. The metal members are selectively heated by heating elements responsive to sensed bowing of the heating units to eliminate or minimize such bowing.

Heat transfer control system for a double backer

A hot plate for a double facer used in the manufacture of corrugated paperboard includes a substantially all copper construction which enhances thermal conductivity and heat transfer efficiency. Steam for heating the plates is provided through an array of copper tubes extending between manifolds on opposite sides of the hot plate, all in a manner which obviates the need for heavy pressure vessel construction. The hot plate is allowed to float on its supporting frame in a manner which accommodates lateral thermal expansion, and the lateral ends are tied vertically to the supporting frame to prevent thermal bowing characteristic of prior art systems.

Hot plate for corrugated paperboard double facer

A hot plate for a double racer used in the manufacture of corrugated paperboard includes a substantially all copper construction which enhances thermal conductivity and heat transfer efficiency. Steam for heating the plates is provided through an array of copper tubes extending between manifolds on opposite sides of the hot plate, all in a manner which obviates the need for heavy pressure vessel construction. The hot plate is allowed to float on its supporting frame in a manner which accommodates lateral thermal expansion, and the lateral ends are tied vertically to the supporting frame to prevent thermal bowing characteristic of prior art systems. The heating system is also applicable to a rotary preheating drum where the same benefits of thermal conductivity and heat transfer efficiency are attained. In addition, a rapid cooling system in which pressurized cooling water is supplied directly to the copper heat tubes is disclosed for use in either the double facer hot plate embodiment or the rotary preheating drum embodiment.

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Park Falls, WI, United States of America

Larry M Krznarich