WO2003006892A1

WO2003006892A1 - Vacuum collection system

Info

Publication number: WO2003006892A1
Application number: PCT/FI2002/000570
Authority: WO
Inventors: Bernard Menotti
Original assignee: Evac International Oy
Priority date: 2001-07-10
Filing date: 2002-06-27
Publication date: 2003-01-23
Also published as: FI20011506A0; FI20011506A

Abstract

The invention relates to a vacuum collection system for collecting and transporting fluid from a fluid source (1). The system comprises a fluid collecting means (5) and a vacuum source (3), whereby an interface valve (2) is arranged to be placed between the fluid source (1) and the fluid collecting means (5). In order to achieve a flexibly applicable arrangement, the interface valve is adifferential valve (2) having an inlet portion (21) under atmospheric pressure and an outlet portion (22) arranged to be set undervacuum. The fluid source may comprise an air-conditioning system or a refrigeration system.

Description

VACUUM COLLECTION SYSTEM

The invention relates to a vacuum collection system for collecting and transporting fluid from a fluid source according to the preamble of claim 1 .

Fluid vacuum collection systems are generally known. Typical vacuum collection systems, however, are provided with one or more discharge valves that are connected to a control arrangement for opening and closing the same, which control arrangement has to be externally monitored. Often conventional gravity systems are also used for the same purposes due to reasons of economy. Installation of such systems is very rigid and space consuming.

The objective of the invention is to provide a vacuum collection system, by which system the above mentioned drawbacks are avoided and by which an efficient and flexibly applicable installation are attained. This objective is achieved by a system according to claim 1 .

The basic idea of the invention is a vacuum based arrangement which can be installed in a minimum space and which allows for collection and transportation of fluid in a continuous and self-controlled manner with respect to the accumulation of fluid that is to be collected. This is achieved by arranging a differential valve between the fluid source and the fluid collecting means connected to the vacuum source.

A non-return valve is advantageously arranged between the differential valve and the fluid collecting means in order to prevent back-flow of fluid.

The fluid collecting means comprises vacuum piping and vacuum level control means, preferably with a flexible vacuum pipe portion and thereto related adapter means in order to facilitate and allow for flexible installation.

The vacuum source is preferably a liquid ring pump or a vacuum central, which may utilize the collected fluid for operational purposes. The vacuum source may also be provided with a control central.

The invention may advantageously be applied to an air-conditioning system or a refrigeration system, where the collected fluid is constituted by the condensate from these systems. The principal structure of the differential valve is defined in claims

1 0 and 1 1 , which structure provides for a reliable function and for a relatively small size valve which is advantageous in view of installation flexibility and space requirement.

In the following, the invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which

Fig. 1 shows a vacuum collection system according to the invention,

Figs. 2 and 3 show the structure and functioning principle of a differential valve as applied to the invention,

Fig. 4 shows an application of the invention, and

Fig. 5 shows another application of the invention.

In Fig. 1 a fluid source is indicated by reference numeral 1 . The fluid source may for example be an air-conditioning system or a refrigeration system, whereby the fluid would be condensate generated by said systems. The fluid from the fluid source 1 is arranged to flow by way of gravity to an inlet portion 21 of an interface valve which is in the form of a differential valve 2. The inlet portion 21 is under atmospheric pressure.

Vacuum is generated by a vacuum source, in this embodiment shown as a liquid ring pump 3. The liquid ring pump 3 has a tank 31 for the working liquid of the pump. The tank 31 is provided with an overflow means 32 and a ventilation means 33.

The liquid ring pump 3 has an inlet port 4 in communication with a fluid collecting means 5, which comprises vacuum piping. The vacuum piping comprises a main vacuum pipe 8 and a flexible pipe portion 6 connected to an outlet portion 22 of the differential valve 2 through a non-return valve 7. The flexible pipe portion 6 is connected to the main vacuum pipe 8 by an adapter 9, advantageously in the form of a quick junction pipe.

Furthermore, the main vacuum pipe 8 is provided with a pressure gauge 1 0, a pressure switch 1 1 and a ventilation means 1 2 for controlling the vacuum level in the main vacuum pipe 8. The said components 1 0, 1 1 and 1 2 are in communication with the main vacuum pipe 8 through a control tube 1 3 fastened to the main vacuum pipe 8 by an adapter 1 5, advantageously in the form of a quick junction pipe.

An electrical control center 14 is connected to the liquid ring pump 3 and the pressure switch 1 1 in order to facilitate control of the vacuum generation and the vacuum level.

Figs. 2 and 3 show a differential valve in section. The differential valve 2 comprises a valve body 20 with an inlet portion 21 , under atmospheric pressure, arranged to be set in communication with a fluid source 1 as described in connection with Fig. 1 . The valve body 20 further comprises an outlet portion 22, arranged to be set under vacuum, in communication with the vacuum collecting means 5, i.e. the vacuum piping 6,8 and the liquid ring pump 3 (Fig. 1 ). The valve body 20 is closed by a cover portion 23 fastened to the valve body 20 by fastening means 24,, e.g. by clips or other suitable means. The cover portion 23 is provided with a ventilation means 25 in order to provide for atmospheric pressure in the chamber limited by the cover portion 23 and a flexible membrane 26.

The cover portion 23 also fastens the flexible membrane 26 to the valve body 20. In a first position the membrane 26 is arranged to rest against a suction nozzle 27 arranged in the outlet portion 22 of the valve body 20 due to the vacuum generated on the side of the outlet portion 22 and the atmospheric pressure on the cover portion 23 side of the flexible membrane 26. The suction nozzle 27 has a central through-flow bore 28. The membrane 26 comprises a rigid central part 29 with a diameter larger than the through-flow bore 28 of the suction nozzle 27.

The diameter of such a differential valve would advantageously be in the region of about 75 mm to 1 75 mm, depending on the application, and the general diameter of the inlet portion 21 and the vacuum piping would advantageously be in the region of about 30 mm to 50 mm. This clarifies the small space required for installation of the system (Figs. 4 and 5).

In the following the operation principle of the vacuum collection system is shortly described.

Fluid FL that is accumulated in or is generated by the fluid source 1 , such as condensate from air-conditioning systems or refrigeration systems, is arranged to flow by way of gravity to the inlet portion 21 of the differential valve 2, which inlet portion 21 is under atmospheric pressure. In a first initial position the flexible membrane 26 of the differential valve rests agains the vacuum nozzle 27. This is due to the atmospheric pressure provided through the ventilation means 25 on the cover portion 23 side of the membrane 26 and on the other hand by the vacuum on the outlet portion 22 side of the membrane 26. An advantageous working vacuum level is 0,25 bar to 0,70 bar (0,75 bar to 0,30 bar absolute pressure), preferably 0,30 bar to 0,50 bar (0,70 bar to 0,50 bar absolute pressure) . The vacuum is provided by the liquid ring pump 3 through the vacuum piping 8,9,6 towards the outlet portion 22 of the differential valve.

As an, advantageously predetermined, amount of fluid FL has been received in the inlet portion 21 , the flexible membrane 26 is pushed away from the suction nozzle 27, whereby fluid FL is sucked thorugh a non-return valve 7 into the vacuum piping 6,9,8 through the through-flow bore 28 (Fig. 3). The movement of the membrane 26 can be controlled by selection of the membrane material and thickness. The fluid FL pushed into the vacuum piping is drawn towards the liquid ring pump 3, where it enters the working liquid tank 31 of the liquid ring pump 3. In order to maintain an appropriate working liquid level, the tank 31 is provide with an overflow means 32. This also means that the pump 3 does not have to be supplied with working liquid from an outside source, which normally would be the case. The tank 31 is ventilated by the ventilation means 33. The non-return valve 7 is arranged at the outlet portion 22 of the differential valve 2 in order to avoid back-flow of fluid FL into the differential valve 2. Such back-flow might occur, if the first portion of the vacuum piping, i.e. the flexible pipe portion 6 in the described embodiment, has a rise a shown in Fig. 1 .

The vacuum level in the vacuum piping is controlled by the electrical control center 1 4 that monitors the liquid ring pump 3 as well as the pressure gauge 1 0, the pressure switch 1 1 and the ventilation means 1 2, which are in communication with the vacuum piping 6,9,8 through a control tube 1 3. The control tube 1 3 may easily be attached to any desired point of the vacuum piping by a quick pipe junction 1 5.

In the following some examples of application of the present invention shall be described.

Fig. 4 shows a building where fluid sources, i.e. air-conditioning units 1 have been installed for the rooms R of the building. The inlet portion 21 of the differential valve 2 may be directly attached to the condensate outlet of the air-conditioning unit 1 . Respective flexible vacuum pipe portions 6 are led along the ceiling of the room R to a main drainage pipe of the building, i.e. the main vacuum pipe 8, which is connected to the vacuum source 3, i.e. a liquid ring pump 3 as described above. The connection between the flexible portion 6 and the main vacuum pipe 8 is arranged by an adapter 9.

A main advantage in applying the system according to the invention in such an application is the simple and economic structure of the differential valve and the small installation space required by the same. Previously, condensate has been collected and transported by separate pumps, which are expensive and require considerable maintenance. Furthermore, such pumps are of a relatively large size, which means they lessen the effective space in a room, or alternatively increase the height of a building, since the air-conditioning unit including the condensate collecting arrangement usually are installed above an intermediate ceiling C. An additional advantage of the present invention may be seen in the flexible installation possibilities of the system, which allows for easy retro-fitting, for example in connection with refurnishing or sanitation of old buildings. Fig. 5 shows how the system according the invention may be used in connection with refrigeration systems, e.g. in large supermarkets. Reference numeral 1 indicates a refrigeration system, for example a freezer, and reference numeral 3 a vacuum central. The other reference numerals correspond to identical parts as described above and are not repeated in this context. The advantages in this application correspond to the ones given above regarding Fig. 4. The flexibility of installation in this application is very important from a more day-to-day viewpoint, since e.g. in supermarkets freezers are frequently moved to different locations for marketing and product related reasons, which further enhances the advantages of the present invention.

An example of an alternative vacuum source that may be used instead of the liquid ring pump described above is a vacuum central. A typical vacuum central would for instance include a vacuum tank to which vacuum is provided by one or more vacuum pumps or ejector devices, means to empty the vacuum tank and a control panel. The vacuum centrals are not described more in detail in this context since they are known to a person skilled in the art.

The invention is not limited to the embodiments disclosed, but several modifications thereof are feasible within the scope of the ensuing claims.

Claims

1 . A vacuum collection system for collecting and transporting fluid from a fluid source (1 ), the system comprising a fluid collecting means (5) and a vacuum source (3), whereby an interface valve (2) is arranged between the fluid source ( 1 ) and the fluid collecting means (5), characterised in that the interface valve is a differential valve (2) having an inlet portion (21 ), under atmospheric pressure, arranged to be in communication with the fluid source ( 1 ) and an outlet portion (22), arranged to be set under vacuum, in communication with the vacuum source (3).

2. A vacuum collection system according to claim 1 , characterised in that a non-return valve (7) is arranged between the differential valve (2) and the fluid collecting means (5).

3. A vacuum collection system according to claim 1 , characterised in that the fluid collecting means (5) comprises vacuum piping (6,8,9), a pressure gauge ( 1 0), a pressure switch ( 1 1 ) and ventilation means ( 1 2).

4. A vacuum collection system according to claim 3, characterised in that the vacuum piping comprises a flexible portion (6).

5. A vacuum collection system according to claim 4, characterised in that the flexible portion (6) of the vacuum piping is arranged to be connected to a main vacuum pipe (8) of the vacuum piping by an adapter means (9).

6. A vacuum collection system according to claim 1 , characterised in that the vacuum source (3) is a liquid ring pump or a vacuum central.

7. A vacuum collection system according to claim 6, characterised in that the vacuum source is a liquid ring pump (3) and that fluid collected from the fluid source ( 1 ) is arranged to be supplied to the working liquid cycle of the liquid ring pump (3).

8. A vacuum collection system according to claim 3, characterised in that the pressure switch ( 1 1 ) and the vacuum source (3) are connected to an electrical control central ( 1 4).

. A vacuum collection system according to claim 1 , characterised in that the fluid source ( 1 ) comprises an air-conditioning system or a refrigeration system. 0. A vacuum collection system according to claim 1 , characterised in that the differential valve (2) comprises a valve body (20) with an outlet portion (22) in communication with the vacuum collecting means (5), a cover portion (23) and an inlet portion (21 ) arranged to be in communication with the fluid source (1 ), whereby the fluid is arranged to be transported from the inlet portion (21 ) to the vacuum collecting means (5) by way of a flexible membrane (26), which is fastened between the valve body (20) and the cover portion (23) and which in a first position is arranged to be positioned against the outlet portion (22) in order to close communication between the inlet portion (21 ) and the vacuum collecting means (5) and in a second position is arranged to be distanced from the outlet portion (22) in order to provide communication between the inlet portion (21 ) and the fluid collecting means (5). 1 . A vacuum collection system according to claim 1 0, characterised in that a suction nozzle (27) with a through-flow bore (28) is arranged in the outlet portion (22) and that the flexible membrane (26) has a rigid central part (29) with a diameter larger than the through-flow bore (28) of the suction nozzle (27) .