Abstract To prevent marine risers' resonance and eliminate potential threats, sufficient inherent dynamic characteristics such as natural frequency, modal displacement, slope, bending moment, shear are necessary to be calculated analyzed. However, most studies calculate the frequencies displacements directly rather than slopes forces. The additional calculations of forces likely result in issue...

The occurrence of the severe slugging phenomenon in multiphase pipelines can cause serious and troublesome operational problems within the receiving process facilities. This paper describes: the pipeline operability studies on the Dunbar to Alwyn multiphase pipeline regarding riser-induced severe slugging; the control scheme selected to prevent this phenomenon; and the subsequent operating expe...

A steel catenary riser (SCR) attached to a floating platform at its upper end encounters fluctuations in and near its touchdown zone (TDZ), which causes the interaction with the seabed. Subsea surveys and the analysis of SCR’s indicated that the greatest stress and highest damage occurred near the touchdown point (TDP), where the SCR first touches the seabed. Nowadays, the linear seabed spring ...

RISER, M., GERAUD, J., RASCOL, X., RISER, A. & SAINTMARC, M. (1957) Syndrome de Guillain-Barr6 et Strohl a evolution ascendante avec hypertension intra-cranienne. Bulletin et MWmoires de la Soci&t medicale des Hopitaux de Paris, 73, 689. SARACCO, J.B., GENEVET, J. & MOULY, A. (1971) Atrophie optique et dissociation albumino-cytologique. Bulletin des socigtts d'ophtalmologie de France, 71, 637. ...

Radial profiles of particle velocities were investigated in a 6.1m high methanol-to-olefins cold model experimental device using a TSI laser Doppler velocimeter. The effect of axial height on flow development was not obvious in fully developed region under the same operating condition. Superficial gas velocity and solid circulating rate had significant influence on particle velocity in the cent...

Vortex induced vibrations (VIV) of long flexible risers subjected to ocean currents exhibit a strongly nonlinear phenomenon. Although significant efforts have been done for the frequency or time-frequency analysis of this complicated phenomenon, an effective method is still lacking. The objective of this paper is to provide a new method — a Prony-based method — for analyzing the time-varying fr...

CFB reactors are increasingly used for both gas catalytic and gas/solid reactions. Gas flow patterns in the riser are important in their design and subject of the present research. A literature review on the gas mixing in the riser highlights the contradictory results of previous investigations for CFB risers: some investigators neglected back-mixing of gas, whereas others report a considerable...

In the conducted investigations, aluminium dross, i.e. solid waste formed in the production and recycling of aluminium, was used as one of the basic raw materials to obtain a material characterised by insulating and exothermic properties, applied to heat riser heads in the process of iron or steel casting. The product was obtained by filtrating the slurry. In the raw mix, aluminium dross played...