JPS5930838B2 - Paper machine dryer surface cleaning method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cleaning the surface of a paper machine dryer, and more specifically, a method for cleaning the surface of a paper machine dryer by pressing a doctor blade of a cleaning doctor device against the surface of the dryer. The present invention relates to a method for cleaning the surface of a paper machine dryer.

In conventional cleaning doctor devices for cleaning the surface of paper machine dryers, a doctor blade is always pressed against the dryer surface with a constant pressure while keeping its contact angle (rake angle) constant. Ta.

However, depending on the type, shape, etc. of the dirt attached to the dryer surface, there is a unique rake angle that is suitable for removing it.If the pressing force and rake angle of the doctor blade are constant as in the conventional method, Since only the type or shape of dirt can be removed, there is a problem in that the dryer surface cannot be sufficiently cleaned.

Incidentally, if dirt and the like on the surface of the dryer are not sufficiently removed, the surface condition of the paper to be made will be inconsistent, resulting in variations in product quality and lowering the commercial value of the product.

In view of the above-mentioned conventional problems, it is an object of the present invention to propose a dryer surface cleaning method that can efficiently clean the dryer surface. hand,
The doctor blade of the cleaning doctor device is moved forward and backward in the direction of approach or separation, so that the doctor blade is brought into pressure contact with the surface of the paper machine dryer while its rake angle changes at appropriate intervals within a predetermined angle range. It is characterized by:

Hereinafter, the method of cleaning the surface of a paper machine dryer according to the present invention will be explained based on the illustrated embodiment. FIGS. 1 to 4 show a cleaning doctor device 2 suitable for carrying out the present invention. .

This cleaning doctor device 2 has a doctor device main body 3 which is made up of a doctor blade 10 in the form of a thin plate attached to the outer surface of a straight tube-like doctor body 8 attached to a doctor shaft 7.
, a doctor device main body movement device (hereinafter simply referred to as a doctor movement device) 4 for moving the doctor device main body 3 back and forth in the front-rear direction (arrow E-F direction) with respect to the surface 1a of the paper machine dryer 1; The device includes a doctor device main body rotation device (hereinafter simply referred to as a doctor device rotation device) 5 for rotating the device main body 3.

The doctor device main body 3 has both ends 7a of its doctor shaft 1.
, 7a are rotatably mounted by being pivotally supported by bearing members 11, 11, which will be described later.

The doctor blade 10 is supported by a blade holder 9 fixed to the doctor body 8 and projects obliquely upward.

A pair of the doctor advancing/retracting device 4 and a doctor rotating device 5 are provided on each of the left and right sides of the doctor device main body 3.

The doctor rotating device 5 includes a pair of left and right air cylinders 17.
, 17 are connected to both ends 7a, 7a of the doctor shaft 7 via arms 27, 27, respectively.

This doctor rotating device 5 constantly urges the doctor shaft 7 in the direction of the dryer surface (in the direction of arrow G) by the air cylinder 17, so that the tip of the doctor blade 10 is always pressed against the dryer surface 1a with a predetermined pressure. It acts on

Note that the doctor rotation device 5 may be replaced with the air cylinder 17 by any suitable device as long as it acts to rotate the doctor device main body 3 and bring the doctor blade 10 into pressure contact with the dryer surface 1a. .

For example, a spring or a weight of appropriate weight may be attached to the arm 27 to apply a rotational moment to the doctor device main body 3.

The doctor advancing/retracting device 4 includes a bearing member 11 for supporting the doctor shaft 7, and a bearing member 11 that moves in the front-rear direction (arrow E-
Two side plates 23 for slidingly guiding in the F direction)
, 23 and the pair of left and right guide members 12:12.
, 12; a pinion gear 14 attached to the rotating shaft 13 and acting to drive the bearing member 11 forward and backward in the forward and backward directions; and an air cylinder 15 for rotating the rotating shaft 13. It is configured with

Note that this pair of left and right doctor advancing/retracting devices 4, 4 share only the rotating shaft 13, and other members, that is, the bearing member 11.
, guide member 12, pinion gear 14, and air cylinder 15 are each used in pairs.

The bearing member 11 is formed to be elongated in a direction horizontally orthogonal to the doctor shaft 7.

Further, horizontally long guide grooves 2 are provided on both sides of the bearing member 11.
1.21 is formed, and a rack gear 22 that meshes with the pinion gear 14 is formed on the lower surface of the bearing member 11.

The guide member 12 has inwardly directed oblong protrusions 24, 24 formed at the upper ends of both side plates 23, 23, respectively.

The horizontally elongated protrusions 24, 24 fit into the respective guide grooves 21, 21 of the bearing member 11 from the outside, and guide the bearing member 11 so that it can slide only in the front-rear direction.

The air cylinder 15 for rotating the rotating shaft 13 is
It is connected to an arm 25 attached to the end 13a of the rotating shaft 13, and the rotating shaft 13 is moved in both forward and reverse directions (arrows C-D direction).

That is, in the doctor advancing/retracting devices 4, 4, when the rod 15a of the air cylinders 15, 15 is contracted (in the direction of arrow B), the rotating shaft 13 is rotated in the direction of the arrow, and the pinion gears 14, 14 and rack gears 21, 21 are rotated. The meshing causes the bearing members 11, 11 to slide in the direction of arrow F, thereby causing the doctor device main body 3 to horizontally slide in the direction closer to the dryer surface 1a (see Fig. 3), and vice versa. When the rods 15a of 15, 15 are extended (in the direction of arrow A), the rotating shaft 13 and the bearing member 11.11 are operated in the opposite directions (in the direction of arrows C and E), and the doctor device main body 3 is moved away from the dryer surface 1a. It acts to horizontally slide in the direction away from you (see Figure 4).

Note that no matter which side of the doctor device main body 3 is moved forward or backward in the front-rear direction (the state shown in FIG. 3 or FIG. 4), the doctor device main body 3 is moved by the air cylinders 17, 17 of the doctor rotation device 5. The doctor blade 1 is always biased in the direction of arrow G (toward the dryer surface 1a side).
0 is always pressed against the surface 1a of the dryer 1 with a constant pressure.

Furthermore, as shown in FIG. 3, at a position where the doctor device main body 3 approaches the dryer surface 1a, the rake angle θ of the doctor blade 10 becomes small (θ=θ1), and conversely, as shown in FIG. 3 is far from the dryer surface 1a, the rake angle θ of the doctor blade 10 is
becomes large (θ=θ2).

Further, the forward and backward movement range of the doctor device main body 3 is set so that the rake angle θ of the doctor blade 10 with respect to the dryer surface 1a can be varied within a range of approximately 15° to 30°.

The maximum movement range of the doctor device main body 3 can be determined by providing an appropriate stopper device (not shown) at an appropriate position of the doctor device 4 to restrict the movement range of the bearing members 11, 11.
It may be regulated by the stopper device.

The doctor advancing/retracting device 4 of the illustrated embodiment includes an air cylinder 1
By expanding and contracting 5 and 15 at appropriate intervals, the doctor device main body 3 acts to move back and forth continuously at a predetermined interval.

That is, in this embodiment, as shown in FIG.
are connected in parallel by air pipes 34 and 35 via a 4-point/3-position switching valve (hereinafter simply referred to as a switching valve) 32 that is automatically switched by a timer 33. Each air cylinder 15.
15 repeats the expansion or contraction action at the same time, thereby causing the doctor device main body 3 to move back and forth continuously.

Also, in this embodiment, each air pipe line is 34.34°35.3°.
A speed control valve 36,36, having a throttle valve 37 and a check valve 38, respectively, is interposed in the middle of the speed control valve 7'36, 36... prevents the air cylinders 15, 15 from rapidly expanding or contracting.

That is, by slowly expanding or contracting the air cylinder 15.15, the rake angle θ of the doctor blade 10 can be adjusted.
is made to change continuously and slowly.

Next, to explain the operation of the illustrated dryer doctor device 2, when the switching valve 32 is switched from the neutral position to the normal connection 32a side by the timer 33, the air cylinder 1
An air line 34 connected to the tail side of the air cylinder 15 is communicated with the compressed air source 31, and compressed air flows into the tail side of the air cylinder 15 through the air line 34.

At this time, the air entering the cylinder head side of the air cylinder 15 is squeezed by the speed control pulp 36 provided in the middle of the air pipe 35 and is pushed out little by little.
5 stretches slowly.

When the air cylinder 15 expands, the rotating shaft 13 is rotated in the direction of arrow C, and the bearing member 11 is further moved backward (in the direction of arrow E), thereby acting to move the doctor device main body 3 backward.

Note that the air cylinder 17 of the doctor rotating device 5 always biases the doctor shaft 1 to rotate in the direction of arrow G, so when the doctor device main body 3 is in the retracted position (the position shown in Fig. 4), the doctor blade is 10 dryer surface 1a
The rake angle θ is large.

The rake angle θ in this case is about 30°.

When the switching valve 32 is switched to the reverse connection 32b side by the action of the timer 33, compressed air from the compressed air source 31 flows into the cylinder head side of the air cylinder 15 through the air pipe 35, and at the same time, the compressed air flows into the cylinder head side of the air cylinder 15 through the air pipe line 35. Air is gradually released through the air line 34, causing the air cylinder 15 to deflate.

Then, the rotating shaft 13 rotates in the direction of the arrow, and the bearing member 11 moves forward (in the direction of the arrow F), causing the doctor device main body 3 to move forward (in the direction of the arrow F).
is moved closer to the dryer surface 1a (FIG. 3).

At this time, the dryer surface 1a of the doctor blade 10
The rake angle θ becomes smaller (approximately 15°)
.

In this way, the angle θ of the doctor blade 10 can be continuously changed within a predetermined angle range based on the cycle set by the timer 33.

In the above embodiment, the air cylinder 15 is used as a power source for the doctor advancement/retraction device 4, but in other embodiments, the arm 25 is reciprocated steplessly by a crank mechanism or a cam mechanism. You can also do that.

Next, the effects of the present invention will be explained. According to the method of cleaning the surface of a paper machine dryer of the present invention, (1) the rake angle θ of the doctor blade 10 with respect to the dryer surface 1a is changed at a predetermined period within an appropriate range; Therefore, various types of dirt etc. attached to the dryer surface 1a can be easily removed regardless of the rake angle specific to each type of dirt, and the cleaning action of the dryer surface 1a can be performed efficiently. ) Since the dryer surface 1a can be efficiently cleaned, the condition of the surface of the paper to be made is made uniform, there is no variation in product quality, and the commercial value of the product can be increased. (3) Dryer surface By eliminating the adhesion of grime to the dryer surface 1a, there are practical effects such as improved heat conduction from the dryer surface 1a to the wet paper, resulting in improved drying efficiency.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a paper machine cleaning doctor device used in an embodiment of the present invention, FIG. 2 is a sectional view taken along the line n-II in FIG. 1, and FIGS. 3 and 4 are respectively It is a side view showing the action of the cleaning doctor device. 1...Paper machine dryer, 1a...Dryer surface, 2...Cleaning doctor device, Total...Doctor device body, 4...Doctor Advancement/retraction device, 5...Doctor rotation device, 1
0...Doctor Blade.

Claims (1)

[Claims] 1 Surface 1a of paper machine dryer 1 rotating in a fixed direction
The doctor blade 10 of the cleaning doctor device 2 is advanced and retreated toward or away from the paper machine dryer while the rake angle θ of the doctor blade 10 changes at appropriate intervals within a predetermined angular range. A method for cleaning the surface of a paper machine dryer, characterized in that the surface is brought into pressure contact with the surface 1a.