Circulating aspirator with improved temperature control

• US 5,582,509 A
• Filed: 08/17/1995
• Issued: 12/10/1996
• Est. Priority Date: 08/17/1995
• Status: Expired due to Fees

• Current Assignee: Bio-Rad Laboratories Incorporated
• Original Assignee: Bio-Rad Laboratories Incorporated
• Inventors: Quilty, John H., Kaste, Keith
• Primary Examiner(s): Gluck, Richard E.
• Application Number:
  US08/516,240
• Time in Patent Office: 481 Days
• Field of Search: 417/77, 417/87, 34/75, 34/407
• US Class Current: 417/77
• CPC Class Codes: F04B 23/12 at least one pump being of the rotary-piston positive-displacement type
• CPC Class Codes: F04B 23/14 at least one pump being of the non-positive-displacement type
• CPC Class Codes: F04F 5/54 Installations characterised by use of jet pumps, e.g. combinations of two or more jet pumps of different type

Abstract

A vacuum aspirator apparatus uses circulating water from a reservoir while avoiding or reducing temperature rise in the circulating water. The apparatus consists of a reservoir with aspiration and cooling circuits, both of which are external to the reservoir, the aspiration circuit containing one or more aspirators with vacuum ports at which a vacuum can be drawn.

Claims

1. A water aspirator system comprising:

(a) a reservoir capable of retaining a body of water;

(b) an aspirator circuit comprising;

(i) a pump external to said reservoir and connected thereto through an inlet line arranged to draw water from said reservoir and a discharge line arranged to return water to said reservoir; and

(ii) at least one aspirator on said discharge line; and

(c) a cooling circuit comprising means for drawing water from said reservoir into a heat exchanger where said water thus drawn is cooled, and for returning water thus cooled to said reservoir.

2. A water aspirator system in accordance with claim 1 in which said heat exchanger is an air-cooled finned heat exchanger.

3. A water aspirator system in accordance with claim 1 in which said reservoir has a bottom and side walls and a designated nominal water level, and said pump is connected to said reservoir to draw water from a location therein at or adjacent to said bottom and to return water thereto to a location above said designated nominal water level.

4. A water aspirator system in accordance with claim 1 in which said pump is defined as a first pump, said reservoir has a bottom and side walls and a designated nominal water level, and said cooling circuit comprises a second pump arranged to draw water from a location below said designated nominal water level and to return water to a location above said designated nominal water level.

5. A water aspirator system in accordance with claim 1 and which said pump is driven by a drive motor, said aspirator system further comprising an electrically operated vent shut-off valve arranged to vent said aspirator to the atmosphere when said drive motor is shut off.

6. A water aspirator system in accordance with claim 1 and which said pump is a positive displacement rotary vane pump.

7. A water aspirator system in accordance with claim 1 and which said aspirator circuit contains two of said aspirators, arranged in parallel.

8. A water aspirator system in accordance with claim 1 in which said reservoir has a designated nominal water level, and said system further comprises a level indicator providing a continuously readable indication of water level in said reservoir.

9. A water aspirator system in accordance with claim 1 in which said pump is defined as a first pump, said cooling circuit is independent of said aspirator circuit and comprises:

(i) a second pump external to said reservoir and arranged to draw water therefrom and return water thereto; and

(ii) means for cooling water drawn by said second pump prior to return of said water to said reservoir.