Mist generating apparatus and method
Apparati for generating a mist are disclosed. One apparatus is disclosed, which has an elongate hollow body ( 12 ) and an elongate member ( 14 ) located within the body ( 12 ). A transport fluid passage ( 16 ) and a nozzle ( 32 ) are defined between the body ( 12 ) and the elongate member ( 14 ). The transport fluid passage ( 16 ) has a throat portion of reduced cross-sectional area and is in fluid communication with the nozzle ( 32 ). The elongate member ( 14 ) includes a working fluid passage ( 26 ) and one or more communicating openings, such as for example, bores, annuli, and combinations thereof, ( 30 ) extending radially outward from the working fluid passage ( 26 ). The openings ( 30 ) permit a working fluid (e.g. water) to be passed into the transport fluid passage ( 16 ), whereupon the working fluid is subjected to shear forces by a high velocity transport fluid (e.g. steam). The shearing of the working fluid results in the generation of a mist formed from droplets of substantially uniform size. Methods of generating a mist using such apparati are also disclosed. Also provided are mists for fire suppression produced using an apparatus disclosed herein, as well as fire suppression systems that include any of the apparati disclosed herein. Further provided are devices, methods, and mists for various other applications including turbine cooling and decontamination.
1. An apparatus for generating a mist comprising:
a) an elongate hollow body; and
b) an elongate member located within the body such that a first transport fluid passage and a nozzle are defined between the body and the elongate member, the first transport fluid passage having a convergent-divergent internal geometry that forms a throat section and being in fluid communication with the nozzle, wherein the elongate member includes:
(i) a working fluid passage;
(ii) one or more first communicating openings positioned down-stream of the throat section and extending radially outwardly from the working fluid passage, the first communicating openings allowing fluid communication between the working fluid passage and the first transport fluid passage; and
(iii) one or more second communicating openings positioned down stream of the throat section and extending radially outward a second transport fluid passage, the second communicating, openings allowing fluid communication between the working fluid passage and the second transport fluid passage within the second communication openings,
wherein the first and second communicating openings are substantially perpendicular to the second and first transport fluid passages, respectively; and
(iv) a third transport fluid passage adapted to supply transport fluid into the second transport fluid passage adjacent the first and second communicating openings,
wherein the second and third transport fluid passages adjacent the first communicating openings have a convergent-divergent geometry.
2. The apparatus of claim 1 , wherein the first and second communicating openings are independently selected from the group consisting of communicating bores, communicating annuli, and combinations thereof.
3. The apparatus of claim 2 , wherein the first and second communicating openings are one or more communicating bores.
4. A mist for fire suppression, which mist is produced using an apparatus according to claim 1 .
5. The apparatus of claim 2 , wherein the first communicating openings are one or more communicating bores and the second communicating openings are one or more communicating annuli.
6. A fire suppression system comprising a mist generating apparatus that includes:
a) an elongate hollow body; and
b) an elongate member located within the body such that a first transport fluid passage and a nozzle are defined between the body and the elongate member, the first transport fluid passage having a convergent-divergent internal geometry that forms a throat section and being in fluid communication with the nozzle, wherein the elongate member includes
(i) a working fluid passage;
(ii) one or more first communicating openings positioned down-stream of the throat section and extending radially outwardly from the working fluid passage, the first communicating openings allowing fluid communication between the working fluid passage and the first transport fluid passage;
(iii) one or more second communicating openings positioned down-stream of the throat section and extending radially outward a second transport fluid passage, the second communicating openings allowing fluid communication between the working fluid passage and the second transport fluid passage within the second communication openings,
wherein the first and second communicating openings are substantially perpendicular to the second and first transport fluid passages, respectively; and
a third transport fluid passage adapted to supply transport fluid into the second transport fluid passage adjacent the first and second communicating openings, wherein the second and third transport fluid passages adjacent the first communicating openings have a convergent-divergent geometry.