- document
-
Kramer, O.J.I. (author)In drinking water treatment plants, multiphase flows are a frequent phenomenon. Examples of such flows are pellet-softening and filter backwashing where liquid-solid fluidisation is applied. A better grasp of these fluidisation processes is needed to be able to determine optimal hydraulic states. In this research, models were developed, and...doctoral thesis 2021
- document
-
Kramer, O.J.I. (author), van Schaik, C. (author), Hangelbroek, J.J. (author), de Moel, P.J. (author), Colin, M.G. (author), Amsing, M. (author), Boek, E.S. (author), Breugem, W.P. (author), Padding, J.T. (author), van der Hoek, J.P. (author)Liquid-solid fluidisation is frequently encountered in drinking water treatment processes, often to obtain a large liquid-solid interfacial surface area. A large surface area is crucial for optimal seeded crystallisation in full-scale softening reactors. Due to crystallisation, particles grow and migrate to a lower zone in the reactor which...journal article 2021
- document
-
Kramer, O.J.I. (author), de Moel, P.J. (author), Baars, E.T. (author), van Vugt, W.H. (author), van der Hoek, J.P. (author)Natural particles are frequently applied in drinking water treatment in up-flow fluidisation processes. Additionally, sedimentation processes are applied to clarify water and to concentrate solids. To estimate the terminal settling velocity of single solid particles in a liquid system, a comprehensive collection of equations is available. For...conference paper 2017
- document
-
Kramer, O. (author), Jobse, M.A. (author), Baars, E.T. (author), van der Helm, A.W.C. (author), Colin, M.G. (author), Kors, L.J. (author), van Vugt, W.H. (author)Softening at drinking water treatment plants is often realised by fluidised bed pellet reactors. Generally, sand is used as seeding material and pellets are produced as a by-product. To improve to sustainability, research has been carried out to replace the seeding material by re-using grained and sieved calcite pellets as seeding material. An...conference paper 2015
- document
-
Hofs, B (author), Baars, ET (author), Palmen, LJ (author), Elings, JA (author), Kors, L.J. (author), Kramer, O.J.I. (author), Koppers, H (author), van der Hoek, J.P. (author)About 50% of the drinking water in the Netherlands is centrally softened by the drinking water companies in a process known as pellet softening. In this process a base and seeding material are mixed in an upflow reactor, where subsequently CaCO3 precipitates on a seed core as pellets. The seeding material is usually sand, but recently CaCO3 was...conference paper 2015