Continuous disc filter apparatus

Abstract

A continuous disc filter apparatus includes a slurry containing tank and a disc filter assembly including a rotor assembly (200) supported for rotation on a horizontal axis (204) and having a filtrate outlet end (208), a plurality of filter discs (212) spaced along the length of the horizontal axis (204) of the rotor assembly, a plurality of discharge tubes (216) spaced apart, and a plurality of disc filter section supports and filtrate passage arms (220). The disc filter sections (224) have disc filter section filtrate outlets (260) therein for exit of filtrate from the disc filter sections (224). The discharge tubes (216) include a discharge tube housing (274) extending along the horizontal axis (204) of the rotor assembly and having longitudinally extending discharge tube filtrate passages (280) therein, the discharge tubes (216) being connected at one end to the filtrate outlet end (208) of the rotor assembly and to corresponding disc filter section filtrate outlets, and each discharge tube filtrate passage (280) being located between adjacent filter sections (224).

Description

Background Technology

[0001] This disclosure relates to improvements to continuous disc filters.

[0002] A typical type of disc filter includes: a slurry containing bath; a disc filter assembly rotatably supported relative to the bath and including a core assembly adapted to rotate on a horizontal axis; and a plurality of sectioned filter discs spaced apart along the core assembly.

[0003] Each filter section includes two opposing suction surfaces covered by a filter screen. As the filter section passes through the slurry tank, a filter cake is deposited on the filter screen by applied air suction. As the filter section exits the slurry tank during the continuous rotation of the filter disc assembly, the deposited layer is subsequently peeled off from the screen.

[0004] Disc filters of this type typically have a series of discharge pipes that extend along the length of the core assembly, with each discharge pipe connected at the location of each segment disc filter unit to a specific filter section that occupies the same angular position along the core assembly.

[0005] The discharge pipe is connected to a vacuum manifold located at one end of the slurry tank. This manifold includes a mechanism that can selectively apply suction to each of the exhaust pipe and the filter section and open it to the atmosphere.

[0006] A conventional continuous disc filter is described with reference to U.S. Patent 3,193,105, published February 6, 1961. Since the improved continuous disc filter of this disclosure incorporates some features of U.S. Patent 3,193,105, reference will be made to U.S. Patent 3,193,105 herein. Figures 1 to 10 Describe these characteristics.

[0007] Figures 1 to 10 The disc filter shown includes a slurry tank 20 in which a rotatable disc filter assembly is installed. This disc filter assembly includes a core assembly 23, which has short shafts 21 and 22 at both ends, mounted on which the core assembly is rotatable. Bearing shafts 21 and 22 extend through the end walls 24 and 26 of the tank 20 and are mounted to rotate within bearings 28 and 30 supported by external bearing supports 32 and 34. A series of segmented filter discs are installed along the length of the core assembly inside the tank. Figure 1 In Chinese, it is usually represented as 36. For example... Figure 2As shown, the left-hand side of the pulp chest 20 is also provided with a series of chutes 38 which are disposed between adjacent filter discs and outside the two end filter discs of the series to receive filter cake which is shed from the segmented screen surface of the filter discs during operation. As Figure 2 As shown generally, Figure 3 Each of the chutes extends upwardly above the level of the slurry so that liquid flows therefrom. Each chute is provided at its lower end with an opening which is connected to the discharge area 40. An extension 42 of each chute extends beyond the top of the core assembly 23 to assist in further collecting filter cake which is shed from the suction screen of a plurality of filter sections as they move into the vertical position by the continued rotational movement of the filter assembly.

[0008] As Figure 2 shown, the core assembly 23 is continuously driven in a clockwise direction by a drive connection which includes a drive belt 44 which runs over a driven pulley 46 on a transversely extending worm drive shaft 43. A worm 50 on a shaft 48 is engaged with a worm wheel 52 which is fixed to the outer end of the core assembly 23. The drive connection, including the worm wheel and shaft, is mounted within a housing 54 which is carried by the bearing housing 34. In the structure shown, additional drive means are also provided for moving one of the jet or shower cleaners back and forth across the screen. The shower cleaner is moved back and forth at different speeds so that an equal amount of water is applied to all parts of the rotating screen. The shower drive means includes a sprocket 56 and sprocket chain 58 at the end of the core assembly opposite the drive connection described above, the sprocket chain passing around the sprocket 56 and a sprocket 69 which is fixed to a short cam shaft 62. As Figures 1 to 4 shown, the movable jet cleaner includes a water supply pipe 64 which extends overhead along the length of the filter assembly and is provided at intervals with downwardly extending portions 66 each of which is equipped with a jet spray 68, one such extending portion and spray being provided for each filter face of each disc filter 36. The water supply pipe 64 is rotatably supported in a bearing 70, as Figure 1 shown, at its left-hand end with a cam follower arm 72 which is engaged with a cam 74 on the cam shaft 62. It is noted that in addition to the jet spray 68, for each side of each disc filter 36, there is provided a fixed jet spray 76 which is directed against the outer edge of the filter cake layer on the screen so as to shed the filter cake layer therefrom, and a fixed jet spray 78 which is directed against the upper end of the chute extension 42 so as to assist in moving the shed filter cake through its chute to the discharge area 40 of the apparatus. Each jet spray 76 is connected to a supply pipe 80 which extends overhead along the length of the filter assembly. Likewise, each jet spray 78 is connected to a supply pipe 82 which is mounted to extend overhead along the length of the filter assembly.

[0009] In this embodiment, each disc filter 36 includes 18 disc filter sections, which are rigidly fixed to the core assembly in a close-fitting relationship. In other embodiments, a different number of disc filter sections may be used. As shown, each disc section includes a base 92 having a lateral extension or foot 94 reinforced by a flange 96 and an additional crossbeam 98 (see Figure 1). Figure 5 Extending outward from the base are a pair of outwardly expanding wedge-shaped filter blades 100. These blades are spaced apart from each other longitudinally along the axis of rotation and are connected in a spaced-apart relationship by a transverse wall 102 that extends outward from the base to the outer periphery of the filter section 90. The outer surface of the filter blades 100 is formed as segmented regions covered by a filter screen 104 and substantially parallel to each other. It should also be noted that the inner surfaces of the blades converge towards each other towards the base 92.

[0010] The suction area of ​​the blades of each filter section covered by the filter screen 104 is provided with radially arranged grooves 106, as shown in the attached figure. Figure 6 As best shown, the groove is tapered in one direction to provide a groove with increasing depth and correspondingly increased cross-sectional area towards the base of the filter section. Each filter section is also provided with transverse grooves 108 that traverse the radially extending grooves 106 to ensure free flow of air and liquid from the suction area of ​​the filter section. At the inner or base end of the filter section, each groove 106 is connected to an exhaust passage 110 in the base 92. This passage connects to two grooves and is sealed by the transverse wall 112 relative to the space between the blades (see [reference]). Figure 6 ).

[0011] like Figure 2 , Figure 3 and Figure 5 As shown, assuming the rotation direction is clockwise, the left or rear edge 114 of each disc filter section 90 sweeps backward from its connection point with the core assembly. Because as... Figure 3 In this arrangement, the trailing edge of the filter disc reaches a horizontal position at a point (essentially above the horizontal plane of the rotation axis of the core bearing assemblies 21, 22) as it rises. In operation of the filter, it is advantageous to adjust the level of the tank so that the trailing edge of each individual filter section leaves the surface of the tank at the same time.

[0012] The base of the filter section enters the pool, followed by the outer portion, thus significantly increasing the immersion time and correspondingly increasing the time the filter section is filled with liquid. Therefore, during suction, the equipment draws in less air.

[0013] The core subassembly 23 of the illustrated apparatus includes core sub-bearing shafts 21, 22, and a plurality of longitudinally extending exhaust tubes 120 associated with the core sub-bearing shafts, which are grouped around the core axis and provide selectable vacuum exhaust, atmospheric pressure supply passages between each individual disc filter and the vacuum exhaust manifold, and an associated atmospheric pressure inlet manifold provided at one end of the pulp chest.

[0014] The number of exhaust tubes corresponds to the number of disc filter units provided for one disc filter unit, and in the illustrated embodiment of the disc filter, eighteen such exhaust tubes 120 are provided grouped around the core axis.

[0015] The exhaust tubes 120 are formed from a series of plates 122, each having a Z-shaped cross-section as shown in Figure 9 and Figure 10 The plates are slightly arcuate in transverse cross-section and are assembled together to form the series of tubes 120. The plates 122 are welded together and are further supported by a series of discs 124, the ends of which are in turn secured to the stub bearing shafts 21, 22, thereby providing a rigid rotatable core subassembly. With particular reference to Figure 9 each plate 122 has formed therein a series of six cutouts 126 (see Figure 9 ), which provide ports for connection with the passages 110 in the base of each disc filter 90. As noted above, the plurality of plates 122 forming the exhaust tubes are rigidly welded together to form a solid core subassembly. An outer frame 128 comprised of two annular bands 130 and a cross beam 132 is mounted on the core subassembly at the location of each filter unit assembly along the length of the core for completely enclosing the passages provided through the exhaust tubes 120, ports 126 and passages 110 to the respective disc filter exhaust area. Each disc filter 90 is rigidly secured to the bands by mechanical screws 134 threaded into the bands 130. The arrangement is such that each exhaust tube 120 is connected with each of the six disc filters 90, each of the filter units 36 occupying the same angular position on the core along the length of the rotatable core subassembly.

[0016] The continuous disc filter further includes conventional mechanisms (not shown) for applying exhaust suction from the plurality of filters through the exhaust tubes 120 while each filter is immersed in the pulp chest, and for replacing standard atmospheric pressure to facilitate the shedding of the deposited filter cake from the screens 104 when the filters 90 are removed from the pulp chest 20. The suction means referred to includes an exhaust manifold (not shown) in the form of a housing connected with one end wall 26 of the pulp chest 20, the ends of the core sub-bearing shafts 22 extending through the exhaust manifold. By means of two exhaust pipes 142, 144 (see Figure 2Exhaust suction is applied to the suction area of the respective disc filter section through the exhaust manifold.

[0017] In addition to the exhaust manifold, an air intake manifold (not shown) is provided through which air at atmospheric pressure is supplied to those exhaust tubes 120 and associated disc filter sections 90 which are located outside the tank and from which the collected filter cake is removed. The means for maintaining the level of the tank associated with the control tank 182 is schematically represented in Figure 2 by a block 183 designated level control means.

[0018] The filter disc assembly is continuously rotated by a drive connection comprising a drive belt 44, a worm 50 and a worm wheel 52. Appropriate air suction is continuously applied to the exhaust manifold through exhaust tubes 142, 144. The air intake manifold is always open to the atmosphere through an air intake tube connection (not shown).

[0019] Figures 1 to 10 The continuous disc filter of Figure 11 is referred to as a central shaft disc filter or CDI disc filter. In the CDI disc filter, the exhaust tubes are located inside the central shaft of the rotor of the disc filter (inside the disc filter section). There is another conventional continuous disc filter, referred to as a central disc perimeter or CDP continuous disc filter 170 (see Figure 11 ). As shown in the schematic view in Figure 11 , the exhaust tubes 174 of the CDP continuous disc filter 170 are located on the outer perimeter of the disc core assembly. The CDP continuous disc filter 170 does not remove a large amount of filtrate 258 from inside the filter section 172 as schematically shown in

[0020] Figure 12 is a schematic end view of another embodiment of a rotor assembly 188 of a conventional CDI disc filter as Figure 2 viewed from the right. The outer diameter of the rotor assembly 188 is 5.2 meters and the hydraulic capacity is 100,000 liters / minute. The exhaust tubes 190 are arranged in a radial pattern between the various filter sections 194 from the geometric center 192.

[0021] It is an object of the present invention to provide an improved continuous disc filter apparatus. SUMMARY

[0022] A continuous pan filter apparatus includes a slurry containing tank and a pan filter assembly including a core assembly, a plurality of filter pans supported for rotation on a horizontal axis and having a filtrate outlet end, a plurality of spaced apart discharge tubes, and a plurality of pan filter section supports and filtrate passage arms. Each pan filter section has a pan filter section filtrate outlet for exit of filtrate therefrom. Each discharge tube includes a discharge tube housing extending along the horizontal axis of the core assembly and having a longitudinally extending discharge tube filtrate passage therein, each discharge tube being connected at one end to the filtrate outlet end of the core assembly and to a respective pan filter section filtrate outlet, each discharge tube filtrate passage being located between adjacent filter sections.

[0023] The continuous pan filter apparatus of the present disclosure provides substantially increased capacity relative to a conventional pan filter of the same size and capacity. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is an internal elevational view of a conventional rotary pan filter, with the lower portion shown in dashed lines to particularly illustrate the arrangement of the slurry containing tank, the pan filter assembly, and the apparatus for shedding the oil layer of material deposited on the screens of the segmented pan filter.

[0025] Figure 2 is an end view of the components shown in Figure 1 , particularly with reference to the drive of the filter assembly and the arrangement of the segmented filter pans shown in dashed lines.

[0026] Figure 3 is a vertical section taken along the line 3-3 of Figure 1 to particularly illustrate the apparatus for shedding the layer of material deposited on the segmented screens (filter cake).

[0027] Figure 4 is a detail view from the left of the mechanism of Figure 1 for controlling the movement of one of the nozzles by which the suction screens are maintained clean.

[0028] Figure 5 is a detail elevational view of one of the pan filter sections of the mechanism of Figure 1 , with a portion of the screen removed to show the arrangement of the undercuts.

[0029] Figure 6 is a section view taken along the line 6-6 of Figure 5 , with a middle portion of the pan filter section removed; the view shows the arrangement of the filter vanes projecting upwardly from the base, and also shows the increasing depth or tapering of the undercuts in the direction toward the base of the filter section.

[0030] Figure 7 is a detailed cross-sectional view taken along the line 7-7 of Figure 6

[0031] Figure 8 Figure 5 is a cross-sectional plan view taken along the line 8-8 of

[0032] Figure 9 is a perspective view of one of the Z-shaped plates that are assembled to form the discharge tubes grouped around the axis of the rotor assembly of the disc filter.

[0033] Figure 10 is an exploded perspective view of the lower or base portion of the disc filter shown, for example, in Figure 7 and Figure 8 forms, with the arrangement of Z-shaped plates and their supporting outer flanges, discharge tubes grouped around the axis of the rotor assembly of the filter.

[0034] Figure 11 is a partial schematic view of another conventional rotor of a disc filter, the discharge tubes of which are located at the periphery of the core outside the filter portion.

[0035] Figure 12 is an end cross-sectional view of another embodiment of a rotor of a disc filter of conventional style, viewed from the right, having an outer diameter of 5.2 meters and a hydraulic capacity of 100,000 liters / minute. Figure 2

[0036] Figure 13 is an end cross-sectional view of a rotor of a disc filter according to the present disclosure, viewed from the right, having an outer diameter of 5.2 meters and a hydraulic capacity of 100,000 liters / minute. Figure 12

[0037] Figure 14 is an end perspective view of a rotor of a disc filter with the filter portion removed, shown in Figure 13

[0038] Figure 15 is an end perspective view of a rotor of a disc filter with the filter portion, shown in Figure 14

[0039] Figure 16 is an enlarged view of some of the filter portions, shown in Figure 13

[0040] Figure 17 is a side perspective view of a portion of a discharge tube having one filter portion and one disc filter portion support and filtrate passage arm.

[0041] Figure 18 is a side perspective view of a portion of a discharge tube having one filter portion and one disc filter portion support and filtrate passage arm with​​​​​​​Figure 17 Enlarged view of the outlet tube connection shown.

[0042] Figure 19 is Figure 18 Right side partial perspective view of the bottom of the filter section shown.

[0043] Figure 20 is a partial schematic view of a rotor of a disc filter of the present disclosure with outlet tubes between adjacent filter sections, showing how filtrate is drawn from the lower right corner of each filter section as the disc filter rotates counterclockwise.

[0044] Before one embodiment of the present disclosure is explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," and "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as other items. The use of "consisting of," and variations thereof is meant to encompass only the items listed thereafter and equivalents thereof. Further, it is to be understood that terms such as "forward," "rearward," "left," "right," "up," and "down" are words of convenience and are not to be construed as limiting terms. DETAILED DESCRIPTION

[0045] The continuous disc filter apparatus of the present disclosure is similar to the continuous disc filter of Figures 1 to 12 but for the core / rotor assembly, as described below.

[0046] The continuous disc filter apparatus according to the present disclosure includes a pulp tank 20 and a disc filter assembly as shown in Figures 13 to 20 , which includes a rotor assembly 200 supported for rotation on a horizontal axis 204 and having a filtrate outlet end 208, a plurality of filter discs 212 spaced along the length of the horizontal axis 204 of the rotor assembly, a plurality of spaced outlet tubes 216, and a plurality of disc filter section supports and filtrate passage arms 220 (see Figure 13 and Figures 16 to 20 ). Each filter disc 212 includes a plurality of filter sections 224 arranged such that the filter sections 224 of each of the plurality of filter discs 212 project outwardly in a plane from the horizontal axis 204.

[0047] As shown in Figure 13 , adjacent disc filter sections 224 form a triangular area 230 extending upwardly from about two-thirds of the inner end of the filter sections 224. As shown in Figure 14 , the triangular area 230 is defined by the inner ends of the filter sections 224, the horizontal axis 204, and the upper ends of the filter sections 224. Figure 13The rotor assembly 200 of the disk filter with the filter sections removed, holds the discharge tubes 216 in spaced apart relation by a plurality of spaced apart arm braces 234 attached between adjacent discharge tubes 216. Figure 15 Various filter sections 224 are shown how they are connected to and supported by the hydraulic tubes 216.

[0048] Each filter section 224 includes a first and second screen face (see Figure 18 ) defining a suction area covered by a filter cake screen, a bottom rail 244 defining a radially inner end proximate the horizontal axis 204 of the rotor assembly, and a top rail 248 forming a radially outer end. Each filter section 224 also includes a first side rail 250 connected at one end to the bottom rail 244 and at an opposite end to one end of the top rail 248. The first side rail 250 also has a bottom portion 254 with a disk filter filtrate outlet 260 therein for the filtrate 258 to exit the disk filter section 224 (see Figure 20 ). Each filter section 224 also includes a second side rail 264 connected at one end to the bottom rail 244 and at an opposite end to the other end of the top rail 248. Each disk filter section 224 also includes spaced apart channel ribs 268 extending between the first side rail bottom portion 254 and the top rail 248 for directing the filtrate 258 to the bottom portion 254 of the first side rail, and a screen 270 extending between the side rails on each face of the disk filter section 224, the screen 270 supporting the ribs 268. The first side rail and the second side rail of adjacent disk filter sections form a triangular area 230 extending upwardly from the bottom rail 244 of the filter section about two-thirds of the way.

[0049] Each discharge tube 216 includes a discharge tube housing 274 extending along the horizontal axis 204 of the rotor assembly and having a longitudinally extending discharge tube filtrate channel 280 therein, each discharge tube 216 being connected at one end to the filtrate outlet end 208 of the rotor assembly. Each discharge tube housing 274 has an inner wall 284 proximate the core horizontal axis 204 having a plurality of spaced apart discharge tube filtrate inlet ports 290 into its respective discharge tube filtrate channel 280. Each discharge tube channel 280 is located between adjacent filter sections 224 and spaced apart from the bottom rail 244 of the disk filter sections and spaced apart from the top rail 248 of the disk filter, except at the location where the discharge tube housing 274 is connected to the filtrate outlet end 208 of the rotor assembly of the filter.

[0050] Each of the plurality of disc filter section supports and filtrate channel arms 220 is spaced along and connected to one of the plurality of discharge tubes 216. Each filtrate channel arm 220 has a filtrate channel inlet 294 in fluid communication with a respective one of the disc filter section filtrate outlets 260 and a filtrate channel arm outlet 298 in fluid communication with one of the discharge tube filtrate inlets 290, such that each discharge tube filtrate channel 280 is connected along the length of the horizontal axis 204 of the rotor assembly with a plurality of disc filter section filtrate outlets 260. Each disc filter section support and filtrate channel arm 220 is located at about one third of the bottom of the disc filter section 224 and each disc filter section discharge tube housing 274 is located at about one third of the middle of the disc filter section 224.

[0051] The discharge tube housing 274 has a quadrilateral cross section in a direction perpendicular to the longitudinal axis of the discharge channel (as shown in Figure 16 and Figure 17 The discharge tube housing 274 also includes a discharge tube partition 232 extending within the discharge tube housing 274 along the longitudinal axis of the discharge tube, the space between the discharge tube partition 232 and the discharge tube inner wall 284 defining the filtrate channel 280. As shown in Figure 17 The discharge tube partition 232 is angled relative to the discharge tube inner wall 284, such that the narrower discharge tube filtrate channel 280 is at the distal end of the discharge tube 216 and the wider discharge tube filtrate channel 280 is at the outlet end 208 of the filter of the discharge tube 216. Figure 16 The discharge tube channel 280 is shown as about two-thirds of the hatched area of the discharge tube housing 274 at the location of the cross section.

[0052] In operation, for a continuous disc filter it is important to remove as much filtrate as possible in each filter section to maximize the amount of fiber removed from the slurry. Any filtrate left in the filter section will result in fibers adjacent to the liquid not ending up in the fiber cake when the slurry leaves the vat.

[0053] As previously mentioned, the liquid in each filter section is removed by a combination of suction and gravity. It is therefore desirable to make the contact of the filtrate with the channel of the discharge tube as long as possible to remove as much filtrate as possible from between the filter sections. In the continuous disc filter of the present disclosure, as shown schematically in Figure 20 the filtrate leaving the filter section 224 remains in contact with the filtrate channel 280, thus, the suction of the filtrate as in a siphon (shown by the bold arrow in Figure 20 plays a role in removing most of the filtrate from the filter section 224.

[0054] In one embodiment, the continuous disc filter of the present disclosure has an outer diameter of 5.2 meters and a hydraulic capacity of 100,000 liters per minute, as shown inFigure 13 As shown, the filter section of the present disclosure is narrower but longer than the CDI filter section, resulting in an increase in the surface area of the filter section from 26.7 square meters to 31.2 square meters. Thus, the available net surface area of the filter section of the continuous disc filter of the present disclosure is increased by about 17% as compared to the conventional CDI disc filter. This means an increase in filter cake production of at least 17%. This is a significant increase in capacity for a disc filter of the same size and capacity as a comparable CDI disc filter. Figure 12 As shown, the filter section of the present disclosure is narrower but longer than the CDI filter section, resulting in an increase in the surface area of the filter section from 26.7 square meters to 31.2 square meters. Thus, the available net surface area of the filter section of the continuous disc filter of the present disclosure is increased by about 17% as compared to the conventional CDI disc filter. This means an increase in filter cake production of at least 17%. This is a significant increase in capacity for a disc filter of the same size and capacity as a comparable CDI disc filter.

Claims

1. A continuous disc filter apparatus, characterized in that The continuous disc filter apparatus comprises: a slurry containing tank (20); and a disc filter assembly comprising: a rotor assembly (200) supported for rotation on a horizontal axis (204) and having a filtrate outlet end (208), a plurality of filter discs (212) spaced along the length of the horizontal axis (204) of the rotor assembly, a plurality of discharge tubes (216) spaced, and a plurality of disc filter section supports and filtrate channel arms (220), each of the filter discs (212) comprising a plurality of filter sections (224) arranged so that the filter sections (224) of each of the filter discs (212) project outwardly in a plane from the horizontal axis (204), each of the filter sections (224) having a disc filter section filtrate outlet (260) therein for exit of filtrate from the disc filter section (224), each of the filter sections (224) comprising: a first screen face and a second screen face defining a cake screen covered suction area, a bottom rail (244) defining a radially inner end proximate the horizontal axis (204) of the rotor assembly, a top rail (248) forming a radially outer end, a first side rail (250) connected at one end to the bottom rail (244) and at an opposite end to one end of the top rail (248), and having a bottom (254): a second side rail (264) connected at one end to the bottom rail (244) and at an opposite end to the other end of the top rail (248), each of the discharge tubes (216) comprising a discharge tube housing (274) extending along the horizontal axis (204) of the rotor assembly and having a longitudinally extending discharge tube filtrate channel (280) therein, each of the discharge tubes (216) connected at one end to the filtrate outlet end (208) of the rotor assembly, and each discharge tube filtrate channel (280) located between adjacent ones of the filter sections (224), each disc filter section support and filtrate channel arm (220) in fluid communication with a respective one of the filter sections (224) and a respective one of the discharge tubes (216), each disc filter section support and filtrate channel arm (220) located at about the lower third of the disc filter section (224), and the discharge tube housing (274) of the disc filter located at about the middle third of the disc filter section (224).

2. The continuous disc filter apparatus according to claim 1, characterized in that each of the disc filter sections (224) further comprising: spaced channel ribs (268) extending between the bottom (254) of the first side rail and the top rail (248) for directing filtrate to the bottom (254) of the first side rail; and a screen (270) located on each face of the disc filter section (224).

3. The continuous disc filter apparatus according to claim 1 or 2, characterized in that The drain tube housing (274) also includes a drain tube bulkhead (232) located within the drain tube housing (274) extending along the longitudinal axis of the drain tube, the space between the drain tube bulkhead (232) and a drain tube inner wall (284) defining the drain tube filtrate passageway (280), the drain tube bulkhead (232) angled relative to the drain tube inner wall (284) such that a narrower drain tube filtrate passageway (280) is located at the distal end of the drain tube (216) and a wider drain tube filtrate passageway (280) is located at the filtrate outlet end (208) of the drain tube (216).

4. The continuous disc filter apparatus according to claim 1 or 2, characterized in that The drain tube housing (274) has a quadrilateral cross section in a direction perpendicular to the longitudinal axis of the drain tube.

5. The continuous disc filter apparatus of claim 3, wherein, The drain tube housing (274) has a quadrilateral cross section in a direction perpendicular to the longitudinal axis of the drain tube.

6. The continuous disc filter apparatus according to claim 1 or 2, characterized in that The first and second side rails (250, 264) of adjacent disc filter sections (224) form a triangular area (230) extending upwardly from the base rail (244) of the filter section approximately two-thirds of the way.

7. The continuous disc filter apparatus of claim 3, wherein, The first and second side rails (250, 264) of adjacent disc filter sections (224) form a triangular area (230) extending upwardly from the base rail (244) of the filter section approximately two-thirds of the way.

8. The continuous disc filter apparatus of claim 4, wherein, The first and second side rails (250, 264) of adjacent disc filter sections (224) form a triangular area (230) extending upwardly from the base rail (244) of the filter section approximately two-thirds of the way.

9. The continuous disc filter apparatus according to claim 1 or 2, characterized in that The base (254) has the disc filter filtrate outlet (260) therein, Each of the drain tube housings (274) has an inner wall (284) closest to the horizontal axis (204), the inner wall (284) having a plurality of drain tube filtrate inlets (290) spaced apart into its respective drain tube filtrate passageway, each of the drain tube filtrate passageways (280) disposed spaced apart from the inner end of the disc filter, spaced apart from the outer end of the disc filter, and between adjacent ones of the filter sections (224), and Each of the plurality of disc filter support and filtrate passageway arms (220) is spaced apart along and attached to one of the plurality of drain tubes (216), each of the filtrate passageway arms (220) having a filtrate passageway inlet (294) in fluid communication with a respective one of the disc filter filtrate outlets (260) and a filtrate passageway arm outlet (298) in fluid communication with one of the drain tube filtrate inlets (290) such that each of the drain tube filtrate passageways (280) is connected along the length of the horizontal axis (204) of the rotor assembly with the plurality of disc filter filtrate outlets.

10. The continuous disc filter apparatus of claim 3, wherein, The base (254) has the disc filter filtrate outlet (260) therein, Each of the drain tube housings (274) has an inner wall (284) closest to the horizontal axis (204) with a plurality of drain tube filtrate inlets (290) spaced apart leading to its respective drain tube filtrate passage, each of the drain tube filtrate passages (280) being disposed spaced apart from the inner ends of the disc filter sections, spaced apart from the outer ends of the disc filter sections, and between adjacent ones of the filter sections (224), and Each of the plurality of disc filter section supports and filtrate passage arms (220) is spaced apart along and attached to one of the plurality of drain tubes (216), each of the filtrate passage arms (220) has a filtrate passage inlet (294) in fluid communication with a respective one of the disc filter section filtrate outlets (260) and a filtrate passage arm outlet (298) in fluid communication with one of the drain tube filtrate inlets (290), such that each of the drain tube filtrate passages (280) is connected along its length to the plurality of disc filter section filtrate outlets along the horizontal axis (204) of the rotor assembly.

11. The continuous disc filter apparatus of claim 4, wherein, The bottom (254) has the disc filter section filtrate outlets (260) therein, Each of the drain tube housings (274) has an inner wall (284) closest to the horizontal axis (204) with a plurality of drain tube filtrate inlets (290) spaced apart leading to its respective drain tube filtrate passage, each of the drain tube filtrate passages (280) being disposed spaced apart from the inner ends of the disc filter sections, spaced apart from the outer ends of the disc filter sections, and between adjacent ones of the filter sections (224), and Each of the plurality of disc filter section supports and filtrate passage arms (220) is spaced apart along and attached to one of the plurality of drain tubes (216), each of the filtrate passage arms (220) has a filtrate passage inlet (294) in fluid communication with a respective one of the disc filter section filtrate outlets (260) and a filtrate passage arm outlet (298) in fluid communication with one of the drain tube filtrate inlets (290), such that each of the drain tube filtrate passages (280) is connected along its length to the plurality of disc filter section filtrate outlets along the horizontal axis (204) of the rotor assembly.

12. The continuous disc filter apparatus of claim 6, wherein, The bottom (254) has the disc filter section filtrate outlets (260) therein, Each of the drain tube housings (274) has an inner wall (284) closest to the horizontal axis (204) with a plurality of drain tube filtrate inlets (290) spaced apart leading to its respective drain tube filtrate passage, each of the drain tube filtrate passages (280) being disposed spaced apart from the inner ends of the disc filter sections, spaced apart from the outer ends of the disc filter sections, and between adjacent ones of the filter sections (224), and Each of the plurality of disc filter section supports and filtrate passage arms (220) is spaced apart along and attached to one of the plurality of drain tubes (216), each of the filtrate passage arms (220) has a filtrate passage inlet (294) in fluid communication with a respective one of the disc filter section filtrate outlets (260) and a filtrate passage arm outlet (298) in fluid communication with one of the drain tube filtrate inlets (290), such that each of the drain tube filtrate passages (280) is connected along its length to the plurality of disc filter section filtrate outlets along the horizontal axis (204) of the rotor assembly. Each of the plurality of disc filter section supports and filtrate passage arms (220) are spaced along and attached to one of the plurality of discharge tubes (216), each of the filtrate passage arms (220) having a filtrate passage inlet (294) in fluid communication with a corresponding one of the disc filter section filtrate outlets (260) and a filtrate passage arm outlet (298) in fluid communication with one of the discharge tube filtrate inlets (290) such that each of the discharge tube filtrate passages (280) is connected along the length of the horizontal axis (204) of the rotor assembly with the plurality of disc filter section filtrate outlets.

Images