US1674845A

US1674845A - Automatic steam control and differential for paper machines

Info

Publication number: US1674845A
Application number: US3106A
Authority: US
Inventors: Stickle Cole
Original assignee: Individual
Current assignee: Individual
Priority date: 1925-01-17
Filing date: 1925-01-17
Publication date: 1928-06-26
Anticipated expiration: 1945-06-26

Description

June 26, 1 928. 1,674,845

C. STICKLE AUTOMATIC STEAM CONTROL AND DIFFERENTIAL FOR PAPER MACHINES Filed Jan. l7, 1925 2 Sheets-Sheet 1 INVENTOR. C015 57764145 June 26, 1928. 1,674,845

C. STICKLE AUTOMATIC STEAM CONTROL AND DIFFERENTIAL FOR PAPER MACHINES Filed Jan. 17, 1925 2 Sheets-Sheet 2 .-1 TTORNE) l5.

Patented June 26, 1928. k

PATENT OFFICE.

COLE $TIGKLE, OF INDIANAPOLIS, INDIANA.

.AUTOMATIC STEAM CONTROL AND DIFFERENTIAL FOR PAPER MACHINES.

Application-filed January 17, 1925. Serial No. 3,106.

' This'invention pertains to a differential pressure control valve for maintaining a (L given differential pressure between the blowing through section and the condensing sec- 1 tion of a paper drying machine.

I It is well known that it is essential to create a difference of steam pressure between the two sections of a drying machine so as to maintain a rapid circulation of steam through the dryers. The so-called blowing through system gives rapid circulation providing a suflicient pressure is used and the system installed does .not equalize. Rapid circulation of the steam through the machine has the advantage of a complete removal of air and condensation at all times, which keeps the dryers as hot as possible and allows for maximum production. The diflicultyheretofore has been in maintaining suflicient differential of pressure between the two sections to cause a rapid circulation of steam therethrough and thereby removing the air and condensation. If the pressure is too low, it can not be operated as a rapid circulating system. Heretofore, a greater differential of pressure has been obtained by creating a vacuum by employing jet condensers. A spray of cold water maintains a vacuum by condensing the steam. To maintain a vacuum in this manner requires sub stantially twenty-five times as much water as steam condensed and there is accordingly a large loss in this method when the excess hot water goes to the sewer, which is usually the case.

The principal=object of this invention is to provide a valve for automatically maintaining a given differential of pressure between the two sections which makes a positive flow of steam through the main section. means of this device, there will be no steam blowing through, and no cold water or spray required toconsume steam in order to maintain a vacuum. While a vacuum pump is employed, the exhaust in the pump is piped tothe steam header so that there is no loss from operating the vacuum pump. This permits of a positive vacuum of ten to fifteen inches without the use of any cooling water, thereby giving perfectly drained dryers at a minimum cost, and is accomplished by means of a valve located between the steam headers of the two sections for controlling the admission of steam from the header. of l the blowing through section to the header of the condensing section. It is desirable that specifically the steam pressure in the latter section be less than that of the blowing through sec tion. This differential is positively controlled by a valve controlled device which will hereinafter be more fully described and forms the subject matter of this invention.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims:

In the drawings, Figure 1 is a diagrammatic illustration of a paper drying system employing the differential pressure control valve. Fig. 2 is a perspective view of the control valve. Fig. 3 is an enlarged view showing the control valve with a portionv thereof in central vertical cross section.-

In the drawings there is illustrated a paper drying machine mounted upon the floor 10 and employing a frame structure 11, 12 and 13 upon which a paper feeding roll 14 is mounted so that the paper 15 may pass thereabout over the drying rolls 16 and rolls 17. The drying rolls 16 are embodied in the blowing through section of the machine, indicated by the group A, whereas the rolls 17 are embodied in the condensing sect ipgmpf the machine, indicated by the group The steam plant, headers and control valves are principally positioned below the floor 10. Said steam is supplied by pipe '18 having an automatically-controlled exhaust steam admission valve 19 to the steam header 20 of group A. Communicating with the steam header 20 there is a plurality of pipes 21 communicating with the respective drying cylinders or rolls 16 so that the steam passes therethrough and returns through the pipes 22'to the return header 23. The ad mission of steam through the valve 19 is controlled in the usual manner by suitable valvecontrolled means which will not be described herein, as forming no part of this invention. The return header is in communication through pipe 123 wlth a receiving trap 24 communicating through a valve 25 with a pipe .26 leading to avacuum pump, not shown.

The steam passes from the return header 23 of the A group through the trap 24 by pipe 124 to the header 26 of the B group. Condensation water is drained from trap 24 through pipe 125 with valve 25 and pipe 26 by a vacuum pump not shown. The header 26 of the B group 15 also in automatically controlled communication with In order to maintain-at all times a givendifference of pressure between the header and the header 26, whereby there will be a rapid circulation of steam between sections A and B, the'valve in the valve casing 27 is automatically controlled by the relative steam pressures existing in the

respective headers

20 and 26. The header 20 is connected through a pipe 31 with the lower side of a diaphragm housing 32, said pipe being controlled by a valve 33. Theheader 26 is connected throu h a pipe 34' with the top of the diaphra m ousing.

Positlone in the housin there is a suitable diaphragm 35 separatlng the top and bottom of the housing. and operatively con-. nected by a plunger 36 with a disk 37 which in turn operates a rod 38. The rod 38 extends upwardly through a suitable frame 39. terminating in a pilot valve-housin '40 and having positioned on the end thereo a valve member 41 for opening and closing the pilot valves Communicating with the pilot valve housing 40 there is a conduit 42 leading'from a source of pressure in the form of elther li uid, air or gas. Connected with the other sideof the valve housing 40 there is a pipe 43 communicating with thelower end of a iston c linder 44. Mounted in "the cyliner 44 t ere is a piston 45 connected with the iston rod 46 upon which may be mounted t e counterbalance weights 47. The up-- per end of the piston rod 46 is connected with a chain48 adapted to pass over the pulleys 49 which are mounted u on a bracket 50, the other end of the chain bemg connected with a valve actuating lever 51.

Slidably mounted upon the lever 51 there is a weight 52 for normally maintaining said lever in lower position. The lever 51 extends througha guide arm 53 and is pivoted at 54 to a valve stem 55," and the lever is pivotally connected through a link 56 with the valve casing 27 .7 The valve stem extends into the valve casing 27 and has secured thereon a valve member 57 for opemn and closing said valve. 7 For counterbalancin'g the movement of the diaphragm and pilot valve there is provided a compression spring 58 positioned between the disk 37, and a collar mounted on the frame 39, said spring-surroundin the rod 38. Pivoted to said rod within t e frame 39 at 59-there is a lever 60 having variable a rapid circulation 0 Weights 61 suspended from one end thereof, the other end of said lever being pivotally connected to said frame through a link 62.

it will be observed From the foregoin that in operation, an assuming. that it is desired to maintain a differential of pressure between the

headers

20 and 26 of ten pounds pressure, the proper weight 61 is placed on the arm 60. The downward pressure exerted thereby on the rod 38 against the diaphragm through the pipe 31, which will maintain the pilot valve 41 in closed position, which, in turn, will preventthe operation of the piston 45 and accordingly the valve member 57, whereby the valve '57 will be; closed. In order to maintain such differential of pressure, u on a ecrease of pressure occurring in the eader 26 due to the closure of the valve 57, the diaphragm'35 will be forced upwardly by the pressure through the pipe 31. This will open the pilot valve and cause pressure to be exerted inthe pump for moving the piston 45 upwardly,permitting the lowering of the lever 51, which will open the valve 57. Steam will pass therethrough into the header 26 in which the pressurewill be raised sufliciently to cause the diaphragm 35 to be forced downwardly, which will close' the ilot valve 41, so that the piston 45 may be orced downwardly by the weights 47 and the lever 51 accordingly elevated, 'so as to close the valve 57. The lowering of the piston 45 is permitted by the escape of fluid through the pet cock 63, which remains slightly 0 en. This control of the valve 57 v will there y cause any variation from the desired differential of pressure to either open or close said valve and'accordingly maintain such differential substantially constant.

Through the automatic control of the valve 57 and by manipulation of the wei ht 61, said valve will maintain a givendi erence in pressure between the sections of the I aper machine headers, with any variations in the drying pressure. This difference in pressure between the two sections provides steam through the dryers of themachin ,-wher eby the dryers are perfectly drained. The invention claimed is:

1. The combinationwith a paper machine having a blowing-through section, a condensing section, a steam supplyheader and return header for eachof said sections,

a connection between the returnheader of the blowing-through section and the steam supply header of the condensing section, and

drying I targets a steam "trap connected with the return header of the blowing-thrugh section and the steam supply header of the condensing section, means for exhausting the condensation water from said trap, and a connection between the steam supply headers of the two sections with a difierential valve mechanism therein which is influenced by pressures in both of said steam headers so that the desired diiference in pressures in said-headers may be automatically maintained regardless of the variations in pressure in the steam supply header in the blowing-through section;

3. The combination With a paper drying machine having a blowing-through section, a condensin section, a steam supply header and return header for each of said sections,

a continuous connection between the return headerof' the blowing-through section and the steam supply header of the condensing tions, a diflerential valve for controlling said last mentioned connection, a pilot valve for controlling the operation of said difierential valve, and means for controllin the pilot valve by the o posing influence 0 the steam pressures in both of said steam supply headers. 4'. The combination with a paper drying machine having a blowing-through section, a condensing section, a steam supply header and return header for each of said sections,

.- a continuous connection between the return eopressure in the steam supp y header to the header of the blowing-through section and the steam supply header of the condensing section, a direct connection between the steam supply headers of both the said sections, a difierential valve for controlling said last mentioned connection, a pilo valve for controlling the operation of said difierential valve, -means for supplyingthe steam pressure in the steam supply header of the blowing-through section -for 0 pilot valve to-cause the opening 0 the ential-valve, means for sup lying the steam condensing section tending to close the pilot valve, fand a weight also tending to close the p1 0t valve an so as to maintain the desired difi'erence in pressures in said headers at all times.

5. The combination witlna pap/ er drying machine having a blowing-through section, a condensing section, a steam supply header and return header for each *of said sections, a continuous connection between the return header of the blowing-through section and the steam supply header of the condensing section, a direct connection between the steam supply headers of both the said sections, a difi'er'ential valve for controlling said last mentioned connection, a pilot valve for controlling theoperation of the difi'erential valve, a diaphragm for controlling. the operation of the pilot valve, means for suplying steam pressure in the steam supply header of the blowing-through section against one side of the diaphragm for opening the pilot valve and causing the opening of the differential valve, means for applying the steam pressure in the steam supply header of the condensing section against the opposite side of the diaphragm and tending to close the pilot valve, and a weighted lever acting on said pilot valve in aid of the steam pressure in theheader of the condensing section for closing the ilot valve and maintaining the desired di erence inpressures in said headers regardless of the variations in pressure in the steam supply header in the blowing-through section.

6. The combination with a paper drying machine having a blowing throu h section,

'a condensing section, and a steam eader for each of said sectlons, of means for mainheader to the other, a iston operabl connected with saidvalve or opening an closing' the same, a pilot valve communicating with said piston for actuating the same when 0 ened, means for actuatin said piston w en said pilot valveis close a diaphragm having one side thereof 'efl'ected by the pressure from one header and the other side efiected by the pressure from the other header, said diaphragm being operatively connected with said pilot valve, and means a connected with said dia hragm for exerting an auxiliary pressure tihereon and thereby maintainin a differential of pressure between said headers.

' Inwitness whereof, I have hereunto affixed my signature. A