Abstract
An apparatus including a sensor configured to sense total pressure within an inner chamber of a housing, and to sense differential pressure between the inner chamber of the housing and work area outside of the housing; a computer processor configured to receive signals from the sensor based on the total pressure and the differential pressure; and wherein the computer processor controls the rate at which the flapper oscillates based on the total pressure signal from the sensor, to thereby control the direction of flow of air from the inner chamber of the housing through the plurality of openings of the blade, through the plurality of openings of the teeth, for optimum containment with ultra stable vortex inside the chamber ; and controls the rate at which exhaust damper modulates based on differential pressure signal to maintain constant face velocity at the apparatus user opening and out an exhaust opening of the housing.
Claims
1. An apparatus comprising: a housing having an inner chamber, and an exhaust opening which allows air to escape from the inner chamber out through the exhaust opening; a first window device, including a first windowpane and a first window frame; wherein the first window device is connected to the housing, so that the first window device can be placed in a first state or a second state; wherein in the first state, the first window device covers a window opening in the housing, and in the second state, the first window device does not cover the window opening in the housing; wherein the window opening in the housing leads to the inner chamber of the housing; and an air device fixed to the housing, wherein the air device has an opening which permits air to go through the opening of the air device, into the housing, and into the inner chamber of the housing, and thereafter to escape out of the inner chamber of the housing through the exhaust opening.
2. The apparatus of claim 1 further comprising a flapper including a blade and teeth, each of which have a plurality of further openings; and wherein the flapper is configured to direct air flow from the inner chamber so that air passes through the plurality of further openings of the blade and the teeth of the flapper, and thereafter escapes out of the inner chamber of the housing through the exhaust opening.
3. An apparatus comprising a sensor configured to sense simultaneously total pressure within an inner chamber of a housing, and differential pressure between the inner chamber of the housing and outside of the housing; a computer processor which is configured to receive a signal from the sensor based on the total pressure and the differential pressure; a flapper connected to the housing adjacent to an exhaust opening of the housing, wherein the flapper has a blade having a plurality of openings, and teeth having a plurality of openings; a damper connected to housing at the exhaust opening of the housing, wherein the damper regulates the amount of air escaping from the inner chamber of the housing through the exhaust opening; and wherein the computer processor is programmed by computer software stored in computer memory to control a rate at which the flapper oscillates based on the total pressure signal from the sensor, to thereby control the direction of the flow of air from the inner chamber of the housing through the plurality of openings of the blade, through the plurality of openings of the teeth, and the computer processor also controls a rate at which the damper regulates the amount of air flow based on differential pressure signal from the sensor, to thereby maintain constant face velocity at the window opening, and out the exhaust opening of the housing.
4. The apparatus of claim 3 wherein one or more baffles with turning vanes are fixed to the housing, inside the inner chamber, and each of the one or more baffles includes one or more slots through which air flows inside of the inner chamber.
5. The apparatus of claim 3 wherein the computer processor is programmed by computer software stored in computer memory to control the damper which regulates the amount of air flow from the inner chamber escaping through the exhaust opening.
6. The apparatus of claim 4 further comprising a turning vane fixed to one of the one or more baffles inside of the inner chamber, adjacent to a slot opening of the one or more baffles.
7. A method comprising receiving air through an opening of an air device into an inner chamber of a housing; exhausting the air from the inner chamber of the housing out through an exhaust opening; wherein a first window device, including a first window pane and a first window frame, is connected to the housing, so that the first window device can be placed in a first state or a second state; wherein in the first state, the first window device covers a window opening in the housing, which is different from the exhaust opening and from the opening of the air device, and in the second state, the first window device does not cover the window opening in the housing; and wherein the window opening in the housing leads to the inner chamber of the housing.
8. A method comprising sensing total pressure within an inner chamber of a housing, and sensing differential pressure between the inner chamber of the housing and work area outside of the housing using a sensor; using a computer processor to receive a signal from the sensor based on total pressure and the differential pressure; using the computer processor to control the rate at which a flapper oscillates based on the signal from the sensor, to thereby control direction of flow of air from the inner chamber of the housing through a plurality of openings of a blade of the flapper, and through a plurality of openings of teeth of the flapper, and out an exhaust opening of the housing, and using the computer processor to control the rate at which a damper modulates air flow escaping from the inner chamber of the housing through the exhaust opening based on the signal from the sensor, to thereby regulate the flow of air from the inner chamber of the housing, and out an exhaust opening of the housing.
9. The method of claim 7 further comprising directing air flow within the housing by use of turning vanes within the inner chamber of the housing.
10. The method of claim 7 comprising opening a window in a vertical direction using an actuator controlled by electrical push button, to allow a window opening to the housing to be exposed and to allow air to flow into the inner chamber of the housing through the window opening.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 illustrates a frontal view of a fume hood in accordance with an embodiment of the present invention;
[0020] FIG. 2 depicts vertical cross sectional side view of fume hood of FIG. 1;
[0021] FIG. 3 illustrates a window system of the fume hood of FIG. 1;
[0022] FIG. 4 depicts a built-in airfoil in a window system of the fume hood of FIG. 1;
[0023] FIG. 5 illustrates a process and instrumentation diagram of fume hood alarm and control system;
[0024] FIG. 6 shows a simplified front view of air-straightening air-guiding automated flapper with oval and round bell mouth for use with the fume hood of FIG. 1, and part of the housing of the fume hood of FIG. 1;
[0025] FIG. 7 shows a simplified bottom view of the air-straightening air-guiding automated flapper with oval and round bell mouth of FIG. 6, and a part of the housing of the fume hood of FIG. 1;
[0026] FIG. 8A shows a simplified side view of the air-straightening air-guiding automated flapper with oval and round bell mouth of FIG. 6, and a part of the housing of the fume hood of FIG. 1, with the flapper in a first state, wherein a pivot blade and teeth of the flapper have been rotated or pivoted to the left
[0027] FIG. 8B shows the simplified side view as in FIG. 8A, but with the flapper in a second state, wherein a pivot blade and teeth of the flapper have been rotated from the state of FIG. 8A, to a central orientation;
[0028] FIG. 8C shows the simplified side view as in FIG. 8B, but with the flapper in a third state, wherein a pivot blade and teeth of the flapper have been rotated from the state of FIG. 8B to being oriented to the right;
[0029] FIG. 9 illustrates a three dimensional view of air-straightening air-guiding automated flapper as a part of a housing of the fume hood of FIG. 1; and
[0030] FIG. 10 depicts simplified three-dimensional view of the fume hood of FIG. 1.
DETAILED DESCRIPTION OF THE DRAWINGS
[0031] In the present application the following terms, in one or more embodiments are defined as follows:
[0032] Face Velocity: The average speed at which air passes perpendicular thru a fume hood opening (window or slots).
[0033] Turning Vanes: Angled smooth structure to change the direction of air in a plenum chamber in order to reduce resistance and turbulence.
[0034] Vortex: A mass of air that spins around very fast and pulls contaminants into its center.
[0035] Airfoil: A streamlined surface designed in such a way that air flowing around it produces useful motion.
[0036] Closed loop control: an automatic control method, apparatus and/or system in which an operation, process, or mechanism is regulated by feedback.
[0037] Microcomputer: a small computer and/or computer processor that contains a microprocessor as its central processor, and is programmed by computer software which may be stored in computer memory of the micro computer or computer processor.
[0038] FIG. 1 illustrates a frontal simplified view of a fume hood 10 in accordance with an embodiment of the present invention, with one or more clear safety glass windows or windowpanes 34a, 34b, 34c, and 34d in a closed state. FIG. 2 depicts simplified vertical cross sectional side view of fume hood 10. Referring to FIGS. 1 and 2, the fume hood 10 includes a damper 12 and an actuator 14. The fume hood 10 further includes an air-straightening air-guiding flapper 16 and its actuator 16a, a microcomputer alarm and control unit 18, a dual function sensor 20, baffles 22 and 24, fume hood interior chamber 46, fixed turning vanes 40a, 40b, 40c, 40d, 26 and 28, baffle slots 51, 52 and 53, a window system built-in multi-functional air foil 30, sliding and swing open horizontal windowpanes 34a, 34b, 34c, and 34d, gliding tracks 36, pivot guide shoes 50a, 50b, 50c and 50d, removable hinge mechanisms 44a and 44b, a vertical clear safety glass windowpane 32, pulleys 41a and 41b, cords 42a and 42b shown by dashed lines actuator 43, vertical sash 32 up/down push button hand control 47, light 38, and work surface 49.
[0039] FIG. 3 is a frontal simplified view of the fume hood 10 with one or more windows or windowpanes 34a-d in an open state. The windowpanes 34c and 34d have been slid to the right and the windowpanes 34a and 34b have been slid to the left from the state of FIG. 1 to the state of FIG. 3. Hinges 44a and 44b provide the ability to make the horizontal windowpanes bi-fold opening. Windowpane 32 opens fully vertically with manual lifting or electrical push button hand control 47 shown in FIG. 1
[0040] FIG. 4 depicts the built-in airfoil 30 in the window system of the fume hood 10. Airfoil components 30a, 30b and 30c are curved to allow the air flow air-wash the inner window surface and work surface 49 in addition to guiding the airflow for stronger vortex formation inside the fume hood chamber. Airfoil component 30a may be utilized as drainage channel from work surface 49 spills.
[0041] FIG. 5 illustrates a process and instrumentation simplified diagram of a dual closed loop control system by the damper 12 with actuator 14 referred to as M 100, the air-straightening air-guiding flapper 16 with actuator 16a referred to M 102, a microcomputer alarm and control unit 18 with dual function pressure differential transmitter referred to PdT 110, a dual function pressure differential control referred to as PdC 108 and a dual function pressure differential indicating alarm referred to PdIA 112, the dual function pressure sensor 20 referred to PE 106 of the fume hood alarm and control system in accordance with an embodiment of the present invention. Vertical window 32 opening/closing or up/down by push button hand control 47 shown in FIG. 1 referred to HC 114 and actuator 43 referred to as M 104. The microcomputer alarm and control unit 18 may include a microprocessor and computer memory, in which is stored computer software for causing the microprocessor to control various components, and to execute various functions as explained in the present application.
[0042] FIG. 5 is a diagram used to describe various components and functions in accordance with one or more embodiments of the present invention. The actuator 16 is also shown by M 102. The actuator 14 is also shown by M 100. The actuator of component 43 is also shown by M 104. The sensor 20 is also shown by PE 106. The components 108, 110, and 112 can be described as functions performed by computer processor 18 as programmed by computer software stored in computer memory of the microcomputer or computer processor 18. The push button hand control 47 is shown by HC 114. The dashed lines from PdC 108 to actuators 14 (M 100) and 16 (M102) and are used to show control signals by the micro processor or microcomputer alarm and control circuit 18 of actuators 14 and 16. The dashed lines from PdT 110 to PE 106 is used to show sensor 20 provides the microcomputer 18 with data or signals, such as pressure differential between inside chamber 46 and the area immediately outside chamber 46. The dashed lines from HC 114 (hand control 47) to M 104, show that an individual can operate the vertical window 32 opening or closing by actuator 43 (M 104).
[0043] FIGS. 6-9 depict details of air-straightening air-guiding flapper 16. Half circle blade 16c and teeth 16b on both sides at the edge are perforated. The component 16a is an actuator to turn the blade shaft 17. The component 16d is shown as an oval bell mouth, whereas 16e is shown as round bell mouth.
[0044] FIG. 8A shows a simplified side view of the air-straightening air-guiding automated flapper 16 with oval and round bell mouth of FIG. 6, and a part of the housing of the fume hood 1 of FIG. 1, with the flapper 16 in a first state, such that the blade 16c and teeth 16b have been rotated or pivoted using pivot pin or shaft 17 of a actuator 16a, to the left. FIG. 8B shows the simplified side view as in FIG. 8A, but with the flapper 16 in a second state, wherein the blade 16c and teeth 16b have been rotated, using pivot pin or shaft 17 of the actuator 16a, from the state of FIG. 8A, to a central orientation. FIG. 8C shows the simplified side view as in FIG. 8B, but with the flapper 16 in a third state, wherein the blade 16c and teeth 16b have been rotated from the state of FIG. 8B to being oriented to the right.
[0045] The actuator 16a may turn the shaft 17 to cause oscillation or movement of the blade 16c and the teeth 16b from the state of FIG. 8A to 8B to 8C, then back to 8B and 8A, in a continuous oscillatory, periodic manner, at a particular rate or speed as determined by microcomputer alarm and control unit 18. The rate may be stored in a computer memory of computer or microcomputer alarm and control unit 18.
[0046] FIG. 10 depicts three-dimensional view of the fume hood in FIG. 1. Additional components identified on FIG. 10 (not identified in FIG. 1-9) are common to most known fume hoods. Components 60a and 60b are wall mounts for installation, 61a and 61b are exterior side panels, 62a and 62b are front posts, 63 is a light on/off switch, 64a and 64b are 120 VAC (volts alternating current) duplex outlets, components 65a, 65b, 65c, 66d are utility (gas) service valve handles, component 66 is a fume hood ceiling panel, and component 67 is a top front panel.
[0047] Referring to FIGS. 1-10, the fume hood 10 provides an ultra stable vortex for improved containment at low airflow with fixed turning vanes 40a, 40b, 40c, 40d, 26 and 28 and automated air-straightening air-guiding flapper 16 and multi-functional airfoil 30 within a fume hood chamber 46 shown in FIGS. 2 and 5. A dual function sensor 20 referred as pressure element (PE) 106, shown in FIGS. 1, 2, and 5 senses total pressure of the vortex in one instance inside of the chamber 46 and provides a signal to a microcomputer alarm and control unit 18, which is comprised of dual function pressure differential transmitter (PdT) 110, dual function pressure differential indicating alarm (PdIA) 112 and dual closed loop pressure differential control (PdC) 108. One output of the dual closed loop control (PdC) 108 modulates air-straightening air-guiding flapper 16 via actuator (M) 102 to direct airflow to slots 51, 52 and 53 of baffles 22 and 24 in order to maintain a ultra stable vortex inside of the inner chamber 46. Loss of ultra stable vortex or total pressure inside of chamber 46 is displayed by a light indication and buzzer sound at the microcomputer alarm and control unit 18. A dual function sensor 20 referred as pressure element (PE) 106, shown in FIGS. 1, 2, and 5 also senses differential pressure in second instance between the chamber 46 and room for face velocity manipulation by providing a signal to microcomputer alarm and control unit 18. A second output of the closed loop control (PdC) 108 of the microcomputer alarm and control unit 18 modulates damper actuator 14 (M 100) automatically to maintain constant face velocity at the window openings. The microcomputer alarm and control unit 18 is configured, in at least one embodiment, to provide dual control signal (i.e. control signal to automated flapper actuator 16a referred to M 102 and to VAV (variable air volume) damper actuator 14 referred to M 100).
[0048] Fume hood 10 eliminates tough to maintain existing fume hood counter balance weight system for a vertical sash opening. The window system including components 34, 36 and 30 operates by sliding horizontal windowpanes 34a, 34b, 34c, and 34d, such as from the position shown in FIG. 1 to the position shown in FIG. 3, swing open window panes with removable hinge mechanisms 44a and 44b (as shown in FIG. 3) or 50% open windows by sliding left and right and fully opening or closing to eighteen inches (in at least one embodiment) of vertical windowpane 32 with push button hand control 47 referred to HC 114 and actuator 43 referred to M 104 shown in FIG. 1 and FIG. 5, thus providing the ability to have full open sash for loading and unloading. Vertical windowpane 32 can be adjusted from an eighteen inches height D1 for restricted sash opening operation 48 shown in FIG. 3 to a full opening of twenty-eight inches for loading and unloading. In at least one embodiment, the window system including components 34a-d, 36, 30, and 32 provides a triple layer of glass for worker safety when windowpane 32 is down and windowpane 32a slid behind 32b or 32d slid behind 34c.
[0049] The fume hood 10 and/or overall window apparatus and system comprises horizontal gliding and swing open windowpanes 34a-b, adjustable vertical opening windowpane 32, gliding tracks 36 and multi-functional airfoil 30. Airfoil 30 combines six important functions: bypass opening, drainage for work surface spills, glider and swing open for horizontal windowpanes, air washes work surface, air washes inner window surface and directs air to form ultra stable vortex.
[0050] Typically, most known fume hoods can be converted to ultra stable high performance low airflow fume hood with installation of multiple turning vanes 40a-d, 26, 28, automated air-straightening air-guiding flapper 16, and a window apparatus and system including components 34a-d, 32, 30, 50a-d, 44a and 44b, and 36.
[0051] The fume hood 10 supports both VAV (variable air volume) and CAV (constant air volume) fume hood applications. Damper 12 with actuator 14 regulates the exhaust air volume to maintain constant face velocity at the face opening for VAV (variable air volume) system applications. Damper 12 may be fixed for hard air balancing in CAV system applications.
[0052] Fume hood 10 is 20% to 30% lighter than any previously known fume hood with sash counter balance weight system making it easier to transport, install and maintain.
[0053] In operation of the apparatus 10, referring to FIG. 2, at all windowpanes closing, the ambient air comes into the inner chamber 46 through the opening between the components 30c and 30b and the opening between the components 30b and 30a. Curved components 30a, 30b and 30c allow the airflow to be directed towards inner surface of the windows 34a, 34b, 34c, and 34d, and along the work surface 49 to air wash the inner surfaces of windows 34a-d and work surface 49 This air flow through the opening between component 30c and 30b and the opening between the component 30b and 30a also functions as bypass and work surface spill drainage channel. When the windows 34a, 34b, 34c, and 34d are in open state, curved components 30a, 30b and 30c allow the airflow in the inner chamber 46 to strengthen a vortex formation inside fume hood inner chamber 46. Component 30b is connected to 30a and 30c, through walls or members, such as side walls or members 62a and 62b, and 61a and 61b shown in FIG. 10, but FIGS. 2, 4, and 5 are simplified to show air flow.
[0054] The sensor 20 senses the total pressure of the inner chamber 46 in one instance and differential pressure between inner chamber and the room ambient air in second instance simultaneously and sends a signal to the to the microcomputer alarm and control unit 18. Based on that total pressure signal the computer 18 controls the rate at which the flapper blade 16c and teeth 16b oscillates from the state of FIG. 8A to 8B to 8C and back to control the direction of air flow from baffle slots 51, 52 and 53, and out of the exhaust opening 12a of the apparatus 10, shown in FIG. 10. In at least one embodiment, this method and apparatus maintains ultra stable vortex inside fume hood chamber 46. In addition the microprocessor or computer 18 is configured to control the damper 12 based on the differential pressure between the ambient air just outside and/or adjacent to the walls of the inner chamber 46 and the pressure inside the inner chamber 46 to maintain constant face velocity at the window opening.
[0055] Although the invention has been described by reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. It is therefore intended to include within this patent all such changes and modifications as may reasonably and properly be included within the scope of the present invention's contribution to the art.
