US3350262A

US3350262A - Web break sensing monitor for paper machines

Info

Publication number: US3350262A
Application number: US402782A
Authority: US
Inventors: Orval J Cummins
Original assignee: Oxford Paper Co
Current assignee: Oxford Paper Co
Priority date: 1964-10-09
Filing date: 1964-10-09
Publication date: 1967-10-31
Anticipated expiration: 1984-10-31

Description

o. .1. CUMMINS 3,350,262

WEB BREAK SENSING MONITOR FOR PAPER MACHINES 2 Sheets-Sheet 2 Oct. 31, 1967 Filed Oct. 9, 1964 FIG. 2 5

Q 45 J ofolk rec A 1 voltage Count 1 B r C d e Couch ,jsa W Break 1 6| Counr 5O 23% C b d f wg m ss) W rec 62 Count 1 24 4 D b c e Sie mess J +I,H;|/F- reu 63 Counr 25 52 9 E f e4 1 b c d f ColencLer g r 5 rec G h F Count 2 b Broke h Couch F" Time PH 35 46 Lost Prg l riori 37 T' c b WE WE: Tlme l i PLreis as 9 TT I 47 1 r 98 I i O 0 1 volmge c s' mg l Vo|T ge Losr Tlme P F 1 r e ss 4 6 32 Losr StockOff e d 4 Time Ai Wm? Time 1 Broke Calender I I Tlme Stock 44 Losr Ti me INVENTOR milafi. 21..

ATTORNEYS United States Patent Ofiiice Maine Filed Oct. 9, 1964, Ser. No. 402,782 13 Claims. (Cl. 162255) This invention relates to monitoring apparatus for a paper making machine, and particularly to apparatus for indicating the occurrence, location and duration of breaks in a paper web.

A paper making machine involves the formation of a continuous web of paper pulp upon a wire screen and the pressing, drying, sizing, calendering, etc. of the paper web in successive processing stages. Throughout the manufacturing process the paper web is subject to tearing and other discontinuities known generally as breaks. The occurrence of a paper web break indicates a malfunction which requires correction before production can proceed. For effective quality control, machine maintenance and production record keeping it is desirable to record the occurrence and duration of paper web breaks and the portion of the machine in which each break occurs. Previously it has been necessary to obtain and record this data manually. Upon the occurrence of a paper web break, one of the operating personnel notes the break and where it has occurred, and manually records this information along with the total down time attributable to the break. Since the primary duty of the operating personnel at this time is to quickly correct the operation to regain a continuous paper web, their record keeping function suflers and the resulting data are frequently incomplete, inaccurate or unreliable.

The present invention provides apparatus for monitoring a paper making machine in which a paper web passes through successive processing stages. The apparatus uses a plurality of sensors for detecting breaks in the paper web, located at respective stations spaced along the path of travel of the web, and the actuation of the sensors is arranged to control the accumulation of the information concerning web breaks. In the preferred embodiment described in detail hereafter, several types of indications are obtained. One type is the number or" breaks occurring at each station, and provision is made so that breaks occurring at a given station are counted only at that station and not at succeeding stations. A second type is the total broke time at each station due to breaks thereat, and similar provision is made so that the time accumulated at a given station is due only to breaks first occurring thereat. A third type is a continuous record of lost time at each station regardless of the cause. Further, overall totals of production time, lost time, number of breaks, etc. are obtained.

These and further features and advantages of the invention will be more readily understood from the following description of a specific embodiment thereof.

In the drawings:

FIG. 1 illustrates schematically a paper making machine and the monitoring apparatus of the invention; and

FIG. 2 is a schematic circuit diagram illustrating relay connections for actuating the various indicators of FIG. 1.

In the paper making machine shown in FIG. 1, paper pulp stock is distributed from a hopper onto a moving Foudrinier wire screen 11 where a paper web 12 is formed. The paper web proceeds to move from the wire screen 11 over a couch pit 13, through a wet press 14, a first dryer 15, a size press 16, a secondary dryer 17, a calender stack 18 and finally onto a reel 19. In this specific embodiment sensors are located at five stations along the path of travel of the paper web. Each of these sensors is onto the reel 19, which is the 3,350,262 Patented Oct. 31, 1967 capable of detecting the presence or absence of the paper web at the sensor station.

A first sensor 21 is located at the end of the Foudrinier wire screen. This sensor in the preferred emb diment is a vacuum-operated switch which responds to variations in couch vacuum, and hence indicates whether or not there is paper stock on screen 11. A second sensor 22 is located at the wet press 14 to detect breaks in the web thereat. This also may be a vacuum-operated switch. The third sensor 23 is positioned between the web press 14 and first dryer 15 to detect wet en-d breaks. The fourth sensor 24 is between the size press 16 and secondary dryer 17, preferably out of reach of coating splatter during normal operation of the size press and hosin-g down during a clean-up period. The fifth sensor 25 is between the calender stack 18 and reel 19. These three latter sensors may be conventional photocell units capable of detecting a break in the paper web as it moves past them. Each of the sensors is capable of energizing an electric relay as hereinafter described.

It will be understood that the paper making machine shown in FIG. 1 is illustrative only, and that the number and location of the sensors may be selected in view of the particular apparatus to be monitored, and the amount of information it is desired to collect. The type of sensor employed at each location may be operating conditions thereat to provide a reliable response.

Associated with the five sensors are a group of indicators as shown in FIG. 1. The first sensor 21 has associated with it an electrical accumulating timer 32 for indi cating the accumulated time during which paper stock is not on the screen 11. This time is identified as Stock Off Wire Time. The timer is resettable and of conventional design, as are all the other data indicators of the monitor.

Associated recorder 35. Counter 33 records the number of paper web breaks first detected by sensor 22. This data is known as Couch Break Count since the web breaks counted are attributable to the couch portion of the process. Timer 34 accumulates the time during which Web breaks are first detected by sensor 22, called Couch Broke Time. Chart recorder 35 records the time of day and duration of all paper web breaks detected by sensor 22 whether first detected at that station or not. This record is called Couch Lost Time.

Similar data recording devices are associated with the other three sensors. Thus, associated with sensor 23 are a counter 36, a timer 37 and chart recorder 38 indicating Wet Press Break Count, Wet Press Broke Time and Wet Press Lost Time, respectively. Counter 39, timer 40 and chart recorder 41 are associated with sensor 24 and give corresponding Size Press data. Counter 42, timer 43 and chart recorder 44 are associated with sensor 25 and give corresponding Additional units are provided to give overall data. Counter 45 is employed to record the total number of breaks occurring in the process. Two

further timers

46, 47 are associated With the last sensor 25. Timer 46 indicates the accumulated time during which the paper web passes Total Production Time. Timer 47 accumulates the time during which paper web breaks are detected by 25. Since during this time no Web passes on to the reel 19, it is called the Total Lost Time.

FIG. 2 shows the circuitry of the monitoring system in more detail. Each of the five sensors 2125, on detecting absence of paper stock on screen 11, or a subsequent web break, actuates a corresponding electromagnetic relay 4852. For convenience these relays are also designated by capital letters AE, respectively. The last sensor 25 actuates relay E through a time delay relay G,

Calender Stack data.

and also actuates a time delay relay F, for purposes to be described. Each of the relays A-G controls switch contacts which are designated by the lower case letter corresponding to the letter designation of the relay controlling them. Thus, switch contacts 54, also designated b, are a normally open set of contacts controlled by relay B. These contacts remain open when sensor 22 does not detect a web break, but close when 22 detects a break and actuates relay B. Contacts 55, also designated 0, are a normally closed set of contacts controlled by relay C. They open when sensor 23 detects a web break.

Considering first the actuation of the four break counters, the counters 33, '36, 39 and 42 are assumed to be of the type which count upon application of an electrical signal thereto, but will not count again until the signal is first removed. As will be observed, the couch break counter 33 is actuated by a signal from sensor 22 passing through line 61 and the normally closed contacts of re lays C, D and E. Thus if a break occurs ahead of the wet press 14, the count will be incremented. As the web ahead of the break passes by succeeding sensors, normally closed contacts c, d and e in line 61 will open in succession. Therefore counter 33 cannot be actuated again until the fault has been repaired and a continuous web again extends from the wet press 14 to the roll 19.

Wet Press Break counter 36 is actuated by a signal from sensor 23 through line 62 containing the normally closed contacts of relays B, D and F. If a break occurs between the wet press 14 and first dryer 15, the count will be incremented. However, if the break occurred ahead of the wet press, relay B will have been actuated, thus breaking the circuit in line 62 before sensor 23 delivers a signal thereto, and counter 36 will not be actuated Once actuated, the subsequent opening of contacts d and f in line 62 will inhibit another actuation until a continuous web extends to roll 19.

Size Press Break counter 39 is similarly actuated by a signal from sensor 24 through line 63 containing normally closed contacts of relays B, C and E. If the break first occurred at a previous station, relay B and/ or C will have ben actuated to break the circuit of line 63 and inhibit actuation of counter '39, so no count will be registered. After counting, the opening of contacts e will inhibit further counting until a continuous web extends to roll 19.

Calender Stack Break counter 42 is actuated by a signal from sensor 25. Here provision is made to prevent counting a break during reel change-over. During normal production, when one reel 19 has been filled, it is removed and the paper web fed to another reel. Although the change-over normally takes only a few seconds, during this interval the web is necessarily broken and may flop around until the change-over is complete. Thus sensor 25 will be actuated during the change-over, and may be actuated several times due to web flutter.

Time delay relay G is employed to introduce a time delay sufficient to allow reel change-over before contacts g are closed, say, five seconds. Thus the sensor 25 cannot apply a signal to line 64 until after this delay, and normal change-overs will not be counted. A break due to malfunctioning will last longer than the delay interval and hence will be counted. Instead of relay G, a photocell unit incorporating a time delay could be used for sensor 25.

Line 64 contains normally closed contacts b, c and d which inhibit a count if the break first occurred at a previous station. The line also contains contacts of relay F, which is a time delay relay providing a short delay, say one second, sufficient to allow the counter 42 to be actuated before contacts 1 open. The contacts remain open until a continuous web again extends to reel 19.

It will be noted that each of lines 61-64 contains in series the contacts of all the relays actuated by preceding sensors with which counters are associated. Thus only the station where a break first occurs is charged with a break count. The lines also contain in series the contacts of relays actuated by all subsequent sensors to inhibit further counting until a continuous web to the reel has again been established. For the latter purpose, instead of using contacts of all subsequent relays, in some instances it may suffice to use only the contacts of the last subsequent relay to inhibit further counting. However, the arrangement shown is advantageous in order to insure that there will be no counts due to web breaking during a rethreading interval, to shorten the intervals during which the counters are held energized, and to facilitate cleaning the photocell light sources during wash up periods without disturbing any of the counts.

In line 62, contacts of relay E could be used in place of those of relay F if a sufficient number of sets of contacts are available.

The Total Break counter 45 is incremented by closure of normally open contacts of any one of relays B, C, D, E. However, there will be only one count per break since closure of the contacts of one relay will establish the energizing circuit for the counter, and closure of the contacts of subsequently actuated relays will establish additional parallel energizing circuits which will prevent a further count increment until all the relays are deenergized, corresponding to a continuous web being fed to the reel.

Couch Broke timer 34 is energized whenever relay B is actuated and relay A is not. This condition corresponds to the situation where a break is detected by sensor 22 but sensor 21 indicates there is paper stock on the screen 11. By analogous connections,

timers

37, 40 or 43 are energized when a break is first detected by

sensors

23, 24 or 25, respectively. Their energization continues while the break continues to be detected by the sensor first detecting it. It will be understood that if a break occurs at one station and actuates the corresponding relay, say B, subsequent relays C, D and E will be actuated in succession as the portion of the web ahead of the break passes by the subsequent sensors. Thus

subsequent timers

37, 40 and 43 will not be energized until the fault has been repaired and a continuous web starts passing by the stations in succession. As each relay deenergizes, the timer at the next station will be energized for a brief period until the web reaches it. Due to the speed of travel of the web, the time accumulated in this manner will be small compared to the time accumulated for actual breaks first occurring at a given station. To reduce the error, normally open contacts of relay E may be placed in series, as shown by contacts e for timer 40.

Chart

recorders

35, 38, 41 and 44 are energized during the detection of paper web breaks by sensors 22-25, respectively, by closure of the respective relay contacts b-e.

Stock Off Wire timer 32 accumulate the time during which relay A is actuated, or in other words the time during which sensor 21 indicates there is no paper stock on screen 11. Total Production timer 46 accumulates the total time during which relay E is not actuated, wherein no web breaks are detected by sensor 25. Total Lost timer 47 accumulates the time during which relay E is actuated, corresponding to the detection of web breaks by sensor 25 land the absence of a continuous web passing to the rec The overall operation will be explained by starting with a shut-down period and applying power to the monitoring apparatus. Initially all sensors 21-25 will be actuated and the corresponding relays A-F will be actuated. The energizing lines 61-64 for break counters 33, 36, 39 and 42 will be open due to the open relay contacts in series therewith, and the counters may be reset to zero or their initial count noted. Total Break counter 45 will be energized, and it may be reset to zero or its count noted. The energizing circuits for

Broke Time accumulators

34, 37, 40 and 43 will be open due to the open relay contacts in series therewith, and they also may be set to zero or their initial accumulated times noted. Lost

time chart recorders

35, 38, 41 and 44 will start recording down time at the four stations. Total Production timer 46 will be inactive, and Total Lost and Stock

Off Wire timers

47, 32 will start operating. They may be .reset to zero or their initial times noted.

After paper stock is placed on screen 11 and operation begins, sensor 21 and its relay-A will deenergize, and Stock 'Off Wire timer 32 will stop accumulating time. As the paper web reaches the detecting stations in succession, the sensors 22-25 and corresponding relays will deenergize in succession and the corresponding Lost

Time chart recorders

35, 38, 41, 44 will stop recording down time and change to running time positions.

Broke Time accumulators

34, 37 will operate in succession for brief intervals determined by the time of travel of the web from one station to the next. Actuation of Broke Time accumulator 40 will be inhibited by the open contacts e, and accumulator 43 will operate momentarily as the web passes from sensor 24 to 25. As the web passes the last sensor 25 and onto reel 19, the deenergizing of relays E and F starts Total Production timer 46, cuts 01f Total Lost timer 47, and completes the closing of the relay contacts in break counter energizing lines 61-64.

The monitor is now ready to indicate breaks in the paper web. When a break occurs, other than that accompanying a reel change-over, the sensor first to detect it will increment the

corresponding break counter

33, 36, 39, 42 and its corresponding relay will energize the corresponding

Broke Time accumulator

34, 37, 40, 43 and increment Total Break counter 45. The actuation of the relay will inhibit the incrementing of counters and actuation of accumulating timers corresponding to succeeding sensors as the portion of the web ahead of the break passes thereby, as previously described, However,

chart recorders

35, 38, 41 and 44 will start recording down time as each sensor is actuated. When the last sensor 25 detects 'a break lasting longer than normal reel change-over, Total Production timer 46 stops and Total Lost timer 47 starts.

When the faulty operation of the machine has been corrected and a continuous web starts toward reel 19, the previously actuated sensors successively return to their normal conditions and the Broke Time accumulators and 1 chart recorders which have been energized are de-energized. When the web reaches the reel, the de-energizing of relays E and F re-establish the energizing lines 61-64, ready for counting the next break. Also, Total Lost timer 47 stops and Total Production timer 46 resumes.

If a break isdetected by the last sensor 25 which is due to normal reel change-over, no break will be indicated since the time delay introduced by relay G will prevent the sensor from being effective during the changeover period.

In practice, indicator lights are used to indicate actuation of the relays, recorders, etc., but these have been omitted in the drawing for simplicity.

It will be understood that various types of indicators other than those specifically described may be used if desired, and that fewer or more indicators or types of indicators may be employed depending on the type and amount of data it is desired to accumulate. Also, various changes may be made in the detailed circuitry within the spirit and scope of the invention.

I claim:

1. Apparatus for monitoring the operation of :a paper making machine wherein a paper web passes through successive processing stages which comprises (a) a plurality of sensors located at respective stations spaced along the path of travel of the paper web for detecting breaks in the web thereat,

(b) a plurality of timers associated with said sensors,

repectively, for accumulating the total timeof breaks at the respective stations,

(c) and circuit means responsive to said sensors for actuating respective timers upon the detection of breaks thereby,

(d) said circuit means including means responsive to the actuation of a preceding sensor for inhibiting the actuation of the timer corresponding to a succeeding sensor along said path of travel, While said succeeding sensor remains in break detection condition.

2. Apparatus for monitoring the operation of a paper making machine wherein a paper web passes through successive processing stages which comprises 7 (a) a plurality of sensors located at respective stations spaced along the path of travel of the paper web for detecting breaks in the web thereat,

(b) a plurality of indicators associated with said sensors respectively,

(0) and circuit means responsive to said sensors fol actuating respective indicators upon the detection of breaks thereby,

(d) said circuit means including means responsive to the actuation of a preceding sensor for inhibiting the actuation of the indicator corresponding to a succeeding sensor along said path of travel while said succeeding sensor remains in break detection condition and including means responsive to the actuation of a succeeding sensor for inhibiting the actuation of the indicator corresponding to a preced- 111g sensor.

3. Apparatus in accordance with claim 2 in which said circuit means includes means responsive to the actuation of each sensor for inhibiting the actuation of the indicators corresponding to all succeeding sensors along said path of travel, and means responsive to the actuation of the last sensor along said path of travel for inhibit- 1ng the actuation of the indicators corresponding to preceding sensors during the actuation of said last sensor.

4. Apparatus in accordance with claim 3 in which said indicators are counters for counting the number of breaks at the respective stations.

Apparatus in accordance with claim 2 in which sai ing to the preceding sensors during the actuation of the last sensor.

6. Apparatus for monitoring the operation of a paper making machine wherein a paper web passes through successive processing stages which comprises (a) a plurality of sensors located at respective stations spaced along the path of travel of the paper Web for detecting breaks in the web thereat,

(b) a plurality of timers associated with said sensors, respectively, for accumulating the total time of breaks at the respective stations,

(c) a plurality of electrical relays actuable by respect1ve sensors upon the detection of breaks thereby and having a plurality of switch contacts,

(d) and a plurality of electrical circuits responsive to the actuation of respective sensors upon the detection of breaks thereby for actuating respective timers,

(c) said electrical circuits which correspond to succeeding sensors along said path of travel including switch contacts of relays corresponding to preceding sensors for inhibiting the actuation of the timer corresponding to a succeeding sensor when a preceding sensor has detected a web break, while said 7 succeeding sensor remains in break detection condition.

7. Apparatus for monitoring the operation of a paper making machine wherein a paper web passes through successive processing stages which comprises (a) a plurality of sensors located at respective stations spaced along the path of travel of the paper web for detecting breaks in the web thereat,

(b) a plurality of counters associated with said sensors, respectively, for counting the number of breaks at the respective stations,

(c) a plurality of electrical relays actuable by respective sensors upon the detection of breaks thereby and having a plurality of switch contacts,

(d) and a plurality of electrical circuits responsive to the actuation of respective sensors upon the detection of breaks thereby for actuating respective counters,

(e) each of said electrical circuits including switch contacts of each relay actuated by a precedin sensor for inhibiting the actuation of the counters corresponding to succeeding sensors when a preceding sensor has detected a web break while said succeeding sensors remain in break detection condition,

(f) and each of said circuits actuated by a preceding sensor including switch contacts of at least the relay actuated by the last sensor for inhibiting further counting of breaks at preceding stations until no break is detected at the last station.

8. Apparatus in accordance with claim 7 in which said paper web passes through said successive processing stages to a reel, and said last sensor is positioned to detect breaks between the last processing stage and said reel.

9. Apparatus in accordance wih claim 7 including a plurality of timers for accumulating total broke time at respective stations, and an energizing circuit for each timer including contacts of the relays actuated by the corresponding and next preceding sensors for energizing the timer upon detection of a break at the respective station with no break detected at the next preceding station.

10. Apparatus in accordance with claim 9 including a counter for accumulating the total number of breaks at all said stations, and an energizing circuit for said counter including switch contacts of said relays in parallel.

11. Apparatus in accordance with claim 10 including a pair of timers for accumulating total production and total lost time, respective energizing circuits for said timers including respective contacts of the relay actuated by the last sensor along the path of travel of the paper web, said contacts being connected to energize one timer during the detection of breaks and the other timer during the absence of breaks.

12. Apparatus for monitoring the operation of a paper making machine wherein a paper web passes through successive processing stages to a reel, the paper web being broken at intervals and fed to different reels during reel change-over periods, which comprises (a) a plurality of sensors located at respective stations spaced along the path of travel of the paper web for detecting breaks in the web thereat,

(b) the last of said sensors being positioned to detect breaks between the last processing stage and the reel in use,

(c) a plurality of indicators associated with said sensors respectively,

(d) circuit means responsive to said sensors for actuating respective indicators upon the detection of breaks thereby,

(c) said circuit means including means responsive to the actuation of a preceding sensor for inhibiting the actuation of the indicator corresponding to a succeeding sensor along said path of travel,

(if) and means for introducing a delay between the detection of a break by said last sensor and the actuation of the respective indicator to prevent indication of breaks during normal reel change-over periods.

13. Apparatus in accordance with claim 9 for monitoring a paper making machine in which the paper web is fed from the last processing stage to a reel and the web is broken at intervals and fed to dilferent reels during reel change-over periods, the last of said sensors being positioned to detect breaks between the last processing stage and the reel in use, said apparatus including means for introducing a delay between the detection of a break by said last sensor and the actuation of the respective counter and accumulating timer to prevent actuation thereof during normal reel change-over periods.

References Cited UNITED STATES PATENTS 1,140,029 5/ 1915 French 162255 2,864,284 12/ 1958 Proffen 162255 FOREIGN PATENTS 365,184 1/ 1932 Great Britain. 146,955 9/ 1962 Russia.

S. LEON BASHORE, Primary Examiner.

Claims

1. APPARATUS FOR MONITORING THE OPERATION OF A PAPER MAKING MACHINE WHEREIN A PAPER WEB PASSES THROUGH SUCCESSIVE PROCESSING STAGES WHICH COMPRISES (A) A PLURALITY OF SENSORS LOCATED AT RESPECTIVE STATIONS SPACED ALONG THE PATH OF TRAVEL OF THE PAPER WEB FOR DETECTING BREAKS IN THE WEB THEREAT, (B) A PLURALITY OF TIMERS ASSOCIATED WITH SAID SENSORS, RESPECTIVELY, FOR ACCUMULATING THE TOTAL TIME OF BREAKS AT THE RESPECTIVE STATIONS, (C) AND CIRCUIT MEANS RESPONSIVE TO SAID SENSORS FOR ACTUATING RESPECTIVE TIMERS UPON THE DETECTION OF BREAKS THEREBY, (D) SAID CIRCUIT MEANS INCLUDING MEANS RESPONSIVE TO THE ACTUATION OF A PRECEDING SENSOR FOR INHIBITING THE ACTUATION OF THE TIMER CORRESPONDING TO A SUCCEEDING SENSOR ALONG SAID PATH OF TRAVEL, WHILE SAID SUCCEEDING SENSOR REMAINS IN BREAK DETECTION CONDITION.