DEVICE FOR GENERATING A NEGATIVE PRESSURE IN THE SEALED ROOM OF A TABLET PRESS AND/OR OF AN ISOLATOR

• US 20070149108A1
• Filed: 12/19/2006
• Published: 06/28/2007
• Est. Priority Date: 12/23/2005
• Status: Active Grant

• Current Assignee: Fette GmbH (LMT Leading Metalworking Technologies GmbH & Company KG)
• Original Assignee: Fette GmbH (LMT Leading Metalworking Technologies GmbH & Company KG)
• Inventors: Behns, Holger, Zingler, Ralf, Heck, Linda, Gand, Enrico
• Granted Patent: US 7,749,053 B2
• Time in Patent Office: Days
• US Class Current: 454/238
• CPC Class Codes: B08B 15/02 using chambers or hoods covering the area B08B15/002 takes precedence
• CPC Class Codes: B30B 15/0082 Dust eliminating means; Mould or press ram cleaning means
• CPC Class Codes: F24F 11/0001 for ventilation F24F11/30 takes precedence
• CPC Class Codes: F24F 2011/0005 to create underpressure in a room, keeping contamination inside
• CPC Class Codes: F24F 2110/40 Pressure, e.g. wind pressure
• CPC Class Codes: F24F 2140/10 Pressure

Abstract

A device for generating a negative pressure in the sealed room of a tablet press and/or of an isolator, with a fan connected to the sealed room and an air opening towards the sealed room, wherein the intake side of an ejector is connected with the sealed room, the working fluid connection of which is connectable with a compressed air source via a valve, with a sensor which is connected to a negative pressure control unit which opens the valve when the sensor measures a pressure in the sealed room which is above a predetermined negative pressure value, a second valve being assigned to the fresh air inlet opening, which depending on the embodiment remains opened or is triggered and closed by the negative pressure control unit.

Claims

1. A device for generating a negative pressure in the sealed room of a tablet press and/or of an isolator, with a fan connected to the sealed room and an air opening towards the sealed room, characterised in that the intake side of an ejector (26) is connected with the sealed room (12), the working fluid connection of which is connectable with a compressed air source via a valve (38a), with the sensor (42) which is connected to a negative pressure control unit (44) which triggers the valve (38a) and a second valve (20) is assigned to the fresh air inlet opening (18) which is triggered by the negative pressure control unit (44), wherein the negative pressure control unit (44) opens the first valve (38a) when the sensor (42) measures a pressure in the sealed room (12) which is above a predetermined negative pressure value, wherein the second valve can remain opened or it is closed.

2. Device according to claim 1, characterised in that the intake side of the ejector (26) is connected to the intake duct (14) of the fan (16), a third valve (32) is disposed between the connecting point and the fan (16) and a fourth valve (38) is disposed in the intake duct (24) of the ejector (26).

3. Device according to claim 2, characterised in that the actuating appliances (30, 34) of the valves (38 and 32) are fluid-actuated.

4. Device according to claim 3, characterised in that the actuating appliances (30, 34) of the third and fourth valve (38, 32) are connected to the pressure duct (36) leading to the ejector (26) at the downstream side of the first valve (38a).

5. Device according to claim 1, characterised in that the valve (38a) opens in the not triggered condition and the valve (20) adopts the position provided according to the embodiment, namely either opened or closed, in the not triggered condition.