Fluid reservoir and method of supplying a fluid

A fluid supply system 100 comprising a fluid reservoir 101, a fluid supply pump 103 having a fluid supply connection 105, a fluid return pump 113 having a fluid return connection 115, and a recirculation droplet ejection head 107. The fluid reservoir 101 comprises a conical portion 101a, a filling portion (110, Fig.4A), a fluid outlet 101a_out and a fluid return inlet 101a_in. The conical portion has a cross-section (101a_s, Fig.2A) on a plane perpendicular to its main axis (101a_a, Fig.2B). The fluid return inlet has a central bore with a main axis (20, Fig.2C). The fluid return inlet is arranged on the conical portion at the cross-section. The angle (μ, Fig.2B) formed in the plane of the cross-section between the main axis of the fluid return inlet bore and a tangent (101a_s_tan, Fig.2B) to the cross-section, at the point where the cross-section is intersected by the fluid return inlet bore main axis, is not equal to 90° such that, in use, a component (20_f_tan, Fig.2B) of the direction of (flow 20_f, Fig.2C) of the fluid entering the conical portion is tangential to the cross-section to encourage flow of fluid around the conical portion.