A pump assembly comprising: a pump casing; an impeller comprising: a front shroud partially disposed within a chamber; inducer vanes located on an inner surface of the front shroud; and a plurality of flow generating vanes extending from an outer surface of the front shroud, wherein the inducer vanes extend toward an axis of rotation of the impeller and are adjacent and in fluid communication with a first delivery passageway and a second delivery passageway, and wherein the flow generator vanes are adjacent and in fluid communication with a first flow circulating passageway a second flow circulating passageway; and a flow directing device mounted to the pump casing to enclose the impeller therebetween, the flow directing device being arranged in use for directing material in relation to the adjacent moving impeller, wherein the flow directing device includes a main body having an inner side and an outer side, and the chamber provided adjacent the inner side of the main body and in communication with the first and the second delivery passageways (91, 92), and wherein said main body includes a peripheral side wall section and a plurality of concentrically arranged ring shaped elements (95, 96, 97) operatively connected together and operatively connected to the peripheral side wall section, the annular spaces between the ring shaped elements defining a plurality of annular passageways (91, 92, 93, 94) that extend between the inner side and the outer side of the main body, wherein the plurality of annular passageways include: the first delivery passageway and the second delivery passageway for the in use delivery of material to an opening of the impeller; the first flow circulating passageway; and the second flow circulating passageway, wherein the first and second flow circulating passageways are for the in use circulation of a flow of material past the impeller. a pump casing; an impeller comprising: a front shroud partially disposed within a chamber; inducer vanes located on an inner surface of the front shroud; and a plurality of flow generating vanes extending from an outer surface of the front shroud, wherein the inducer vanes extend toward an axis of rotation of the impeller and are adjacent and in fluid communication with a first delivery passageway and a second delivery passageway, and wherein the flow generator vanes are adjacent and in fluid communication with a first flow circulating passageway a second flow circulating passageway; and a flow directing device mounted to the pump casing to enclose the impeller therebetween, the flow directing device being arranged in use for directing material in relation to the adjacent moving impeller, wherein the flow directing device includes a main body having an inner side and an outer side, and the chamber provided adjacent the inner side of the main body and in communication with the first and the second delivery passageways (91, 92), and wherein said main body includes a peripheral side wall section and a plurality of concentrically arranged ring shaped elements (95, 96, 97) operatively connected together and operatively connected to the peripheral side wall section, the annular spaces between the ring shaped elements defining a plurality of annular passageways (91, 92, 93, 94) that extend between the inner side and the outer side of the main body, a front shroud partially disposed within a chamber; inducer vanes located on an inner surface of the front shroud; and a plurality of flow generating vanes extending from an outer surface of the front shroud, wherein the inducer vanes extend toward an axis of rotation of the impeller and are adjacent and in fluid communication with a first delivery passageway and a second delivery passageway, and wherein the flow generator vanes are adjacent and in fluid communication with a first flow circulating passageway a second flow circulating passageway; and a flow directing device mounted to the pump casing to enclose the impeller therebetween, the flow directing device being arranged in use for directing material in relation to the adjacent moving impeller, wherein the flow directing device includes a main body having an inner side and an outer side, and the chamber provided adjacent the inner side of the main body and in communication with the first and the second delivery passageways (91, 92), and wherein said main body includes a peripheral side wall section and a plurality of concentrically arranged ring shaped elements (95, 96, 97) operatively connected together and operatively connected to the peripheral side wall section, the annular spaces between the ring shaped elements defining a plurality of annular passageways (91, 92, 93, 94) that extend between the inner side and the outer side of the main body, wherein the plurality of annular passageways include: the first delivery passageway and the second delivery passageway for the in use delivery of material to an opening of the impeller; the first flow circulating passageway; and the second flow circulating passageway, the first delivery passageway and the second delivery passageway for the in use delivery of material to an opening of the impeller; the first flow circulating passageway; and the second flow circulating passageway, wherein the first and second flow circulating passageways are for the in use circulation of a flow of material past the impeller.