# US 6,296,451 B1 · Process and installation for the regulation of a central unit for the production of medical vacuum

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- Number: US 6,296,451 B1
- Document ID: US6296451B1
- Status: Granted
- Kind: B1
- Application number: 09/484,274
- Filed: 2000-01-18
- Granted: 2001-10-02
- Earliest claimed: 1999-02-02
- Assignees: Air Liquide Sante (International)
- Inventors: Emmanuel Guillet-Belaud; Robert Montausier; Didier Beauvois
- Web page: https://patentgrep.com/patent/US6296451B1

## CPC

- G05D 16/2026: {with a plurality of throttling means}
- F04D 19/04: specially adapted to the production of a high vacuum, e.g. molecular pumps
- F04D 27/02: Surge control {(surge detection F04D27/001)}
- G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02)

## Abstract

A process and installation for the regulation of the vacuum level prevailing in a network of vacuum conduits in a hospital building comprises one or several vacuum pumps connected pneumatically to the vacuum conduits (CV); elements (C2) for determining the pressure to determine the underpressure prevailing in the vacuum conduits (CV); a pilot device (MP) controlling at least one vacuum pump, at least one line for connection to the atmosphere (L1, L2) having a first end connected pneumatically to the vacuum conduits and having a second free end; and control elements (EV1, EV2) for the flow of fluid arranged in the line for connection to the atmosphere (L1, L2) to permit controlling the passage of air in the line connecting to the atmosphere.

## Claims

### Claim 1

Process for regulating the level of underpressure prevailing in at least one portion of at least one vacuum conduit, in which said level of underpressure is susceptible of variation with time, which comprises:
(a) determining an underpressure value (VD) prevailing in at least one portion of the vacuum conduit, (b) comparing the value of underpressure (VC) determined in step (a) with a predetermined maximum value of underpressure (VDmax) wherein VDmax<105 Pa,
(c) when in step (b) VD>VDmax, causing a decrease in pressure in said vacuum conduit by pneumatic pumping by means of several vacuum pumps connected pneumatically to at least one portion of said vacuum conduit,
(d) when the value of the underpressure (VD) prevailing in at least one portion of the vacuum conduit subjected to pumping in step (c) is such that VD≦VDmini, wherein VDmini is a predetermined minimum value of underpressure wherein VDmini<VDmax<105 Pa,
(i) stopping at least one vacuum pump that has operated for a predetermined duration (dt); and
(ii) placing at least a portion of said vacuum conduit in pneumatic communication with a source of gas having a compensation pressure (Pc) such that Pc>VDmax, while continuing to operate pneumatic pumping by means of at least one vacuum pump connected pneumatically to at least one portion of said vacuum conduit.

### Claim 2 (depends on 1)

The process according to claim 1, wherein in step (d), the source of gas having a compensation pressure (Pc) is the atmosphere.

### Claim 3 (depends on 2)

The process according to claim 2, wherein in step (d), the placing in pneumatic communication of the vacuum conduit with the atmosphere is carried out by at least one line (L1, L2) communicating with the atmosphere, having a first end connected pneumatically to said vacuum conduit and having a second free end.

### Claim 4 (depends on 1)

The process according to claim 1, wherein the passage of the gaseous flow in at least one line (L1, L2) communicating with the atmosphere is controlled by a control means (EV1, EV2) for the passage of fluid arranged in at least said line communicating with the atmosphere, and the flow rate of passage of the gaseous flow through said one line (L1, L2) communicating with the atmosphere is effected by at least one calibrated orifice (01, 02) arranged in said line (L1, L2) communicating with the atmosphere.

### Claim 5 (depends on 1)

The process according to claim 1, wherein:
VDmini is comprised between 30,000 Pa and 38,000 Pa;
VDmax is comprised between 42,000 Pa and 50,000 Pa; and/or
dt is comprised between 1 and 120 minutes.

### Claim 6 (depends on 5)

The process according to claim 5, wherein dt is comprised between 5 and 90 minutes.

### Claim 7 (depends on 1)

The process according to claim 1, wherein said at least one vacuum conduit is a part of a network of vacuum conduits traversing a hospital building.

### Claim 8 (depends on 1)

The process according to claim 1, wherein from 2 to 15 vacuum pumps (P1, P2, P3, P4) are pneumatically connected to the vacuum conduit (CV).

### Claim 9 (depends on 1)

The process according to claim 1, wherein several of said vacuum pumps are arranged in parallel.

### Claim 10 (depends on 4)

The process according to claim 4, wherein the control means (EV1, EV2) for controlling the passage of fluid are selected from the group consisting of electrovalves and pneumatic valves.

### Claim 11 (depends on 3)

Proces s according to claim 3, wherein control means (EV1, EV2) for controlling the passage of fluid are controlled by a pilot device (MP), in a combined or autonomous manner.