A fluid distribution cap (301) for a fluidized bed reactor, comprising a tunnel shaped structure having two opposing walls for attaching to a fluid distribution plate (103), and at least one opening at an end of the tunnel shaped structure. The tunnel shaped structure has an inner surface (302) and an outer surface (303), wherein the inner surface (302) has a curved cross section, and wherein the outer surface (303) has a substantially V-shaped cross section. A fluid distribution plate (103) for a fluidized bed reactor, comprising a plate having a plurality of fluid vent holes (113), a plurality of fluid distribution caps (301), wherein for each fluid vent hole (113) a fluid distribution cap (301) is mounted over said hole (113). At least two mutually neighboring fluid distribution caps (301) are positioned with an opening of a first of the two neighboring fluid distribution caps facing a side of the second of the two neighboring fluid distribution caps. A fluidized bed reactor having a fluid distribution plate (103) and a fluid distribution cap (301).