US3815256A - Grooved dryer - Google Patents

Grooved dryer Download PDF

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Publication number
US3815256A
US3815256A US00339741A US33974173A US3815256A US 3815256 A US3815256 A US 3815256A US 00339741 A US00339741 A US 00339741A US 33974173 A US33974173 A US 33974173A US 3815256 A US3815256 A US 3815256A
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United States
Prior art keywords
web
dryer
drums
groove
paper
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00339741A
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English (en)
Inventor
D Ely
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beloit Corp
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Beloit Corp
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Filing date
Publication date
Application filed by Beloit Corp filed Critical Beloit Corp
Priority to US00339741A priority Critical patent/US3815256A/en
Priority to JP2726974A priority patent/JPS5313006B2/ja
Application granted granted Critical
Publication of US3815256A publication Critical patent/US3815256A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
    • D21F5/00—Dryer section of machines for making continuous webs of paper
    • D21F5/02—Drying on cylinders
    • D21F5/021—Construction of the cylinders

Definitions

  • This invention relates to papermaking and more particularly is directed to new and improved methods and means for removing moisture from a traveling paper web in a dryer section.
  • a traveling paper web is generally passed sinuously up and down between upper and lower tiers ofdryer drums with-an upper and lower felt guided by guide rolls holding the web onto the respective surfaces of the heated dryer drums.
  • air is carried onto the dryer drum surfaces by the oncoming paper web. This air thus entrapped builds up a layer of air under pressure between the web and the dryer surface causing not only poor heat transfer to the web but also causing the traveling web to float, wrinkle, break or otherwise deviate from its path of travel to the detriment of efficient operation.
  • FIG. 3 is a graphical representation of drying rates for paper as a function of dryer steam pressure
  • F IG. 4 is an enlarged partial elevational view of the structure shown in FIG. 2;
  • FIG. 5 is an enlarged partial sectional view of a portion of a dryer cylinder constructed in accordance with the present invention.
  • FIG. 6 is an essentially schematic view illustrating a groove configuration provided on a dryer drum surface in accordance with the principles of the instant invention
  • FIG. 7 is another schematic view illustrating another groove configuration utilized on a dryer drum surface in accordance with the principles of the invention.
  • a traveling paper web W such as is received'from a press section of a papermachine, is guided by means of an idle roll 11 into the dryer section, generally indicated .at 10, to be carried over a series of cylindrical dryer drums illustratedin sequence at 12, 13, 14 and '15. While only a portion of the dryer section is shown, the web W will pass sequentially in serpentine fashion over moredryer drums until a desired degree of dryness is obtained.
  • the dryer drums are arranged in tiers, with the upper tier being represented by dryer drums 12 and 14 and the lower tier by dryer drums 13 and 15.
  • the dryer drums are suitably heated, as indicated diagrammatically at H, and include means for heating the outer periphery of the dryer drum surface via axial feed or heating fluid to the respective inner peripheries of the drying drums.
  • other suitable. heating means may be provided.
  • the web W travels at a speed determined by the speed of rotation of the various dryer drums andsev- ,eral means (not shown) can be provided for driving the dryer drum at predetermined speeds.
  • each of the dryer drums are interconnected and driven at controlled speeds as will be appreciated by those skilled in the art, and such mechanisms need not be discussed further. 1
  • the traveling web W is guided and held onto the individual dryer drum peripheral surfaces by dryer felts F-l and F-2.
  • the felts F-l and F-2 are formed of a porous material and may be of any type of fabric which will allow air and steam to pass through it.
  • the felts may also be formed of plastic fabric or screen.
  • a suitable material being a foraminous plastic screen or fabric of the type known as Formex" fabric,-which permits moisture vapor to be driven through the fabric by heated air.
  • the web W alternately travels around the rolls l2 and 14 of the upper tier and the rolls 13 and 15 of the lower tier.
  • FIG. 3 is a graphical representation showing pounds of paper dried per square foot of dryer surface per hour as a function of the 'dryer equivalent stream pressure in psi.
  • dry creped tissue as well as kraft machine glazed paper is dried by forcibly pressing the moist web against the surface of a polished drying cylinder. This paper thus pressed onto the cylinder surface remains in firm contact therewith throughout a substantial portion of its circumference so that there is no possibility of an insulating layer of air being built up between the paper web and the dryer surface.
  • Kraft paper on the other hand, is dried in the conventional manner, that is, in the manner illustrated in FIG. 1. It should further be appreciated that the weight per 3,000 square feet of kraft machine glazed paper and the weight per 3,000 square feet of kraft paper are for all practical purposes similar. It will thus be noted from the graphical representation of FIG. 3 that for an equivalent steam pressure of psi, 3.4 lbs. of kraft machine glazed paper can be dried per square foot of dryer surface per hour whereas only 1.0 lbs. of kraft paper can be dried with the equivalent dryer surface and in the same amount of time. The difference of 2.4 lbs. of paper dried at the same steam pressure between kraft machine glazed paper and kraft paper are thus substantial.
  • the dryer drums are provided with a plurality of circumferentially alternating grooves and ridges and certain configurations.
  • the grooves may be in the form of continuous spiral extending over the entire drum periphery.
  • the helically grooves may be relatively opposed defining diamondshaped land areas on the peripheral surface of the dryer drums.
  • the relatively narrow uniformly spaced grooves act as venting means to purge air carried over the dryer drum surface by the oncoming paper web, and also to vent moisture vapor which forms between the dryer drum surface and the web during the drying process.
  • the groove is filled with air and pressure starts to build up resulting in an outward flow of air as indicated by the arrows C. Due to an increase in the temperature of the air as it enters the groove this pressure buildup is quite rapid and the velocity of the outflowing air C is larger than the velocity of the ingoing air A.
  • This outward rush of air C creates a vacuum condition in the remaining groove space indicated at D by virtue of which the web W is urged towards the roll periphery thereof enhancing the web-to-dryer surface contact and increasing the drying rate.
  • the grooves also provide more actual surface area on the dryer surface, thereby allowing greater heat transfer from the heated, dryer drum to the contacting web.
  • the plurality of alternative grooves and ridges may be directly cut or machined onto a dryer drum surface with appropriate means, or the drum surface may be so formed in the manufacturing process thereof.
  • suitable drum sleeves or covers can be formed from an appropriate heat conductive heat material, such as stainless steel or aluminum, with the grooves and ridges being formed on the sleeve and then the sleeve can be appropriately fitted over a plain surface dryer drum. This approach is particularly advantageous where the shell thickness of existing dryer drums is too thin to permit the cutting of relatively deep grooves into the dryer drum periphery.
  • the preferred grooved dryer drum 40 is shown in fragmentary detail in FIG. 5, and the grooves 41 are shown as having a substantially uniform axially dimension 42, which is substantially in the range of 0.025 to 0.200 inch between generally cylindrical smooth land areas or ridges 44 having an axial dimension 45 that is substantially in the range of 0.1 to 2.0 inch.
  • the grooves are thus defined between generally radially extending parallel sidewalls substantially to the bottom 46 thereof which may be rounded with a radius of about one-half the groove width 42.
  • This groove construction accommodates a sufficient volume of air and steam while at the same time eliminating structural stresses (because of unfavorable stress concentration in sharp corners) and facilitates cleaning or venting of the grooves since there are no corners present where fuzz or other like material can accumulate.
  • the minimum groove depth should be approximately 0.015 inch
  • the minimum groove width should be approximately 0.030 inch
  • the maximum lead of a spiral groove or the distance between grooves in the event that annular grooves are used should be approximately 2 inches.
  • the maximum depth should be preferably not exceed 0.200 inches, this dimension being largely governed by stress considerations of the most commonly used drying shells.
  • the maximum width should preferably not exceed 0.200 inches since an excessive width may cause marking of the paper web while the minimum lead should preferably not be less than 0.1 to 0.5 inches.
  • a high speed web drying apparatus for paper machines including:
  • drums having peripheral surfaces provided with a web traction means to urge the traveling web toward said dryer surfaces thereof enhancing the web-to-dryer surface contact to prevent deviation of the web from its normal path around said dryer surfaces,
  • said traction means comprising a plurality of alternating generally circumferentially aligned grooves and ridges wherein a portion of each groove has a vacuum zone by virtue of the velocity of the air flowing out of the groove being greater than the velocity of the air flowing into the groove.
  • a high speed web drying apparatus for paper machines in accordance with claim 1, wherein:
  • the grooves have an axial dimension at the groove periphery substantially in the range of from 0.025 to 0.200 inches and extend generally radially inward for a distance substantially in the range of from 0.015 to 0.200 inches along generally parallel sidewalls, said sidewalls terminating in a bottom portion having a radius one-half of the groove width and the ridges each present a generally circumferentially outer peripheral land area having an axial dimension substantially in the range of from 0.1 to 2.0 inches at the roll periphery.
  • a high speed web drying apparatus for paper machines in accordance with claim 1, wherein:
  • the web traction means on the peripheral surfaces of the dryer drums provide a relatively greater surface area on said surfacesfor increased heat transfer from said dryer surface to the traveling web.

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  • Drying Of Solid Materials (AREA)
  • Paper (AREA)
US00339741A 1973-03-12 1973-03-12 Grooved dryer Expired - Lifetime US3815256A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US00339741A US3815256A (en) 1973-03-12 1973-03-12 Grooved dryer
JP2726974A JPS5313006B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1973-03-12 1974-03-11

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00339741A US3815256A (en) 1973-03-12 1973-03-12 Grooved dryer

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US3815256A true US3815256A (en) 1974-06-11

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US00339741A Expired - Lifetime US3815256A (en) 1973-03-12 1973-03-12 Grooved dryer

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US (1) US3815256A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
JP (1) JPS5313006B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4495712A (en) * 1982-06-28 1985-01-29 Beloit Corporation Paper making machine dryer section drive
US4495711A (en) * 1982-06-28 1985-01-29 Beloit Corporation Dryer section drive arrangement for paper making machines
US4510698A (en) * 1982-09-29 1985-04-16 Beloit Corporation Dryer felt run
FR2580063A1 (en) * 1985-04-03 1986-10-10 Strasbourg Ste Indle Forges Apparatus for drying wood veneer
EP0227442A1 (en) * 1985-12-21 1987-07-01 Scapa-Porritt Limited Improvements to papermachine and like clothing
US4874469A (en) * 1986-08-12 1989-10-17 Beloit Corporation Heated extended nip press with porous roll layers
US5082533A (en) * 1990-04-10 1992-01-21 Beloit Corporation Heated extended nip press with porous roll layers
WO1993015267A1 (en) * 1992-01-27 1993-08-05 Asea Brown Boveri Inc. Dryer cylinders
US5553392A (en) * 1993-11-15 1996-09-10 Tokushu Paper Mfg. Co., Ltd. Process and apparatus for drying sheet materials

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6058392B2 (ja) * 1977-04-23 1985-12-19 コニカ株式会社 写真材料の乾燥装置
JPS5513591A (en) * 1978-07-14 1980-01-30 Sanyo Electric Co Ltd Tuning state display circuit
DE3744212A1 (de) * 1987-12-24 1989-07-06 Ruhrchemie Ag Verfahren zur herstellung von 2-methylbutanal

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3198697A (en) * 1964-06-26 1965-08-03 Beloit Corp Paper press roll assemblies
US3405855A (en) * 1966-03-11 1968-10-15 Beloit Corp Paper guide and drive roll assemblies
US3429256A (en) * 1960-11-28 1969-02-25 Cellophane Investment Co Ltd Apparatus for separating the components of a suspension
US3445938A (en) * 1967-04-27 1969-05-27 Huyck Corp Ventilation system for a papermaking machine

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3429256A (en) * 1960-11-28 1969-02-25 Cellophane Investment Co Ltd Apparatus for separating the components of a suspension
US3198697A (en) * 1964-06-26 1965-08-03 Beloit Corp Paper press roll assemblies
US3405855A (en) * 1966-03-11 1968-10-15 Beloit Corp Paper guide and drive roll assemblies
US3445938A (en) * 1967-04-27 1969-05-27 Huyck Corp Ventilation system for a papermaking machine

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4495712A (en) * 1982-06-28 1985-01-29 Beloit Corporation Paper making machine dryer section drive
US4495711A (en) * 1982-06-28 1985-01-29 Beloit Corporation Dryer section drive arrangement for paper making machines
US4510698A (en) * 1982-09-29 1985-04-16 Beloit Corporation Dryer felt run
FR2580063A1 (en) * 1985-04-03 1986-10-10 Strasbourg Ste Indle Forges Apparatus for drying wood veneer
EP0227442A1 (en) * 1985-12-21 1987-07-01 Scapa-Porritt Limited Improvements to papermachine and like clothing
AU594730B2 (en) * 1985-12-21 1990-03-15 Scapa-Porritt Ltd. Improvements to papermachine and like fabrics
US4874469A (en) * 1986-08-12 1989-10-17 Beloit Corporation Heated extended nip press with porous roll layers
US5082533A (en) * 1990-04-10 1992-01-21 Beloit Corporation Heated extended nip press with porous roll layers
WO1993015267A1 (en) * 1992-01-27 1993-08-05 Asea Brown Boveri Inc. Dryer cylinders
US5553392A (en) * 1993-11-15 1996-09-10 Tokushu Paper Mfg. Co., Ltd. Process and apparatus for drying sheet materials

Also Published As

Publication number Publication date
JPS49117707A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1974-11-11
JPS5313006B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1978-05-06

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