Methods, systems, and apparatus for mass flow are provided. The apparatus can include a housing, an inlet disposed at a first end of the housing, and an outlet disposed at a second end of the housing. The housing can include a first section and a second section. The second section can have at least one tapered sidewall that slopes away from an inner surface of the first section toward the outlet. The apparatus can also include a divider disposed at least partially within the first and second sections of the housing. The divider can have at least one tapered surface disposed proximate the at least one tapered sidewall of the second section. An edge of the divider can be located between the outlet and a point within the second section where the cross-sectional area of the second section is about three times or less a cross-sectional area of the outlet.