Claims
- 1. A fume hood apparatus, comprising:
an enclosure defining a workspace and an access opening, the enclosure including a header panel; a movable sash for closing the access opening; an air chamber having an inlet for drawing a quantity of room air at a predetermined airflow into the air chamber and a discharge proximate to the movable sash; and a pressure pipe having an inlet for drawing a quantity of air from the air chamber and an outlet for supplying a quantity of air into the workspace,
wherein the pressure pipe increases a relative pressure difference between the movable sash and the header panel, thereby minimizing contamination.
- 2. The fume hood apparatus of claim 1, wherein the outlet of the pressure pipe is positioned between the movable sash and the header panel.
- 3. The fume hood apparatus of claim 1, wherein the air chamber includes a centrifugal fan having an outlet for creating a pressure within the air chamber.
- 4. The fume hood apparatus of claim 3, wherein the inlet of the pressure pipe is proximate to the outlet of the centrifugal fan.
- 5. The fume hood apparatus of claim 1, wherein the airflow from the outlet of the pressure pipe is in a range between about 5 to about 15 cubic feet/minute.
- 6. A fume hood apparatus, comprising:
an enclosure defining a workspace and an access opening, the enclosure including a header panel; a movable sash for closing the access opening; an air chamber including an upper portion, a middle portion, and a lower portion, the middle portion having an inlet for drawing a quantity of outside air at a predetermined airflow into the air chamber, and a discharge adjacent the movable sash for directing an unimpeded flow of air from the lower portion of the air chamber through the access opening and into the workspace; and a pressure pipe having an inlet for drawing a quantity of air from the upper portion of the air chamber and an outlet for directing a flow of air into the workspace,
wherein the pressure pipe increases a relative pressure difference between the movable sash and the header panel, thereby minimizing contamination.
- 7. The fume hood apparatus of claim 6, wherein the outlet of the pressure pipe is positioned between the movable sash and the header panel.
- 8. The fume hood apparatus of claim 6, wherein the air chamber includes a centrifugal fan having an outlet for creating a pressure within the air chamber.
- 9. The fume hood apparatus of claim 8, wherein the inlet of the pressure pipe is proximate to the outlet of the centrifugal fan.
- 10. The fume hood apparatus of claim 6, wherein the airflow from the outlet of the pressure pipe is in a range between about 5 to about 15 cubic feet/minute.
- 11. A method of minimizing airborne contaminants from escaping a workspace of a fume hood having a movable sash and a header panel, comprising the steps of:
supplying an airflow to an air chamber of the fume hood; drawing a portion of the airflow within the air chamber into a pressure pipe; and supplying a quantity of air from the pressure pipe into the workspace of the fume hood,
whereby the flow of air from the pressure pipe increases a relative pressure difference between the movable sash and the header panel, thereby minimizing airborne contaminants from escaping through the face of the fume hood.
- 12. The method according to claim 11, wherein the quantity of air from the pressure pipe is directed between a movable sash and a header panel of the fume hood.
CROSS NOTING TO RELATED APPLICATIONS
[0001] This application is a Continuation-In-Part of application Ser. No. 09/922,037 filed Aug. 3, 2001.
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
09922037 |
Aug 2001 |
US |
Child |
10013392 |
Dec 2001 |
US |