Filtration Fundamentals

Rushton, A.; Ward, A. S.; Holdich, Richard

doi:10.1002/9783527614974.ch02

Cited by 1 publication

(5 citation statements)

References 21 publications

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“…The wash ratio is described with eq 1: 14 where V wash (in m 3 ) is the total volume of the wash solvent and V pore (in m 3 ) is the void space volume of the cake being washed. V pore can be calculated from the void fraction ε (also known as the porosity of the cake), as described in eqs 2 and 3: 14,18 V m (1 ) pore cake s =…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…To prove the hypothesis on mother liquor removal, eq 4, 18 which is derived from Darcy's Law, is used to describe the filtration process:…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…The wash ratio is described with eq : wash .25em ratio = V wash V pore where V wash (in m 3 ) is the total volume of the wash solvent and V pore (in m 3 ) is the void space volume of the cake being washed. V pore can be calculated from the void fraction ε (also known as the porosity of the cake), as described in eqs and : , V pore = m cake ε ( 1 − ε ) ρ normals ε = 1 − m cake ρ normals l normalc A where l c (in m) is the cake thickness, A (in m 2 ) is the surface area of the cake, ρ s (in kg/m 3 ) is the API true density, and m cake (in kg) is the total mass of cake on the plate. When the filter was operated continuously with a complete filtration cycle of 3.25 min, the wash ratios at different wash rates are given in Table .…”

Section: Resultsmentioning

confidence: 99%

“…To prove the hypothesis on mother liquor removal, eq , which is derived from Darcy’s Law, is used to describe the filtration process: 1 A normald V normald t = Δ P μ 1 false( R normalc + R normalm false) Here Δ P (in Pa) is the pressure drop across the cake and filter medium, which is considered constant when the same cake and filter plate medium are used. In this study, an average Δ P of 23.9 kPa was measured when the unit was operated under a state of control.…”

Section: Resultsmentioning

confidence: 99%

“…If the cake deforms significantly under stress, then the cake is referred to as compressible. If its porosity is time-independent and uniform across the cake, then the cake is referred to as incompressible. , In the beginning of cake filtration, the resistance to flow is supplied only by the filter medium. As the process continues, the cake accumulated on the filter surface provides additional resistance.…”

Section: Introductionmentioning

confidence: 99%

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A Continuous Rotary Filtration for the Separation and Purification of an Active Pharmaceutical Ingredient

Wu,

Sayin,

Shvedova

et al. 2023

Org. Process Res. Dev.

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As pharmaceutical manufacturers are looking for ways to shift toward continuous manufacturing, one of the biggest challenges has been the continuous separation and purification of active pharmaceutical ingredients (APIs). To address these challenges, a continuous rotary filter was developed, and its design space was investigated using a commercially available API. The filtration unit consists of a rotatable plate that receives a continuous flow of feed material that is distributed along the radius of the plate, forming a thin cake. The cake is continuously filtered, washed, and removed from the plate. An additional plate wash continually cleans the filter medium, enabling long-term operations. A slurry containing the selected API and two main impurities was processed by a continuous rotary filter. The performance of the unit was assessed both as a standalone entity and as a component of an integrated continuous manufacturing line. We observed that longer cake residence times (3.25 vs 2.5 min) on the filter plate and higher wash rates (among 12, 9, 6, and 3 mL/min) improved purification performance, though the latter plateaued above certain levels. Elevated crystallization temperatures (up to 70 °C) also increased the purification efficiency while not significantly impacting the yield. Finally, feed material with lower impurity concentrations resulted in a reduction in residual impurity ratio (down to 0.001). Yield studies demonstrated that the final crystallization temperature and cake wash rate impact the overall filtration yield (98.05% yield was obtained). In both settings, the rotary filter isolated and purified the cake to the required quality specifications, proving its effectiveness and robustness during continuous operations.

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Section: ■ Results and Discussionmentioning

confidence: 99%

“…To prove the hypothesis on mother liquor removal, eq 4, 18 which is derived from Darcy's Law, is used to describe the filtration process:…”

Section: ■ Results and Discussionmentioning

confidence: 99%