Technical Characterization of Dialysis Fluid Flow of Newly Developed Dialyzers Using Mass Transfer Correlation Equations

Abstract

Dialysis fluid flow and mass transfer rate of newly developed dialyzers were evaluated using mass transfer correlation equations of dialysis fluid-side film coefficient. Aqueous creatinine clearance and overall mass transfer coefficient for APS-15S (Asahi Kasei Kuraray) as a conventional dialyzer, and APS-15SA (Asahi Kasei Kuraray), PES-150Salpha (Nipro), FPX140 (Fresenius), and CS-1.6U (Toray) as newly developed dialyzers were obtained at a blood-side flow rate (QB) of 200 ml/min, dialysis fluid-side flow rates (QD) of 200-800 ml/min and a net filtration rate (QF) of 0 ml/min. Mass transfer correlation equations between Sherwood number (Sh) containing dialysis fluid-side mass transfer film coefficient and Reynolds number (Re) were formed for each dialyzer. The exponents of Re were 0.62 for APS-15S whereas approximately 0.5 for the newly developed dialyzers. The dialysis fluid-side mass transfer film coefficients of the newly developed dialyzers were higher than those of the conventional dialyzer. Based on the mass transfer correlation equations, introduction of short taper, full baffle of dialyzer jacket and further wave-shaped hollow fiber improves the dialysis fluid flow of the newly developed dialyzers.

Identical Dependence of Dialysate-side Mass Transfer Coefficient on Reynolds Number Using Dimensionless Correlation Based on the Mass Transfer Model in Newly Developed Dialyzers and a Downsized Dialyzer

“…Moreover, for the abovementioned dialyzers, the dimensionless correlation can be obtained with Equation (9) [4].…”

“…New design elements including a jacket with a full baf e and short taper structure, and a new wave design for the hollow ber membranes have been introduced in new dialyzers to achieve a more even dialysis ow and better solute removal performance. The relationship between dialysis uid ow and the above-mentioned new design concepts can be veri ed [4,5].…”

“…Hence, the recently developed dialyzers are based on new design concepts incorporating jackets or hollow bers that provide an evenly distributed ow [3][4][5]. We previously reported the results of quantitative analyses of the dialysis uid ow and solute removal performance using mass transfer correlation equations [4].…”

“…We previously reported the results of quantitative analyses of the dialysis uid ow and solute removal performance using mass transfer correlation equations [4]. The dimensionless correlation is related to the Sherwood number (Sh ≡ k D d e /D) and Reynolds number (Re ≡ d e uρ/μ) including the mass transfer coef cient of the dialysate-side lm (k D ) in a mass transfer model as well as the dialysate-side equivalent diameter (d e ), and has been used for evaluating the solute removal performance of a device from the viewpoint of design concept [2,4]. New design elements including a jacket with a full baf e and short taper structure, and a new wave design for the hollow ber membranes have been introduced in new dialyzers to achieve a more even dialysis ow and better solute removal performance.…”

“…Hence, the recently developed dialyzers are based on new design concepts incorporating jackets or hollow bers that provide an evenly distributed ow [3][4][5]. We previously reported the results of quantitative analyses of the dialysis uid ow and solute removal performance using mass transfer correlation equations [4]. The dimensionless correlation is related to the Sherwood number (Sh ≡ k D d e /D) and Reynolds number (Re ≡ d e uρ/μ) including the mass transfer coef cient of the dialysate-side lm (k D ) in a mass transfer model as well as the dialysate-side equivalent diameter (d e ), and has been used for evaluating the solute removal performance of a device from the viewpoint of design concept [2,4].…”