CONFLOW

President Engineering Group Ltd (PEGL) was established in 2010 through a management buyout from the Flow Group involving the Conflow and Bestobell Valves businesses.

Conflow manufactures dust suppression, fire suppression, and water control equipment for mining industries, supplying mainly international markets.

Dans le but d'evaluer la possibilite que des eruptions sous-marines puissent se produire a des profondeurs depassant 1 km, on a eu recours au programme de modelisation numerique 1D CONFLOW. Ce programme permet de tenir compte de la composition magmatique, du diametre et de la longueur du conduit ainsi que de la temperature et de la pression initiales a la base du conduit, dans le calcul du gradient de pression dans un conduit de lumiere constante, de l'enthalpie du magma, de la viscosite du melange des composantes magmavolatiles sous des conditions P-T definies, de la profondeur de fragmentation ou le volume du gaz fractionne atteint 75 % ([v.sub.g] [congruent to] 0.75), de meme que de la velocite a la sortie du melange des composantes magmatiques-gazeux.

The main focus is on CONFLOW (Mastin and Ghiorso, 2000) modelling, which is used to investigate the depth limits of pyroclastic eruptions in a subaqueous environment.

To evaluate the conditions necessary for a submarine pyroclastic eruption to occur at depths of greater than 1 km and even those greater than 3.5 km (beyond the critical point of seawater), we applied the 1-D numerical model CONFLOW (Mastin and Ghiorso, 2000).

To constrain the number of models generated using CONFLOW, we have chosen to present a model using Burnham's criteria for a shallow level magma chamber (1.4 km below sea floor) erupted in 3.5 km water depth.

The CONFLOW model predicts that magmatic fragmentation will occur at 5, 10, 12, and 15 wt.

The CONFLOW model predicts that magmatic fragmentation will occur for all water contents tested, from just below saturated (5 wt.

Combining the use of volatile phase expansion and modelling using CONFLOW, the plausibility of deep submarine pyroclastic volcanism becomes apparent.

The CONFLOW and volume expansion models presented in this paper only take the pure water system into consideration.