Tabletop bio-safty air curtain

Abstract

A tabletop laminar flow HEPA filtered air curtain, for use as a bio-safety separation barrier for the personal protection of individuals from a respired aerosol, is provided. The air curtain has a rectangular cabinet. The cabinet is partitioned into a fan housing, in fluid communication, with a HEPA filter box. The fan housing has an air intake. A fan assembly is mounted in the fan housing. The fan assembly has a ducted housing, in fluid communication with the ambient air intake, and a blower. A horizontal HEPA filter is mounted in the filter box so that a blower discharge passes through the HEPA filter, and upwardly and uniformly through an elongated laminar flow nozzle in a top wall of the filter box.

I claim: 
     
         1 . A tabletop laminar flow air curtain of for the protection of individuals from a respired aerosol, comprising:
 (a) a rectangular cabinet, of a ducted construction, having top, bottom, side and end-cap walls, wherein said ducted construction is partitioned into a fan housing in fluid communication with a HEPA filter box;   (b) at least one ambient air intake opening in said fan housing;   (c) a fan assembly, mounted in said fan housing, including a ducted housing being in fluid communication with said air intake, and adapted to redirect an aerosolized volume of said ambient air, in a specific direction, as an blower discharge air into a lower portion of said filter box;   (d) a horizontal HEPA filter mounted above said lower portion of said filter box so that said blower discharge air is a filtered blower discharge air, by passing upwardly through said HEPA filter, in said filter box; and   (e) an elongated nozzle in said top wall of said filter box having a gap being adapted to uniformly pass said filtered blower discharge air as a vertical laminar flow curtain of air so that a biosafety barrier is maintained between the individuals to be protected.   
     
     
         2 . The tabletop laminar flow air curtain according to  claim 1 , further comprising at least one grill attached to an outside wall of at least one of said side walls. 
     
     
         3 . The tabletop laminar flow air curtain according to  claim 1 , wherein the fan is a centrifugal fan. 
     
     
         4 . The tabletop laminar flow air curtain, according to  claim 2 , wherein the grill is a removable filter housing, and further comprising a media filter positioned in said removable filter housing. 
     
     
         5 . The tabletop laminar flow air curtain, according to  claim 3 , wherein the nozzle gap is in a range of 11 to 14 millimeters and the velocity of the filtered blower discharge an air-flow-rate in the range of 3 to 5 meters per second. 
     
     
         6 . The tabletop laminar flow air curtain, according to  claim 3 , wherein the tabletop laminar flow air curtain has a Volumetric Flow Rate in the range of 0.02 to 0.05 m3/s. 
     
     
         7 . A method for using of a tabletop laminar flow air curtain, as a bio-safety separation barrier, for the protection of individuals being seated oppositely from one another, from a large droplet respired aerosol transmission of a viral agent, comprising the steps of:
 (a) Providing a rectangular cabinet, of a ducted construction, having top, bottom, side and end-cap walls, wherein said ducted construction is partitioned into a fan housing in fluid communication with a HEPA filter box;   (b) Providing at least one ambient air intake opening in said fan housing;   (c) Providing a fan assembly, mounted in said fan housing, including a ducted housing being in fluid communication with said air intake, and adapted to redirect an aerosolized volume of said ambient air, in a specific direction, as an blower discharge air into a lower portion of said filter box;   (d) providing a horizontal HEPA filter mounted above said lower portion of said filter box so that said blower discharge air is a filtered blower discharge air, by passing upwardly through said HEPA filter, in said filter box;   (e) providing an elongated nozzle in said top wall of said filter box having a gap being adapted to uniformly pass said filtered blower discharge air as a vertical laminar flow curtain of air so that a biosafety barrier is maintained between the individuals to be protected;   (f) positioning the bottom wall of the rectangular cabinet on a tabletop between the seated individuals to be protected; and   (g) powering the fan assembly wherein the individuals to be protected are separated by the bio-safety separation barrier.   
     
     
         8 . The method according to  claim 7 , further comprising, the steps of providing at least one grill attached to an outside wall of at least one of said side walls. 
     
     
         9 . The method according to  claim 7 , wherein the fan is a centrifugal fan. 
     
     
         10 . The method according to  claim 7 , wherein the viral agent is an RNA virus. 
     
     
         11 . The method according to  claim 9 , wherein the grill is a removable filter housing and further comprising, the step of providing a media filter positioned in said removable filter housing. 
     
     
         12 . The method according to  claim 9 , wherein the nozzle gap is in a range of 11 to 14 millimeters and the velocity of the filtered blower discharge air is at an air-flow-rate in the range of 3 to 5 meters per second. 
     
     
         13 . The method according to  claim 9 , wherein the tabletop laminar flow air curtain has a Volumetric Flow Rate in the range of 0.02 to 0.05 m3/s. 
     
     
         14 . The method according to  claim 9 , wherein the centrifugal fan generates a pressure in the range of 150-250 Pa. 
     
     
         15 . The method according to  claim 9 , wherein the centrifugal fan generates a suction velocity inlet boundary condition measured at an outer surface of the media filter 3-6 m/s and a discharge velocity condition measured at the nozzle in the range of 3-6 m/s. 
     
     
         16 . The method according to  claim 9 , wherein the HEPA filter is 65 mm thick.