SUPRAdisc™ II Stacked Disc Filters

Classic stacked disc modules represent first generation module design, but they have performance disadvantages.

SUPRAdisc II modules eliminate the disadvantages of classic stacked disc modules. They offer increased capacity, reliability, handling advantages, and robustness, which satisfies customer needs and requirements for a higher performing product.

 

Basic construction of classic stacked disc modules

To better appreciate the design advancements of SUPRAdisc II filter modules, an understanding of the basic features and construction of stacked disc modules should be considered.

Since their inception, classic stacked disc modules have been manufactured leaving the cells of media fully exposed within the filter housing (Figures 1 and 2).

• Individual cells are made from two sheets of depth filter media with a polypropylene separator in between them. This separator is sandwiched inside the cell, on the downstream side of the two sheets, as the flow path is from the outside surface of the sheets to the inside (Figure 3).
• A polypropylene seal around the outside edge is used to bind the two sheets together, thus forming one complete cell.
• The cells are stacked on top of each other until the desired height is achieved.
• End caps are then affixed to the center core, thus locking each cell in place and forming a complete stacked disc module.

 

Design limitations of classic stacked disc modules

Classic stacked disc modules have inherent design limitations.

• Depth media is exposed
  • The integrity of the media can be compromised during shipping, handling, installation and removal. Extra care must be taken to avoid damage.
  • Modules can fall apart when removed from the housing.
• Individual cell proximity to one another is very close. During steaming, rinsing, or filtration, the cells may shift or warp causing individual cells to touch. This causes blinding of portions of each cell, which reduces the effective filtration area.
• Classic stacked disc designs do not withstand any back pressure. With only the downstream support layer (the separator), even as little as 0.05 bar (0.7 psid) of back pressure can rupture the unsupported media in these modules. This is seen as a half moon tear on either the top sheet of the top module or the bottom sheet of the lowest module in the stack, creating fluid bypass areas and compromising filtrate quality.
• Classic stacked disc modules are sensitive to high temperature operations such as hot water sanitization, steaming, or hot filtration. Deformation caused by high temperature exposure is a common problem (Figure 4).

Construction technology of SUPRAdisc II modules

 

SUPRAdisc II modules (Figure 5) incorporate a double separator concept.

• Alternating outside separators, discs of depth media, and inside separators are affixed to a rigid polypropylene core until the desired height is achieved.
• Two techniques are used to connect the separators:
  • For 287 mm (12 inch) diameter modules, the unique Clip-Seal Interlock is created by using a hydraulic ram to apply pressure and snap and lock the outside to the inside separators. Each disc of filter media is thus sealed in between the separators.
  • For 410 mm (16 inch) diameter modules, the inside/outside separators are connected by ultrasonic welding.
• Locking end caps are then applied to the center core, creating a complete module.

 

Design features of SUPRAdisc II modules

 

The unique separator design provides both upstream and downstream support of the filter media. The media is sealed inside a polypropylene cage assembly and is no longer exposed. The unique Clip-Seal Interlock and the welded design connects the outside to the inside separators resulting in an extremely robust design (Figures 6,7).

Each sheet of filtration media is individually sealed and separated. Depth sheets cannot come into contact with each other, eliminating blinding of the media.

Due to the separator channels, SUPRAdisc II modules have close to 100 % effective filtration area that is dimensionally stable during shipment and handling, filtration and removal.

Deformation or cell collapse is no longer an issue and sheet damage during use is minimized. Backflushing to regenerate the modules is now possible.

 

Backflushing SUPRAdisc II modules

 

With the use of a backflush set consisting of supporting discs and intermediate distance discs (Figure 8), modules can be backflushed either with water or product in order to remove contaminants and prolong their life.

For more detailed information on backflushing and availability of backflush sets, please contact Pall.

 

Benefits of SUPRAdisc II modules

 

SUPRAdisc II modules offer a multitude of benefits that overcome the disadvantages of the classical stacked disc design (Figures 9, 10, 11). These benefits result in important cost savings.

• Longer onstream life, due to highest utilization of the filter sheet area, no blinding of filter surfaces, open design of the separators, optimized drainage, and distribution of incoming fluid to each filter sheet via the outside separator
• Repeated use is possible due to regenerability of the modules with backflushing
• Higher operational security, due to resilience against vacuum or back pressure shocks, and no cell or module deformation from hot operation or sanitization and steaming
• Better handling before and after operation, due to robust design and protection of filter media from exposure and damage
• Higher yields, as rest filtration in reverse flow mode is possible
• High filtrate quality, without chance of bypass, due to module design and use of proven and reliable filter media recipes
• Higher microbial safety due to closed design
• Significant reduction in oxygen uptake due to minimized system volume and closed housing design

 

SUPRAdisc II Housings

Pall Corporation has used design, cost, and industry expectation as the creative foundation of our depth filter technology. In combination with our stringent manufacturing standards, we have developed a line of depth filter module housings for food and beverage applications.

Pall Corporation has used design, cost, and industry expectation as the creative foundation of our depth filter technology. In combination with our stringent manufacturing standards, we have developed a line of depth filter module housings for food and beverage applications.

The modules available for on-line purchase are shown in the table below. For additional sizes and configurations, please contact a Pall representative. Accessories are sold separately.

 

Material	Housing Diameter	Number of Modules	Inlet/Outlet Connection	Housing Volume
WSFZ162F31UT5J	16 in	2	2 in Triclamp	105 L
WSFZ164F31UT5J	16 in	4	2 in Triclamp	191 L

SUPRAdisc II Backflush Adaptor Kit

SUPRAdisc II modules can be multi-cycle water flushed in a forward flow direction, enabling a very good release of contaminants soluble in hot water without denaturing proteins that could cause premature plugging of the modules. The modules can additionally be regenerated by backflushing multiple times, to release surface load of hop particulates and residues, yeast and other particles. Flushing in forward and reverse direction is a common operation used in breweries to increase the overall throughput of the modules.

For breweries using reverse flushing as part of their regeneration process, Pall recommends backflush devices for additional support. A backflush support kit is available for on-line purchase:

Part number : 20041342

Description:  Backflush support set for WSFZ Series filter housings

 

SUPRAdisc II filter media options

 

K Series

With 13 different grades of permeability, the K Series modules represent Pall's standard depth filter series. These sheets consist of a cellulose matrix with very fine kieselguhr (diatomaceous earth or DE) mixtures and perlite, as filtration-active substances.

Table 1: Removal performance of K Series Modules

Sheet Media Type	Application	Examples of use
EKS, EK1, EK, KS 50, KS 80	Fine Filtration	Microorganism reduction in beer with moderate to high microbial load
K100, K150, K200, K250, K300	Polishing Filtration	Microorganism reduction in beer with low microbial load Fine filtration of beer and yeast removal Fine filtration of beer following DE prefiltration Polishing filtration of beer
K700, K800, K900	Coarse Filtration	Clarification of beer

These modules are used for a wide range of very fine to coarse filtration in many food and beverage applications.

SUPRAdisc II Standard Range

This is a guide to the Part Numbering structure only. For specific options, please contact Pall

 

Part Number:

200 [Table 1] [Table 2] [Table 3] [Table 4] [Table 5] W

Example Part Number:

200 X100 C 232 S P W

See bold reference codes in tables

Table 1

Code	Sheet Media Type
K Series
XEKS	EKS
XEK1	EK1
XEKO	EK
X050	KS50
X080	KS80
X100	K100
X150	K150
X200	K200
X250	K250
X300	K300
X700	K700
X800	K800
X900	K900

Table 2

Code	Adapter	Nominal Height
C	Flat gasket	272 mm (10.7 in)

Table 3