GB2488132A

GB2488132A - Removal of condensate or other liquids from air conditioning systems or other installations

Info

Publication number: GB2488132A
Application number: GB1102710.9A
Authority: GB
Inventors: Robert Covey; Joseph Rose
Original assignee: Aspen Pumps Ltd
Current assignee: Aspen Pumps Ltd
Priority date: 2011-02-16
Filing date: 2011-02-16
Publication date: 2012-08-22
Also published as: WO2012110800A1; US20140075979A1; RU2013142059A; EP2676078A1; WO2012110800A4; GB201102710D0

Abstract

A method of preventing siphoning of a liquid through a pump 23 having an inlet and an outlet, the outlet being coupled to a discharge line 24 having an air inlet valve 10 that admits air to prevent a body of water to build up and cause the liquid to siphon from the discharge line back through the pump. The liquid may be condensate collected from a condenser 20 of an air conditioning installation, of particular benefit for use with piston pumps, which may be used in coffee machines. The admission of air through the valve does not allow a body of liquid build up downstream of the valve such that there is an inadequate weight of liquid to cause siphoning from the discharge line upstream of the pump. Therefore, the pump always contains liquid and prevents it from running in the dry state. Also claimed is an air inlet valve (fig 4) which may be a non-return or one way duck bill valve (33) made of an elastomeric material.

Description

Improvements in or Relating to Air Conditioning and other Installations The present invention relates to improvements in or relating to air conditioning and other installations, in particular to the removal of condensate and other liquids.

In an air conditioning installation, a condenser is used to cool fluid which is used for space-cooling. The condenser produces condensate water which must be removed.

Typically, a positive displacement pump is used as a condensate pump to remove condensate from a reservoir adjacent the condenser to a drain via a small bore tube forming a discharge line. A float valve is used to sense when condensate needs evacuating from the reservoir and actuates the pump in response, switching off the pump when all condensate has been removed. The condensate pump is a self-priming pump, but nevertheless, such pumps are typically very noisy when picking up air as they start. Such pumps include a reciprocating metal piston in a cylindrical body and damage can be suffered when the pump runs with no water in it.

Condensers are typically mounted at an elevated position with respect to the drain.

As such, once the pump has been switched off in response to the float valve sensing no further condensate, condensate left upstream of the condensate pump tends to siphon through the pump to the drain leaving the pump with no condensate in it and hence leading to increased noise on the next start-up of the pump and increased wear on the pump surfaces and thus a decreased lifespan for the pump, often as little as a few months.

The present invention seeks to provide a solution to this problem. Accordingly, in its broadest sense, the present invention provides a method of preventing siphoning of a liquid through a pump having an inlet and an outlet, which outlet is coupled to a discharge line; the method comprising providing an air inlet valve in the discharge line.

Preferably, the air-inlet valve is positioned at a height not less than slightly below the height of the outlet of the pump.

Accordingly, in a second aspect, the present invention provides an air-inlet valve.

The air-inlet valve comprises a valve body having a liquid inlet and a liquid outlet and a through-bore therebetween further comprising an air-inlet in fluid communication with the through-bore.

Preferably, the air-inlet comprises a non-return or one-way valve. More preferably, the valve is a duck-bill valve.

The above and other aspects of the invention will now be described in further detail with reference to the accompanying drawings in which: Figure 1 is a perspective view of an embodiment of an air-inlet valve in accordance with the present invention; Figure 2 is a schematic view of a portion of a typical air-conditioning installation incorporating the valve of Figure 1; Figure 3 is an exploded view of the valve of Figure 1; and Figure 4 is a cross-sectional view of the valve of Figure 1.

The embodiment of the air-inlet valve in accordance with the present invention illustrated in the figures has a valve body 10, a liquid inlet 11 and liquid outlet 12.

Liquid inlet 11 is couplable to a source of liquid, such as the outlet of a pump liquid outlet 12 is couplable to a drain, such as by means of a discharge line 24. The valve further comprises an air-inlet valve 13 within the valve body 10.

Figure 2 shows the air-inlet valve in a typical air-conditioning installation in which a condenser 20 collects condensate water from the air-conditioning unit. This collects in a reservoir 21. A float valve 22 senses when the water level in reservoir 21 reaches a predetermined level and activates pump 23 in response thereto. Pump 23 removes condensate to drain through a discharge line 24. Air-inlet valve 10 is interposed into discharge line 24 downstream of pump 23. Valve 10 can be positioned slightly below pump 23 but is preferably positioned level with or above the height of pump 23.

The air-inlet valve is illustrated in further detail in Figures 3 and 4. Body 10 of the valve has a bore 30 communicating the inlet 11 and outlet 12; and a cavity 31 in fluid communication with bore 30 by means of a communicating line 32.

Cavity 31 is fitted with a uni-directional valve, as shown, in the form of a duck-billed elastomeric valve 33 held in position within cavity 31 by means of a rctaining cap 34.

As condensate flows through bore 30 as a consequence of the operation of pump 23 air is caused to enter cavity 31 through valve 33 from the atmosphere.

As a consequence of the admission of air to the condensate flowing through the air-inlet valve, a body of water does not build up downstream of the valve. As a consequence, there is an inadequate weight of condensate liquid to cause condensate to siphon from that part of the discharge line upstream of the pump (that is to say between float valve 22 and pump 23). A full body of condensate is therefore maintained in pump 23 such that the pump noise and damage apparent with prior art arrangements is avoided.

The present invention is of particular benefit for use with piston pumps, for which this is a particular problem and so will find utility also in other uses, such as coffee machines. Such pumps typically include an internal valve, for example providing the self-priming function, typically providing a bias into a closed position against a spring force. The duck-billed valve 33, or other valve, will be selected to be rated at less than the spring force of any internal pump valve to avoid siphoning.

Claims

CLAIMS: 1. A method of preventing siphoning of a liquid through a pump having an inlet and an outlet, which outlet is coupled to a discharge line; the method comprising providing an air inlet valve in the discharge line.
2. A method as claimed in claim 1 wherein the air-inlet valve is positioned at a height not less than slightly below the height of the outlet of the pump.
3. An air-inlet valve comprising a valve body having a liquid inlet and a liquid outlet and a through-bore thercbetween further comprising an air-inlet in fluid communication with the through-bore.
4. A valve as claimed in claim 3 wherein the air-inlet comprises a non-return or one-way valve.
5. A valve as claimed in claim 4 wherein the valve is a duck-bill valve.
6. A valve as claimed in claim S wherein the valve is made of an elastomeric material.