Acrylic Sepa CF Cell, 75 mil Channel Depth

The Sepa cell is a laboratory-scale filtration unit that is designed to evaluate a wide variety of membrane separation processes. Acrylic cell body enables users to visualize the flow patterns in the cell and monitor fouling at the membrane surface. Acrylic Sepa has a 75 mil (1.9mm) feed channel.
  • SKU
    1160035
$2,580.86
+ -
Acrylic Sepa CF Cell, 75 mil Channel Depth Icon

The Sepa crossflow system provides continuous lab scale filtration that efficiently simulates the flow dynamics of larger, commercially available membrane elements such as industrial spiral wound membrane elements. By using a combination of Stainless Steel (SS) shims, feed spacers, and membranes, users can vary the operating conditions and fluid dynamics over broad ranges.

Acrylic Sepa cell Features and Benefits:

  • Accepts polymeric flat sheet membrane coupons
  • Mimics both laminar or turbulent flow conditions
  • Provides fast and accurate performance data
  • Offers judicious membrane use with small membrane active area

Sepa cell has a membrane active area of 140 cm2 (24 in2).

Sepa cell is available in Stainless Steel with a maximum operating pressure of 1000 psi (69 bar), which allows operators to conduct high pressure testings. 

Sepa cell is also available in Acrylic with a maximum operating pressure of 400 psi (27.5 bar). Acrylic Sepa cell provides a great opportunity to visually investigate the hydrodynamic conditions in the cell or the local fouling intensity.

In order to operate the Sepa cell additional parts and equipment may be required, which include:

Please visit Crossflow Cell System Components for the list of all the parts and equipment required to build a complete filtration system configured with Sepa cell and other cross/tangential flow cells Sterlitech offers.

ASK AN EXPERT

Or call us at 1-877-544-4420

Cross/tangential flow test cells are typically used in membrane applications such as :

  • Biological or biopharmaceutical processing
  • Concentration of fruit juices and extracts
  • Food and beverage processing
  • Desalination of brackish water or seawater
  • Purification of rinse water in electroplating tanks
  • Municipal or industrial water and wastewater purification

Specifications by Material:

Product Family Innovator Explorer Developer
 
CF042D-FO
CF016D
CF042A-FO
CF016SS
CF042A-FO
CF016P
CF042A-FO
CF016A
CF042D-FO
CF042D
CF042SS-FO
CF042SS
CF042P-FO
CF042P
CF042A-FO
CF042A
Sepa CF-FO
CF042H
Sepa CF-FO
Sepa CF
Sepa CF-FO
AC Sepa
Material Acetal (Delrin)    316 Stainless Steel Virgin PTFE Acrylic Acetal (Delrin) 316 Stainless Steel Virgin PTFE Acrylic Hastelloy 316 Stainless Steel Acrylic

Torque Settings

(in-lbs)

60 NA 15 70 60 NA 15 NA 70 NA 70
Max. Pressure

69 bar

(1000 psig)

69 bar

(1000 psig)

27.6 bar

(400 psig)

27.6 bar

(400 psig)

69 bar

(1000 psig)

69 bar

(1000 psig)

27.6 bar

(400 psig)

27.6 bar

(400 psig)

69 bar

(1000 psig)

69 bar

(1000 psig)

27.6 bar

(400 psig)

Max Temperature

82°C

(180°F)

150°C

(302°F)

260°C

(500°F)

88°C

(190°F)

82°C

(180°F)

150°C

(302°F)

260°C

(500°F)

88°C

(190°F)

150°C

(302°F)

150°C

(302°F)

88°C

(190°F)

General Cross Flow Cell Specifications:

  CF016 CF042 Sepa
 Active Membrane Area 20.6 cm2 (3.2 in2) 42 cm2 (6.5 in2) 140 cm2 (22 in2)
 Hold-Up Vol. 13 mL (0.44 oz) 17 mL (0.57 oz) 70 mL (2.4 oz)

 Connections
Feed:1/4 in FNPT (base of cell) 
Concentrate1/4 in FNPT (top of cell) 
Filtrate:1/8 in FNPT (base of cell) 
Feed:1/4 in FNPT (base of cell) 
Concentrate1/4 in FNPT (top of cell) 
Filtrate:1/8 in FNPT (base of cell) 
Feed:1/4 in FNPT (base of cell) 
Concentrate1/4 in FNPT (top of cell) 
Filtrate:1/8 in FNPT (base of cell) 
 Outer Dimensions 12.7 x 10 x 8.3 cm (5 x 4 x 3.25 in) 12.7 x 10 x 8.3 cm (5 x 4 x 3.25 in) 16.51 x 21.3 x 5 cm (6.5 x 8.38 x 2.07 in)
 Active Area Dimensions 4.52 x 4.52 cm (1.78 x 1.78 in) 9.207 x 4.572 cm (3.625 x 1.8 in) 9.7 x 14.7 cm (3.81 x 5.78 in)
 Slot Depth 0.23 cm (0.09 in) 0.23 cm (0.09 in) 0.19 cm (0.075 in)
SEPA CF Cell Flow Diagram  PDF
SEPA CF Cell Operation Manual PDF
Sterlitech Crossflow Cell Handbook PDF
Hydracell Pump Options PDF
Acrylic Chemical Resistance PDF

In order to operate the SEPA CF Cell additional parts and equipment are required, which include:

Additional Resources:

 

Below is animated diagram showcasing how the Sepa CF cell works:


Complete Sepa CF Membrane Test Cell System Animated Demo


Q. What is the difference between Sepa CF and Sterlitech HP4750?

A. The Sterlitech HP4750 is an enclosed batch system (limited to 300ml) with direct filtration under pressure. There is a stir bar mixing the solution and pressures up to 1000 psi may be applied.

The Sepa CF is a crossflow system that allows continuous sampling and testing under different pressure and flow rate parameters depending on the pump and fluid.

Q. Does the feed spacer penetrate the membrane?

A. The mesh spacer usually leaves an imprint on the membrane which is not a problem - unless too thick of a mesh is used - then it could damage the membrane.

Q. How do I calculate Reynolds number based on the feed cross-flow velocities for the various feed spacers?

A. The Sepa CF cell for use with high fouling spacer has a flow area width and height of 3.7 inches by 0.068 inches. Once a spacer material is placed in the channel the actual flow channel cross section is significantly reduced. We have not calculated that. We typically operate the cell and estimate the Reynolds number at the transition from laminar to turbulent flow by monitoring the increase in pressure drop as the crossflow is increased.

Another usage implementation which we have used is the placement of a rubber gasket in the flow channel. A specifically sized flow channel can be cut out of the gasket to define a flow channel of the desired cross section.

We actually have done more study of the CF cell for use with standard spacer (3.7 in. by 0.034 in. cell cross-section). We evaluated that cell for various cross flow velocities at various feed flow rates.

Q. How do I distinguish between the low foulant (34ml) feed spacer and the high foulant (68ml) feed spacer when I hold them in my hands?

A. The low foulant has smaller squares and bends slightly easier.  It feels lighter.  It is not stiff like the medium foulant.  The high foulant spacer has corragated ridges in it like cardboard.  No holes.

Q. Is the low foulant spacer the same as the permeate carrier?

A. No, the low foulant spacer is under the membrane and the permeate carrier is on top. The membrane is sandwiched between the spacer and permeate carrier.

Q. In the instruction manual of the Sepa CF, tubular and mesh spacers are mentioned. Can I conclude that the tubular is the low foulant and the mesh is the high foulant?

A. The mesh spacer is a low (34 ml) and also the medium spacer (68 ml).

The tubular spacer is for high foulants (68 ml) and looks like corregated cardboard.

Q. Could the filter cloth of industrial filters be used in the Sepa filtrations units, after cutting it to proper size?

A. The Sepa CF can potentially work for any media that can be fitted into the chamber.

One thing that could be an issue for some types of filter media is whether or not a sufficient seal is made between the O-ring and the media. For membranes, this is not a problem because membranes have a relatively smooth surface, which affords good mechanical seal when pressed together. A large fiber woven material, for example, may need to be modified or filled with some type of potting compound to level the surface in order to get a non-bypass seal.

Q. How is the Sepa System repassivated?

A. Passivation is a process that will remove free iron deposits and will add future protection to your Sepa System. To passivate the Sepa System, swab the entire unit with either a 20% Nitric Acid (1st choice) or Phosphoric Acid (2nd choice) solution. Make sure to use good Nitric Acid or Phosphoric Acid handling precautions such as gloves, eye goggles, etc. when performing passivation. Rinse unit off with conditioned water such as distilled.

Q. Can I use the Sepa CF membrane cell without spacers?

A. Using the cell without any spacers will usually cause wrinkles in the membrane. The depth of the cell is made to accommodate the spacer that will fit in it (34 or 68 ml).

Q. How can I set the maximum flow from my Sepa CF?

A. Most separations and flux through membranes are controlled by the nature of the fluid. For salt rejecting membranes, such as RO and NF, the dominant variables are operating pressure and osmotic pressure (a solute concentration-dependent property which reduces net operating pressure with increased solute concentrate).

The pumping rate or fluid velocity across the membrane is another important operating parameter; an increased velocity results in improved mixing of the layer of feed solution directly above the membrane. The removal of fluid through the membrane results in accumulation of rejected solutes in this layer, often referred to as the boundary layer. The boundary layer can contribute a significant resistance to flux through the membrane as levels of solutes increase.

The accumulation of solutes in the boundary layer is often the most limiting factor in membrane flux, particularily for the larger pored membranes (NF, UF, and MF). There generally is a finite operating pressure, above which provides little or no flux benefit.

An increase in the feed solution velocity across the membrane, combined with turbulence promoting mesh spacers, can provide the optimal combination of operating conditions. Consideration of energy imput and mechanical load due to pressure drop across the membrane are practical limitations for operation of membrane systems.

To find maximum flux, we set the feed flow to a maximum practical rate, and increase the operating pressure incrementally while monitoring flux (filtrate) output. A given operating pressure will yield a certain maximum output for a specific feed solution.

If the feed solution becomes more concentrated, such as occurs for a dewatering objective, the optimal operating pressure will typically decrease as the solute concentration increases (the exception to this would be if the osmotic pressure increase due to concentration becomes significant). The input energy may be better applied to higher cross flow velocity if practical.

A practical method may include operation at a pressure setting slightly lower than the maximum initial rate determined. This is produce highest flow, best flux, and least amount of build up on membrane.

Q. What is the definition of GFD?

A. GFD = Gallons Per Square Foot of Membrane Per Day

Q. Will there be a difference in flow rate on the Sepa CF if it is run continuously or in intervals?

A. If permeate flow rate verses time for both membranes are plotted will there be a difference?

There should be a difference in the plots - at least initially. There is typically a "conditioning" affect that occurs as the result of mechanical compression, some of this affect is reversible to an observable amount if operation is intermittent.

This will yield a "zigzag" appearance to a graph of operation vs. time or cumulative hours of operation. The trend with the intermittent operation would be to gradually approach a standard.

Q. What fluid do I use in my Hydraulic hand pump for my Sepa CF?

A. The unit uses standard grade hydraulic oil. It has a reservoir located under the handle at the furthest end with a cap on the reservoir.

The amount of oil used will depend on the length of line, hose.

The recommended oil has a viscosity rating at 100°F.

SUS rating 150-165

SAE 10 wt oil Hydraulic oil (do not use other types of oils)

General purpose

150-165 thickness

Rating 210°F 42-45

Q. What is the proper way to store the membranes for the Sepa CF after they have been used?

A. We recommend that the membranes for the Sepa CF be kept wet once used. Either keep the water fresh (change every couple of days), or add ~0.5 sodium metabisulfite (preferred) to keep bacteria from growing.

Q: What are the torque settings for the CF042 and Sepa CF Cells?

A: Best practices for plumbing of polymer (Acrylic, Delrin, and PTFE cells) CF042 cells, include the use of PTFE tape properly installed on 1/4npt threaded coupling, and the use of a light coat of PTFE-based pipe thread sealant, then the coupling needs to be seated in the base of the cell using the following torque settings:

  • Delrin- 60 inch pounds
  • Acrylic -70 inch pounds
  • PTFE -15 inch pounds OR until the fitting "shoulders" out on the base of the CF042 cell*

*extreme caution should be used to assure that the fitting is not started incorrectly (cross-threaded).  In normal installation, the fitting should easily turn in several turns without tooling (by "hand") before using the torque wrench.