  The flow of a charged-stabilized suspension through a single constricted
channel is studied experimentally by tracking the particles individually.
Surprisingly, the behavior is found to be qualitatively similar to that of
inertial dry granular systems: For small values of the neck-to-particle size
ratio (D/d<3), clogs form randomly as arches of particle span the constriction.
The statistics of the clogging events are Poissonian as reported for granular
systems and agree, for moderate particle volume fraction ($\phi\approx20\%$),
with a simple stochastic model for the number of particles at the neck. For
larger neck sizes (D/d>3), even at the largest $\phi$ ($\approx60\%$)
achievable in the experiments, an uninterrupted particle flow is observed,
which resembles that of an hourglass. This particularly small value of D/d at
the transition to a practically uninterrupted flow is attributed to the low
effective friction between the particles, achieved by the particle's
functionalization and lubrication.
