WO2017021938A1

WO2017021938A1 - Spiral channel spacer for ion selective membrane stack devices

Info

Publication number: WO2017021938A1
Application number: PCT/IB2016/054753
Authority: WO
Inventors: Haobing Liu
Original assignee: Wisewater Pte. Ltd
Priority date: 2015-08-05
Filing date: 2016-08-05
Publication date: 2017-02-09

Abstract

A spiral channel spacer structure for ion selective membrane stack devices can include: a plate having a first side and a second side; a plurality of fluid passageways formed into the plate, each extending from a passageway opening in the first side of the plate to a passageway opening in the second side of the plate; and at least one spiraling fluid flow path formed in the plate and fluidly coupling one of the fluid passageways located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path. In one aspect, at least one of the fluid passageways is not fluidly coupled with the at least one spiraling fluid flow path.

Description

SPIRAL CHANNEL SPACER FOR ION SELECTIVE

MEMBRANE STACK DEVICES

CROSS-REFERENCE

[001] This patent application claims priority to U.S. Provisional Serial No. 62/201,272 filed August 5, 2015, which provisional application is incorporated herein by specific reference in its entirety.

BACKGROUND

[002] Generally, ion selective membrane stack based devices, including electro-dialysis (ED), electro-deionization (EDI), membrane capacitive deionization (MCDI) and recently introduced ion concentration polarization desalination (ICP) and polarized electro-dialysis (PED) devices, all uses spacers to separate membranes from each other and form liquid flow paths between membranes. Traditionally there are two kinds of spacers according to their flow path configuration, sheet flow spacer, and tortuous path spacer.

[003] The sheet flow spacer and tortuous path spacer structures are proper for ED. For example, in the sheet flow spacer, the flow path is like a gap sheet between membranes and liquid flows from one end of the gap to the other end of the gap without changing direction. A net or spacer screen is placed in the flow path to support the membranes and increase turbulence, which promotes mixing of the water and transfer of the ions between membranes. In the tortuous path spacer, there are bars in the spacer to force the liquid to change the flow direction back and forth, thus increases length of the flow path. Typically there is also a spacer screen in the tortuous path to help support the membranes and promote turbulence.

[004] However, the sheet flow spacer, and tortuous path spacer structures are not suitable for ICP and PED membrane stacks. The turbulence flow in ED spacers breaks or disrupts an ion concentration polarization boundary layer near the membrane surface, which is preferred by ED, but such breaking or disruption of an ion concentration polarization boundary layer should be prevented in ICP and PED. That is, the ion concentration polarization boundary layer should be retained in ICP and PED devices. The ICP and PED membrane stacks have enhanced functionality with laminar flow between the membranes. The ion concentration polarization boundaries of both ion depletion zone near one side of the membrane and ion enrichment zone near the other side of the membrane should be kept stable without disruption, until liquid in the ion enrichment zone and ion depletion zone can be separated by a physical partition at the end of the flow path. To keep the laminar flow, smooth and narrow flow channels of a few millimeters wide, instead of a spacer screen, are typically used to support the membranes in ICP and PED stacks. To utilize a relatively large area of membrane, in some previous designs, multiple narrow channels have been arranged in parallel to cover the membrane area. It is preferred that the water flow speeds in each narrow channel are similar in order to retain optimal efficiency of the device. However, in practice it is difficult to reach even water distribution by the distributing/collecting groove for so many narrow channels. In addition, the flow path length is limited by the membrane length, thus is not optimal for many applications when a higher salt and impurity removal ratio is needed, thus longer flow paths can be preferred. The tortuous path structure in ED devices can help increase path length, but it is not applicable for ICP and PED devices because the corners of the tortuous path introduce unwanted turbulence.

SUMMARY

[005] In one embodiment, a spiral channel spacer structure for ion selective membrane stack devices can include: a plate having a first side and a second side; a plurality of fluid passageways formed into the plate, each extending from a passageway opening in the first side of the plate to a passageway opening in the second side of the plate; and at least one spiraling fluid flow path formed in the plate and fluidly coupling one of the fluid passageways located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path. In one aspect, at least one of the fluid passageways is not fluidly coupled with the at least one spiraling fluid flow path.

[006] In one aspect, the at least one spiraling fluid flow path includes smooth surfaces and a narrow width inducing laminar fluid flow. In one aspect, the at least one spiraling fluid flow path provides a preserved ion concentration polarization boundary layer in laminar fluid flow. In one aspect, the fluidly coupled fluid passageway located within the center of the spiraling fluid flow path is an inlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow path is an outlet. In one aspect, the fluidly coupled fluid passageway located within the center of the spiraling fluid flow path is an outlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow path is an inlet. In one aspect, the plate defines at least one spiraling fluid flow path extending between and opening to both the first side and the second side so as to fluidly couple the first side and second side.

[007] In one embodiment, a spiral channel spacer structure for ion selective membrane stack devices can include: a plate having a first side and a second side; a plurality of fluid passageways formed into the plate, each extending from a passageway opening in the first side of the plate to a passageway opening in the second side of the plate; and at least one spiraling fluid flow path with straight flow path sections formed in the plate and fluidly coupling one of the fluid passageways located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path. In one aspect, at least one of the fluid passageways are not fluidly coupled with the at least one spiraling fluid flow path.

[008] In one aspect, the at least one spiraling fluid flow path has the straight sections connected by arcuate sections configured in an alternating manner. In one aspect, the at least one spiraling fluid flow path is devoid of sharp corners. In one aspect, the at least one spiraling fluid flow path with straight sections includes smooth surfaces and a narrow width inducing laminar fluid flow. In one aspect, the at least one spiraling fluid flow path provides a preserved ion concentration polarization boundary layer in laminar fluid flow. In one aspect, the fluidly coupled fluid passageway located within the center of the spiraling fluid flow path is an inlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow path is an outlet. In one aspect, the fluidly coupled fluid passageway located within the center of the spiraling fluid flow path is an outlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow path is an inlet. In one aspect, the plate defines at least one spiraling fluid flow path extending between and opening to both the first side and the second side so as to fluidly couple the first side and second side.

[009] In one embodiment, a spiral channel spacer structure for ion selective membrane stack devices can include: a plate having a first side and a second side; a plurality of fluid passageways formed into the plate, each extending from a passageway opening in the first side of the plate to a passageway opening in the second side of the plate; and a plurality of spiraling fluid flow paths formed in the plate and fluidly coupling one of the fluid passageways located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path. In one aspect, at least one of the fluid passageways are not fluidly coupled with the plurality of spiraling fluid flow paths. [010] In one aspect, the plurality of spiraling fluid flow paths each include smooth surfaces and a narrow width inducing laminar fluid flow. In one aspect, the plurality of spiraling fluid flow paths each provide a preserved ion concentration polarization boundary layer in laminar fluid flow. In one aspect, the fluidly coupled fluid passageway located within the center of the spiraling fluid flow paths is an inlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow paths is an outlet. In one aspect, the fluidly coupled fluid passageway located within the center of the spiraling fluid flow paths is an outlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow paths is an inlet. In one aspect, the plate defines the plurality of spiraling fluid flow paths extending between and opening to both the first side and the second side.

[011] In one embodiment, a spiral channel spacer structure for ion selective membrane stack devices can include: a plate having a first side and a second side; a plurality of fluid passageways formed into the plate, each extending from a passageway opening in the first side of the plate to a passageway opening in the second side of the plate; and at least one spiraling fluid flow path with sinusoidal sections formed in the plate and fluidly coupling one of the fluid passageways located within the center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path. In one aspect, at least one of the fluid passageways are not fluidly coupled with the at least one spiraling fluid flow path. In one aspect, the sinusoidal sections are comprised of smooth waves. In one aspect, the sinusoidal sections are comprised of sharp ridges. In one aspect, the fluidly coupled fluid passageway located within the center of the spiraling fluid flow path is an inlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow path is an outlet. In one aspect, the fluidly coupled fluid passageway located within the center of the spiraling fluid flow path is an outlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow path is an inlet. In one aspect, the plate defines at least one spiraling fluid flow path extending between and opening to both the first side and the second side so as to fluidly couple the first side and second side.

[012] In one embodiment, a membrane stack for an ICP can include: at least two ion exchange membranes; at least two spiral channel spacer structures placed between two of the at least two ion exchange membranes, wherein the at least two spiral channel spacer structures include a first spiral channel spacer structure and a different second spiral channel spacer structure; and a partition positioned between the first spiral channel spacer structure and second spiral channel spacer structure, the first spiral channel spacer structure being between a first ion exchange membrane and the partition and the second spiral channel spacer structure being between a second ion exchange membrane and the partition.

[013] In one embodiment, a membrane stack for an ICP can include: at least two cation exchange membranes; at least two spiral channel spacer structures placed between two of the at least two cation exchange membranes, wherein the at least two spiral channel spacer structures include a first spiral channel spacer structure and a different second spiral channel spacer structure; and a partition positioned between the first spiral channel spacer structure and second spiral channel spacer structure, the first spiral channel spacer structure being between a first cation exchange membrane and the partition and the second spiral channel spacer structure being between a second cation exchange membrane and the partition.

[014] In one embodiment, membrane stack for an ICP can include: at least two anion exchange membranes; at least two spiral channel spacer structures placed between two of the at least two anion exchange membranes, wherein the at least two spiral channel spacer structures include a first spiral channel spacer structure and a different second spiral channel spacer structure; and a partition positioned between the first spiral channel spacer structure and second spiral channel spacer structure, the first spiral channel spacer structure being between a first anion exchange membrane and the partition and the second spiral channel spacer structure being between a second anion exchange membrane and the partition.

[015] In one embodiment, a membrane stack for an ICP can include: at least two of the same, all cation or all anion, exchange membranes positioned at opposing ends with elements there between; the elements including a partition positioned between two spiral channel spacer structures, a first spiral channel spacer structure adjacent to the first cation or anion exchange membrane and a second spiral channel spacer structure adjacent to the second cation or anion exchange membrane.

[016] In one embodiment, membrane stack for a PED can include: at least two cation exchange membranes and at least one anion exchange membrane positioned in between the cation exchange membranes, and between the cation and anion exchange membranes is: at least one pair of spiral channel spacer structures positioned between the at least one first cation exchange membrane and one anion exchange membrane, with at least one partition placed in between the pair of spiral channel spacer structures, and at least a second pair of spiral channel spacer structures positioned between the anion exchange membrane and a second cation exchange membrane, with at least one partition placed in between the pair of spiral channel spacer structures.

[017] In one embodiment, a membrane stack for a PED can include: at least two anion exchange membranes and at least one cation exchange membrane positioned in between the anion exchange membranes, between the cation and anion exchange membranes is: at least one pair of spiral channel spacer structures positioned between the at least one first anion exchange membrane and one cation exchange membrane, with at least one partition placed in between the pair of spiral channel spacer structures, and at least a second pair of spiral channel spacer structures positioned between the cation exchange membrane and a second anion exchange membrane, with at least one partition placed in between the pair of spiral channel spacer structures.

[018] In one embodiment, a membrane stack for an ED can include: at least two cation exchange membranes and at least one anion exchange membrane positioned in between the cation exchange membranes, there between the cation and anion exchange membranes: at least one spiral channel spacer structure positioned between the at least one first cation exchange membrane and one anion exchange membrane, and at least a second spiral channel spacer structure positioned between the anion exchange membrane and a second cation exchange membrane.

[019] In one embodiment, a membrane stack for an ED can include: at least two anion exchange membranes and at least one cation exchange membrane positioned in between the anion exchange membranes, there between the cation and anion exchange membranes; at least one spiral channel spacer structure positioned between the at least one first anion exchange membrane and one cation exchange membrane, and at least a second spiral channel spacer structure positioned between the cation exchange membrane and a second anion exchange membrane.

[020] In one embodiment, a spiral channel spacer structure pair can include: a first spiral spacer structure comprising a first configuration; a second spiral spacer structure comprising a second configuration, wherein both the first configuration and the second configuration are configured to be fluidly coupled via a plurality of fluid passageways when in a membrane stack, wherein a first portion of the plurality of fluid passageways are formed into the first spiral spacer structure and a second portion of the plurality of fluid passageways are formed into the second spiral spacer structure, each fluid passageway extending from a passageway opening in a first side of the respective spiral spacer structure to a passageway opening in a second side of the spiral spacer structure; at least one spiraling fluid flow path formed in each spiral channel spacer structure and fluidly coupling one of the fluid passageways located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path, wherein at least two of the fluid passageways are not fluidly coupled with the at least one spiraling fluid flow path for each spiral channel spacer structure; the first spiral channel spacer structure having one of the fluid passageways configured for a concentrate fluid flow, wherein passage of the concentrate fluid flow proceeds from a concentrate inlet fluid passageway located within a center of the spiraling fluid flow path to a concentrate outlet fluid passageway located outside of the spiraling fluid flow path; and the second spiral channel spacer structure having one of the fluid passageways configured for a dilute fluid flow, wherein passage of the dilute fluid flow proceeds from a dilute inlet fluid passageway located within a center of the spiraling fluid flow path to a dilute outlet fluid passageway located outside of the spiraling fluid flow path.

[021] In one embodiment, a spiral channel spacer structure pair can include: a first spiral spacer structure comprising a first configuration and a second spiral spacer structure comprising a second configuration, wherein both the first configuration and the second configuration are fluidly coupled via a plurality of fluid passageways, wherein the plurality of fluid passageways are formed into the first and second spiral spacer structures, each fluid passageway extending from a passageway opening in a first side of the spiral spacer structure to a passageway opening in a second side of the spiral spacer structure; at least one spiraling fluid flow path formed in the spiral spacer structure and fluidly coupling one of the fluid passageways located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path, wherein at least two of the fluid passageways are not fluidly coupled with the at least one spiraling fluid flow path; a concentrate fluid flow, wherein passage of the concentrate fluid flow proceeds from the fluid passageways located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path and subsequently through the second configuration of the second spiral spacer via the fluid passageway located outside of the spiraling fluid path not fluidly coupled to the center of the spiraling fluid flow path; and a dilute fluid flow, wherein passage of the dilute fluid flow proceeds from the fluid passageway located outside of the spiraling fluid path not fluidly coupled to the center of the spiraling fluid flow path of the first configuration of the first spiral spacer and subsequently through the second configuration of the second spiral spacer via the fluid passageway located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path.

[022] In one embodiment, a pair of spiral channel spacer structures can include: a first spiral channel spacer structure having a first configuration, the first spiral channel spacer structure comprising: a first plate having a first side and a second side; a plurality of first fluid passageways formed into the first plate, each extending from a passageway opening in the first side of the first plate to a passageway opening in the second side of the first plate; and at least one first spiraling fluid flow path formed in the first plate and fluidly coupling one of the first fluid passageways located within a center of the first spiraling fluid flow path to one of the first fluid passageways located outside of the first spiraling fluid flow path, wherein at least two of the first fluid passageways are not fluidly coupled with the at least one first spiraling fluid flow path; and a second spiral channel spacer structure having a second configuration that is different from the first configuration, the second spiral channel spacer structure comprising: a second plate having a first side and a second side; a plurality of second fluid passageways formed into the second plate, each extending from a passageway opening in the first side of the second plate to a passageway opening in the second side of the second plate; and at least one second spiraling fluid flow path formed in the second plate and fluidly coupling one of the second fluid passageways located within a center of the second spiraling fluid flow path to one of the second fluid passageways located outside of the second spiraling fluid flow path, wherein at least two of the second fluid passageways are not fluidly coupled with the at least one first spiraling fluid flow path.

[023] In one embodiment, a pair of spiral channel spacer structures can include: a first spiral channel spacer structure having a first configuration with two first inner fluid passageways located within a first spiral fluid flow path and two first outer fluid passageways located outside the first spiral fluid flow path, a first inner fluid passageway coupled to a first outer fluid passageway with the first spiral fluid flow path; and a second spiral channel spacer structure having a second configuration different from the first configuration and with two second inner fluid passageways located within a second spiral fluid flow path and two second outer fluid passageways located outside the second spiral fluid flow path, a second inner fluid passageway coupled to a second outer fluid passageway with the first spiral fluid flow path, wherein the first spiral fluid flow path does not align with the second spiral fluid flow path when the first spiral channel spacer structure is stacked on the second spiral spacer structure and the two first inner and outer fluid passageways align with the two second inner and outer fluid passageways.

[024] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE FIGURES

[025] The foregoing and following information as well as other features of this disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings.

[026] Figure 1 shows an embodiment of a spiral channel spacer structure.

[027] Figure 2 shows another embodiment of a spiral channel spacer structure.

[028] Figure 3 shows an additional embodiment of a spiral channel spacer structure.

[029] Figure 4 shows yet another embodiment of a spiral channel spacer structure.

[030] Figure 5 shows an embodiment of an ICP having a spiral channel spacer structure.

[031] Figure 6 shows another embodiment of an ICP having a spiral channel spacer structure.

[032] Figure 7 shows an embodiment having a spiral channel spacer pair placed between adjacent membranes.

[033] Figure 8 includes a graph that shows data of an ICP module having spiral channel spacer structures.

[034] Figure 9 shows an embodiment of a PED that includes a spiral channel spacer structure.

[035] Figure 10 shows another embodiment of a PED that includes a spiral channel spacer structure.

[036] Figure 11 shows an embodiment of an ED that includes a spiral channel spacer structure.

[037] Figure 12 shows an embodiment of a spiral channel spacer pair for an ED. DETAILED DESCRIPTION

[038] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subj ect matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.

[039] Now, it has been found that a spacer structure having a spiral flow channel (e.g., spiral channel spacer structure) can retain the laminar flow and provide the benefits of the ion concentration polarization boundary layer being retained. Accordingly, a spiral channel spacer structure 10 can be used for ion selective membrane stack devices, as shown in Figure 1, which can include the spiral channel spacer structure 10 between membranes. In such a structure, firstly, one or only a few narrow spiral flow channels 12 defined by a body 14 are used in each spacer structure 10 in order to achieve even water distribution. Secondly, the spiral flow channel 12 can be as long as needed or desired or optimized in a limited membrane area and length. Thirdly, the whole flow path of the spiral flow channel is smooth without sharp corners, and thus laminar flow of water in the spiral flow channels 12 is achievable. The number of spiral flow channels 12 can be one or a few, which is significantly less channels than in the prior designs. In addition, the one or few spiral flow channels 12 makes it easy for degassing and preventing of air pocket blockage in the spiral channels. Figure 1 is an example of a spiral channel spacer structure 10 with a typical single spiral flow channel 12. For the spiral flow channel 12, it is not necessary the all the channels are curved. As shown, there is an inlet circular fluid passageway 16 that extends from a first side 18 to a second side (not shown) of the plate (e.g., body 14) and an outlet circular fluid passageway 20 that extends from the first side 18 to the second side of the plate with the spiral fluid channel 12 extending between the inlet circular fluid passageway 16 to the outlet circular fluid passageway 20. The plate also has two pass through fluid passageways 22, 24. It is noted that the inlet 16 is in the center of the spiral and the outlet 20 is outside of the spiral, but the orientation can be switched. Also, both pass through fluid passageways 22, 24 can be in the center of the spiral or outside the spiral, or one inside or one outside as shown. There is a center hole 26 configured for a bolt; however, fastener holes may be located anywhere depending on the design.

[040] Figure 2 demonstrated another single spiral channel spacer structure 10 with some straight portions in the channel. Figure 3 is an example of spacer structure with two spiral channels. There can be more than two spiral channels, such as three, four, five, six or more as desired and feasible to retain the laminar flow. It is noted that there are no tight corners that cause turbulence in fluid flow, which allows for the laminar flow to be retained. It is noted that the spiral channel spacer structures of Figures 2 and 3 can include the passageway features and bolt holes as described in connection to Figure 1.

[041] Figure 2 further shows straight sections 30 connected arcuate sections 32 to form the spiral. Pin holes (unlabeled) are also shown that can receive pins that connect adjacent structures or for alignment.

[042] Figure 3 further shows a plurality of spiral fluid channels 12.

[043] In one embodiment, the spiral channel structure is also applicable to ED devices. Since turbulence flow in the channel is preferred for ED, small waving shapes are applied to the channel sides, as shown in Figure 4. In this case the device still gets the benefit of longer flow path. In addition the waving channel sets the turbulence flow in a more regulated way, and the turbulence strength and pressure drop can be more easily optimized.

It is noted that the spiral channel spacer structure of Figures 4 can include the passageway features and alignment holes as described in connection to Figure 1.

[044] Figure 4 further shows the spiral fluid channels includes waves 34, that have peaks and troughs, and shown as rounded.

[045] To test the performance of the spiral channel spacer structures with smooth channels as illustrated in Figure 1 were included in an ICP membrane stack module. The membranes were separated by smooth spiral channel spacers. The ICP membrane stack module includes repeated layers of cation selective membrane, concentrated spacer (e.g., a spiral channel spacer structure), partition, and diluted spacer (e.g., a spiral channel spacer structure) clamped in between a pair of end plates, electrodes, electrode rinsing chambers, by bolts and nuts. In one example, partition is made of nylon mesh with pores, with most of the surface covered by glue or a cover layer, and thereby only pores between part of the channel length are exposed to allow liquid communication. The pores can be in a spiral shape to match the spiral channels. [046] An exploded view of an ICP module showing how the spiral channel spacers (e.g., concentrated spacer and diluted spacer) are used in an ICP module is illustrated in Figure 5. A spacer half a (Sha), a partition (P), and a spacer half b (Shb) were clamped in between two cation exchange membranes (C). Thus, a membrane period includes a membrane (C), a spiral channel spacer structure (Shb or Sha), a partition (P), a spiral channel spacer structure (other of Shb or Sha), and the periods repeat from one end to the other and terminated by a final membrane (C). In this configuration, the spiral channel in Sha guides the feed water to the dilute output, while the spiral channel in Shb guides the feed water to the concentrated output. Two cation exchange membranes (C), together with two spacer half a (Sha), two spacer half b (Shb), and two partitions (P) form a cell pair in the ICP module, which may contain many cell pairs, and a specific membrane may be considered to part of both of the adjacent cell pairs.

[047] In one embodiment, the ICP of Figure 5 can have the cation exchange membranes all substituted with anionic exchange membranes ("A"), and thereby each "C" in Figure 5 can be substituted with a "A" as shown in Figure 6.

[048] Figure 7 shows the spiral channel spacer pair that is placed between adjacent membranes. Here, it is shown that one center circular fluid passageway of Sha is an inlet for a dilute spiral channel that couples with one outer center circular fluid passageway. The other center circular fluid passageway of Sha is a pass through for the concentrated flow and it is not connected to the spiral channel or the outer circular fluid passageway that is also for concentrated flow. It is also shown that one center circular fluid passageway of Shb is an inlet for a concentrated spiral channel that couples with one outer center circular fluid passageway. The other center circular fluid passageway of Shb is a pass through for the dilute flow and it is not connected to the spiral channel or the outer circular fluid passageway that is also for dilute flow. As such, one aspect of the invention is a pair of spiral channel spacers with one of the spacers having a concentrated spiral channel and the other having a diluted spiral channel. The concentrated spiral channel is fluidly coupled to the concentrated fluid passageways.

[049] In some cases for an ICP stack, there can be only one input passageway and two output passageways. Thus, there can be only one passageway that is not coupled with the spiral channel. In the special case of MCDI (membrane capacitive deionization) stack, there is only one input passageway and one output passageway. [050] In one aspect, the shape of the fluid passageways do not have to be circular, but can be any shape such as any polygon.

[051] An example of the device of Figure 5 was tested for desalination. The desalination performance of the constructed ICP module was tested with NaCl solution sample of 1790 ppm (conductivity 3450μ8/αη). As shown in Figure 8, when applying a different voltage and current to the stack, the salt removal ratio can reach more than 80% in one pass, thanks to the long spiral channel (800mm channel length). As a comparison, another embodiment with straight shorter channels (100mm channel length) can reach only 50% salt removal in one pass. The graph also shows a current efficiency trend of the ICP stack. When working at current density below limiting current (about 30mA in this case), the current efficiency can reach more than 100%, and remains more than 80% in most working conditions except when very high current is used, which is acceptable for the embodiment.

[052] The present technology provides a novel spiral channel spacer structure for ion selective membrane stack devices. In desalination applications, the test results proved that the longer spiral channel packed in a limited stack size by this structure helps to reach higher ion removal ratio while maintaining higher current efficiency.

[053] A PED that uses the spiral channel spacer structures is illustrated in Figure 9. A typical PED stack has two inputs and four outputs. A spacer half a (Sha), a partition (P), and a spacer half b (Shb) were clamped in between a cation exchange membrane (C) and an anion exchange membrane (A), and a spacer half c (She), a partition (P), and a spacer half d (Shd) were clamped in between the anion exchange membrane and another cation exchange membrane (C). Thus, a membrane period includes a cationic exchange membrane, a spiral channel spacer structure, a partition, a spiral channel spacer structure, a cationic exchange membrane, a spiral channel spacer structure, a partition, and a spiral channel spacer structure. In this configuration, the spiral channel in Sha guides the feed water to the purified output, the spiral channel in Shb guides the feed water to the diluted or partially purified output, the spiral channel in She guides the feed water to the concentrate output, while the spiral channel in Shd guides the feed water to the high concentrated output. The cation exchange membrane, Sha, Shb, She, Shd, two partitions, and anion exchange membrane form a cell pair in the PED module, which may contain many cell pairs, and a specific membrane may be considered to part of both of the adjacent cell pairs. Figure 10 shows the Sha, Shb, She, and Shd spiral channels for the PED. [054] An ED that uses the spiral channel spacer structures is illustrated in Figure 11. A spacer a (Sa) was clamped in between a cation exchange membrane (C) and an anion exchange membrane (A), while a spacer b (Sb) was clamped in between the anion exchange membrane (A) and another cation exchange membrane (C). Thus, a membrane period includes a cation exchange membrane, a spiral channel spacer structure, an anion exchange membrane, and a spiral channel spacer structure. In this configuration, the spiral channel in Sa guides the feed water to the dilute output, while the spiral channel in Sb guides the feed water to the concentrated output. The cation exchange membrane, Sa, Sb, and anion exchange membrane form a cell pair in the PED module, which may contain many cell pairs, and a specific membrane may be considered part of both of the adjacent cell pairs. Figure 12 shows the Sa and Sb spiral channel spacer pair for the ED.

[055] In one embodiment, the hybrid devices of U.S. Provisional No. 62/073,442 can use the spiral channel spacer structures described herein instead of the spacer structures that are illustrated, and thereby this provisional application is incorporated herein by specific reference. The ED/PED hybrid (Figures 1A and 3 A and 3B and 4A and 4B and 4B1 and 4C and 4C1) can include the appropriate spiral channel spacers in accordance with the ED and PED embodiments described herein. The ED/ICP hybrid (Figures IB and 4A1 and 5 and 5A) can include the appropriate spiral channel spacers in accordance with the ED and ICP embodiments described herein. The PED/ICP hybrid (Figures 6 and 6A) can include the appropriate spiral channel spacers in accordance with the PED and ICP embodiments described herein. The PED/ED/ICP hybrid (Figures 7 and 7A) can include the appropriate spiral channel spacers in accordance with the ED and PED and ICP embodiments described herein. Also, the embodiments shown in Figures 8A1, 8A2, 9A and 9B can use the spiral channel spacers instead of the straight channel spacers shown in Figure 8B or 8C.

[056] In view of Figures 11 and 12, the membranes can be C-A-C or A-C-A. Then more pairs of C-A or A-C can be added to the stack for the full stack device.

[057] In one embodiment, the PED devices of PCT/SG2014/000124 published as WO 2014/142756 can use the spiral channel spacers described herein and thereby this PCT application is incorporated herein by specific reference. For example, in Figure 4, the spacers 403, 405, 407, 409, 411, 413, 415, and 417 may be replaced with the spiral channel spacers.

[058] One skilled in the art will appreciate that, for this and other processes and methods disclosed herein, the functions performed in the processes and methods may be implemented in differing order. Furthermore, the outlined steps and operations are only provided as examples, and some of the steps and operations may be optional, combined into fewer steps and operations, or expanded into additional steps and operations without detracting from the essence of the disclosed embodiments.

[059] The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds compositions or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[060] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

[061] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., " a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., " a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

[062] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[063] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as "up to," "at least," and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth.

[064] From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

[065] All references recited herein are incorporated herein by specific reference in their entirety: R. Kwak, V. S. Pham, B. J. Kim, L. Chen, and J. Han, "High throughput salt/bio- agent removal by ion concentration polarization for water desalination, purification and monitoring," presented at the Seventeenth International Conference on miniaturized systems for chemistry and life sciences: Microtas 2013, Freiburg, Germany, 2013, pp. 660- 662; H. Liu, "Polarized Electrodialysis," PCT/SG2014/000124 published as WO 2014/142756 Al; American Water Works Association, Electrodialysis and electrodialysis reversal, 1st ed. Denver, CO: American Water Works Association, 1995; H. Strathmann, Ion-exchange membrane separation processes, 1st ed. Amsterdam ; Boston: Elsevier, 2004; U.S. Provisional No. 62/073,442; and U.S. Provisional No. 61/783,575.

Claims

1. A spiral channel spacer structure for ion selective membrane stack devices, comprising:

a plate having a first side and a second side;

a plurality of fluid passageways formed into the plate, each extending from a passageway opening in the first side of the plate to a passageway opening in the second side of the plate; and

at least one spiraling fluid flow path formed in the plate and fluidly coupling one of the fluid passageways located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path, wherein at least one of the fluid passageways is not fluidly coupled with the at least one spiraling fluid flow path

2. The spiral channel spacer structure of claim 1, wherein the at least one spiraling fluid flow path includes smooth surfaces and a narrow width inducing laminar fluid flow.

3. The spiral channel spacer structure of claim 1, wherein the at least one spiraling fluid flow path provides a preserved ion concentration polarization boundary layer in laminar fluid flow.

4. The spiral channel spacer structure of claim 1, wherein the fluidly coupled fluid passageway located within the center of the spiraling fluid flow path is an inlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow path is an outlet.

5. The spiral channel spacer structure of claim 1, wherein the fluidly coupled fluid passageway located within the center of the spiraling fluid flow path is an outlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow path is an inlet.

6. The spiral channel spacer structure of claim 1, wherein the plate defines at least one spiraling fluid flow path extending between and opening to both the first side and the second side so as to fluidly couple the first side and second side.

7. The spiral channel spacer structure of claim 1, further comprising:

the at least one spiraling fluid flow path having straight flow path sections formed in the plate and fluidly coupling one of the fluid passageways located within the center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path.

8. The spiral channel spacer structure of claim 7, wherein the at least one spiraling fluid flow path has the straight sections connected by arcuate sections configured in an alternating manner.

9. The spiral channel spacer structure of claim 7, wherein the at least one spiraling fluid flow path is devoid of sharp corners.

10. The spiral channel spacer structure of claim 7, wherein the at least one spiraling fluid flow path with straight sections includes smooth surfaces and a narrow width inducing laminar fluid flow.

11. The spiral channel spacer structure of claim 7, wherein the at least one spiraling fluid flow path provides a preserved ion concentration polarization boundary layer in laminar fluid flow.

12. The spiral channel spacer structure of claim 7, wherein the fluidly coupled fluid passageway located within the center of the spiraling fluid flow path is an inlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow path is an outlet.

13. The spiral channel spacer structure of claim 7, wherein the fluidly coupled fluid passageway located within the center of the spiraling fluid flow path is an outlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow path is an inlet.

14. The spiral channel spacer structure of claim 7, wherein the plate defines at least one spiraling fluid flow path extending between and opening to both the first side and the second side so as to fluidly couple the first side and second side.

15. The spiral channel spacer structure of claim 1, further comprising a plurality of spiraling fluid flow paths formed in the plate and fluidly coupling one of the fluid passageways located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path.

16. The spiral channel spacer structure of claim 15, wherein the plurality of spiraling fluid flow paths each include smooth surfaces and a narrow width inducing laminar fluid flow.

17. The spiral channel spacer structure of claim 15, wherein the plurality of spiraling fluid flow paths each provide a preserved ion concentration polarization boundary layer in laminar fluid flow.

18. The spiral channel spacer structure of claim 15, wherein the fluidly coupled fluid passageway located within the center of the spiraling fluid flow paths is an inlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow paths is an outlet.

19. The spiral channel spacer structure of claim 15, wherein the fluidly coupled fluid passageway located within the center of the spiraling fluid flow paths is an outlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow paths is an inlet.

20. The spiral channel spacer structure of claim 15, wherein the plate defines the plurality of spiraling fluid flow paths extending between and opening to both the first side and the second side.

21. The spiral channel spacer structure of claim 1, further comprising:

the at least one spiraling fluid flow path including sinusoidal sections formed in the plate and fluidly coupling one of the fluid passageways located within the center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path.

22. The spiral channel spacer structure of claim 21, wherein the sinusoidal sections are comprised of smooth waves.

23. The spiral channel spacer structure of claim 21, wherein the sinusoidal sections are comprised of sharp ridges.

24. The spiral channel spacer structure of claim 21, wherein the fluidly coupled fluid passageway located within the center of the spiraling fluid flow path is an inlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow path is an outlet.

25. The spiral channel spacer structure of claim 21, wherein the fluidly coupled fluid passageway located within the center of the spiraling fluid flow path is an outlet, and the fluidly coupled fluid passageway located outside of the spiraling fluid flow path is an inlet.

26. The spiral channel spacer structure of claim 21, wherein the plate defines at least one spiraling fluid flow path extending between and opening to both the first side and the second side so as to fluidly couple the first side and second side.

27. A membrane stack for an ICP, comprising:

at least two ion exchange membranes;

at least two spiral channel spacer structures each being independently configured as in claim 1, wherein the at least two spiral channel spacer structures are placed between two of the at least two ion exchange membranes, wherein the at least two spiral channel spacer structures include a first spiral channel spacer structure and a different second spiral channel spacer structure;

a partition positioned between the first spiral channel spacer structure and second spiral channel spacer structure, the first spiral channel spacer structure being between a first ion exchange membrane and the partition and the second spiral channel spacer structure being between a second ion exchange membrane and the partition.

28. A membrane stack for an ICP, comprising:

at least two cation exchange membranes;

at least two spiral channel spacer structures each being independently configured as in claim 1, wherein the at least two spiral channel spacer structures are placed between two of the at least two cation exchange membranes, wherein the at least two spiral channel spacer structures include a first spiral channel spacer structure and a different second spiral channel spacer structure;

a partition positioned between the first spiral channel spacer structure and second spiral channel spacer structure, the first spiral channel spacer structure being between a first cation exchange membrane and the partition and the second spiral channel spacer structure being between a second cation exchange membrane and the partition.

29. A membrane stack for an ICP, comprising:

at least two anion exchange membranes;

at least two spiral channel spacer structures each being independently configured as claim 1, wherein the at least two spiral channel spacer structures are placed between two of the at least two anion exchange membranes, wherein the at least two spiral channel spacer structures include a first spiral channel spacer structure and a different second spiral channel spacer structure;

a partition positioned between the first spiral channel spacer structure and second spiral channel spacer structure, the first spiral channel spacer structure being between a first anion exchange membrane and the partition and the second spiral channel spacer structure being between a second anion exchange membrane and the partition.

30. A membrane stack for an ICP, comprising:

at least two of the same, all cation or all anion, exchange membranes positioned at opposing ends with elements there between: the elements including a partition positioned between two spiral channel spacer structures each being independently configured as in claim 1, a first spiral channel spacer structure adjacent to the first cation or anion exchange membrane and a second spiral channel spacer structure adjacent to the second cation or anion exchange membrane.

31. A membrane stack for a PED, comprising:

at least two cation exchange membranes and at least one anion exchange membrane positioned in between the cation exchange membranes, between the cation and anion exchange membranes is:

at least one pair of spiral channel spacer structures each being independently configured as in claim 1, the at least one pair of spiral channel spacer structures being positioned between the at least one first cation exchange membrane and one anion exchange membrane, with at least one partition placed in between the pair of spiral channel spacer structures, and at least a second pair of spiral channel spacer structures positioned between the anion exchange membrane and a second cation exchange membrane, with at least one partition placed in between the pair of spiral channel spacer structures.

32. A membrane stack for a PED, comprising:

least two anion exchange membranes and at least one cation exchange membrane positioned in between the anion exchange membranes, between the cation and anion exchange membranes is:

at least one pair of spiral channel spacer structures each being independently configured as in claim 1, the at least one pair of spiral channel spacer structures being positioned between the at least one first anion exchange membrane and one cation exchange membrane, with at least one partition placed in between the pair of spiral channel spacer structures, and at least a second pair of spiral channel spacer structures positioned between the cation exchange membrane and a second anion exchange membrane, with at least one partition placed in between the pair of spiral channel spacer structures.

33. A membrane stack for an ED, comprising: at least two cation exchange membranes and at least one anion exchange membrane positioned in between the cation exchange membranes, there between the cation and anion exchange membranes:

at least one spiral channel spacer structure positioned between the at least one first cation exchange membrane and one anion exchange membrane, and at least a second spiral channel spacer structure positioned between the anion exchange membrane and a second cation exchange membrane,

each spiral channel spacer structure being independently configured as in claim 1.

34. A membrane stack for an ED, comprising:

at least two anion exchange membranes and at least one cation exchange membrane positioned in between the anion exchange membranes, there between the cation and anion exchange membranes;

at least one spiral channel spacer structure positioned between the at least one first anion exchange membrane and one cation exchange membrane, and at least a second spiral channel spacer structure positioned between the cation exchange membrane and a second anion exchange membrane,

35. A spiral channel spacer structure pair, comprising:

a first spiral spacer structure comprising a first configuration;

a second spiral spacer structure comprising a second configuration, wherein both the first configuration and the second configuration are configured to be fluidly coupled via a plurality of fluid passageways when in a membrane stack, each spiral channel spacer structure being independently configured as in claim 1;

wherein a first portion of the the plurality of fluid passageways are formed into the first spiral spacer structure and a second portion of the plurality of fluid passageways are formed into the second spiral spacer structure, each fluid passageway extending from a passageway opening in a first side of the respective spiral spacer structure to a passageway opening in a second side of the spiral spacer structure; at least one spiraling fluid flow path formed in each spiral channel spacer structure and fluidly coupling one of the fluid passageways located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path,

wherein at least two of the fluid passageways are not fluidly coupled with the at least one spiraling fluid flow path for each spiral channel spacer structure; the first spiral channel spacer structure having one of the fluid passageways configured for a concentrate fluid flow, wherein passage of the concentrate fluid flow proceeds from a concentrate inlet fluid passageway located within a center of the spiraling fluid flow path to a concentrate outlet fluid passageway located outside of the spiraling fluid flow path; and

the second spiral channel spacer structure having one of the fluid passageways configured for a dilute fluid flow, wherein passage of the dilute fluid flow proceeds from a dilute inlet fluid passageway located within a center of the spiraling fluid flow path to a dilute outlet fluid passageway located outside of the spiraling fluid flow path.

36. A spiral channel spacer structure pair, comprising:

a first spiral spacer structure comprising a first configuration and a second spiral spacer structure comprising a second configuration, wherein both the first configuration and the second configuration are fluidly coupled via a plurality of fluid passageways, each spiral channel spacer structure being independently configured as in claim 1,

wherein the plurality of fluid passageways are formed into the first and second spiral spacer structures, each fluid passageway extending from a passageway opening in a first side of the spiral spacer structure to a passageway opening in a second side of the spiral spacer structure;

at least one spiraling fluid flow path formed in the spiral spacer structure and fluidly coupling one of the fluid passageways located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path,

wherein at least two of the fluid passageways are not fluidly coupled with the at least one spiraling fluid flow path; a concentrate fluid flow,

wherein passage of the concentrate fluid flow proceeds from the fluid passageways located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path and subsequently through the second configuration of the second spiral spacer via the fluid passageway located outside of the spiraling fluid path not fluidly coupled to the center of the spiraling fluid flow path; and

a dilute fluid flow,

wherein passage of the dilute fluid flow proceeds from the fluid passageway located outside of the spiraling fluid path not fluidly coupled to the center of the spiraling fluid flow path of the first configuration of the first spiral spacer and subsequently through the second configuration of the second spiral spacer via the fluid passageway located within a center of the spiraling fluid flow path to one of the fluid passageways located outside of the spiraling fluid flow path.

37. A pair of spiral channel spacer structures comprising:

a first spiral channel spacer structure having a first configuration, the first spiral channel spacer structure comprising:

a first plate having a first side and a second side;

a plurality of first fluid passageways formed into the first plate, each extending from a passageway opening in the first side of the first plate to a passageway opening in the second side of the first plate; and

at least one first spiraling fluid flow path formed in the first plate and fluidly coupling one of the first fluid passageways located within a center of the first spiraling fluid flow path to one of the first fluid passageways located outside of the first spiraling fluid flow path, wherein at least two of the first fluid passageways are not fluidly coupled with the at least one first spiraling fluid flow path; and

a second spiral channel spacer structure having a second configuration that is different from the first configuration, the second spiral channel spacer structure comprising:

a second plate having a first side and a second side; a plurality of second fluid passageways formed into the second plate, each extending from a passageway opening in the first side of the second plate to a passageway opening in the second side of the second plate; and at least one second spiraling fluid flow path formed in the second plate and fluidly coupling one of the second fluid passageways located within a center of the second spiraling fluid flow path to one of the second fluid passageways located outside of the second spiraling fluid flow path, wherein at least two of the second fluid passageways are not fluidly coupled with the at least one first spiraling fluid flow path.

38. A pair of spiral channel spacer structures comprising:

a first spiral channel spacer structure having a first configuration with two first inner fluid passageways located within a first spiral fluid flow path and two first outer fluid passageways located outside the first spiral fluid flow path, a first inner fluid passageway coupled to a first outer fluid passageway with the first spiral fluid flow path; and

a second spiral channel spacer structure having a second configuration different from the first configuration and with two second inner fluid passageways located within a second spiral fluid flow path and two second outer fluid passageways located outside the second spiral fluid flow path, a second inner fluid passageway coupled to a second outer fluid passageway with the first spiral fluid flow path,

wherein the first spiral fluid flow path does not align with the second spiral fluid flow path when the first spiral channel spacer structure is stacked on the second spiral spacer structure and the two first inner and outer fluid passageways align with the two second inner and outer fluid passageways.