Decontamination

A decontaminating system comprising:

• a decontaminant reservoir;
• a transport fluid source;
• and
• a mist generating apparatus having a longitudinal axis, the apparatus comprising:
• a curved divergent-convergent first fluid passage having a first fluid inlet in fluid communication with the decontaminant reservoir, the first fluid inlet defining an inlet area, an annular first fluid outlet defining an outlet area, and an intermediate portion defining an intermediate area greater than each of the inlet area and the outlet area, the curved divergent-convergent first fluid passage having an outer surface with a curved profile between at least the intermediate area and outlet area;
• and
• a convergent-divergent second fluid passage having a second fluid inlet in fluid communication with the transport fluid source and an annular second fluid outlet,
• wherein the first fluid passage surrounds the second fluid passage, and
• the first and second fluid outlets are oriented relative to one another such that they have an angle of incidence of less than 90 degrees;
• wherein a cross-sectional area of the second fluid outlet is larger than a cross-sectional area of the first fluid outlet;
• and
• the second fluid passage includes a throat portion located between the second fluid inlet and the second fluid outlet, the throat portion having a smaller cross sectional area than that of either the second fluid inlet or the second fluid outlet such that the area ratio between the throat portion and the second fluid outlet is between 2:3 and 1:4.

A method of generating a decontaminating mist, the method comprising:

• passing a decontaminant fluid through a curved divergent convergent first fluid passage of a mist generating apparatus, wherein the first fluid passage has an annular first fluid outlet defining an outlet area, and an intermediate portion defining an intermediate area greater than each of an inlet area and the outlet area, the curved divergent-convergent first fluid passage having an outer surface with a curved profile between at least the intermediate area and outlet area;
• passing a transport fluid through a convergent-divergent second fluid passage of the mist generating apparatus, wherein the second fluid passage has an annular second fluid outlet and a throat portion, the throat portion having a smaller cross sectional area than the second fluid outlet, wherein the first and second outlets are oriented relative to one another such that they have an angle of incidence between 5 and 30 degrees;
• wherein a cross-sectional area of the second fluid outlet is larger than a cross-sectional area of the first fluid outlet;
• accelerating the flow of transport fluid through the throat portion of the second fluid passage;
• and
• ejecting the decontaminant and transport fluids from their respective outlets such that a stream of accelerated transport fluid issuing from the second fluid outlet imparts a shear force on a stream of decontaminant fluid issuing from the first fluid outlet, thereby at least partially atomising the decontaminant fluid to create a dispersed droplet flow regime.

A method of generating a decontaminating mist, the method comprising:

• passing a decontaminant fluid through a curved divergent-convergent first fluid passage of a mist generating apparatus, wherein the first fluid passage has an annular first fluid outlet defining an outlet area, and an intermediate portion defining an intermediate area greater than each of an inlet area and the outlet area, the curved divergent-convergent first fluid passage having an outer surface with a curved profile between at least the intermediate area and outlet area;
• passing a transport fluid through a convergent-divergent second fluid passage of the mist generating apparatus, wherein the convergent-divergent second fluid passage has an annular second fluid outlet and a throat portion, the throat portion having a smaller cross sectional area than the second fluid outlet such that the area ratio between the throat portion and the second fluid outlet is between 2:3 and 1:4, wherein the first and second fluid outlets are oriented relative to one another such that they have an angle of incidence of less than 90 degrees;
• wherein a cross-sectional area of the second fluid outlet is larger than a cross-sectional area of the first fluid outlet;
• accelerating the flow of transport fluid through the throat portion of the second fluid passage;
• and
• ejecting the decontaminant and transport fluids from their respective outlets such that a stream of accelerated transport fluid issuing from the second fluid outlet imparts a shear force on a stream of decontaminant fluid issuing from the first fluid outlet, thereby at least partially atomising the decontaminant fluid to create a dispersed droplet flow regime.

A method of providing a decontamination system comprising:

• providing a decontaminant reservoir;
• providing a transport fluid source;
• and
• providing a mist generating apparatus having a longitudinal axis, the apparatus comprising:
• a curved divergent-convergent first fluid passage having a first fluid inlet in fluid communication with the decontaminant reservoir, the first fluid inlet defining an inlet area, an annular first fluid outlet defining an outlet area, and an intermediate portion defining an intermediate area greater than each of the inlet area and the outlet area, the curved divergent-convergent first fluid passage having an outer surface with a curved profile between at least the intermediate area and outlet area;
• and
• a convergent-divergent second fluid passage having a second fluid inlet in fluid communication with the transport fluid source and an annular second fluid outlet,
• wherein the first fluid passage surrounds the second fluid passage, and the first and second outlets are oriented relative to one another such that they have an angle of incidence between 5 and 30 degrees;
• wherein a cross-sectional area of the second fluid outlet is larger than a cross-sectional area of the first fluid outlet;
• and
• the second fluid passage includes a throat portion located between the second fluid inlet and the second fluid outlet, the throat portion having a smaller cross sectional area than that of either the second fluid inlet or second fluid outlet.

A method of providing a decontaminating system comprising:

• providing a decontaminant reservoir;
• providing a transport fluid source;
• and
• providing a mist generating apparatus having a longitudinal axis, the apparatus comprising:
• a curved divergent-convergent first fluid passage having a first fluid inlet in fluid communication with the decontaminant reservoir, the first fluid inlet defining an inlet area, an annular first fluid outlet defining an outlet area, and an intermediate portion defining an intermediate area greater than each of the inlet area and the outlet area, the curved divergent-convergent first fluid passage having an outer surface with a curved profile between at least the intermediate area and outlet area;
• and
• a convergent-divergent second fluid passage having a second fluid inlet in fluid communication with the transport fluid source and an annular second fluid outlet,
• wherein the first fluid passage surrounds the second fluid passage, and
• the first and second outlets are oriented relative to one another such that they have an angle of incidence of less than 90 degrees;
• wherein a cross-sectional area of the second fluid outlet is larger than a cross-sectional area of the first fluid outlet;
• and
• the second fluid passage includes a throat portion located between the second fluid inlet and the second fluid outlet, the throat portion having a smaller cross sectional area than that of either the second fluid inlet or the second fluid outlet such that the area ratio between the throat portion and the second fluid outlet is between 2:3 and 1:4.