Apparatus and method protecting against attack by particulate chemical or biological agents

Abstract

Potentially harmful particulate materials introduced into an airflow drawn into a structure's HVAC system are sensed by sensors provided on an intake fan and protective measures are taken in response to such sensed presence.

1 . Apparatus comprising:
 a duct;   a fan impelling an air flow through the duct;   a sensor material on said fan which detects the presence of potentially harmful particulate material in the air flow impelled by the fan;   a duct closure mechanism located in the duct a distance downstream from the air flow impelled by the fan;   a controller coupled to said sensor material, to said fan, and to the duct closure mechanism, wherein the controller stops said fan and actuates the duct closure mechanism to seal a contaminated portion of the duct in response to receiving signals from the sensor material indicating that the sensor material detected potentially harmful particulate material in the air flow impelled by the fan; and   a plurality of measuring ports located downstream the fan for sampling to determine a depth to which the potentially harmful particulate material has reached within the duct.   
   
   
       2 . Apparatus according to  claim 1  wherein said sensor material is a piezoelectric material. 
   
   
       3 . Apparatus according to  claim 1  wherein said sensor material is an electrically resistive material. 
   
   
       4 . Apparatus according to  claim 1  wherein said sensor material is an electrical capacitive material. 
   
   
       5 . Apparatus according to  claim 1  wherein said sensor material is a chemically reactive material. 
   
   
       6 . Apparatus according to  claim 1  further comprising a fan brake coupled to said fan and to said controller for quickly stopping impelling operation of said fan upon detection of potentially harmful particulate material in an air flow impelled by the fan. 
   
   
       7 . (canceled) 
   
   
       8 . Apparatus according to  claim 1  further comprising
 a decontamination system coupled to said duct and to said controller which introduces into the portion of said duct between said fan and said duct closure mechanism a material effective to render harmless any potentially harmful particulate material impelled thereinto by the fan upon in response to the measuring ports detecting potentially harmful particulate material in the air flow impelled by the fan, and wherein the measuring ports detection determines an extent to which the duct needs to be decontaminated.   
   
   
       9 . Apparatus comprising:
 a structure;   a fan impelling an air flow;   ductwork within said structure communicating with said fan and distributing the impelled air flow within said structure;   a sensor material on said fan which detects the presence of potentially harmful particulate material in the air flow impelled by the fan;   a duct closure mechanism located in the ductwork a distance downstream from the air flow impelled by the fan;   a controller coupled to said sensor material, to said fan, and to the duct closure mechanism, wherein the controller stops said fan and actuates the duct closure mechanism to seal a contaminated portion of the ductwork in response to receiving signals from the sensor material indicating that the sensor material detected potentially harmful particulate material in the air flow impelled by the fan; and   a plurality of measuring ports located downstream the fan for sampling to determine a depth to which the potentially harmful particulate material has reached within the duct.   
   
   
       10 . Apparatus according to  claim 9  further comprising a fan brake coupled to said fan and to said controller for quickly stopping impelling operation of said fan upon detection of potentially harmful particulate material in an air flow impelled by the fan. 
   
   
       11 . Apparatus according to  claim 9  further comprising
 a decontamination system coupled to said ductwork and to said controller which introduces into the portion of said ductwork between said fan and said duct closure mechanism a material effective to render harmless any potentially harmful particulate material impelled thereinto by the fan in response to the measuring ports detecting potentially harmful particulate material in the air flow impelled by the fan, and wherein the measuring ports detection determines an extent to which the ductwork needs to be decontaminated.   
   
   
       12 . A method comprising:
 providing sensors for particulate material on the blades of an intake fan which impels a flow of air into a duct of a HVAC system;   sensing with the sensors the presence of potentially harmful particulate material in the air flow impelled by the fan;   responding to the sensed presence of potentially harmful particulate material by stopping operation of the fan and actuating a duct closure mechanism to seal a contaminated portion of the duct in response to receiving signals from the sensor material indicating that the sensor material detected potentially harmful particulate material in the air flow impelled by the fan; and   sampling airflow with a plurality of measuring ports located downstream the fan to determine a depth to which the potentially harmful particulate material has reached within the duct.   
   
   
       13 . A method according to  claim 12  wherein the provision of sensors comprises applying to the blades of an intake fan a material which responds electrically to the presence of potentially harmful particulate material. 
   
   
       14 . A method comprising:
 sensing at an airflow impelling fan the presence of potentially harmful particulate material in an air flow impelled by the fan through a duct;   responding to the sensed presence of potentially harmful particulate material by stopping operation of the fan and actuating a duct closure mechanism to seal a contaminated portion of the duct in response to receiving signals from the sensor material indicating that the sensor material detected potentially harmful particulate material in the air flow impelled by the fan, wherein actuating the duct closure mechanism blocks distribution of the impelled airflow downstream of the fan, and trapping a contaminated portion of the impelled airflow;   sampling the airflow with a plurality of measuring ports located downstream the fan to determine a depth to which the potentially harmful particulate material has reached within the duct   decontaminating the trapped portion of the airflow in response to the measuring ports detecting potentially harmful particulate material in the airflow impelled by the fan, wherein the measuring ports detection determines an extent to which the duct needs to be decontaminated.   
   
   
       15 . (canceled) 
   
   
       16 . Apparatus according to  claim 1 , further comprising
 a secondary uncontaminated source of air released to circulate in the portion of the duct having the contaminated air flow in a counter current direction with respect to the air flow.   
   
   
       17 . Apparatus according to  claim 16 , further comprising:
 a container releasing an agent into the portion of the air duct to inactivate the contaminated air directed by the secondary uncontaminated source of air released in the counter current direction.   
   
   
       18 . Apparatus according to  claim 17 , further comprising
 a holding vessel to trap a mist containing the contaminated air mixed with the agent related into the portion of the air duct.   
   
   
       19 . (canceled) 
   
   
       20 . A method according to  claim 12 , further comprising
 releasing a secondary uncontaminated source of air released in the portion of the duct having the contaminated air flow in a counter current direction with respect to the air flow.   
   
   
       21 . A method according to  claim 20 , further comprising:
 releasing an agent from a container into the portion of the air duct to inactivate the contaminated air directed by the secondary uncontaminated source of air released in the counter current direction.   
   
   
       22 . A method according to  claim 21 , further comprising
 trapping in a holding vessel a mist containing the contaminated air mixed with the agent released into the portion of the air duct.   
   
   
       23 . The method of  claim 1 , wherein the plurality of measuring ports comprises at least three measuring ports located sequentially along the duct. 
   
   
       24 . The apparatus of  claim 9 , wherein the plurality of measuring ports comprises at least three measuring ports located sequentially along the ductwork. 
   
   
       25 . The method of  claim 12 , wherein the plurality of measuring ports comprises at least three measuring ports located sequentially along the duct. 
   
   
       26 . The method of  claim 14 , wherein the plurality of measuring ports comprises at least three measuring ports located sequentially along the duct.