BHS Filtration, Drying & Process Testing Thin-Cake

Product Announcement from BHS-Filtration Inc.

BHS Filtration, Drying & Process Testing Thin-Cake-Image


The new brochure highlights the BHS testing capabilities for thin-cake filtration, cake washing and drying. It contains information on the BHS Laboratory for preliminary filtration and drying tests as well as pilot units for onsite testing. Glassware reactions and filtration testing are also conducted.

Here is a summary of the technical information related to the lab mixing and testing of aquous raw materials of precipitated reaction solids and Pyridine, which forms a slurry.

Desired Deliverables from BHS Process & Filtration Lab Testing Applicable slurry characteristic data such as drying curve, chemical properties, etc. BHS Report that recommends optimum thin-cake filter technology and scale-up Path forward actions for on-site rental system

Timing for Lab Testing Three weeks from receipt of reaction chemicals and all operating data

Raw Material Quantities Precipitated Reaction Solids by BHS Required pyridine by client

MSDS Information The MSDS are provided under separate e-mail attachments.

TECHNICAL PROCESS OVERVIEW: Titration Reaction Precipitated Reaction Solids (aqueous) + Pyridine --------> Slurry

Use stoichiometric amount of pyridine Reaction is run at mild conditions (mixed batch reactor at ambient temperature) under inert nitrogen atmosphere. Reaction in a 6 L vessel; reaction rate is essentially instantaneous. Mild exothermic temperatures rise based on lab studies; the temperature rise is mainly attributed to heat of mixing. Reaction solids precipitate out of solution as a solid. About 10% solid solution from reactors

Recovery of solids by Thin-Cake Pressure or Vacuum Filtration The agglomerated and individual particle size distribution by BHS Agglomerated d50, d80 and d97 Individual particle size d50, d80 and d97 Depending on method of isolation of solids, wet cake will be between 30-50% solids and very sticky and pasty Dried product is easy to handle and does not appear to dust very much

Precipitated Reaction Solids Wash Wash excess NaOH, NaCl, free Pyridine and other components from the solids. Wash water to be 40-50°C in order to meet chloroform-insoluble specification. Extremely acidic wash water should be avoided to prevent product decomposition. Target pH on final water exiting wash is pH = 7-8.

Aqueous Waste Disposal: Waste will be generated due to washing to meet target pH. The aqueous waste composition is estimated to contain Water, NaOH, NaCl, and Pyridine and trace amounts of other solvents All waste will be shipped back to client for aqueous waste disposal.

Drying Target dryness of maximum 1.0 wt % water. Product is microcrystalline and does not aggregate when dry. The solid has good flowability when dry. To prevent concerns around flammability with pyridine (FP = 20°C), drying should be done under a nitrogen-blanketed atmosphere. The drying temperature to be below 100°C (Maximum temperature = 150°C).

BHS Summary Report Summary Test Purposes Test Methods Test Facilities Test Data Test Results 6.1 Filtrate Quality 6.2 Filtration Time 6.2.1 Filtration Time vs. Feed Volume 6.2.2 Filtration Time vs. Pressure 6.2.3 Cake Height vs. Feed Volume 6.3 Cloth Blinding 6.4 Cake Discharge

Selection of Production Equipment and Scale-Up Conclusions and Path Forward Actions For further information about BHS process reaction and filtration testing capabilities, please contact the BHS process department or visit You can also visit our BHS partner CHD specializes in consulting for the development and improvement of existing chemical plants, manufacturing processes and unit operations, hands on process simulation and improvement studies and testing and selection of specific applications in cooperation with BHS-Filtration Inc.


BHS-Filtration Inc. uniquely specializes in thin-cake filtration, cake washing and drying technologies. BHS filters provide alternatives to centrifuges, nutsche filters, rotary vacuum filters and filter presses as well as manual plate filters.