JPS61115699A - Slurry treatment method and apparatus - 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 FIELD OF INDUSTRIAL APPLICATION The present invention relates to a method and apparatus for processing slurry. 5. Prior art and its problems In the paper industry, wood chips are digested in a pulping liquor at high temperatures. In the pulping process, the cellulosic binding components are dissolved in the pulping liquor, but after pulping, the waste liquor is collected from the valve, and the liquor is treated to recover its waste heat, and at the same time, the cooking chemicals are also recovered. It is desirable to do so. It is desirable that the waste liquid be recovered with as much solid content as possible. This is because the first stage of the recovery process is concentration of the liquid by evaporation. Therefore, very little water should be used to flush the valve in order to make the recovery process most effective.

Traditionally, the most common process for recovering pulping liquor uses a rotating barrel vacuum filter. Since one pass is usually insufficient to clean the valve, the valve is usually reslurried with wash water and refiltered. This procedure is
The process is repeated, usually countercurrently, to flush the valve and recover the necessary pulping liquid.

Rotary filters require substantial fresh water to flush the valves. This is due to the need for a reslurry operation and because copper P filters require very low slurry content to operate effectively.

Therefore, recovering the pulping liquor from the washing process using a rotary vacuum 1)N filter requires substantial energy to concentrate the pulping liquor that has been diluted in the recovery process.

To overcome the difficulties encountered with rotating barrel filters, attempts have been made to filter the slurry on a moving horizontal belt-like filter. For example, U.S. Pat. No. 4,046,521 shows a system in which a diluted slurry is deposited on a horizontal overbelt that moves past a series of suction boxes. Wash water is added to the downstream suction box, and water passing through the mat supported on the horizontal belt is fed cocurrently through the various suction boxes to the upstream end of the system.

U.S. Pat. No. 4,154,644 also discloses a valve cleaning system in which a diluted valve slurry is applied to the top of a moving horizontal transit belt. Patent No. 4.15
No. 4,644, a hood is sealed over a porous endless belt, the belt is passed over a series of suction boxes, and the liquid removed from the slurry is recirculated countercurrently to the preceding section of the cleaning apparatus. Ru. The gases and vapors drawn into the suction box along with the cleaning liquid are separated from the liquid and recycled to the hood to control the air pressure within the hood.

The desired differential pressure is thus maintained during operation of the cleaning device.

As the moving horizontal belt supporting the valve mat moves over a series of vacuum or suction boxes of the system shown in Patent Nos. 4.046.627 and 4.154.644, it takes virtually no effort to move the belt. There is a certain amount of frictional resistance. Due to the increased frictional resistance, the drive system requires more power, and - excessive belt wear also occurs, reducing belt life.

U.S. Patent Nos. 4.160.297 and 4,246.66
No. 9 shows a system in which the valve layer or mat is held between two endless belts. In these patents horizontal 14 are each mounted in a wash tank containing a wash liquid, - a pipe mat held between overbelts passes under each wash and through the liquid contained in the tank. . The cleaning fluid from the tank passes inwardly through a valve mat held between the belts, or may alternatively flow outwardly from the barrel through the mat to the tank.

A countercurrent cleaning liquid system is used in which the cleaning liquid passes between the cleaning tanks in its own flow due to gravity flow.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved method and apparatus for processing liquid slurries containing solid materials, such as slurries consisting of cellulosic bulb stock and digester or pulping fluids. . A flowable cellulose slurry is distributed over the top of a moving endless porous belt in layers or mats, and after drainage of the liquid from the initial mat;
A second moving endless porous belt is brought into contact with the top surface of the mat. The two belts move through converging paths over individual roller groups and liquid is extracted from the mat.

The mat held between the belts is then passed through a series of conditioning stages where the valve mat is diluted with cleaning fluid for cleaning and passed through a cycle in which it is drained. In the last downstream stage, fresh water is supplied to the mat, and after passing through the mat, the cleaning liquid cascades in countercurrent through the various conditioning stages due to gravity.

Following the final conditioning stage, the belt moves through the divergence path and the mat is separated from the belt.

The working valve mat is held between two moving belts so that the position of the mat is fully controlled throughout all cleaning operations.

Since the system does not use a stationary vacuum box, there is no vacuum frictional resistance to belt movement. This reduces the power required to operate the belt while also extending the life of the belt.

Furthermore, the reduction in frictional resistance and the corresponding reduction in belt wear has the advantage that it is also possible to use seamed belts instead of textile endless belts. Using a spliced belt eliminates the hassle of splicing the belt after it is installed on the machine. If an off-the-shelf endless belt is used, the rolls must be cantilevered in order to attach the belt, but the cantilevered configuration greatly increases the overall cost of the cleaning system construction.

Since the valve web is held completely between the moving belts, the conditioning stages can be arranged in cascade so that the wash water flows countercurrently from section to section by gravity. As a result, there is no need to feed cleaning fluid, and foaming of the fluid is minimized.

limited.

The cleaning system of the present invention uses much less water than rotating barrel systems, allowing digestive fluids to be recovered at a substantially lower cost. Alternatively, more conditioning stages can be used in the cleaning device if the same power source is used.

Other objects and advantages will become apparent from the description below. The drawings depict the best mode presently believed to carry out the invention.

EXAMPLE FIG. 1 schematically shows an apparatus for cleaning liquid slurries containing solid substances, in particular paper valve stock.

The apparatus includes a frame or support structure 1 and a pair of porous overbelts 2 and 3, each moving in a separate endless path on the support structure 1.

In the present invention, a layer of valves or mat 4 is held between two series of belts 2 and 3, and the mat is conditioned or washed as it passes through the system and the pulping liquor is recovered.

The lower-overbelt 2 is mounted on a tension roll 5 and passes under a headbox 6 which lays a valve layer in the form of a mat 4 on the upper side of the belt 2.

The belt 2 carrying the mat 4 then passes through an initial extraction section 7 where a portion of the pulping liquid is squeezed out of the mat 4, and then the belt passes through a treatment or conditioning section 8 where the mat is washed with a cleaning solution. Washed and pulping liquid removed. After passing through the conditioning section 8, the lower filter belt 2 passes around the driven Karachi roll 9 and is fed on its return journey over a series of support rolls 10, 11, 12 and 13. The rolls 10-13 are suitably pivoted for rotation in the support structure 1, and the rolls 12
is mounted so as to be tiltable in a horizontal plane in a support structure. Adjustment of the rolls 12 is accomplished by known methods to maintain belt alignment on the various rollers and to prevent the belt from shifting to one side or the other.

Tension roll 5 is horizontally movable and applies appropriate tension to belt 2. For this purpose, the tension roll 5 is pivoted on a carriage 14 which moves in a track on the support structure 1. Although not shown, the desired tension in the belt 2 is maintained by adjusting the position of the carriage 14 relative to the frame using a series of jacks.

The upper overbelt 3 is attached to the tensioning hole 15 in the same manner as the tensioning roll 5 and runs on a pair of guide rollers 16 and 17 which are journalled on the supporting MA structure. As shown in FIG. 1, the upper belt 3 moves through a converging path relative to the belt 2 in section 7, during which the mat 4 held therebetween is squeezed and liquid is extracted from the mat.

After passing through the conditioning section 8, the upper belt 3 is wound around the driven Karachi roll 18 and then makes a return journey around the roll 1.
9, 20, 21 and 22 and returned to the tension roll 15. As with roll 12, roll 22 is mounted obliquely in the horizontal plane, so that the alignment of belt 3 on the various rolls is maintained.

The tension roll 15, like the carriage 14, is rotatably mounted on a carriage 23 which is movable on a track carried by the support structure 1. Although not shown, a jack connects the carriage 23 to the structure 1 and allows the carriage to move relative to the support structure 1 so that the upper belt 3 is provided with the necessary tension.

The belts 2 and 3 are preferably porous and made of plastic or metal mesh so that the cleaning liquid can easily penetrate them.

As can be seen in FIG. 2, the valve slurry, which is flowably diluted with water, is discharged by gravity to the upper surface of the belt 2 through the oblong slot 24 on the lower surface of the head box 6.

In the lower part of the headbox 6 there is a molded board 25 with a series of slots 26, through which part of the liquid contained in the slurry deposited on the belt 2 passes into the lower part of the support channel return body 1. It is discharged into an attached trough 27. The liquid discharged into the trough 27 is pumped out from the drain outlet 28 in the trough 27 and is recovered.

The initial extractor 7 includes a series of parallel spaced apart rolls 29, each of which is rotatably journalled on the support structure 1. Belt 2 rolls 29 as the belt moves through section 7
supported above. A liquid deflection plate 3o is attached between adjacent rolls 29 and 29, and the upper end of the plate 30 is provided with a bent end portion 31 extending in the upstream direction. The deflection plate 3° prevents the separation liquid that the mat passes over the roll 29 from being discharged from the mat 4 and scattering from the negative roll to other rolls.

The first stage extractor 7 also has a cross beam 3 having a pivot portion 35 at one end.
4 includes an upper roll assembly 32 consisting of a frame 33 pivoted to the support structure 1, so that the frame is pivoted perpendicularly to the support structure 1. A pair of jacks 36 are pivotally connected to opposite ends of the frame 33 for pivoting the frame, and each jack is mounted within a nut 37 mounted on a cross support 38 fixed to the support structure 1. It has a thread groove. Jyatsuki 36
By providing a threaded groove in the frame 33, the frame 33 can move around the pivot 35 along a vertical path.

As shown in FIG. 1, a series of rollers 39 are pivoted on brackets 40 attached to frame 33. As shown in FIG.

Each roll is attached to a respective bracket 40 by an adjustment mechanism and is adjustable perpendicularly to the bracket 40. The adjustment mechanism can individually adjust the three rolls with respect to the support frame 33.

The frame 33 is adjusted by the action of the jack 36, so that the upper filter belt 3 adjoining the roll 39 moves along a converging path towards the lower belt, squeezing the mat 4 between the two belts, Squeeze the liquid out of the valve mat. As shown in FIG. 1, the upper roll 39 and the lower roll 29
In particular, the downstream rolls 39 are arranged in the space between the lower rolls 29,
As a result, the belts 2 and 3 carrying the mat 4 move through the undulations of the downstream part of the section 7. The undulating tracks alternately compress and release the mat, thereby facilitating extraction of liquid from the mat.

The treatment section 8 consists of a series of conditioning stages 42, 43, 44 and 45, at each stage the valve mat is subjected to water dilution and drainage action. Although FIG. 1 shows an example using four stages, any number of stages may be used depending on the particular operations involved.

Since each of the stages 42 to 45 has a similar configuration, the description will be given to the stage 45, but the configurations of the stages 42 to 44 are also the same.

As shown in FIG.
passes under the roll 46 and then the finned roll 47
pass above. As shown in FIGS. 4-6, roll 47 consists of a cylindrical copper 48 attached to 149. A plurality of radially extending fins 50 project outwardly from the barrel 48 to define a series of compartments 51. An end ring 52 is secured to each end of the fin 50 and spaced radially upwardly and outwardly from the barrel 48 .

Roll 47 also includes a pair of end covers 53 with a shaft 49 extending outwardly through each cover.

One end of the shaft 49 is connected to a suitable drive mechanism, not shown, so that the shaft 49 and the barrel 48 rotate relative to the fixed cover 53. Appropriate seals are drum 48 and ring 5
2 and maintain a seal between the parts as the barrel is rotated.

The interior of each shroud 53 is connected by conduit 54 to a suitable vacuum source, such as a vacuum pump 55, and each shroud has approximately 90
A slot 56 is provided which extends an arcuate length of .degree. and communicates with the space between the end ring 52 and the drum 48.

Conduit 54 is connected to the suction side of vacuum pump 55, while the discharge side of bomb 55 is connected via conduit 57 to collection trough 58. This configuration allows vacuum or reduced pressure to be applied to each cover 5.
3 and vacuum is applied to compartment 51 as roll 47 rotates.
through each slot 56 so that cleaning liquid is suctioned as the mat passes over the roll 47.

The liquid supply unit 60 is attached to the upper part of the finned roll 47, and functions to supply fresh water onto the mat 4 in a curtain shape when the mat 4 held between the belts 2 and 3 passes over the roll 47. do. As shown in FIG. 6, the liquid supply unit 60 includes a housing 61 and an inlet vibrator 62 connected to the housing to supply fresh water to the housing. A rising weir 63 is installed near the center of the housing 61, and water flows through the weir 6.
3 and flows down the inclined plate 64 to the finned roll 4.
Move away from 7 and reach mat 4. 1. The cleaning liquid flowing through the mat 4 from the supply unit 60 is sent to the trough 58 along with the liquid sucked from the mat by the vacuum pump 55. From the trough 58, the liquid is passed by gravity through a drain line 66 to the next upstream liquid supply unit 60 shown in FIGS. 1 and 3. This unit 60 is located at a lower height than the bottom of the trough 58 as shown in FIG. Since the center of the train line 66 is lower than the height of the next succeeding feed unit as shown in FIG. 3, air is not drawn through the trough 58 to the preceding unit 60. Similarly, cleaning fluid is conveyed by gravity from each conditioning stage to the next preceding stage. Also, upstream stage 4
From 2 the liquid flows into a trough 27 and is finally drained via a drain line 28. This cascading feed system eliminates the need for pumps that pump liquid countercurrently through the cleaning device.

Additionally, in addition to the pressure differential applied to the finned roll 47, a pressure plate assembly 67 is located immediately downstream of the roll 47 to extract liquid from the mat 4, and acts to roughly squeeze the liquid from the valve mat 4. do. As shown in FIG. 4, pressure plate assembly 67 includes a flexible metal plate 68 secured at one end to a leg 69 extending downwardly from a generally horizontal beam 70. As shown in FIG. A series of adjustment rods 71 are connected at their lower ends to plate 68 and are threaded in nuts 72 carried by beams 70. By providing threads in the rod that correspond to the nuts 72, the plate 68 is bent and given the desired shape or contour to the plate 68.

Another adjustment is made by a jack 73 coupled to beam 70 and threaded within turnbuckle 74. By operating the jack 73, the angle between the beam 70 and the plate 68 is adjusted.

As shown in FIG. 4, the plate 68 is generally arranged at a shallow acute angle to the path of movement of the belts 2 and 3 holding the mat 4. This convergence angle squeezes the mat 4 and squeezes more liquid out of the mat.

After passing through the final conditioning stage 45, the composite belt structure including the mat 4 passes through a pair of rolls 75 and 76, suitably pivoted relative to the support structure 1, and then through a line 78.
The air passes over a vacuum box 7 which is connected to a suitable atmospheric pressure or vacuum source via a vacuum box. The top surface of the vacuum box 78 has a series of perforations or slits so that the mat 4 is attracted by the vacuum to the lower belt 2 just before the belts 2 and 3 are separated at the end of the run.

An air distribution conduit 79 is connected by line 80 to a suitable source of pressurized air for injecting a curtain of high pressure air or other gas onto the upper surface of belt 3 to further facilitate removal of mat 4 from the upper belt.

With the mat 4 attached to the lower belt, the lower belt passes around the Karachi roll 9, where the mat is separated from the lower belt, usually under the action of gravity. A second air exhaust conduit 81 is mounted adjacent to roll 9 and is connected via line 82 to a suitable source of pressurized air.

The air discharged from the conduit 81 against the belt 2 serves to detach the web 4 from the belt in the event that it was not separated from the belt by gravity as it passed around the rolls 9.

A suitable doctor blade 83 is attached to the surface of the roll 10 and a rough cleaning water shower 84 is applied to the roll 10 to remove cellulose material adhering to the roll 10.
1 and sprays a cleaning curtain or membrane onto the roll 11 and belt 3 to clean the roll and belt.

Similarly, a water shower 85 and a doctor blade 86 cooperate with the roll 2 to clean cellulose material adhering to the upper belt 3 and the roll 21.

FIG. 11 shows a modification of the conditioning stages 42 to 45, in which pressure is used instead of vacuum to remove liquid from the mat 4. The modified stage shown in FIG. 11 includes a roll 87 having the same function as the roll 46, and the composite belt structure consisting of belts 2 and 3 holding the mat 4 is formed by the roll 87.
．． 88 and then downwardly around a finned roll 89 having a similar configuration to roll 47. Roll 8 includes a pair of end covers as previously described, with a shear curvature at the bottom of each cover extending approximately 90'' and communicating with compartment 92 located between fins 93 and 93 of roll!89. A slot 91 is provided.

Each shroud 90 is connected via a conduit to a suitable source of pressurized air, so that the pressurized air introduced into the shroud passes through slots 91 into the compartment between fins 93 and 93 and further blows the mat 4. passes through and flows outward.

The cleaning liquid is supplied to a liquid supply unit 9 having the same configuration as the unit 60.
5 to the roll 89. In this form of the invention, the liquid supply unit 95 supplies a stream of cleaning liquid to the upper side of the compartment of the roll 89. As the roll 89 rotates, the water contained within the compartment flows out into the mat 4, and as the mat engages and passes the slot 91, air pressure drives the water outwardly through the mat, causing the water to flow into the trough 58. It is collected in

FIG. 8 shows a modification of the conditioning stages 42-45, in which the upper filter belt 3 is separated from the mat 4 when cleaning liquid is added to the mat. In this embodiment the composite structure, i.e. the mat 4 held between the belts 2 and 3, passes around a roll 96 which functions similarly to the roll 46, and the lower belt 2, together with the mat 4, passes around said roll. It passes over a finned roll 97 similar to 47. The separated upper belt 3 moves around rolls 98 and 99 suitably pivoted on the support structure 1 and then re-engages the mat 4 at a position immediately downstream of roll 97. The cleaning liquid is supplied to the mat 4 through a water supply unit 100 similar to the water distribution unit 60 described above, the water flowing down to the mat 4 through the upper belt 3 which is not in contact with the mat 4 at this point. The water is then drawn through the mat and lower belt by a vacuum applied to finned roll 97.

A pressure plate assembly 101, similar to pressure plate assembly 67, is mounted immediately downstream of roll 97 to advance air as liquid is squeezed from the mat.

FIG. 9 shows a modification of the first extraction section 7, in which plates are used instead of the roller rows 29 and 30.

In this example, two of the four downstream rolls have a perforated plate 1 with a series of perforations or holes 103 for discharging the extracted liquid.
Replaced by 02. Disposed above plate 102 is a second solid plate 104 mounted at an angle thereto, thereby forming a convergence path for the composite belt structure. When spaced apart rolls 39 are used as shown in FIG. 1, liquid tends to foam between the rolls 39 and move laterally to the side edges of the belt 3. The embodiment of FIG. 9 prevents this effect by using a solid, unperforated upper pressure plate 104.

FIG. 10 shows a modification of the pressure plate assembly 67.

In the configuration of FIG. 10, the pressure plate 67 is mounted inside a movable endless belt 105 which is mounted on a pair of rolls 106 and 107 which are journalled in the support structure 1.

Belt 105 can move on an endless path around rolls 106 and 107, and the pressure plate assembly of FIG.
The power requirements of the system are reduced by providing little frictional resistance to the motion of the system. The flexible plate 68 is adjustable in profile as described above, and the belt 105 follows the contour of the plate 68, thereby providing the necessary travel path for the belts 2 and 3.

12 and 13 show a modification of the valve cleaning device according to the invention. The cleaning apparatus includes a frame or support structure 108, a headbox 109 containing a cellulosic slurry is attached to the frame 108, and the vertical position of the headbox is determined by an adjustment rod 110 connecting the front end of the headbox to the frame 108.
Adjusted by See Figure 12B.

A weir 111 is provided within the head box 109 and its vertical position is adjusted by a pair of adjustment rods 112.

The paper stock contained in the head box 109 is approximately 2
% solids and is discharged through an outlet 113 to form a mat 115 on a porous belt 114 having a similar configuration to belts 2 and 3 of the first embodiment. A belt 114 carrying a mat 115 passes over a molded board 116 having a plurality of slits or perforations 117, and a portion of the liquid is discharged from the mat 115 through the slits 117.

P carrying the mat 115 after leaving the molding board 116
``AA belt 114128 passes over a row of rolls 118 arranged in a substantially curved or concave shape as shown in the figure.

The axis of roll 118 is journalled in bearing blocks 119 supported on curved beams 120 extending between vertical supports of frame 108 .

The belt 114 connects the side edge of the mat 115 to the molded board 116.
Side plates 120 are fixed to the frame 108 and are disposed on both sides of the movement path of the belt 114 in order to confine the belt 114 when it moves over the first roller group 118.

As a result of making the row of rolls 118 curved, the mat 115
The belt 114 carrying the mat is particularly attached to the outer periphery of each roll 118, thereby facilitating the extraction of liquid from the mat.

It is contemplated that the roll(s) 118 - such as the second and third rolls from the upstream end - may be powered at a speed greater than the feed speed of the belt 114 to further facilitate extraction of liquid from the mat 115. This change in speed creates a vacuum pulse at a downstream location where the belt leaves the roll, thereby facilitating dewatering of the mat.

As in the first embodiment, a liquid deflection plate 121 is mounted between adjacent O-rules 118, and the upper end of the plate 121 is provided with a bent end extending in the upstream direction. Board 1
21 prevents the liquid from scattering from one roll to another when the liquid is discharged from the mat 115.

As in the first embodiment, the upper porous filter belt 122 is fed through a convergent path relative to the belt 114, squeezing the mat 115 held therebetween and extracting liquid from the mat. As shown in FIG. 128, the upper belt 122 passes around an adjustable roll 123 that is pivoted between the ends of a pair of pivotable arms 124. The arm 124 is pivotally connected to the one frame 108 by a pivot portion 125. The arm 124 is pivoted relative to the frame by a pair of jacks 126 interconnecting the outer portion of the arm to the frame 108. By properly adjusting the jack 126, the convergence angle of the belts 122 and 114 can be varied as desired.

The belt 122 extends from the adjustment roll 123 to the frame 10 in the upstream direction.
It is supported by a roll 127 which is pivotally supported by a roller 8. The position of roll 127 maintains a uniform tension on belt 122 during adjustment of roll 123.

Liquid extracted from the mat through the forming board 116 and the upstream portion of the roller bank 118 is discharged into a tank 128 attached to the frame 108, while liquid extracted from the downstream portion of the roll bank 118 is discharged into the tank 128 in FIG. 12B. Tank 1 as shown in
28 is collected in a second tank 129 provided alongside. Suitable baffle plates 1 for tanks 128 and 129
30° 131 and 132 are provided, and as a result, the liquid is slowly discharged to the bottom of the tank and foaming is suppressed.

The liquid in tank 128 is discharged through outlet 133, with a portion of the liquid discharged through outlet 133 being used to dilute the feedstock, and a second portion being treated to remove fibers.
It is then fed to an evaporator for concentration. Similarly tank 1
The liquid in 29 is discharged through outlet 134 to the evaporator and then chemically converted.

The belt 114 supporting the mat 115 is initially fed through an ascending path over rolls 118 which serve to slow down the feedstock fed from the headbox and facilitate initial liquid extraction. Mat 115 then converges with belt 114
and 122 to further remove liquid from the mat. The composite structure consisting of the belt 114, the mat 115, and the belt 122 then passes through the center of the row of rolls 118, and then passes through the downstream portion, which has a larger curvature, and is attached around the rolls, thereby removing the liquid from the mat 115. The removal of

After leaving the downstream roll 118, the composite structure 135 passes under a doctor blade 136, which serves to scrape liquid from the top surface of the belt 122, as shown in FIG. 12C.

The liquid is collected in a tray 137 attached to the frame 108,
This collected liquid is drained to tank 129 through drain line 138.

Composite structure 135 then passes under a dewatering roll 140 having a rubber or elastic surface, which is pivoted on frame 10B. The composite M4 structure 135 is 20 degrees or more, preferably about 50 degrees
'' arc length around roll 140, the compressive action of which further dewaters mat 115, so that the mat leaving roll 140 generally has a solids content in the range of between 12% and 14%.

Water extracted from the mat 115 as the composite structure 135 passes around the rolls 140 is collected in a tank 114, into which an inclined baffle plate 142 is mounted and which drains the water. Suppresses foaming of liquid. Liquid in tank 141 can overflow into tank 129 through outlet 143.

Mat 115, held between belts 114 and 122, is subjected to a series of cleaning stages as it passes through a plurality of cleaning stages indicated at 144-149. Since the cleaning stages 144 to 149 have the same configuration, only the cleaning stage 144 will be described in detail. The cleaning stage 144 shown in FIG. 12C includes a trough 150 having an inlet 151. The cleaning stage 144 shown in FIG. A perforated plate 152 is provided laterally at the bottom of the trough 150, and an adjustable weir 153 is attached to the plate 152.
installed adjacent to. Cleaning fluid entering trough 150 through inlet 151 passes through the perforation plate and over weir 153 to reach composite structure 135 .

The cleaning stage 144 also includes a pair of side walls 154 extending downstream of the weir 153 for allowing cleaning fluid to remain on the surface of the composite structure as it is passed through the ascending passage. This is shown in FIG.

Preferably, the composite structure is guided through an uphill path inclined at approximately 5 to 30 degrees, preferably approximately 10 degrees, relative to the horizontal plane as the cleaning liquid is applied to its upper surface.

As a result of the upward slope of the path, more liquid penetrates into the mat 115 for a given feed. - If the slope is too steep, the liquid will flow backwards without penetrating the pine properly. On the other hand, if the composite structure 135 is being fed horizontally while the cleaning liquid is being applied, the length of the cleaning stage must be extended if desired liquid penetration into the mat 115 is to be achieved.

After passing through the cleaning stage 144, the composite structure 155 is transferred to the dewatering roll 1.
55 and liquid is extracted from the mat 115 by compression. The squeezed liquid is drained into a basin 156 having an outlet 157 connected to a line 158. The receiver is plate 15
The liquid collected at 6 is the final wash liquid and is sent through line 158 to the evaporator for chemical conversion.

After passing through the dewatering roll 155, the composite structure 135 is transferred to the frame 108.
The mat 115 then enters a second cleaning stage 145 where the cleaning liquid is applied to the top surface of the composite structure moving on an uphill path, with the mat 115 Impregnated with cleaning solution as described above.

Composite structure 135 then passes over a pair of dewatering rolls 162 and 163, which are suitably pivoted to frame 108.

The water extracted from mat 115 is collected in trough 164, and the liquid is then directed by gravity through outlet 165 in trough 164 and via line 166 to inlet 151 of wash stage 144, as shown in FIG. 12C.

After passing through dewatering rolls 162 and 163, the cleaning liquid is again applied to composite structure 135 in cleaning stage 146 as it is sent uphill. The composite structure 135 is then attached to a pair of dewatering rolls 167 and 16 which are suitably pivoted on the frame 108.
8 and the liquid extracted from the mat 115 is collected in a trough 169. Trough 169 is provided with an outlet 170 and line 171 connects outlet 170 to the inlet of trough 150 of wash rP stage 145.

This process is repeated with the wash liquid extracted at each wash stage and fed by gravity to the next upstream wash stage.

Fresh water is introduced into the inlet 151 of the cleaning stage 149 via a line 171a.

After passing through the washing stage 149, the composite structure 135 passes over a compression dewatering roll 172 where water is extracted from the mat and
As described above, it is sent to the subsequent downstream washing stage. After passing over the 20-rolls 172, the composite structure 135 is passed through a drive roll 173 which is driven in a suitable manner. Drive roll 173 serves to drive composite structure 135 .

As shown in FIG. 12A, belt 122 carrying mat 115 is separated from belt 114 as these belts leave drive roll 173. Bell 122 and mat 115 pass downwardly across air nozzle 174 which serves to separate mat 117 from belt 122.

Belt 122 then passes under rolls 175 and the separated mats 115 fall by gravity into box 176;
Here, it is disassembled and discharged by an auger 177.

Belt 122 then passes over roll 178 and for some reason a doctor blade 179 attached to roll 178 prevents mat 115 from falling into box 176
It acts to remove it if it is attached to it.

After this, the belt 122 passes under a fresh water washing shower,
The wash water is collected in a basin 181 having an outlet 182. After cleaning the belt 122, the belt passes around a roll 183 and under a tension roll 184, which is adjustable horizontally with respect to the frame 108 and maintains the tension on the belt 122 appropriately. Belt 122 then passes over guide rolls 185 and rolls 127 . Further, it is sent to the adjustable roll 123 described above.

The eroded belt 114 separated from the belt 122 is the 12th A
As shown, the mat 1''15 is fed through the underside of the air nozzle 186 when it is attached to the belt 114.

The belt 114 then passes over a second drive roll 187, which has a doctor blade 188 that scrapes the mat from the drive roll 187 if the mat is accidentally transferred to the roll.

Belt 114 is then fed downwardly into contact with trough 189 formed in the end of box 176.

If the mat adheres to the belt 114 for any reason,
Troughs 189 scrape mat from the belt and deposit it into box 176.

After this, the belt 114 passes near a cleaning water spray 190 and further passes over a roll 191.

Water from the wash shower drains into a basin 19 having an outlet 193.
It is collected in 2.

Belt 114 then passes around a pair of rolls 194 and 195, and then over tension roll 196, which is retractably mounted to frame 108. After passing through tension roll 196, belt 114 passes over rolls 197, 198 and 199 and is fed to forming box 116 as described above.

Effects of the invention In the cleaning device shown in Figs. 12 and 13, two filter belts 1 are used.
Mat 115, held between 14 and 122, is fed on a curved path over a series of rolls 118. Because of the curved path, the web is partially attached around each roll, so that the web experiences natural compression as it moves along its path, improving the dewatering effect.

The system also provides more effective cleaning by directing the composite structure 135 up an uphill path below the pool of cleaning fluid. This configuration improves fluid penetration into a length of feed of the composite structure.

In the system of FIG. 12, endless belts 114 and 1
Twenty-two return passes are used for the cleaning stage, reducing the overall length of the system and minimizing belt tension and guidance problems.

Generally speaking, in the configuration shown in FIG. 12, there is no return path that would obstruct the drainage system, and therefore the drainage device is also simplified.

In the pipe cleaning system of the present invention, the pipe mat is held between the porous filter belts during the entire operating cycle, and the mat can move through any angular path. As a result, the cleaning or conditioning stages can be provided at different heights, so that the cleaning liquid can be conveyed countercurrently by gravity from stage to stage. As a result of utilizing gravity flow, expensive feeding equipment is not required and the foaming effects normally associated with feeding operations are also minimized.

In the system of the present invention, cleaning fluid is extracted by passing a composite overbelt structure over rotatable rolls. Since the rolls are rotatable, there is less frictional resistance to the movement of the filter belt, which extends the life of the fabric and reduces the power required to drive the belt.

The reduced power requirements mean that a smaller capacity drive can be used for the same number of conditioning stages, and a larger number of conditioning stages can be used for the same capacity drive. do.

A seamed belt can be used instead of an endless woven fabric because the frictional resistance and tension on the woven fabric is reduced. Using a seamed belt allows the free ends to be joined together after the belt is installed on the machine. When using off-the-shelf endless belts, cantilever rolls must be used to attach the belt to the machine, but the cantilever configuration substantially increases the overall cost of the machine.

As noted above, the present invention provides a method and apparatus for processing liquid slurries containing solid materials, such as slurries of cellulosic valve stock and piping fluid. The flowable slurry is distributed in a mat on the upper surface of the endless porous belt, and every second movable endless belt is brought into contact with the upper surface of the mat after the liquid is first drained from the mat. The two belts move over their respective groups of rollers through converging paths to further drain liquid from the mat.

The mat held between two belts is then passed through a series of conditioning stages where the valve mat is alternately diluted and liquid extracted by passing the web around compression rolls. Fresh water is supplied to the mat at the final downstream stage, and the water passes countercurrently through the conditioning stage in the form of islands due to gravity.
be dropped. After the final conditioning stage, the belts are separated and the mat is removed from between the belts.

Various ways are contemplated for carrying out the invention within the scope of what is to be considered particularly pointed out and distinctly claimed invention in the following claims.

[Brief explanation of the drawing]

1A and 1B are schematic diagrams of a pipe cleaning system according to the present invention; FIG. 2 is an enlarged view of the first stage liquid extraction portion of the cleaning system shown in FIG. 1; and FIG. 3 is an enlarged view showing a pair of conditioning stages. 4 is a side view of the pressure plate, 5 is an external view of the finned roller, 6 is a partially enlarged side view of the finned roller and cleaning liquid supply unit, and 7 is the finned roller. FIG. 8 is a side view of a variant of the invention in which the upper belt is separated from the mat before approaching the conditioning installation, jf! Figure 9 is a side view of a modified example of the first liquid extraction stage.
FIG. 10 is a side view showing a modified example of the pressure plate using a feed belt, FIG. 11 is a diagram showing a modified example of the conditioning stage that extracts liquid from the web using fluid pressure, 12A, 128
12C are diagrams showing a modified preferred embodiment of the present invention, and FIG. 13 is a sectional view taken along line [113-13] in FIG. 12. 1.33.108...Frame, 2,3,122...-overbelt, 4.115...Mat or web, 5゜1
5.184.196...Tension roll, 6.109...
・Head box, 7... First stage extraction part, 8.42゜4
3.44.45...Conditioning part, 9.18...Karachi roll, 10.11.12.13.19°20.2
1,22,29.39.46,75°76.87,88
．． 96.98,99,106°107.118,123
,127,175,178°183.191,194,
195,197,198°199...roll, 14.
23... Carriage carriage, 16°17.185... Guide roller, 24.26.56... Slot, 25,116.
・・Molded board, 27゜58.150, 164.169
... Trough, 28... Drain outlet, 30... Deflection plate, 31... Bent end, 32... Upper roll assembly, 34... Cross beam, 35.125... Pivotal Branch, 36. A3.126... Jack, 37.72.
...Nut, 38...Support part, 40...Bracket, 47,89.97...Finned roll, 48...
Body, 49... Axis, 50.93... Fin, 51.9
2... Compartment, 52... End ring, 53°90...
・End cover, 54.57.79.81... Conduit, 55
...Vacuum pump, 6.0.95...Liquid supply unit, 61...Casing, 62...Inlet vibe, 63,11
1゜153...Weir, 64...Slanted plate, 66...
Drainage line, 67.101...Pressure plate assembly, 68,
102°121... Plate, 6... Legs, 70... Beam, 71, 110°112... Adjustment groove, 74... Turnbuckle, 77, 178... Vacuum box, 80. 82,158. 166°171...
Line, 83, 86, 136, 179° 188... Doctor blade, 84... Cleaning water shower, 85...
・Water shower, 91...Curved slot, 100...
water supply unit, 103... borehole or hole, 104...
... Muku board, 105 ... Endless belt, 113.
133,134,143,157,165°170.1
82,193...Exit, 114...Belt, 117
...Slit, 119...Bearing block, 120.
...Curved beam, 120a, 154...Side plate, 124...
・Arm, 128, 129, 141...Tank, 13
0゜131.132.142...Baffle plate, 135
...Composite structure, 137,156,181.192・
...The receiver is a plate, 138...The drain line, 144.
145° 146.147, 148.149...Cleaning stage, 151...Inlet, 152...Perforation plate, 140,
155°162.163, 167.168.172...
・Dewatering roll, 173.187... Drive roll, 17
4゜186...Air nozzle, 176...Box, 177
...Auger, 189...Tanibe, 190...Cleaning spray.

Claims (32)

[Claims] (1) A slurry processing method for processing a liquid slurry containing a solid substance, which includes the steps of: applying a layer of slurry on the upper surface of a first movable porous belt to form a mat; and a second movable porous belt. contacting the upper surface of the mat and sandwiching the mat between the belts to form a composite belt structure; moving the belt through a converging path to extract liquid from the mat; and moving the composite structure through a curved path. applying a cleaning liquid onto the composite structure and permeating the liquid into the mat held between the belts; A method comprising the steps of removing cleaning liquid from the mat by passing the body around rotatable rolls, and then separating the mat from between the belts. (2) Passing the composite structure through a curved path comprises passing the structure over a series of generally parallel rolls arranged in a curved configuration, wherein the composite structure 2. A method as claimed in claim 1, in which each roll is partially attached to its surroundings as it passes through. 2. The method of claim 1, further comprising the step of: (3) moving said composite structure through an upwardly sloped feed path as cleaning fluid is applied to the top surface of said structure. 4. The method of claim 3, wherein the cleaning liquid is applied in liquid form to the top surface of the structure. 5. The method of claim 3, wherein the composite structure is moved on a path inclined upwardly from 5 to 30 degrees with respect to the horizontal plane. (6) The method according to claim 1, wherein the step of removing the cleaning liquid comprises the step of bringing the composite structure into contact with the outer circumference of the roll at an arc of more than 20 degrees. (7) A slurry processing method for processing a liquid slurry containing a solid substance, the method comprising: applying a layer of the liquid slurry containing a solid substance to an upper surface of a first movable porous belt to form a mat; contacting the upper surface of the mat with a movable porous belt, sandwiching the mat between the belts to form a composite belt structure, and rolling the structure over a series of parallel rolls arranged in a curved configuration. passing the structure partially into contact with each roll as it passes over each roll, thereby extracting liquid from the mat; applying a cleaning liquid to the top surface of the composite structure in a series of cleaning stages; permeating the mat with a liquid at each stage and removing the cleaning liquid from the mat after each cleaning stage by passing the structure around rotatable rolls;
A method comprising the steps of removing liquid from the mat by compressive action and separating the mat from between the belts. Claim 7 further comprising: (8) adding fresh water to the composite structure in a final cleaning stage of the series of stages, and directing the liquid extracted from the mat in each cleaning stage to the preceding upstream cleaning stage. Method described. (9) A method according to claim 8, wherein the cleaning liquid is guided by gravity to the preceding upstream cleaning stage. 10. The method of claim 7, wherein the composite structure is moved in an upwardly inclined path with respect to a horizontal plane when the cleaning liquid is added thereto. (11) moving the belts through the convergent path with respect to each other;
8. The method of claim 7 including the step of contacting a belt of the mat with the mat, squeezing the mat between the belts thereby extracting liquid from the mat. (12) A slurry processing method for processing a liquid slurry containing fibrous material, comprising the steps of applying a slurry layer containing fibrous material to the upper surface of a first movable porous belt to form a mat;
bringing a movable porous belt into contact with the upper surface of the mat and sandwiching the mat between the belts to form a composite belt structure; passing the belt through a convergence path to extract the feed liquid from the mat; passing the composite belt structure over a hollow rotatable roll, applying a differential pressure to the impregnated mat as it passes over the roll, thereby extracting the liquid from the mat; The method consists of adding a cleaning liquid as it passes over the rolls, further impregnating the mat with the liquid. 13. The method of claim 12 including the step of applying pressure to the composite structure after it has passed through the rolls to extract further liquid from the mat. (14) The step of applying pressure comprises transporting the composite structure into contact with a pressure plate disposed at a converging angle with respect to the feed path of the composite structure. the method of. (15) feeding the belt within the converging path includes supporting a first belt on a first series of spaced parallel transverse rollers; and a second series of spaced parallel transverse rollers; 1st
13. The method according to claim 12, further comprising the step of engaging the upper surface of the second belt so as to lie within a plane forming an acute angle with respect to the plane of the second roller. (16) disposing at least a portion of the second roller partially in the space between the first roller and the roller, so that the belt structure is fed on an undulating path. The method described in section. (17) the hollow roll has a series of radially extending fins forming a plurality of circumferential compartments, and the step of applying a pressure differential applies a vacuum to a group of adjacent compartments to cause liquid 13. The method of claim 12, comprising the step of suctioning from said mat into said compartment. 18. The method of claim 17, wherein the step of applying the cleaning fluid comprises the step of distributing the fluid to a portion of the composite belt structure immediately after it passes through the group of compartments. 19. The method of claim 17, further comprising the step of separating a second belt from the web immediately before applying the cleaning liquid to the web. (20) Pivotably mounting the second series of rollers along a vertical path and adjusting the position of the second series of rollers to form the convergent path. 1
The method described in Section 2. (21) rotating at least one of the parallel rolls faster than the feed rate of the first belt to create a vacuum pulse, thereby facilitating removal of the liquid from the mat; The method described in Section 7. (22) A slurry processing apparatus for processing a liquid slurry containing a solid substance, the headbox containing a liquid slurry of the solid substance, means for applying a layer of the slurry to an upper surface of a porous belt, and the first drive means for moving the belt through the endless path; and a drive means for moving the belt through the endless path;
a second porous belt configured to move in a path that converges with the first belt, thereby sandwiching the mat therebetween and forming a composite belt structure; a second drive means for moving the mat through the composite structure; means for applying a cleaning liquid to the upper surface of the composite structure and permeating the liquid into the mat; an extraction roll; and means for separating the mat from the belt; Apparatus characterized in that the body is mounted to be passed through a curved path over the extraction roll to extract cleaning liquid from the mat. (23) The apparatus includes a series of cleaning stages that supply a cleaning liquid to the upper surface of the composite structure, and is located downstream from each cleaning stage with respect to the feeding direction of the composite structure, and extracts the cleaning liquid from the mat. 23. The apparatus of claim 22, including an extraction roll. 24. The apparatus of claim 23, including means for moving the composite structure in a path inclined upwardly at an angle of from 5 DEG to 30 DEG with respect to the horizontal plane as the cleaning liquid is applied to the composite structure. (25) Each cleaning stage includes a means for flowing the cleaning liquid so as to form a pool on the upper surface of the composite structure, and a holding means disposed on both sides of the composite structure to prevent the pool from flowing away from both sides of the structure. 24. The apparatus of claim 23 comprising: (26) A slurry processing apparatus for processing a liquid slurry containing a solid substance, comprising: a first endless belt attached to move in an endless path; and a liquid slurry containing a solid substance on the upper surface of the first porous belt. a supply means for applying a layer, the mat being mounted to move in an endless path and configured to move in a path that converges with the first belt at a location downstream of the supply means; a second porous filtration belt forming a composite structure sandwiched between;
a first-stage liquid extraction unit disposed downstream of the convergence path to extract a liquid from the mat; the supply means and the first-stage extraction unit disposed downstream of the first-stage extraction unit for adding a cleaning liquid to the upper surface of the composite structure; A cleaning stage located higher up,
An apparatus comprising liquid removal means located downstream of each washing stage to remove liquid from the mat, and means located downstream of the last liquid removal stage to separate the mat from the belt. (27) Claim 26, comprising means for supplying new wash water to the last downstream washing stage, and means for guiding the washing liquid removed at each removal stage to the next succeeding upstream washing stage. Device. (28) Each downstream washing stage is located at a higher level than the preceding washing stage, so that the washing liquid flows by gravity to the adjacent upstream washing stage. Device. (29) The device of claim 26, wherein the separation means is located on the same side of the device as the supply means. (30) The first stage extraction unit includes a plurality of substantially parallel rotatable rolls arranged in a curved shape, and the composite structure is arranged to be moved on the rolls. Apparatus according to clause 26. 31. The apparatus of claim 30, wherein the curvature of the shape is greater at the downstream end of the extraction unit. (32) The apparatus according to claim 30, including a substantially vertical deflection plate disposed between adjacent first rolls.