Programmable logic controller-based system and user interface for air

Abstract

A system and method for sampling air at multiple locations in a controlled environment. The system and method includes automatic adjustment of mass flow rates and duration of vacuum connections (either via time elapsed or indirectly by volume) based on rates set by an operator. Additionally, the system and method enables users to monitor and control aspects of the system via network-connected devices. Additionally, the system enable a vacuum pump to be disconnected from power in response to a physical emergency button, a software-based emergency stop button available on network connected devices, and an automatic power disconnection in response to an abnormal mass flow reading that could potentially impact the vacuum pump.

1 - 30 . (canceled) 
     
     
         31 . A system for sampling air at multiple locations in a controlled environment comprising:
 a plurality of air sampling devices, each configured to monitor and test a volume of air within a controlled environment;   a plurality of vacuum connections, each configured to receive the volare of air from one of the plurality of air sampling devices;   a vacuum pump configured to draw the volume of air from the plurality of air sampling devices through the plurality of vacuum connections;   a contactor configured to deliver and control power to the vacuum pump; and   a flow center including a programmable logic controller (PLC) configured to monitor and control mass flow rates of air received by the plurality of vacuum connections,   wherein the system is configured to disconnect power to the vacuum pump in response to a determination that the mass flow rate of the volume of air received by one of the vacuum connections in flow communication to the vacuum pump is below a predetermined threshold.   
     
     
         32 . The system of  claim 31 , wherein the contactor comprises an emergency stop button configured to disconnect the power to the vacuum pump. 
     
     
         33 . The system of  claim 31 , further comprising:
 a graphical user interface (GUI) for receiving one or more setpoints indicative of a desired. mass flow rate at one of the air sampling devices;   
     
     
         34 . The system of  claim 33 , wherein the graphical user interface comprises an emergency stop button configured to disconnect power to the vacuum pump. 
     
     
         35 . The system of  claim 33 , wherein the graphical user interface is output by an operator interface terminal co-located with the flow center. 
     
     
         36 . The system of  claim 33 , wherein the graphical user interface is output by an operator interface terminal co-located with one of the plurality of air sampling devices. 
     
     
         37 . The system of  claim 33 , wherein the graphical user interface is output by a server to a network connected device. 
     
     
         38 . The system of  claim 33 , wherein the graphical user interface is output by a web server to a web browser of an internet-connected device. 
     
     
         39 . The system of  claim 33 , further comprising:
 a plurality of flow control valves, each configured to control a mass flow rate of the volume of air received by one of the vacuum connections;   a plurality of actuators, each configured to open and close one of the flow control valves; and   a plurality of flow sensors, each configured to sense the mass flow rate of the volume of air received by one of the vacuum connections, wherein   the flow center controls the mass flow rate of air received by the plurality of vacuum connections by:   determining errors indicative of the differences between the measured flow rates and the setpoints; and   outputting control signals to the plurality of actuators to reduce the differences between the measured flow rates and the setpoints.   
     
     
         40 . The system of  claim 39 , wherein:
 the plurality of air sampling devices comprises a first air sampling device and a second air sampling device;   the plurality of vacuum connections comprises a first vacuum connection configured to receive the volume of air from the first air sampling device and a second vacuum connection configured to receive the volume of air from the second air sampling device, the first and second vacuum connections in flow communication with the vacuum pump via a manifold; and   the PLC is configured to reduce the difference between the measured flow rate of the volume of air received by the first vacuum connection and the setpoint indicative of the desired mass flow rate at the first air sampling device caused by a change in the volume of air through the second vacuum connection.   
     
     
         41 . The system of  claim 39 , wherein the each of the flow control valves are configured to adjust such that a change in position of the flow control valve is proportional to the size of the difference between the set point and the measured flow rate of the vacuum connection corresponding to the respective flow control valve. 
     
     
         42 . The system of  claim 39 , wherein the each of the flow control valves are configured to adjust such that a rate of change in position of the flow control valve is proportional to a rate of change of the difference between the set point and the measured flow rate of the vacuum connection corresponding to the respective flow control valve. 
     
     
         43 . The system of  claim 31 , wherein the system is configured to output data indicative of the mass flow rates of the volumes of air received by the plurality of vacuum connections to an external device via a network connection. 
     
     
         44 . The system of  claim 43 , wherein the external device is a supervisory control and data acquisition system or data collection system. 
     
     
         45 . The system of  claim 43 , wherein the network connection includes communication via the internet and the external device receives the data via a web browser or remote desktop application. 
     
     
         46 . A method for sampling air at multiple locations in a controlled environment, the method comprising:
 monitoring and testing, by a plurality of air sampling devices, volumes of air within a controlled environment;   receiving, by a plurality of vacuum connections, the volumes of air from each of the plurality of air sampling devices;   drawing, by a vacuum pump, the volumes of air from the plurality of air sampling devices through the plurality of vacuum connections;   delivering and controlling power to the vacuum pump by a contactor;   monitoring and controlling, by a flow center including a programmable logic controller (PLC), mass flow rates of air received by the plurality of vacuum connections; and   disconnecting power to the vacuum pump in response to a determination that the mass flow rate of the volume of air received by one of the vacuum connections in flow communication to the vacuum pump is below a predetermined threshold.   
     
     
         47 . The method of  claim 46 , wherein the contactor comprises an emergency stop button configured to disconnect the power to the vacuum pump. 
     
     
         48 . The method of  claim 46 , further comprising:
 a graphical user interface (GUI) for receiving one or more setpoints indicative of a desired mass flow rate at one of the air sampling devices:   
     
     
         49 . The method of  claim 48 , wherein the graphical user interface comprises an emergency stop button configured to disconnect power to the vacuum pump. 
     
     
         50 . The method of  claim 48 , wherein the graphical user interface is output by an operator interface terminal co-located with the flow center. 
     
     
         51 . The method of  claim 48 , wherein the graphical user interface is output by an operator interface terminal co-located with one of the plurality of air sampling devices. 
     
     
         52 . The method of  claim 48 , wherein the graphical user interface is output by a server to a network connected device. 
     
     
         53 . The method of  claim 48 , wherein the graphical user interface is output by a web server to a web browser of an internet-connected device. 
     
     
         54 . The method of  claim 48 , further
 controlling, by a plurality of flow control valves, mass flow rates of the volumes of air received by each of the vacuum connections;   sensing, by a plurality of flow sensors, the mass flow rates of the volumes of air received by each of the vacuum connections;   determining the differences between the measured flow rates and the setpoints; and   outputting control signals to a plurality of actuators to adjust the flow control valves and reduce the differences between the sensed mass flow rates and the setpoints.   
     
     
         55 . The method of  claim 54 , wherein:
 the plurality of air sampling devices comprises a first air sampling device and a second air sampling device;   the plurality of vacuum connections comprises a first vacuum connection configured to receive the volume of air from the first air sampling device and a second vacuum connection configured to receive the volume of air from the second air sampling device, the first and second vacuum connections in flow communication with the vacuum pump via a manifold;   the PLC reduces the difference between the measured flow rate of the volume of air received by the first vacuum connection and the setpoint indicative of the desired mass flow rate at the first air sampling device caused by a change in the volume of air through the second vacuum connection.   
     
     
         56 . The method of  claim 54 , wherein the actuators adjust the flow control valves such that a change in position of the flow control valve is proportional to the size of the difference between the set point and the measured flow rate of the vacuum connection corresponding to the respective flow control valve. 
     
     
         57 . The method of  claim 54 , wherein the actuators adjust the flow control valves such that a rate of change in position of the flow control valve is proportional to a rate of change of the difference between the set point and the measured flow rate of the vacuum connection corresponding to the respective flow control valve. 
     
     
         58 . The method of  claim 56 , further comprising:
 outputting data indicative of the mass flow rates of the volumes of air received by the plurality of vacuum connections to an external device via a network connection.   
     
     
         59 . The method of  claim 58 , wherein the external device is a supervisory control and data acquisition system or data collection system. 
     
     
         60 . The method of  claim 58 , wherein the network connection includes communication via the Internet and the external device receives the data via a web browser or remote desktop application.