Moving bulk solids

The new building, which is on Greenwich University’s campus at Chatham Maritime, houses large scale test facilities, such as flow-through hoppers, which mirror the operations of real industrial plant. The purpose built facilities at Medway are up and running although some of the larger test rigs are still being installed and commissioned and will not be brought into operation until later in the year.

‘Business is going well,’ says centre director, Professor Alan Reed. ‘All of our pilot facilities are up and running. We are now prioritising our efforts on the bigger rigs. The majority of our work is powder related, centred round the rapid filling of tankers and containers.’ One of the department’s research goals is ‘getting material to flow reliably in a dust-free way’.

In today’s process industries, especially in the food and beverage and pharmaceuticals sectors, ingredients are sourced from many suppliers and although they may be chemically identical, there are often physical differences between materials from various sources. ‘Users rarely think about the physical nature of their raw materials,’ commented Reed. And this is where the Wolfson Centre can help with its valuable research on the flowability of materials.

Earlier last year, the centre was praised by the government’s Lambert Review of Business-University Collaboration for its work with the pharmaceutical giant GlaxoSmithKline, which led to substantial savings for the company. The report cited the centre as an example of good practice and for providing value to businesses with the research it undertakes.

Contract research is the centre’s primary function. Focused teams provide research, consultancy and educational services to industry in technologies associated with the storage, handling and physical processing of powders and granular solid material.

The University of Greenwich specialists have undertaken more than 270 research, consultancy and educational contracts for industrial organisations in the past nine years. These contracts have been with numerous small and medium-sized businesses, alongside programmes for such multi-nationals as BP, Blue Circle-Lafarge, Corus, Exxon, GlaxoSmithKline, ICI, Kellogg’s, Nestle and Tate & Lyle.

The Wolfson Centre has a worldwide reputation for research, specialising in the design and use of machinery for handling bulk materials. These include diverse products such as sugar, cement, coal, pharmaceuticals and chocolate cake mix. Its staff advise manufacturers in the chemical, oil, food and mineral sectors.

The Centre has an international reputation as a world-leader in its field. In recognition of its importance not only did the Wolfson Foundation — a major charitable organisation committed to the advancement of science and technology, health, education, the arts and humanities — assist with the initial development of the centre and its research programmes but, in a rare move for a charitable trust, it has made a second contribution to the new and improved facilities at Chatham Marine.

The Wolfson Centre has specialised in solving materials handling problems since its foundation in 1973. It began its existence researching problems associated with pneumatic conveying of powders and granular solid material in pipelines and has since expanded its main areas of research interest to include hopper and silo design, and instrumentation and control of bulk solids handling systems.

Recent research and development work has focused on the issue of product quality — in particular predictive techniques relating to the propensity for some particulate materials to degrade during handling operations, segregate or cake in storage. A common theme to all of the work is its applied nature to industrial problems.

The Wolfson Centre is continually improving the understanding of the behaviour of particulates in handling and storage systems and can offer design, research and other consultancy services to industry. ‘Many clients value our complete independence from equipment suppliers,’ says Reed. ‘leaving us free to recommend equipment purely on the basis of fitness for purpose and not because of any vested interest.’

The Centre’s expertise base was widened in 1980 to include hopper and silo design, and instrumentation and control of bulk solids handling systems. In 1987 more facilities, accounting for more than 1000m2 of floor space, were completed at the Woolwich Dockyard site.

The move to Chatham Marine became necessary when the Centre needed more room. The need to replicate the plant used to process powders in the industrial environment became apparent. And this requirement meant that the laboratories needed to be bigger, especially in height. The building design, however, is sympathetic to others around it following close liaison with Medway Council during the design and construction phases.

SIDEBAR

Research activities at the Wolfson Centre are aimed at addressing problems found in industry and increasing the understanding applied to bulk solids handling. Recent research projects include:

• Analysis of particle erosion in pneumatic conveying pipelines
• Modelling of flows in the vicinity of  local exhaust ventilation
• Segregation of free flowing particulate materials
• Pressure loss in pneumatic conveying pipelines
• Particle degradation in pneumatic  conveying systems
• Design of silos and hoppers for reliable  gravity flow
• Analysis and control of pulverised fuel in pneumatic conveying pipelines
• Development of a method for predicting wear in hoppers and chutes
• The influence of temperature and work hardening on the solid particle  erosion of steels
• Predictive model for determining the life  of pneumatic conveyor bends subject to erosive wear
• Investigations into caking tendencies for particulates
• Teaching Company Scheme
• New development of online flow property measurement for bulk solids
• New modelling of elutriation effects and subsequent segregated deposition of fine particulates
• New engineering ‘the Green State of  Powder Products’