Apparatus and a method for generating droplets

A method comprising:

• generating a droplet stream from a liquid dispenser comprising a liquid outlet adapted to generate a collimated droplet stream;
• generating a confinement fluid flow within a first fluid flow device to confine the trajectory of the droplet stream, wherein the droplet stream is generated within the confinement fluid flow and exits from an outlet of the first fluid flow device, wherein the liquid outlet is arranged so as to dispense the droplets within a first conduit of the first fluid flow device;
• and
• generating a reaction fluid flow within a second fluid flow device for reacting with droplets in the droplet stream, wherein the confinement fluid flow is generated within the reaction fluid flow, and wherein the droplet stream exits a second conduit of the second fluid flow device.

A method of generating a collimated stream of droplets from a flow focusing nozzle comprising a discharge orifice, a first fluid dispenser comprising a liquid outlet adapted to generate the collimated stream of droplets, wherein the liquid outlet is arranged so as to dispense the collimated stream of droplets within a first conduit of the first fluid dispenser, and a second fluid dispenser, wherein the stream of droplets exits a second conduit of the second fluid dispenser, and wherein the second fluid dispenser is arranged to accelerate, with a carrier fluid, a fluid being dispensed from the first fluid dispenser out of the discharge nozzle, the method comprising configuring the flow focusing nozzle to obtain a geometric standard deviation of the disbursement of droplets from the collimated stream of droplets of less than 1.6 according to the expression:

• (
• D
• 2
• ⁢
• Δ
• ⁢
• ⁢
• P
• 2
• ⁢
• ρ
• l
• 2
• ⁢
• Q
• l
• σ
• ⁢
• ⁢
• μ
• l
• 3
• )
• 1
• /
• 4
• ≤
• 1
• +
• 0.5
• ⁢
• (
• ρ
• l
• ρ
• d
• )
• 1
• +
• 0.018
• ⁢
• (
• μ
• l
• μ
• d
• )
• where D is the nominal diameter of the discharge orifice, AP is the pressure of the carrier, ρl is the density of the fluid being dispensed, Ql is the flow rate of the fluid being dispensed from the first fluid dispenser, σ is the surface tension between the fluid being dispensed and the carrier fluid, μl is the viscosity of the fluid being dispensed, ρd is the density of the carrier fluid, and μd is the viscosity of the carrier fluid.