Patent Application
20070262279
The present invention relates to a device for the regulation of the amount of a flow, having an adjustable Kvs-value, in a heating and cooling system.
The object of a device according to the present invention is to keep the flow constant by combining a pressure difference valve with an integrated check device. The check device can also be varied by choosing in a stepless manner a more or less open check device in order to in this way in the separate case let the desired flow reach a chosen pressure difference level.
The already known devices, designed to meet these objects, and in these cases primarily pressure difference regulators or flow regulation valves, are impaired by various drawbacks.
A device, based on a pressure difference regulator, in principle can limit the flow to a level, which depends on the chosen pressure difference across the valve and the size of the valve, i.e. the flow, which it is chosen to be able to limit the pressure for. The limitation is caused by the fact, that, when a smaller flow is needed, a flow, which is smaller than the predicted one, to the valve, which is related to a definite pressure difference, must be added a valve, which eliminates this too large flow. In this case this separate valve can be allowed to operate with a pressure level, which may cause noise, since the chosen pressure difference valve cannot check this smaller flow and thus not limit the pressure for this smaller flow. Consequently, two different valves must be combined. One pressure difference valve and one flow regulating valve in order to obtain the desirable regulation functioning is of course an expensive solution.
A device, based on a flow regulation valve, can of course limit the flow, but such a system must include valves, which also limit the available pressure difference across the flow limitation valve. This means, that regardless of what system of the two mentioned above, which is chosen, the set-up must comprise at least two separate units, one which limits the pressure difference level and one which regulates the flow.
In small set-ups, e.g. in small houses, the pressure levels are normally not so high, that the above-mentioned combination of difference- and flow limitation functions are required. In these set-ups radiator valves are used, which can be designed to allow the opening between the cone and the seat of the valve to vary in various ways in order to be able to regulate the flow in a better way.
Examples of solutions for small set-ups are described in SE 8600679-8 and in DE 27 56 118.
For large set-ups, i.e. often set-ups with high pressure differences, there are constructions, which are based on a limitation of the flow in steps, which arrangement is described in e.g. EP 0 591 873 A 1, and as an alternative a use of a pressure difference valve according to e.g. U.S. Pat. No. 6,196,259 B1.
In all these existing solutions the total cost is high, in case a satisfactory functioning in a set-up is to be achieved, partly because several units are required and partly because the existing pressure difference valves often are complicated constructions. Since at least one pressure reducing function and one flow limiting function are required, in most set-ups, the final cost for the client will be high. Two components must be installed and these often require some type of maintenance or control, which means elevated costs.
The object of the present invention is to counteract and as far as possible eliminate the above-mentioned problem. Also, the invention is to develop the art in this field in various respects. The object of the invention particularly is to develop a complete valve, which can be used during changing operation conditions.
These objects are achieved according to the present invention by means of a device of the type described in the Summary of the Invention.
Additional characterizing features and advantages of the invention are set forth in the following description, reference being made to the enclosed drawings in which:
a is cutaway view of a pressure difference regulating part according to the invention:
a shown in a fully open position;
b is a cutaway view of a pressure difference regulator part according to the invention, showing a position, in which the passage is partially eliminated.
a is a check valve part according to the invention showing the valve fully open; and
b is a check valve part according to the invention showing the valve with its cone partially closed; and
c is a bottom perspective view of the valve in which the stop shoulder for the check device if shown.
Also, the valve is provided with a stop valve 6, mounted in extended part 9 of return connection 8 of the valve. This stop valve can advantageously be a ball valve, in which is mounted with sealing elements 10 and a stop ball 11 and in which place these parts are fixed in an axial direction by means of a stop nut 12.
The regulating function of the complete valve consists of two interacting parts, which are mounted in the common valve housing 1. The upper part, which contains check valve function 3, is mounted in the valve housing by fixing top piece 13 to housing 1 through locking nut 14, lower annular part 15 of the top piece being pressed against gasket 38, which is inserted into cylinder head 16 of the pressure difference part, which in its turn presses pressure difference part 2 downwards against control plane 18 of valve housing 1. On upper, outer thread 46 of top piece 13 a protective cover 37 is suitably mounted, which after its installation can be replaced by a suitable type of adjusting means—not shown in the figure.
A sealing in order to prevent outer leakage between the valve housing and the top piece is done by means of O-ring 19. In a similar way outer leakage via the inner components of check valve part 3 is prevented by the mounting of O-rings 20 and 21 respectively.
The construction of the pressure difference part is shown in
In
Thus, when inlet pressure Pi increases, basket-like part 24 will be pressed downwards and will consequently restrict/reduce passage 26 and the result of this will be a pressure loss of from level Pi to level Pd. The pressure difference between Pd and the pressure level of outlet side 8, called Pr, is chosen to let the Pd-force times the upper surface of sleeve-like part 25 compress spring 23 into a position, in which the spring force jointly with the force, which pressure Pr times the surface, on which Pr acts in space 39 between basket-like part 24 and the inner diameter of the cylindrical casing, is balanced. Thus, the pressure difference between Pd and Pr is constant and not dependent on pressure level Pi of inlet side 7. This constant pressure difference is the basis of the operation of check valve 3.
Thus, in case Pi increases, from the position shown in
The construction of the check valve part is shown in
The check valve will, due to its construction, always make it possible to choose an opening degree, which makes it possible to choose exactly the maximal flow, which is appropriate for the separate application case, and simultaneously it is possible to restrict this flow by means of the axial movement of check device 34.
The desired maximal flow is guaranteed thanks to the fact, that the pressure difference part always provides a constant, maximal drop of pressure, which the check valve must manage. With this drop of pressure as a starting point it is then possible to choose the flow, which the valve is to provide by rotating check device 34 in a stepless manner, the chosen opening degree corresponding to the desired flow. Check device 34 cooperates with fixed check veil 32, which is mounted into top piece 13. On top piece 13 it is advantageous to attach a graduated collar 17, according to
Thus, through the described pre-adjustment it is possible to always dimension the opening degree of the valve, the so called Kvs-value, depending on the present need, and thus, it is not necessary to choose a valve having rigid steps between different openings degrees, different flows.
In addition to this function, the one with a stepplessly chosen KVS-value, it is also possible to restrict this flow by means of a cone 31, which can be displaced in an axial direction along spindle 33. The axial movement can always be utilized in its entire length, regardless of the opening degree, which has been chosen by means of check device 34. This means, that it is really possible to regulate the flow, regardless of whether the valve/cone is to restrict a small or a large flow.
When the cone reaches its lowest position, i.e. when the valve is to stop the flow entirely, this has been secured by letting the cone be lowered and sealed against rubber gasket 38, provided on top of cylinder head 16 of the pressure difference valve. In this position, when the cone seals, pressure level Pi, present in the system, would press the cone upwards. By introducing a small slot 44 between spindle 33 and cone 31 a small leakage flow up to the upper side of the cone is permitted and in this way a decompression of the cone is achieved and consequently the undesirable effect of a pressure/force increase on the cone is prevented and in this way the sealing functioning is secured. The decompression also implies, that the closing per se can be accomplished through minor forces, and it will be easy to operate the valve.
The check valve is provided with O-rings 20 and 21 in order to prevent an outer leakage via the inner parts in top piece 13 and also an O-ring 27 in order to limit an inner leakage. O-ring 19 will prevent an outer leakage between top piece 13 and valve housing 1.
In
Of course, the solution described above for a device, designed for a flow regulation, can be modified to some extent within the scope of the inventive idea.
| Number | Date | Country | Kind |
|---|---|---|---|
| 0402206-7 | Sep 2004 | SE | national |
This application is a national stage completion of PCT/SE2005/001122 filed Jul. 7, 2005 which claims priority from Swedish Application Serial No. 0402206-7 filed Sep. 15, 2004.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/SE05/01122 | 7/7/2005 | WO | 3/13/2007 |
