JPH03885A - Failure diagnosis of dryer in papermaking machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is useful for determining whether vibration is normal or abnormal in a dryer (drying section) of a paper machine that is operated under severe conditions such as drying at high temperatures and high speeds. The present invention relates to a fault diagnosis method for a paper machine dryer, in which, in the case of an abnormality, the cause can be analyzed and displayed.

[Prior Art] For example, a dryer in a paper machine is a part placed next to a press section to dehydrate wet paper by heating and drying, and is operated at high speed.

As partially shown in FIGS. 8 and 9, the paper machine dryer described above has drying drums 1 arranged in two stages, upper and lower, with their vertical positions shifted from each other in a staggered arrangement, and the shaft of each drying drum 1 is It is rotatably supported on a frame 3 via a bearing 2, and the shafts of the upper and lower drying drums l are connected to each other by a plurality of gear trains 4 for power transmission provided on the drive side. An endless upper canvas (felt) B is alternately wrapped around the upper drying drum 1 and the canvas roll 5 using canvas rolls 5 arranged in parallel between the drums 1, so that the upper surface of each upper drying drum 1 is Similarly, for the lower drying drum 1, an endless lower canvas 8 is installed using canvas rollers between the lower drying drums 1 to cover the lower surface of each lower drying drum 1. The wet paper 9 led from the press section is passed through a smoothing press 10 at the entrance of the drying section to smooth the surface of the paper, and then the surface of the wet paper 19 is applied to the surface of the lower drying drum 1.
The opposite side of the wet paper 19 is applied to the upper drying drum 1, and the moisture in the paper is removed between the upper and lower canvases 6.8 and each drying drum 1 by sequentially running it along the two upper and lower drying drums 1. In addition, steam is ejected into each drying drum 1, and the release of latent heat of the steam transfers heat to the paper through the wall of each drying drum 1, thereby drying the paper. 11 is a drum for drying the canvas, 12 is a campus guide roll, and 13 is a gear case.

[Problems to be Solved by the Invention] However, such a paper machine dryer is exposed to a harsh environment where it is operated at high speed in a high temperature drying state, and each drying drum 1 used in such a location is The bearings 2 of the drying drums 1 are easily damaged, and the drive system such as the gear train 4 that connects the drying drums 1 is easy to wear out. For this reason, conventional measures have been taken such as supplying a lubricating pond to the drive system such as the bearing 2 and gear train 4, but under the above-mentioned adverse environment, the bearing 2 may be damaged and vibrate. This has caused problems such as vibrations caused by vibrations, vibrations caused by wear of the drive system such as the gear train 4, or other causes, such as generation of noise and adverse effects on paper quality.

Therefore, the present invention aims to constantly monitor bearings and the like used in high-speed operation as described above, and when an abnormality occurs, immediately diagnose and display the details of the abnormality.

[Means for Solving the Problems] The present invention detects the vibration acceleration of at least the rotating body bearing part during normal operation, which is the cause of vibration of the paper machine dryer, and inputs the frequency characteristics to a calculation device as reference data. Thereafter, the vibration acceleration is detected in the same way, its frequency characteristics are input to the arithmetic unit, the overall value is compared with the reference data, and the diagnosis is made as to whether it is normal or abnormal based on the magnitude of the overall value. Display the results on the display device, and if an abnormality is diagnosed, compare whether the frequency of each vibration generation cause matches the measured dominant frequency, and if they match, identify the cause and take measures. The present invention relates to a method for diagnosing a failure of a paper machine dryer, which is characterized by displaying information on a display device.

[Function] When the frequency characteristics obtained from the vibration acceleration detected at the rotating body bearing part etc. are input into the calculation device, the overall value is compared with the reference data inputted in advance to the calculation device, and the overall value is calculated. A diagnosis is made as to whether it is normal or abnormal depending on the size, and the diagnosis result is displayed on the display device. Furthermore, if an abnormality is diagnosed, the cause of the occurrence of a frequency that matches the predominant frequency at which the abnormality was diagnosed is diagnosed, and the cause and countermeasure are displayed on the display device.

[Example〕 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a paper machine dryer to which the method of the invention is applied.

As shown in FIGS. 8 and 9, the paper machine dryer has a plurality of drying drums 1 arranged in two stages, upper and lower, in a staggered manner, and both ends of each drying drum 1 are supported rotatably by bearings 2. A gear train 4 for transmitting power to each drying drum 1 is arranged alternately between the upper and lower drying drums 1 on the drive side of each drying drum 1 and housed in a gear case 13. While bringing the endless upper campus B into contact with the upper surface side,
The structure is such that an endless lower canvas 8 is brought into contact with the lower surface side of each lower drying drum 1, and the wet paper 9 led from the press section is passed between the lower drying drum 1 and the lower canvas 8. After that, the next upper drying drum 1 and upper canvas 6
Afterwards, the wet paper 9 is similarly guided up and down to dry.

The paper machine dryer failure diagnosis method of the present invention detects the vibrations of each part in the dryer, investigates the abnormality of each part, the degree of the abnormality, and the cause, and displays the diagnosis results.

Therefore, as shown in FIG. 1, vibration accelerometers 14 are provided at the driving side bearing 2 and the operating side bearing 2° of the drying drum 1, which are the sources of vibration that cause vibrations, and the bearings of the canvas roller, A vibration accelerometer 14 is also provided in each of the vapor roll, the hot air roll bearing, the dryer base 15, the frame 3, etc. (not shown), and the detection signal from each vibration accelerometer 14 is sent manually to the scanner 17 via the preamplifier 1B. That's how it is.

Each vibration accelerometer 14 input to the scanner 17
The detection signals are sequentially switched by a scanner 7, and a frequency characteristic signal 19 subjected to frequency analysis by a frequency analyzer 18 is input to an arithmetic unit 20.

The arithmetic device 20 is configured to receive signals from an input device 21 manually. As shown in detail in FIG. 6, the input device 21 is configured to input papermaking conditions such as basis weight, papermaking speed V (dryer standard: Vm/min), canvas length, measurement frequency band, etc. In addition, the hood type, number of dryer groups, number and diameter of each of drying drums, canvas rolls, vapor rolls, and hot air rolls, bearing specifications, gear specifications, and natural frequency of the rotating body are input as dryer manual conditions. It has become.

In addition, the arithmetic unit 20 has information on the normal state of each vibration generation cause (
When the vibration is small), the vibration acceleration is measured by the vibration accelerometer 14, and the vibration acceleration is measured by the frequency analyzer 18.
The frequency characteristics obtained by frequency analysis are input in advance as reference data, and therefore, the frequency characteristic signal 19 that is subsequently measured and input is compared with the reference data as an overall value to obtain an overall value (amplitude). ) is larger than a set value (this is called a dominant frequency), an abnormality is determined and can be displayed on a display device 22 such as a display or a printout.

'12 Figure 84 This is the overall value (amplitude) of the frequency characteristics measured and determined at each measurement point that causes vibration, and this overall value is the standard data (0, 0, IQ) up to 2 times <0.29) is considered normal, and between 2 times (0,20) and 6 times (0,89) is considered to be normal.
A value of 6 times (0, H) or more is determined to be abnormal.

Figure 3 shows an example of the measured frequency characteristics when the measurement frequency band is 0 to 50Hz at a machine speed of 800m/s+1n.The drying drum, canvas roll, and hot air roll each have their own acceleration level peaks at their own frequencies. 4, and similarly, the measurement frequency band is set to 0.
An example of the frequency characteristic when the frequency is ~500 Hz is shown, and there is a peak of the acceleration level of the first-order gear meshing and the second-order gear meshing acceleration level at a unique frequency.

For each cause of vibration, the papermaking speed was set to 825 m/win.

FIG. 5 collectively shows each frequency at which the acceleration level shows a peak in the frequency characteristics when the speed is varied such as 700 m/win and 800 m/sin.

In this way, each vibration generation cause has its own unique frequency, so when an abnormality is detected based on the above-mentioned overall value, its predominant frequency is determined and It is sequentially checked whether the frequency indicating the peak of the acceleration level that appears in the frequency characteristic obtained from the above matches the predominant frequency, and if there is a match, the cause and countermeasures are diagnosed and displayed on the display device. 22.

Next, the operation of the above embodiment will be explained.

As shown in FIGS. 1 and 6, the human power device 21 (from
Paper making conditions, dryer input conditions, standard data, etc. are included in the calculation bag W.
A frequency characteristic signal 19 is obtained by sequentially switching the detection signals from the vibration accelerometer I4 provided at each measurement point that is the cause of each vibration occurrence and sequentially frequency-analyzing the frequency analysis by the frequency analyzer 18. is the computing device 2
It is entered as 0. At this time, in FIG. 6, the reference data is shown as a O (0, 19), and the overall value from the frequency characteristic signal 19 is shown as 81.

The arithmetic device 20 first displays on the display device 22 that the overall value a1 is normal.

In the event of an abnormality, several values including the predominant frequency 'MAX' are determined and displayed, and the following detailed diagnosis is performed.

First, in order to check whether the vibration is caused by the rotational frequency of each rotating body, the rotational frequencies of each rotating body are matched. At this time, the rotation frequency of the drying drum is fl, the rotation frequency of the canvas roll is fz, the rotation frequency of the paper roll is fg, and the rotation frequency of the hot air roll is f4.

Cause A> Determine whether the vibration is of the first-order rotational frequency of the rotating body.

If fゎ, -fl, the main cause of the vibration is the first-order vibration of the rotational frequency of the drying drum, and the countermeasure is to correct the unbalance of the drying drum.
Display on 2.

Also, if the cause of vibration is not the drying drum, fHlx-
fz to determine whether the cause is the campus roll, and if they do not match, use the same method to determine whether the vapor roll or hot air roll is the cause.
Perform display.

Cause B> Determine whether the vibration is an integral multiple of the rotational frequency of the rotating body.

fHAx−Kf+ , Kfz , Kfz , Kfa(K
-2, 3, 4...), and if they match, the causes and countermeasures are displayed in the display bag [22].

Cause C> Determine whether the next vibration occurs.

It is checked to see if there is a match, and if they match, the cause and countermeasure are displayed on the display device 22.

Cause D> Determine whether there is a resonance phenomenon that depends on the natural frequency of the rotating body.

Natural frequencies of each rotating body fo1, fo2, fo3, fo4
is fHll −fo + , fo 2 , fo 3, f
oa is checked, and if they match, the cause and countermeasure are displayed on the display device 22.

Cause E> Determine whether the vibration is caused by the bearing.

Frequency f1, fcl based on bearing inner ring, outer ring, and rolling elements
Find fb and check whether they match fMAX,
If they match, the cause and countermeasure are displayed on the display device 22.

Cause F> Determine whether the vibration is dependent on the meshing frequency of the gears.

, fMAX−Zf+ , 2Zf+ , 3Z, f+ −(
Z - number of gear teeth of the drying drum), and if they match, the cause and countermeasures are displayed on the display device 22.

Cause G Determine whether the vibration depends on the campus period.

If they match, the causes and countermeasures are displayed on the display device 22.

Cause H> Determine whether vibration is observed in the foundation, and display the cause and countermeasures. Also, let the frame vibrate.

Cause I Determine whether electrical vibrations are possible.

If there is torsional vibration in the drive system, its cause and countermeasures are displayed on the display device 22.

Each of the above diagnostic results can be displayed on the display device 22 as a list.

On the other hand, if all the diagnoses are NO, the display device 22 displays that the cause is unknown.

In the above embodiment, in order to simplify the explanation, the judgment criterion based on the overall value (amplitude) of the frequency characteristic was set to dn.
Although we have explained the case where the value (d: axis diameter of the rotating body, n: rotational speed) is set constant, by changing the criterion for the di value in accordance with the dn value as shown in Fig. 7. , it is possible to make a more accurate determination.

The paper machine dryer failure diagnosis method of the present invention is not limited to the above-described embodiments, and the measurement points of vibration acceleration using a vibration accelerometer, input conditions, etc. may vary depending on the weight and weight of the vibration that causes the vibration. Of course, it can be arbitrarily selected and various changes can be made without departing from the gist of the invention.

[Effects of the Invention] As explained above, according to the paper machine dryer failure diagnosis method of the present invention, abnormality in vibration of the paper machine dryer can be constantly diagnosed and displayed, and when the abnormality is diagnosed, Since the cause and countermeasure can be immediately diagnosed and displayed, countermeasures can be taken before the product deteriorates due to a malfunction, and measures such as repair of the abnormal part can be taken by displaying the cause of the abnormality and the countermeasure. It can be done accurately and quickly and can produce excellent effects.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of an apparatus for carrying out the method of the present invention, FIG. Fourth
The figure is a diagram showing the relationship between the frequency of the frequency characteristic obtained by detection and the acceleration level. Figure 5 is a diagram showing the frequency of the peak of the acceleration level that occurs for each cause of vibration when the machine speed is changed. Figure 6 is a flowchart of the present invention;
FIG. 7 is a diagram showing another example of the criteria for determining the overall value, FIG. 8 is a side view showing an example of a paper machine dryer, and FIG. 9 is a side view of the drive side gear train of the drying drum. l is the drying drum, 2.2" is the bearing, 3 is the frame, 5.
7 is a campus roll, 14 is a vibration accelerometer, 15 is a dryer base, 1B is a preamplifier, 17 is a scanner, 1
8 is a frequency analyzer, 19 is a frequency characteristic signal, 20 is an arithmetic device, 21 is an input device, 22 is a display device, ag is reference data, and al is an overall value.

Claims (1)

[Claims] 1) Detect the normal vibration acceleration of at least the bearing of the rotating body, which is the cause of vibration in the paper machine dryer, and input its frequency characteristics to the calculation device as reference data. The frequency characteristics are input to the arithmetic unit and the overall value is compared with the reference data, and depending on the magnitude of the overall value, it is determined whether it is normal or not.
Diagnose the abnormality and display the diagnosis result on the display device, and if an abnormality is diagnosed, compare the frequency of each vibration generation cause with the measured dominant frequency and check whether they match. A method for diagnosing a failure in a paper machine dryer, characterized by displaying the cause and countermeasures on a display device when the problem occurs.