US20050201882A1

US20050201882A1 - Vacuum pumping system

Info

Publication number: US20050201882A1
Application number: US11/078,249
Authority: US
Inventors: Cristian Maccarrone; Massimiliano Titolo
Original assignee: Varian SpA
Current assignee: Varian SpA
Priority date: 2004-03-15
Filing date: 2005-03-11
Publication date: 2005-09-15
Also published as: EP1577559B2; DE602004005154T2; EP1577559B1; JP2005264938A; DE602004005154D1; EP1577559A1

Abstract

A vacuum pumping system has at least two vacuum pumping devices with vacuum pumps, local electronic control units for monitoring and controlling the operating parameters of the pumps and a control station remotely located relative to the vacuum pumping devices. The control station is equipped with a remote control unit. The remote control unit and local control units are equipped with wireless communication modules for communicating data and commands and controlling the operation of the vacuum pumping devices. The wireless communication module of the remote control unit directly communicates with the wireless communication modules of the local control units.

Description

FIELD OF THE INVENTION

The present invention relates to a vacuum pumping system.
More particularly, the present invention concerns a vacuum pumping system of the kind comprising one or more vacuum pumping devices and a corresponding electronic control unit for controlling and monitoring the operation of these pumping devices.

BACKGROUND OF THE INVENTION

Vacuum pumping systems are known for instance from the U.S. Pat. No. 5,733,104, “Vacuum Pump System”.
In case of high vacuum, i.e. in case of pressures in the range 10⁻⁴to 10⁻⁸mbar, the pumping systems generally comprise a turbomolecular vacuum pump associated with a backing pump or fore pump, for instance of mechanical type, allowing the turbomolecular pump to evacuate gas at atmospheric pressure.
An example of turbomolecular pump is disclosed in the U.S. Pat. No. 5,238,362 “Turbomolecular Pump” in the name of the Applicant of the present invention.
Both the turbomolecular pump and the fore pump request a local electronic control unit for controlling and monitoring the operation of the pump and of the accessory devices, if any, mounted on board or associated with the pumping device, such as for example valves, pressure detectors, cooling systems and similar devices.
Electronic control units for vacuum pumps are known for instance from the EP Patent Publication 0 597 365 A1, “Vacuum Pump with Converter”.
The vacuum pump operation can be controlled by a remote electronic control unit. The remote unit and the local electronic control unit of the pump are generally equipped with serial interfaces and they can be connected together by cables, permanently or only occasionally, when necessary.
U.S. Pat. No. 6,204,776, “Communication Abnormality Detecting/Coping Device and Vacuum Pump Remote Monitor Control Device” discloses a device for the remote control of a vacuum pump, in particular a turbomolecular pump equipped with magnetic suspensions, comprising a local control unit mounted on board of the pump and a remote control unit, the units being arranged to communicate with each other due to a connection by means of an RS232 serial cable.
In case of more complex pumping systems, comprising a plurality of pumps of different types, either mutually connected through a vacuum line or independent of one another, the remote control unit comprises a multiple interface capable simultaneously communicating with the interfaces of all local control units in order to monitor and control the respective vacuum pumps.
A pumping system of the above type is disclosed for instance in the U.S. Pat. No. 5,971,711, “Vacuum Pump Control System” disclosing a system consisting of multiple pumps of different kinds (turbomolecular, mechanical, cryogenic and other pumps), each having its own local control unit, connected through an RS232 serial cable with a corresponding communication gate of a single remote control unit.
Connections by means of serial cables between the remote control unit and the local control units are a considerable drawback, since they give rise to a number of problems in the installation phase of the vacuum pumping system, as far as both the positioning of the individual vacuum pumps and the distances between the vacuum pumps are concerned.
Moreover, during operation, serial cables can be accidentally disconnected or damaged, with a consequent interruption of the communication between the remote control unit and the corresponding local control unit.
Therefore, the higher the number of vacuum pumps in the pumping system, the more severe the drawbacks.
It is the main object of the present invention to provide a vacuum pumping system, which is equipped with a remote central control unit, overcoming the above mentioned drawbacks.
This and other objects are achieved by the vacuum pumping system as claimed in the appended claims.

SUMMARY OF THE INVENTION

According to the present invention a vacuum pumping system comprises a plurality of vacuum pumping device. Each vacuum pumping device has a vacuum pump and a local electronic control unit, which monitors and controls operating parameters of the vacuum pump. A control station is remotely located relative to the vacuum pumping devices. The control station is equipped with a remote control unit. The remote control unit and the local electronic control units are equipped with respective wireless communication modules. The wireless communication module of the remote control unit directly communicates with the wireless communication modules of the local control units.
Due to the use of wireless communication interfaces for communication between the remote control unit and the local control units of the vacuum pumps, the constraints on the pumping system installation, related to the use of serial cables, are eliminated. The vacuum pumps forming the system can thus be located in the most suitable positions and at greater mutual distances without any limitation related to the use of wired connections.
According to the invention, the remote control unit is free from any physical connection with the local control units, a mobile and portable remote unit could be provided, instead of a fixed station as taught in the prior art.
The pumping system according to the invention can be advantageously built starting from conventional control units, since it will be sufficient to connect said control units (both the local units and the remote one) with corresponding wireless interface modules.
A preferred embodiment of the vacuum pumping system according to the invention, given by way of non-limiting example, will be described in more detail hereinafter with reference to the accompanying drawing, which shows a block diagram representing the operation of the vacuum pumping system according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawing is incorporated in and form a part of the specification. It illustrates the present invention and, together with the description, serves to explain the principles of the invention.
FIG. 1 shows a diagrammatic view of a vacuum pumping system having vacuum pumping devices, local electronic control units with wireless communication modules and a remotely located control station, which is equipped with a remote control unit with wireless communication module communicating directly with the wireless communication modules of the local control units.

DETAILED DESCRIPTION OF THE INVENTION

In the embodiment shown in FIG. 1, a vacuum pumping system 1 comprises a high-vacuum pumping device 11 and a backing or fore pumping device 31.
The pumping devices 11 and 31 are mutually connected through a vacuum line (not shown), so that a gas flow sucked from a chamber under high vacuum conditions by the high-vacuum pumping device 11 can be evacuated at atmospheric pressure through the backing pumping device 31.
Pumping device 11 is preferably equipped with a high vacuum pump 13, for instance a turbomolecular pump, and further comprises a local electronic control unit 15 for monitoring and controlling the operation parameters of the high vacuum pump 13, by driving the electric motor of the pump and other electromechanical devices that will be described hereinafter.
Similarly, pumping device 31 is equipped with a fore pump 33, preferably a mechanical pump, for instance an oil pump, and comprises a local electronic control unit 35.
The local electronic control units 15, 35 are preferably powered through the mains voltage by means of corresponding power supply cables 17, 37.
Pumping device 11 is further equipped with a set of secondary apparatuses, which also can be controlled by the local control unit 15. If high vacuum pump 13 is a turbomolecular pump, the apparatuses may comprise a pressure detector 19 for monitoring the residual pressure inside the pump, a cooling fan 21, a vent valve 23 controlling the admission of a gas for slowing down the pump during the stopping phase, a purge valve 25, controlling the admission of a dilution gas before discharging the pumped gas to the outside environment, when the pumped gas is a corrosive or harmful gas.
Similarly, local control unit 35 can control the secondary apparatuses of pumping device 31, which is equipped with a pump 33. If the fore pump 33 is an oil mechanical pump, these apparatuses may comprise a pressure detector 39 for monitoring the residual pressure inside the pump, an oil detector 41 for monitoring the level and the temperature of the oil bath, a foreline valve 43 located in the vacuum line connecting high-vacuum pumping device 11 with backing pumping device 31.
Pumping system 1 further comprises a single remote control station 51 which comprises a remote control unit 53, usually equipped with or connected to an electronic processor, for central management and control of pumping system 1.
Both the remote control unit 53 and the local control units 15, 35 of the pumping devices 11, 31 must be equipped with interfaces for two-way communication of data and commands for controlling the pumping system operation.
According to the present invention, each local control unit 15, 35 is equipped with a wireless communication module 27, 47 allowing the local control units 15, 35 to dialogue with a corresponding communication module 55, also of wireless type, connected with remote control unit 53.
As known in the art, the most widely used technologies in the wireless technology field are those in which transmission employs radiofrequencies (RF) or infrared radiation. Since such technologies and the devices exploiting them are well known, they will not be described further herein.
Wireless communication module 55 of remote control unit 53 is chosen so that it can dialogue with wireless communication modules 27, 47 of each local control unit 15, 35.
Module 55 can be for instance a multi-channel communication module, communicating on each channel with the communication module of a different local control unit. That solution allows, among others for avoiding potentially disturbing crosstalk between the communication signals of contiguous pumping devices or of different pumping systems, equipped each with its control station and located close to one another.
As an alternative, the use of an encoding system can be envisaged, so that the signals directed to and/or coming from the individual local control units can be discriminated.
Thus, the local control units of a plurality of pumps, even of different types, can be managed by means of a single remote control station 51, both when the pumps are connected together by a vacuum line, as in the example disclosed, and when they are mutually independent and are used for degassing different environments.
Advantageously, according to the present invention, all wired connections between control station 51 and pumping devices 11, 31 controlled by the station can be eliminated, so that the only wired connections in pumping system 1 consist in power supply cables 17, 37, 57 of the pumping system and the control station, for connection to the mains.
Advantageously as well, control station 51, if it is not connected to the mains but is powered otherwise, for instance by means of batteries, can be built as a portable device instead of being a fixed station.
Moreover, that pumping system 1 according to the present invention does not require use of special control units, but it can be built by connecting conventional control units 15, 35, 53 with corresponding wireless communication modules 27, 47, 55, for instance through serial connections 29, 49, 59.
The use of wireless communication modules, allows for controlling a plurality of vacuum pumping devices, arranged in any manner and located at a great distance from one another, from a remote control station. For that reason, use of the pumping system according to the present invention is particularly advantageous in case of complex applications, using a pumping system comprising multiple vacuum pumps of different types, connected together by a vacuum line, as in the example disclosed, or independently operating.
It will be understood that the above description has been given only by way of non-limiting example and that changes and modifications are possible without departing from the scope of the invention, which is being defined by the claims.

Claims

1. A vacuum pumping system (1) comprising:

a plurality of vacuum pumping devices (11; 31), each comprising a vacuum pump (13; 33) and a local electronic control unit (15; 35), which monitors and controls operating parameters of said pump; and

a control station (51) remotely located relative to said plurality of vacuum pumping devices (11; 31) and equipped with a remote control unit (53),

said remote control unit (53) and said local electronic control units (15; 35) being equipped with respective wireless communication modules (27, 55; 47, 55),

wherein said wireless communication module of said remote control unit is in a direct communication with said wireless communication modules of said local control units.

2. The vacuum pumping system of claim 1, wherein said plurality of pumping devices comprises at least two pumping devices.

3. The vacuum pumping system of claim 2, wherein said wireless communication module (55) of said remote control unit (53) is a multi-channel communication module, which communicates on each channel with the communication module (27;47) of the local control unit (15;35) of each said pumping device avoiding crosstalk between communication signals addressed to different pumping devices.

4. The vacuum pumping system of claim 1, wherein said vacuum pumping devices (11,31) operate at pressures lower than 10⁻⁴mbar.

5. The vacuum pumping system of claim 1, wherein at least one of said pumping devices (11) comprises a turbomolecular pump (13).

6. The vacuum pumping system of claim 1, wherein at least one said pumping device (11) comprises a backing pump (33)

7. The vacuum pumping system of claim 1, comprises at least two vacuum pumping devices (11, 31), which are connected by a vacuum line and each comprises a vacuum pump (13, 33) and a local electronic control unit (15, 35) monitoring and controlling the operating parameters of a respective pump, each said local control unit (15, 35) is equipped with a wireless communication module (27, 47) conducting dialogue with said wireless communication module (55) of said remote control unit (53).

8. The vacuum pumping system of claim 7, wherein said at least two pumping devices (11, 31) comprise a turbomolecular pump (13) and an oil mechanical pump (33), respectively.

9. The vacuum pumping system of claim 1, comprises at least two independently operating vacuum pumping devices comprising each a vacuum pump and a local electronic control unit for monitoring and controlling the operating parameters of the respective pump, each said local control unit being equipped with a wireless communication module conducting a dialogue with said wireless communication module (55) of said remote control unit (53).

10. The vacuum pumping system of claim 9, wherein said pumping devices further comprise a plurality of secondary apparatuses, which control and monitor operating parameters of said pumping devices.

11. The vacuum pumping system of claim 10, wherein said secondary apparatuses comprises:

a pressure detector (19, 39) monitoring the residual pressure inside said pumping device;

a fan (21) cooling said pumping device;

a vent valve (23), a purge valve (25);

an oil detector (41) monitoring a level and a temperature of an oil bath; and

a valve (43) controlling opening/closing of a vacuum line providing connection with another pumping device.

12. The vacuum pumping system of claim 1, wherein said remote control unit (53) is associated with an electronic processor, by means of which the operating parameters of said vacuum pumps (13, 33) are monitored and controlled through said local electronic control units (15, 35).

13. The vacuum pumping of claim 10, wherein the operating parameters of one or more of said secondary apparatuses can be monitored and controlled by means of an electronic processor, which is associated with said remote control unit (53).

14. The vacuum pumping system of claim 1, wherein said wireless communication modules (27, 47, 55) are infrared communication modules.

15. The vacuum pumping system of claim 1, wherein said wireless communication modules (27, 47, 55) are radiofrequency communication modules.

16. The vacuum pumping system of claim 1, wherein said control station (51) is a portable device.