WO1995021356A1

WO1995021356A1 - A device in a heating or cooling system with a continuous flow of system liquid in a closed conduit circuit

Info

Publication number: WO1995021356A1
Application number: PCT/SE1995/000063
Authority: WO
Inventors: Björn CARLSSON
Original assignee: Carlsson Bjoern
Priority date: 1994-02-07
Filing date: 1995-01-24
Publication date: 1995-08-10
Also published as: SE501484C2; SE9400393D0; SE9400393L

Abstract

A device in a heating or cooling system with a continuous flow of system liquid in a closed conduit circuit (1), including a deaerator circuit (3 - 13) with a deaerator (7) for deaerating a diversion flow (4) from said system liquid and a replenish liquid (11) that is delivered to the deaerator circuit. A valve means (5) is arranged to optionally feed the diversion flow (4) and the replenish liquid (11), respectively, to a reducing means (6) that is connected to the deaerator. A pump device (8) is arranged to sustain a sufficient liquid flow and to feed the deaerator diversion flow and the deaerator replenish liquid, respectively, to the conduit circuit.

Description

A device in a heating or cooling system with a continuous flow of system liquid in a closed conduit circuit

FIELD OF THE INVENTION

The present invention relates to a device in a heating or cooling system with a continuous flow of system liquid in a closed conduit circuit, the conduit circuit having a de¬ aerator circuit which includes valve means, the inlet of which being connectable to the conduit circuit via inlet means in order to receive a diverted flow from the conduit circuit, and the outlet of the valve means being connect¬ able to the inlet of a deaerator, the outlet of which is connectable to the conduit circuit by means of outlet means in order to return said diverted flow to the conduit circuit.

BACKGROUND ART

One of the most serious problems in a heating or cooling system is the build-up of gases, especially oxygen, in the liquid. The oxygen is absorbed by the system liquid from air that may diffuse into the system liquid via packings, pumps or the like, and which is often trapped in air cushions of pipe bends or the like. The oxygen will, eventually, cause corrosion, rust and coating accu¬ mulations. No satisfactory method has been proposed for the deaerating of the system liquid from oxygen, neither of the existing flowing system liquid, nor of the new, so called replenish liquid which now and then has to be in¬ troduced into the system to compensate for the leakage, evaporation and so on.

EP 0 187 683 discloses a device of the kind mentioned above, which deaerates the system liquid and the replenish liquid as well. However, the known device has serious drawbacks. It requires a throttling of the main flow when a flow is to be diverted therefrom for deaerating. This will seriously restrain the continuous operation of the system. Moreover, the known device utilizes a deaerator with a liquid tank, which requires extremely extensive and expensive control electronics.

SUMMARY OF THE INVENTION

The object of the present invention is, therefore, to pro- vide a device of the kind mentioned by way of introduc¬ tion, where a deaerating of the existing system liquid and also of the replenish liquid can be done continuously, and also by means of very simple and cheap means, which may even, at need, be operated in a purely manual fashion.

This object will be achieved by a device according to the invention having the characteristics set forth in Claim 1.

Further embodiments of the invention are set forth in the subclaims.

BRIEF DESCRIPTION OF THE DRAWING

The invention will be described in more detail by refe- rence to the accompanying drawing which illustrates a preferred embodiment of the invention.

The Figure shows a circuit diagram of a device according to the invention for deaerating the existing system li- quid and the replenish liquid as well.

PREFERRED EMBODIMENT

The Figure shows a conduit circuit 1 in the shape of a so called main flow circuit ("main line") for a system liquid flowing continuously in the direction of arrow 2 in a hea¬ ting or cooling system, not shown in detail. A device ac- cording to the invention comprises a deaerator circuit in the form of a series coupling of the following successive components: an inlet means 3 in the form of a manually operated shut-off valve (so called hand valve) in order to receive from conduit circuit 1 a diverted flow, symbolized by arrow 4; a preferably spring biased non-return valve 5; a reducing means (reducing valve) 6, that will substanti¬ ally reduce the pressure of the diverted flow 4, so that any gases in the liquid will be released; a deaerator 7 for removal of any such released gas; and a pump device 8 for sustaining a sufficient liquid flow and for increasing the pressure of the liquid to a level equal to the pressu¬ re of the system liquid flowing in conduit circuit 1, and for feeding, via a hand valve 9, the deaerated liquid from deaerator 7 to conduit circuit 1.

Connectable to the inlet 6a of reducing means 6 is - via a shut-off valve 12 (so called replenish valve, which may be either a hand valve or an automatically operated valve) and a non-return valve 13 (preferably spring biased) - an only schematically shown source 10 for a replenish flow, symbolized by arrow 11.

Non-return valve 5 is so dimensioned that it will close if the pressure at its outlet 5b will exceed the pressure at its inlet 5a. Thus, if the replenish liquid 11 will be de¬ livered to reducing means 6 at a higher pressure than the pressure of the diverted flow 4, non-return valve 5 will close, so that reducing valve 6 will only feed replenish liquid to deaerator 7. If valve 12 is closed, the delivery of replenish liquid to reducing valve 6 will be interrup¬ ted, such that the high pressure at the outlet 5b of re¬ ducing valve 5 will drop, so that non-return valve 5 will open and release the diverted flow 4 from conduit circuit 1, such that this diverted flow will now be deaerated.

The function of the device is as follows: In normal operation, the two shut-off valves 3 and 9 are open, whereas replenish valve 12 is closed. Then a diver¬ ted flow 4 will continuously pass through deaerator 7, i. e. a continuous deaerating of the system liquid of the conduit circuit 1 will successively occur. When the system liquid needs to be replenished by new system liquid, only one simple operation has to be carried out, i. e. the ope¬ ning of replenish valve 12. Thereby non-return valve 5 will automatically be closed, since the replenish flow 11 has a greater pressure at the outlet of non-return valve 5 than the pressure of the diversion flow 4 at the inlet 5a of non-return valve 5. Thus, the diversion flow 4 will now be stopped by non-return valve 5, so that only the reple¬ nish flow 11 will pass through deaerator 7, where it will be deaerated and then delivered to conduit circuit 1 via the always open shut-off valve 9.

After sufficient delivery of replenish liquid, replenish valve 12 will again close manually, thereby opening non- return valve 5 since the pressure of the replenish liquid is no longer acting at outlet 5b of non-return valve 5, such that the diversion flow 4 will again pass through deaerator 7 and then back to conduit circuit 1 via the open shut-off valve 9.

According to the invention an automatic deaerating of the replenish liquid 11 will be achieved whenever this is de¬ livered to reducing means 6, while the diversion flow 4, that is diverted from conduit circuit 1, will be continu- ously deaerated during the time intervals when no reple¬ nish liquid is being delivered to reducing means 6.

The delivery of replenish liquid and simultaneous deaera¬ ting thereof can, accordingly, be initiated by one simple operation, i.e. manipulating replenish valve 12, thus ren¬ dering the device according to the invention revolutionary simple as compared with previous known replenish devices. It is obvious that non-return valve 5 may be replaced by a three-way valve, not shown. The function of non-return valve 5 may, alternatively, be obtained by for instance a manual closing of shut-off valve 3 as soon as replenish liquid has to be delivered to reducing means 6.

Deaerator 7 may for instance be a so called cyclone deae¬ rator sold under the tradename Airclon®, or a turbulence deaerator sold under the tradename Spirovent®.

Claims

C l a i m s

1. A device in a heating or cooling system with a conti¬ nuous flow of system liquid in a closed conduit circuit (1), the conduit circuit (1) having a deaerator circuit (3-13) which includes valve means (6), the inlet (6a) of which being connectable to the conduit circuit (1) via inlet means (3) in order to receive a diverted flow (4) from the conduit circuit, and the outlet (6b) of the valve means being connectable to the inlet (7a) of a deaerator (7), the outlet (7b) of which is connectable to the con¬ duit circuit (1) by means of outlet means (8, 9) in order to return said diverted flow to the conduit circuit (1), c h a r a c t e r i z e d in that the valve means is a reducing means (6), the inlet (6a) of which is also con¬ nectable to a source (10) of a replenish liquid flow (11), a valve device (5, 12) being arranged to optionally con¬ nect the diverted flow (4) or the replenish liquid flow (11), respectively, to the inlet (6a) of the reducing means, so that the diverted flow (4) or the replenish li¬ quid flow (11), respectively, may optionally be deaerated in the deaerator (7) and then be delivered to the conduit circuit via said outlet means (8, 9).

2. A device according to Claim 1, c h a r a c t e r i ¬ z e d in that the valve device (5, 12) includes a non¬ return valve (5), the inlet (5a) of which is connected to said inlet means (3), and the outlet (5b) of which is con¬ nected to the inlet (6a) of the reducing means (6).

3. A device according to Claim 2, c h a r a c t e r i ¬ z e d in that the pressure of the replenish liquid flow (4) is dimensioned greater than the pressure of the diver¬ ted flow (4), so that the non-return valve (5) will stop the diverted flow (4) whenever the replenish liquid flow (11) will be received by the reducing means (6).