US 12,458,926 B2
Electrodialysis stack
John H. Barber, Guelph (CA); Wojciech Gutowski, Guelph (CA); Yongchang Zheng, Westborough, MA (US); and Russell James MacDonald, Westborough, MA (US)
Assigned to BL TECHNOLOGIES, INC., Minnetonka, MN (US)
Filed by BL TECHNOLOGIES, INC., Minnetonka, MN (US)
Filed on Jan. 9, 2024, as Appl. No. 18/408,133.
Application 18/408,133 is a division of application No. 17/955,445, filed on Sep. 28, 2022, granted, now 11,904,278.
Application 17/955,445 is a division of application No. 16/609,406, granted, now 11,484,839, issued on Nov. 1, 2022, previously published as PCT/US2017/031060, filed on May 4, 2017.
Prior Publication US 2024/0139684 A1, May 2, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. B01D 61/50 (2006.01); B01D 63/08 (2006.01)
CPC B01D 61/50 (2013.01) [B01D 63/085 (2013.01); B01D 2313/14 (2013.01); B01D 2325/42 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A spacer for positioning between adjacent membranes in an electrodialysis stack having an electrode with a recessed edge and a total number of electrodialysis cell pairs (total cp), the spacer defining apertures therein for forming a distribution manifold that includes manifold ducts of a concentrated stream when the spacer is a part of the electrodialysis stack, the spacer comprising:
an impermeable membrane supporting area surrounding a flow field fluidly linking an inlet port and an outlet port;
electrically resistant structures positioned in the flow field proximate the inlet and outlet ports, and having a thickness equal to the thickness of the membrane supporting area;
wherein, when the spacer is positioned between the adjacent membranes in the electrodialysis stack:
i) the electrically resistant structures contact each of the adjacent membranes to reduce the area on the adjacent membranes available for an electrically conductive fluid connection, and;
(ii) the electrically resistant structures make up about 50% to about 75% of the surface area of the flow field from the inlet and outlet ports to a line spaced from the recessed edge of the electrode in a direction away from the inlet and outlet ports by an overlap distance that is about equal to:
(0.062 cm−1)*(exp(−60/total cp)*(area in cm2 of the manifold ducts of the concentrated stream at the recessed edge).