FI109817B - Shoe roll shoe element cooling arrangement - Google Patents

Description

109817

Shoe roll shoe element cooling arrangement

The invention relates, for example, to a cooling arrangement of a shoe roll shoe element according to the preamble of claim 1.

The invention also relates, for example, to a shoe roll shoe element according to the preamble of claim 4.

The shoe calender consists of a stationary body with an endless belt around it. The shoe roll has a shoe element resting on a shoe nip between the shoe roll and its counter roll via the hyd-10 roller cylinders underneath the shoe element. The shoe roll shoe element can be pressurized by hydraulic cylinders mounted on the frame to provide a so-called nip pressure in the roll nip between the shoe element and the shoe roll counter roll.

In order to reduce the friction between the shoe element and the stationary body of the shoe calender, and to cool the shoe calender shoe element 15, there is an endless rotation of the shoe element and its rotating end. a fluid lubrication usually arranged between the strip at the roll nip. Depending on the type of shoe element, the lubrication method is either dynamic or stationary or partially stationary and partly dynamic. It is common to all these lubrication methods that the oil is introduced from the hydraulic unit through the shoe element to the roll nipple or its immediate. 20 in the vicinity. Especially in dynamic or semi-dynamic lubrication: v. A large proportion of the lubricating oil travels along the surface of the shoe element from the first side of the roll nip to the other side of the roll nip and further to the shoe roll body oil collecting tray. the list of air that must be removed before returning the lubricating oil to the lubrication cycle.

'... * Due to the air contained in the lubricating oil, the Hydraulic Power Units have to be dimensioned with a large pipe size and power.

. · · ·. In addition to calendering, shoe rolls are used to squeeze water from the fibrous web.

•; The invention is intended to eliminate the disadvantages of the prior art.

Thus, the main object of the invention is to provide a shoe roll lubrication system, t ·: where the size and power of the hydraulic unit would be substantially smaller than the sensing: '·. * supported lubrication solutions.

2 109817

The lubricating strain according to the invention and the shoe element used therein achieve the above objectives. The invention relates, for example, to the cooling arrangement of a shoe roll shoe element according to claim 1. The invention also relates, for example, to a shoe roll shoe element according to claim 4.

5 The shoe roll has a stationary frame with an endless spindle arranged on it. At the roll nip between the shoe roll and its counter roll, the shoe roll has a shoe element resting on the frame through the hydraulic cylinders below it. At least two separate fluid cycles pass through the shoe element. At least one of the fluid cycles is a simulated lubricant circuit between the shoe element and the endless rotating belt 10 rotating thereon. The shoe element is also arranged to cool at least one coolant circuit. The fluids circulating in the lubricant circuit and the coolant circuit are not substantially mixed together within the shoe element. The shoe roll shoe element has at least one lubricant circuit flow passage that leads to the outer surface of the shoe element. In addition, the shoe element 15 also has at least one coolant circulation flow passage that passes through the shoe element so that the coolant circulating in the coolant flow channel is not mixed with the lubricant flowing in the lubricant flow channel.

The lubricant circuit flow channel and coolant circuit flow channel are also sometimes referred to in the text as the lubricant flow channel and the coolant flow channel.

; * The present invention is based on the separation of the lubricant and coolant cycles of the shoe roll shoe element, whereby "only as much lubricant as is needed is supplied to the lubricant circuit" to reduce the friction between the rotating endless belt and the shoe element. . Shoe Element ·: ··: Cooling is provided through a separate, air-tight coolant circuit, which significantly reduces air flow from the shoe element coolant and lubricant circuit.

The advantage of the present invention is that the lubricating fluidization of the invention and the shoe element provide an advantage over the prior art that the power and the size of the transfer tubes required for the recycling of liquids are considerably smaller than previously used.

. ···. This is due to the fact that only the lubricant circuit enters air into the fluid circuit, whereby the fluid removal time from the oil tank is considerably less than: if the lubricant circuit were used both to reduce friction between the shoe and the belt and to cool the shoe; in the latter case, the lubricant fluid 109817

J

The volume of air is significantly larger, and the volume of air entering it is also increased proportionally. The pressure of the cooling oil may be low, whereby the heating of the oil due to pressure drops is minor. Smaller hydraulic units the main benefit is cheaper price and simpler hardware.

5 It should be noted in this connection that a shoe roll and a shoe element are both a shoe roll and a shoe element used for both shoe calendering and wet fiber extrusion. The machine direction in this application refers to the direction of the advancement of the fibrous web.

The invention will now be described in more detail with reference to the accompanying drawings.

Figure 1 is a schematic cross-sectional view of a shoe roll having a Convex type shoe element viewed from the end of a pair of rollers.

Figure 2 also shows a shoe roll having a stationary lubrication zone as a cross-sectional view from the end of a pair of rollers.

Figure 1 illustrates an embodiment of a cool-down step of a shoe roll shoe element according to the invention. The figure shows only the implementation of cooling and lubrication fluid cycles in the vicinity of the shoe element.

Fig. 2 illustrates another embodiment of a cooling stiffening of a shoe roll shoe element according to the invention. The figure illustrates in greater detail the shea butter. feed and return paths for rolling and coolant cycles, as well as hydraulic fluid circuits; * 20 to pressurize the hydraulic cylinder rows beneath the shoe element to provide nip pressure between the shoe element and the counter roll.

Figure 1 shows a Convex-type shoe element 1 of a shoe roll 4 and a counter roll 2 opposite it. A roll nipple remains between the shoe element 1 and its counter roll 2. · · ·. N wherein the fibrous web W is calendered on its surface when the roll nip between the shoe roll and its counter roll is compressed. The fibrous web passes through the lubrication system shown in the figure. from left to right. The shoe roll 4 has a stationary body (not shown ['in this figure) on which the shoe element shown in the figure is supported by the hydraulic cylinders 7 below it. The hydraulic cylinders track the desired nip •: · ·: pressure on the roll nip N between the shoe roll and its counter roll and the hydraulic cylinders form ·· *. 30 are formed by two rows of hydraulic cylinders 7; 7a and 7; 7b which rest at their lower part on the shoe roll body. The end of the shoe roll 4 is rotatably provided with an end strip: · In the pattern, the strip rotates from left to right in the direction of motion of the fiber web W. To prevent belt 6 from being worn between the outer surface la of the shoe element 4109817 and the endless belt 498, the lubrication is tracked by a lubricating oil cycle 3 where the lubricating oil is pumped through a lubricating oil flow channel 3 "onto the outer surface of the shoe element 5. On the outer surface la of the shoe element, lubricating oil is carried mainly between the shoe element 1 on the roll nip N and the endless belt 6 and further away along one edge B of the shoe element to the collecting tray (not shown). The lubricating oil 10 discharged from the edges of the shoe element is partially mixed with air and these lubricating oil flows are then led to a hydraulic unit (not shown) where de-airing the oil, then feeding the lubricating oil back into the lubricating oil cycle 3. The lubricating oil cycle described above is hydrodynamic in nature, since the lubricating oil moves from the lubricating oil flow passage 3 through the shoe element; The shoe element shown in the figure also has a separate coolant circuit 5, which circulates the same lubricating oil as the lubricating oil circuit. travels in opposite directions to ensure a uniform temperature of the shoe in the machine direction. The figure shows only the coolant flow channels 5a; 5a " 5b ". The coolant flow channels are located in the shoe element 1 perpendicular to the machine direction, i.e. along the longitudinal axis of the shoe element. The coolant pumped into the coolant circuit 5 usually has to be cooled: ': with a suitable heat exchanger The coolant circuit and the lubricant circuit functionality.

'* As can be seen from the lubrication and coolant circuits shown in Fig. 1,' ... · air is added to the fluid circuits only through the lubricant circuit because the coolant circuit 5 is substantially airtight in the vicinity of the shoe element. Above, · · ·. in the embodiment described, in the coolant circuits 5; The circulating coolant 5a and 5; 5b was not mixed with the lubricating oil flowing in the lubricant circuit even with the hydraulic:. 'On the machine.

5, 109817

The shoe roll 4 shown in Figure 2 has the same basic structure as the shoe roll shown in Figure 1j. The figure also shows the stationary body 10 of the shoe roll into which the hydraulic cylinder rows 7; 7a, 7b are supported and lubricating oil collecting basin 11. The figure shows lubrication, cooling and hydraulic fluid circuits to the hydraulic machine piston H and back. In the shoe roll 4 shown in the figure, a substantially stationary lubrication zone is formed between the shoe element 1 and the endless belt W rotating thereon with a pocket formed on the outer surface 1a of the shoe element. The lubricating fluid circulation 3 of the shoe element and the endless belt is arranged such that the lubricating oil is supplied from the hydraulic unit to the lubricating oil supply channel 3; 3 'along the largest

10 to a lubricating oil flow passage 3 in the middle of the shoe element; 3 "and thereafter into a substantially stationary zone (pocket) between the shoe element and the endless belt. Air is mixed with the lubricating oil as it moves from the outer surface of the shoe element to the oil collecting basin. The coolant circulation 5 of the shoe element is in turn arranged so that the cooling oil is supplied from the hydraulic unit H to the coolant supply channel 5; 5 'along the coolant flow passage 5 passing through the shoe element; 5 ". In this case, the coolant circulation of the shoe element is formed by only one coolant circuit 5 and a flow channel 5" thereon, which is now transverse to the longitudinal axis of the shoe element, i.e. in the machine direction. From the flow passage 5 ", the cooling oil is led back to the hydraulic unit down to the coolant outlet 5" '. Hydraulic fluid circulation: · * 8 is normal in itself and pumps hydraulic fluid from the hydraulic unit H

: 25 hydraulic fluid supply channels 8; 8 'down to the hydraulic cylinders 7, of which the excess': returns the hydraulic fluid outlet 8; 8 "'along the back to the hydraulic unit.

The hydraulic fluid flowing in the inlet and outlet ducts of the hydraulic fluid circuit 8 is: • cooled by a water-circulating heat exchanger 9. Preferably, the same oil is used in the hydraulic, cooling and lubrication: '* *: fluid circuit.

30 It is noteworthy in the above described coolant lubrication and hydraulic fluid circuits that '* the air circulates only through the lubricant circuit, which reduces the size of the fluid transfer lines and the size of the hydraulic pump unit H and.;

In the embodiment of the invention shown in Figure 2, the fluid streams coming from the different fluid circuits to the hydraulic 35 unit are preferably the same lubricating oil so that they can be allowed to mix with the hydraulic unit after degassing the lubricating oil from the lubricating oil cycle.

Only one of the lubricating elements of the shoe roll according to the invention is shown above! stiffening and shoe element. However, it is clear to one skilled in the art that The invention may be implemented in a number of other ways within the scope of the claims.

Thus, the lubricating and coolant circulation of the shoe element is shown above only for some typical shoe rollers currently used. If the shape of the shoe element differs from the above, the structure of the fluid circuits is also altered, but the lubricant and coolant circuits are kept separate. Lubricating oil cycles are well known in the art, and various different semi-dynamic, partially static, or purely dynamic or static lubricating oil cycles have been described in the literature for various shoe elements. The lubrication, coolant and hydraulic fluid circuits can be either completely separate or completely or partially identical. In part or all of the same circulatory systems, the fluid circuits are preferably connected within a hydraulic unit. For example, shoe roll lubrication and hydraulic fluid circulation may be combined but coolant circulation separate.

In the coolant circuit, the cross-sectional profile of the coolant flow channels, in turn, may, if appropriate, deviate from the circular shape. The number and direction of the 20 flow channels may also vary; for example, in some cases, the cooling channels may pass through the shoe element so that their orientation differs both from the machine direction and also from the longitudinal axis of the shoe roll.

...: The coolant circulating in the coolant circuit is usually cooled ···. water circulation heat exchanger 25 in the supply channel of the coolant circuit.

The above exemplary embodiments relate to shoe elements used in shoe calendering and their lubrication sequencing. ··: However, presses are also used to remove water from the fibrous web. The water is then "": impregnated into the wires above and below the fibrous web or, in some cases, introduced into a press having a structure similar to a shoe roll. The shoe element and lubrication stretching according to the invention can also be used in conjunction with such presses.

• * *

Claims (6)

1. Cooling arrangement in a shoe element (1) of a shoe roll, in which the shoe roll (4) has a stationary body (10) on which an endless belt (W) is arranged to run around, at the roll nip (N) between the shoe roll and its counter roll (2), the shoe roll has a shoe element which supports the body (10) by mediating hydraulic cylinders (7) located below the shoe element, characterized in that - at least two separate liquid circuits pass through the shoe element (1) in the liquid circuit - the shoe element (1) and a circulating endless belt (6) have: arranged at least one lubricant circuit (3) and - the shoe element is arranged to be cooled by at least one coolant circuit (5) and - those in the lubricant circuit (3) and 5) circulating liquid combo does not substantially interfere with each other within the shoe element. Cooling arrangement for a shoe element according to claim 1, characterized in that the shoe element (1) is arranged to cool two coolant circuits (5), in which flow channels (5a ", 5b") the coolant flows in opposite directions. Cooling arrangement for a shoe element according to any preceding claim, characterized in that the coolant circuit (5) is substantially airtight in the vicinity of the shoe element. The shoe element (1) in a shoe roller, wherein the shoe roller (4) has a stationary body (10) on which an endless belt (W) is arranged to run around, at the roller nip (N) between the shoe roller and its counter roll (2). the shoe roller has a shoe element which supports the body (10) by mediating hydraulic cylinders (7) located below the shoe element and the shoe element comprises at least one flow channel (3 ") provided for the liquid liquid circuit which leads to the outer surface (of the shoe element) Characterized in that the shoe element (1) also comprises at least one coolant (5 ") flow channel (5") which runs through the shoe element so that the coolant circulating coolant (5 ") is not mixed with the coolant (3) of the coolant (5). flow channel (3 ") flowing lubricant liquid. Shoe element (1) according to Claim 4, characterized in that the flow channels (5; 5a ", 5b") which are parallel to the machine direction are provided by the shoe element at least two flow channels (5; 5a ", 5b"). Shoe element (1) according to claims 4-5, characterized in that the flow channel (5; 5 ") of the coolant circuit is substantially airtight.