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https://www.nwo-i.nl/nwo-domein-enw/onderzoeksprogrammas/industrial-partnership-programmes/nr-i36-heat-mass-transport-and-phase-transition-in-dense-bubbly-flows/

Geprint op :
14 december 2018
10:30:54

Approved Industrial Partnership Programme

 

Number i36
Title Heat, mass transport and phase transition in dense bubbly flows (DBF)
Executive organisational unit BUW
Programme management Prof.dr.ir. J.A.M. Kuipers
Duration 2014-2019
Cost estimate M€ 1.6
Partner(s) AkzoNobel, DSM, Sabic, Shell Global Solutions, Tata Steel

Objectives
The objective of the proposed programme is to study the fundamentals of heat & mass transport and phase transitions in dense bubbly flows, inspired by questions from the industrial practice, through a concerted action of three groups with a considerable expertise in the study of multiphase flows, with the aid of experimental, theoretical, and numerical techniques. Furthermore, we aim to educate people on a PhD level in the field of multiphase flows.

Background, relevance and implementation
Dispersed multiphase flows, i.e. flows with dispersed elements such as particles, droplets or bubbles, are frequently encountered in a variety of large scale manufacturing processes such as the large scale oil production and exploration, base chemicals and other products (polymers, fertilizers and detergents, to name just a few), as well as in cryogenic applications. Other examples involving multiphase flows include power production (combustion processes, electricity, and steam generation), natural and environmental phenomena (dune formation, sediment transport in rivers and coastal areas, and dispersion of pollutants). Multiphase flows and the (possible) interplay with the mass and heat transport processes are unfortunately very poorly understood which for a large extent can be attributed to the complex flow structure prevailing at the macroscopic scale, i.e., the scale of the process equipment. As a direct consequence thereof the design and scale-up of these processes is extremely cumbersome in practice (requiring extensive and time consuming experimentation).

Up till now practically all research on dispersed gas-liquid flow systems has focused on low volume fraction, homogeneous bubbly flows excluding the interplay between heat & mass transport and phase transitions in dense bubbly flows. However, in industry gas-liquid flow systems are not operated in the homogeneous flow regime, but rather in the heterogeneous flow regime, which is characterized by the presence of a distribution of small and big bubbles, resulting from the interplay between turbulence, coalescence and breakup. Furthermore, the complex heat and mass transport in heterogeneous bubbly flow systems, in particular in the presence of phase transitions, is not well understood.

Given the urgent need from industry, it is proposed (after consultations with the industrial partners) to focus on bubbly flows at high void fraction involving heat & mass transport and phase transition. This implies that we will focus on systems in heterogeneous flow regimes that typically arise at high superficial gas velocities. The scientific challenges can be summa­rized in terms of the following questions:
- What is the mass and heat transfer in heterogeneous bubbly flow, i.e. how do bubble swarm effects influence heat & mass transport and phase transition?
- What is the effect of heat & mass transport and phase transitions on the large scale system behaviour (flow structure, hold-up, large scale circulation patterns)?
- What are the combined effects of scale of operation (column diameter) and operating condi­tions on the hydrodynamics (flow structure, hold-up, large scale circulation patterns, coalescence and breakup)?

Remarks
The progress of the programme will be reported and presented bi-annually to the users committee, which consists of representatives of the involved industrial partners. In addition, workshops will be organised in consultation with the industrial partners on topics of interest for the programme. Staff exchange is planned both for the academic and industrial researchers to optimize knowledge exchange. The programme committee is responsible for the monitoring of the progress of the programme. Proposals for changes in the programme content and/or budget have to be granted by the steering committee. The chair of the programme committee acts as the programme leader. The final evaluation of this programme will consist of a self evaluation initiated by the programme leader and is foreseen in 2019.