US1547481A - Temperature control in paper drying - Google Patents

Description

July 28, 1925.

G. s. WITHAM, SR, ET AL TEMPERATURE CONTROL IN PAPER DRYING 5 Sheets-Sheet 1 Filed March 31, 1921 G. s. WITHAM, SR.) ET AL TEMPERATURE CONTROL IN PAPER DRYING July 28, 1925 Filed March 31, 1921 5 Sheets-Sheet' 2 lo I. I I

July 28, 192s G. S. WITHAM, SR, ET AL TEMPERATURE CONTROL IN PAPER DRYING 5 Sheets-Sheet 5 &

Filed March 31, 1921 m/b M July 28, 192 5., 1,547,481

G. s. WHTHAM, SR}, ET AL TEMPERATURE CONTROL IN PAPER DRYING Filed March 31, 1921 5 Sheets-Sheet 4 upentoz July 28, 1925. 1,547,481

G. S. WlTHAM, SR, ET AL TEMPERATURE CONTROL IN PAPER DRYING Filed March 31, 1921 5 Sheets-Shet 5 Patented July 28', 1925, I l

UNITED .STATES PATENT, OFFICE-1Y5?" GEORGE STRONG WITHAM, SR, AND GEORGE STANFORD WITH A M, JR., OF HUDSON FALLS, NEW YORK.

TEMPERATURE CONTROL IN PAPER DRYING. Application flled- March 31, 1921. Serial No. 457,304.

7'0 all 201207)), it may concern: Another object is to provide in connection lie it known that we, GEORGE S. WITHAM, with the exhaust steam manifold, a relief S12, and Gannon S. lVrrnAM, Jr., residing at valve, adapted to open when the pressure lludsonl alls, in the county of \Vashington, exceeds a predetcrn'iined amount, and a nor- State of New York, whose post oflice admally closed valve between the said mani- 00 dress is A, Union Bag &. Paper Corporafold and the feed water heater, controlled to tion. lludson Falls, New York, have in open position when the livesteam supply is vented certain new and useful Improvements connected to the cylinders. in Zlemperature Control in Paper Drying; A further object is to provide mechanism and we do hereby declare the following to for separating the liquid of the condensate 65 be a full, clear, and exact description of the from the air and Vapor, and for removing invention, such as will enable others skilled the liquid from the cylinders as it forms. in the'art to which it appertains to make I Another object is to provide a series of and use the same. means, arranged at intervals between the Our inventionis an improvement in temdrip header for the cylinders and the return 70 perature controls for paper making m'apipe, for connectingsaid header to the pipe, chines, and relates especially to mechanism and means for operating the saidconnectingl or controlling the temperatureof the rolls means, to connect anddisconnect the header over which the paper web is drawn to dry and the pipe, controlled by the level of the the same, after it-has been formed. liquid. and operated by fluid under pressure. 75

An object of the invention is to provide, In the'drawings; I in connection with the drying cylinders of Figures 1 and 1", taken together, show in a paper making machine, means for maindiagrammatic form and conventionalized the taining the temperature of the cylinders heating system of a set of drying rolls, substantially uniform, and controlled by the Figures 2 and 2", together, constitute a 80 temperature of certain of the cylinders. similar view of the mechanism for collecting Another object is to provide means for the condensate and returning it to the feed heating the cylinders to progressively higher water heater. d temperatures from the wet to the dry end Figure 3 is a vertical section through one of the dryer, and controlled by the temperaof the controlling units, ture of selected cylinders. Figure 4 is a section on the line 4-4 of Another object is to provide in a paper Figure 3, g making machine, mechanism for heating the Figure 5 is a vertical section through one drying" cylinders with exhaust, steam, conof the controlling valves, trolled by the temperature of the rolls, and Figure 6 is a similar View of one of the auxiliary heating means also controlled by separators. the temperature of the rolls, for supple- In the usual construct on of paper dryers mcnting the exhaust steam, when necessary wherein the heating rolls or cylinders are to maintain a'uni'form temperature. heated by steam, the control of'the tem- Another object is to provide in machines perature functions upon variations of steam of the character wherein the drying cylinpressure, or uponchanges in tension of the (ltl'S are heated by exhaust. steam, means paper. Because of the fact that a certain controlled by the temperature of selected pressure does not always mean a definite cylimlers, for varying the quantity of steam temperature of the heating cylinders, con admitted to the rolls in accordance with the trols based upon the pressure do not give temperature desired. the desired results. The same is true con- Another object is to provide mechanism earning those controls which depend upon in connection with the controlling means for the tension of the paper, for they do not adjusting the same to provide for any defunction when no paper is running.- A sired temperature of the cylinders. definite steam pressure in the manifold does Anothcrobject is toprovide means nornot produce corresponding temperatures in malty operative for closing the discharge the cylinders, due to conduction, condensaend of the exhaust steam manifold and contion, poor circulation and air pocketing. In trolled to open position when the live steam the present invention the su ply of heating 55 supply isconnected to the cylinders, medium is controlled direct y by the tam, no

sisting of arranged i each of these supply condensate. The 7 temperature perature in selected cylinders, and mechanism is provided for ridding the system out for quickly removing the control is shown in-connection-with the dryer of a paper making machine, the said dryer con- 21. number of cylinders 1 of usual construction, about which the paper web is drawn to remove the moisture. The cylinde'rs are supplied with a heating medium, in the form of exhaust steam, from an exhaust steam header 2. The cylinders are in sets of seven in the present instance, and each set of cylinders is en plied with steam from a manifold 3. upply pipes 4 lead from the manifold to the cylinders, extending, into the cyhnders at the axis thereof and at one end of the cylinder, in a usual and well-known manner. The header 2 is connected to each manifold se c tion 3 by means of a supply pipe 4, and m pipes there is arranged a cut-ofi valve 5, and 'a controlling valve 6 arranged within a valve casing 7 which is interposed in the length of the pipe. Cutoff valves--8 are arranged between the secentrapped air and tions of the manifold, so that all of the sec-.

tions may be connected if desired. Each of the valves 6 has connected therewith a. stem 9, and the end of the stem remote from the valve is connected to a diaphragm 10 which is arranged within a casing 11 supported by the valve casing 7 A. s ring 12 is arranged between each stem an the casing 7, and acts normally to hold the valve open, as shown in Figure 5. The casing 11 forms with the diaphragm a closed compartment, and fluid under pressure is admitted to this compartment, under circumstances to be presently set forth, for closing, or partially closing, the valve, against the resistance of the spring. Fluid under pressure is supplied to the several casings 11 by means of pipes 13, and the supply of fluid under pressure is controlled by mechanism to be described. r

Within a selected cylinder of each series there is arranged a thermostatic bulb, each of which is adapted to contain a liquid volatile at ordinary temperatures, as for instance ether. The bulb is not entirely filled,

and hence contains partly vapor and partly liquid. Each bulb is connected by a pipe 14 with an expansible and contractable casing or capsule 15. Each capsule or casing is resilient, so that it will expand or contract in accordance with the expansion and contraction of the liquid, and each capsule is supported'in fixed position within a substantially cylindrical casing 16 having a circular. observation opening normally closed by a plate 17 of transparent material, as for inst nce glass. A lever 18- is pivoted intermediate its ends to a bracket 19 in the casing 16, and through this lever there is "the base of the "side of the bracket '19 from the screw 20.

ueaamr threaded a screw 20 whose inner end engages one side wall of the capsule 15. A spring-21 is arranged between the lever and casing 16, on the opposite This spring engages a pin 22 on the casing 16 at one end of the spring, end of the spring is engaged by a set screw 23 threaded through the lever, the set screw permitting the tension of the springto be varied. The outer end of the screw 20 is polygonal as shown, and the screw is coaxial with an eyelet 24 which is arranged at the center of the sheet 17. Through this eyelet access may be had to the screw to turn the same, whereby to regulate the-extent of movement-of the lever under the influence of the diaphragm'. The position of the screw is indicated by means of an indi eator 25 fixed to the screw, and cooperating with a scale on a dial 26 held by the lever.

Two types of controllers are used, differing from each other only in the number of valvesgwhich they control. In the simplex type, each lever 18 controls one valve, while in the duplex type,- .one of which is shown in Figure 3 the lever controls two valves; In this construction, the valves v27 and 28 are connected to the lever by means of stems 29, the stems. being held to the through a packing nut 30 between the valve and the lever. The pipe 13 which leads from the source of supply .of fluid under pressure is interrupted at the casing 16. The ends of the pipe at the. said casing are connected by a passage consisting of portions 31' and 32' offset laterally with respect to each other. At one end of the connecting portionbetween the offset portions of the passage there is provided a seat 33 with which the'valve 27 cooperates, and the inner end of the-packing nut 30' is recessed as shown, to receive the valve, to permit it to fully open. Theconstrnction at the valve 28 is precisely the same. In the simplex con- .valve 6. The'sections' are intended to be heated to progressively higher temperatures,

from the wet to the dry end of the dryer.

and the other In the present arrangement means provided for supplementing the exhaust steam with live steam, and such means is controlled-by the temperature controlling mechanism just described in those two sections of the dryer which are at the dry end of the dryer. 34, which has branches. 35 leading to the 1 pipes 4 of the two sections of the dryer at The live steam is supplied by a pipe,

the dry into the. pipes 4 between the valves 6'and the manifold sections 3, and each branch is controlled by a-valve 6, arranged in a casing' 7, 'which, is interposed in the branch adjacent to the pipe'4. A cutout valve 36 is arranged in each branch, between the casing 7 and the su ply pipe 34. The pipes 13 which supply fl iiid under pressure to the diaphragm c ambers of the casings 11 controlling the valve 6 of the branches 35,'are controlled by thevalve 27 before mentioned. It will be obvious that solong as a predetermined degree of expansion of the volatile liquid in the capsule 15 and connected parts is maintained, so long will the lever 18 be held in a position such that-the valve 27 is closed, and the valve 28 is opened, When the valve 28 is open, the full pressure .of-

the fluid under pressure, isadmitted tothe diaphragm chamber of the. valve 6 which controls the live 'steam supply :to that section of the dryer, and-the valve6 controlling the live steam supply will be held tightly closed to its seat. valve 6 which contr ls the admissionof exhaust steam to thatj fold, will have no fl id pressure, because of the fact that the valve 27, controlling the flow of fluid under chamber is held closed. 1 Hence the valve 6 controlling the supply ofexhaust steam to that section of the dryer will beheld open by its spring, and the -full supplylof'exhaust steam will be admitted tothat section of the dryer. Should the; temperature of such section fall below the predetermined degree which is indicated on-the scale of the dial 26, the volatile. liquid will contract, or decrease in 'volume, and the. capsule;.1 5 .,will contract to correspond with-the contraction of the liquid. This will permit the lever 18 to swing under the influence ofthezspring 21, in a direction to open thervalve 27,-and to close the valve 28. Theextenboffimove ment of the lever 18 determinesthe amount of fluid under pressure which is admittedto' the diaphragm casings conirollingatheqvalve' of the exhaust supply andthatuofthe. live steam supply, and the amount offluid: under pressure admitted to thev said diaphragm chambers determines thew extent of the opening or closing movement ofithe valves, so that the live steam controllingvalve will be opened or partially opened,-and the exhaust steam supply controlling valvef'will be closed or partiallyclosed, to vary; the relative amount of live 'ste'am'ande haust steam admitted. Solong as the temperature remains at the degree determined, "and shown by the scale on the "dial 26, solong will the live steam supply controlling valve be closed. When however the temperature falls below this predetermined degree, the lever 18 will be operated to open the. live end. These branch pipes open pipe 37 which has branches The diaphragm chamberlof that a section 3 i of the manipressure/to the said thermostat in point, and like ranged at the other the manifold to supplement the heating action of the exhaust steam. At thesame time the supply of exhaust ste'amwill be lessened I or out 01f. The fluid under pressure is supplied to the controllingmechanism, by means of a 38 leading to the duplex and to the s1mplex controls. In the duplexcontrolsthese branchesas shown in igure 1 are controlled by the valves 28. Branches 39 lead from the branches 38, and these branches are controlled by the valves 27 andin turn control the supply of exhaust steam to the manifold.

Aboard 40 is provided for each section of the dryer, and upon these boards is mounted the simplex or duplex controller, as the case may be. In addition each board carries a temperature recorder indicated at 41, and an air pressure recorder 42. Pressure gages 43 are arranged in the pipes 13 and39,:a gage being-arranged in the pipe 13 on each side of the valve 27, and these the-pressure in the several gages indicate lines. A dial steaminlet pressure gage44 and a dial thermometer 45 are'also providedin connection with each board. The instruments 41 and 45 are connected to the the selected cylinder, in the same manner as is the capsule 15. By

means of these instruments we-liavea complete record of, the entire "drying operation. When the temperature has been determined for .a certain weight of paper, it is only necessary to set the mechanisms to that and with tained.

At that endof'the 'exha-ust'hea der 2 re mote from the engine ;'and in each pipe 4 there is arranged a pipe 47 lead's from adjacent I to the header, steam separator 46; A the separator at the end of the exhaust pipe remote from the engine to a steam trap. At

the opposite end ofthe-exhaust header there is provided a back pressure or emergency valve. A branch pipe 48 leads from the header to a pipe'49,"whoseoneend iscoxinected to the feed'water heater, the back pressure valve indicated at '50 'beingarend ofthe pipe. The valveidesig'ned to open under a predetermined pressure Within the header, and a-valve51 is arranged between the branch-48 and the feed water heater for valve 50 is a safety controlling-the communication of the header with the heater. This' valve Ellis-of the sameconstructionas that shown'in Figure '5. but it is so arranged that'thespring 52 thereof encircling the stem "53 normally stem remote from the valve is connected with a diaphragm in a diaphragm chamber 54. This chamber is supplied with fluid I results at. different intervalsdiflerent operatorswill be at- V holds the valve' closed. That end of the 40,- and the said board 57 carries gages 58 and 59 recording the back pressure and the tions. branch, near the top connected 63 which place pressure of the main air supply respectively. The boardjalso carries a back 'pressuregage 60. When the paper machine for any reason is shut down, the exhaust controlling valves in the pipes 4 will close, and the valve 51 will open, thus permitting the condensate to pass to the feed water heater, and-these operations 'willbe recorded by the several instruments above mentioned.

In order to insure a rapid circulation of steam through the dryer," and consequent; elimination of dead air and steam pockets, and to remove the condensate as it is formed, we provide the mechanism shown in Figures 2 and 2". Atthe opposite side of the ryer from the exhaust manifold sections, we provide a manifold, consisting of connected sections 61, which are separated by valves 62, and each-section 61 of the manifoldis connected with the cylinders ofa section of the dryer. T e manifold sections 61 are to the cylinders by branch pipes the interior of the cylinders in communication with the manifold see- A separator 64 is arranged in each rater has a pair or inclined baflies 65 and 66 which are spaced apart and parallel, as shown in Figure 6. The flow from the cylinder 1 'will"enter the casing of the separator 64 and the condensate will form a seal at the, bottom of the baflie 65. It will be noted referring to Figure 6-thatl;the lower end of this bafiie 65 is below the upper end of the brittle 66. A gas and vapor outlet pipe 67 leads from each separator to a collector 68 adjacent to the cylinder, and the collector 68 leads to a vacuum: pump to be later described. Themanifold sections 61 communicate by means of pipes 69 with float chambers 70 of the character shown and described v in Patent No. 1,196,020, granted August 29, 1916. The said chambers communicate by means ofpipes 71 with the sections 7 2 of a drip header, the severalsections being separated by valves 73. Thus each sec ionv of the manifold 61 communicates wi 11 an adj acent section 72 of the drip header. iValves 74 and 75 are arranged, in the pipe 69 and 71 respectively for permitting sai pipes to be controlled manually when desired. The flow through the pipe 71, which is a discharge pipe for the manifold section, is controlled by a valve similar to the yalve 6 of Figure 5, and arranged in a similar casing 76 interposed in the length of the same. Each of these valves the pipe 55 with'the supthereof, and each sepa-" earner stem"77 andfis normallyheld clesedby a a ring "iaphragm in Fluid under pressure issupplied to eachdiaphragm chamber by means of a branch 79 irom'a common pi through each pipe 79 float in the float of the liquid in and is connected with a as shown,

a diaphragm chamber thefloat chamber attains a predetermined point, fluid under pressure will be admitted to the diaphragm chamber,

chamber 78.

-79 80, and the flow I is controlledby a valve not shown, which is operated by the 70. When the level"? and'the valve will be opened, permitting the condensate to flow fromv the float chamber intothe drip header. The air and-vapor lsg separated from the condensateby separaitorsshown in Figure 6, and is returned-by the' collectors 68 to thefeed water way of heater jacent indicated at 81.

end of the, dri

indicated at 83 18 so connected to this 'pi 82, that the flow from theheoder may be di'- the feed water heater, or by way: of Referring to Figure 22,,

rect to the vacuum pump. it will be seen that the vacuum pum ranged are closing by-pess. At its opposite end header provided in a by-pass84, and ,thatv'a ves' 85 the pipe 82betweenthe ends of the the dri delivers to the boiler 86, the ow being controlled by a cranetilt trap indicated A valve controlled connection 88 is i at 87.

: arranged'at the for connecting system.

said end of the drip header,

in the form of cemstorage tank 89; A purifier 9Q'is interposed in the supply 91 ora betweenthe mechanisms whichcthe fluid. operates,

the storage under pressure and compressed air is supplied to tank, by means of a compressor compressor92ll Theformer 1s abelt is an electrically. controlled compressor, be-

ing drivenbyfa suitable motor 93; be understood that the pipe 37 also derives 1-16 It will its supply .from the tank 89. The operation ofthe improved temperature controller is as follows z--- The pointer or indicator board pertaining is set at the tem -to maintain in t .to each series of cylinders rature which it is desired simplex-controllers when the temperature of the cylinders exceeds-the degree desired,

or falls below the same,

the valve 27 will be actuated to increase or decrease the supply of .fluid under pressure to the diaphragm chamber of that valve 6 which controls the pp y inders.

of heatingfluid tothat series of cyl- .With the duplex controller'whenhas a ever the supplyjof exhaust steam ismsuflisaid header to the heating for closing the bypass, or for water storage tank and the while. the latter 25 of the master 0 set of'cylinders- In the v cient to maintain the desired degree of tem perature, thev lever 18 will be actuated to 1 open the valve 28, to admit live steam to the manifold of the series. So long as the desired degree of temperature is maintained b the exhaust steam, no live steam is admitte The exhaust from the cylinders passes into the'drip header sections, the vapor and air being separated from'the condensate by the separators, and such air and vapor isreturned to the feed water'heater, where it is vented to the atmosphere through a vent 94.

The condensate is returned to the boiler or to the feed water heater. The improved controller is controlled by the temperature of the cylinders, and is not dependent upon steam pressure, nor upon themovement of the web. Each series of cylinders may be set to be heated to a predetermined degree, and the temperature of the series s progressively increased from the wet endto the dry end of the dryer.

It will be noted that all of the separators vacuum'pu'mp 83, and this pump maintains in each cylinder a reduced pressure or partial vacum, permitting a continuous outlet of steam and vapor and possibly some-condensate to the water heater 81. Thls arrangement is directly responsible for the rapid circulation of the steam within the drying cylinders, and for the elimination-of dead air and steam pockets.

We claim: a

1. In paper making machines, the combination with the drying cylinders and the means for heating the same, of auxiliary heating means, and means controlled by the 1111mm i h the drying cylinders, of means ture of the cylinders for regulating the supply to maintain a predetermined temperature, and auxiliary means controlled by the temperature of select'ed cylinders for admitting live steam to the cylinders when the temperature of the selected cylinders falls below a predetermined degree.

3. In a paper making machine, the combination with the drying cylinders, and the exhaust steam supply for heating the cylinders, of an auxiliary li.ve steam supply, and means controlled by the temperature of selected cylinders for connecting and disconnecting said live steam supply with the cylinders. 4;. In a paper making machine, the combination with the drying cylinders and the exhaust steam supply for heating the cylinders, of means controlled by the'temperature of selected cylinders for admitting the i ders, of

steam to the cylinders in accordance with the needs the .eof to maintain uniform. temperature. I 5. In a paper making machine, the combination with the drying cylinders and the exhaust steam supply for heating the cylinmeans controlled by -the temperature of selected 0 linders for admitting the steam-to the cylinders in accordance with the needs thereof to maintain a substantially uniform temperature, a live steam supply and means controlled by the temperature of selected cylinders for connecting and disconnecting the live steam supply with the cylinders. 1

6,.In paper making machines, the combi-- nation with the drying cylinders,of automatically controlled cylinders to progressively higher temperatures from thewet to the dry end.

a substantially 7. In paper making machines, the combination with the drying cylinders, of means for heating said cylinders to progressively higher temperatures from the wet to the dry end, and means controlled by the temperature of selected cylinders for maintainthe cylinders subfor heating groups of selected cylinders independently of the cyllnders of other groups, and'eontrolled by the temperature of a se lected cylinder of the group to maintain the temperature of the cylinders of the group uniform and at a predetermined degree.

10. In paper making machines, the combination with the drying cylinders, of means for heating groups of selected cylinders, controlled by the temperature of a cylinder of the group, and independently adjustable wliei'eby'to provide for different temperatures in the several groups.

11. In paper making machines, the combi nation with the drying cylinders, of a common heating means for the cylinders, and means controlled by the temperature of cylinders selected from the series at intervals for connecting and disconnectingsaid cylinders and adjacent cylinders to the heating means.

12. In paper making machines, the combi-- controlled by the temperature of cylinders selected from the series at intervals for condry end, auxiliary selected from the series at intervals for con-- necting and disconnecting said cylinders and adjacent cylinders to the heating means,

each or the said means being independently adjustable to provide for progressively higher; temperatures cylinders and controlled by ;the temperature the auxiliary heating means and the cylinders.

14. In a machine of the character specified, the combination with the drying cylinders, and the steam supply for heatmg the same, of acommon drip header-forthe cyl inders, a return ipe for the condensate,

and means contro ed by the liquid level in i.

the return pipe for controlling the flow of H aid-from the header to the return pipe.

15 .'In a machine of the character specifled, the combination with the drying cylind'ers, and the steam supply for heating the same,'of a common drip header for the cylreturn inders, a return ipe for the condensate, means controlled y the liquid level in the forscontrolling the flow of liquid 1pc from t e header to the return pi e, and

. means interposed between the cylin ers and vapor the dri header for separating the air and 0m the liquid. I V 16. In paper making machines, the combination with the drying cylinders, of means controlled by the temperature of selected cylinders for mamtaining the temperature from the wet to the: heating means, and means. in connection with sundry of said selected.

manner of the cylinders, uniform, and means-tor removing vapor from the cylinders vent air pockets and the like.

117. In paper making machines, the combination with the drying cylinders, of means controlled by the tem erature of selected connected with the ,c linders for receiving the condensate there om, and means confor 1 trolled by the level of the liquid condensate for. gradually removing the same from the header.

18. Ina paper machine, the combination with the dryin cylinders, and the means for supplying a eating fluid to the I cylinders to heat the same, of means for thereof for connecting and disconnecting controlling said suppl ing means to maintain asubstantially umforin temperature of the cylinders, v fluid means for operating t e said controlling means, said means including a volatile li uid subjected to the heat of thee linders an an expansible and contractablh element in which the liquid is held.

19; In a machine of to'heat the same, of means for maintaining.

ressure; controlled 7 i he character speci fled, the combmation with the drying cylina partial-vacuum in the said cylindersfor the purpose specified 20. .In paper making machines, the combination with the drying means, of means'for heating the same, auxiliary heating means,

and means directly' responsive to the temratureof the drying means for connectmg and disconnecting the auxiliary heating means.

In testimony tures. V

whereof we aflix our signamica STANFORD WITHAM, In areas: snore wlrnm, st.

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