An entry mixing element for mixing an incoming fluid flow having first and second unmixed components arranged so as to define a transverse flow cross-section perpendicular to a flow direction of the incoming fluid flow, the entry mixing element comprising: a central axis configured to be aligned with the flow direction of the incoming fluid flow; an entry dividing wall extending parallel to the central axis, and a planar front panel comprising an upper front panel portion and a lower front panel portion, the planar front panel being arranged at a leading edge of the entry dividing wall and extending generally transverse to the central axis, wherein the entry dividing wall and the planar front panel are positioned to divide the incoming fluid flow into a first fluid flow portion and a second fluid flow portion, each of the first and second fluid flow portions containing an amount of the first component and an amount of the second component, wherein the planar front panel and the entry dividing wall define an upper fluid gate in a first quadrant of the planar front panel through which the first fluid flow portion is directed, and define a lower fluid gate in a second quadrant of the planar front panel through which the second fluid flow portion is directed, wherein the upper front panel portion has a first edge that partially defines the lower fluid gate and a second edge opposite the first edge that partially defines an upper fluid slot that extends from the upper fluid gate, wherein the lower front panel portion has a first edge that partially defines the upper fluid gate and a second edge opposite the first edge that partially defines a lower fluid slot that extends from the lower fluid gate, wherein the entry dividing wall and the planar front panel are configured to divide the incoming fluid flow into the first and second fluid flow portions in any rotational orientation of the entry mixing element about its central axis relative to the transverse flow cross-section of the incoming fluid flow, wherein the planar front panel assists the entry dividing wall in dividing the incoming fluid flow into the first and second fluid flow portions, wherein the first fluid flow portion is directed through the upper fluid slot in addition to the upper fluid gate, and the second fluid flow portion is directed through the lower fluid slot in addition to the lower fluid gate, and wherein the planar front panel has a first dimension measured in a first direction transverse to the central axis and a second dimension measured in a second direction transverse to the central axis, the first direction and the second direction being perpendicular to one another and the first dimension being smaller than the second dimension so as to define the upper fluid slot and the lower fluid slot. a central axis configured to be aligned with the flow direction of the incoming fluid flow; an entry dividing wall extending parallel to the central axis, and a planar front panel comprising an upper front panel portion and a lower front panel portion, the planar front panel being arranged at a leading edge of the entry dividing wall and extending generally transverse to the central axis, wherein the entry dividing wall and the planar front panel are positioned to divide the incoming fluid flow into a first fluid flow portion and a second fluid flow portion, each of the first and second fluid flow portions containing an amount of the first component and an amount of the second component, wherein the planar front panel and the entry dividing wall define an upper fluid gate in a first quadrant of the planar front panel through which the first fluid flow portion is directed, and define a lower fluid gate in a second quadrant of the planar front panel through which the second fluid flow portion is directed, wherein the upper front panel portion has a first edge that partially defines the lower fluid gate and a second edge opposite the first edge that partially defines an upper fluid slot that extends from the upper fluid gate, wherein the lower front panel portion has a first edge that partially defines the upper fluid gate and a second edge opposite the first edge that partially defines a lower fluid slot that extends from the lower fluid gate, wherein the entry dividing wall and the planar front panel are configured to divide the incoming fluid flow into the first and second fluid flow portions in any rotational orientation of the entry mixing element about its central axis relative to the transverse flow cross-section of the incoming fluid flow, wherein the planar front panel assists the entry dividing wall in dividing the incoming fluid flow into the first and second fluid flow portions, wherein the first fluid flow portion is directed through the upper fluid slot in addition to the upper fluid gate, and the second fluid flow portion is directed through the lower fluid slot in addition to the lower fluid gate, and wherein the planar front panel has a first dimension measured in a first direction transverse to the central axis and a second dimension measured in a second direction transverse to the central axis, the first direction and the second direction being perpendicular to one another and the first dimension being smaller than the second dimension so as to define the upper fluid slot and the lower fluid slot.