This application claims priority of European application No. 07018752.1 filed Sep. 24, 2007, which is incorporated by reference herein in its entirety.
The invention relates to a mixing device for mixing substances, especially liquids or gases with different temperatures, with a moveable, adjustable valve control disk and at least one fixed valve seat disk.
With a mixing system, a mixing module, for example, is supplied through two separate circuits in each case with a substance to be mixed. In this way, the mixing module takes a proportion of the different substances to be mixed in order to enable a mixed substance with a required character to be produced. Several valves for distributing and conducting or mixing the various substances are required for this purpose. This makes the mixing system or the mixing module complicated and not cost effective. The control of the mixing system is impractical due to the use of a large number of valves. Furthermore, to protect a mixing module or compensate for the circuits, a mixing path in the mixing system is frequently bridged by one or more bypasses though which a substance to be mixed is passed in each case. The bypass is normally controlled by an extra manual rotary valve and is therefore not variable.
A multivalve has also been developed which combines two valves to form a single valve. The multivalve is provided with two fixed bores, each for a bypass. Although this enables the number of valves used to be reduced, a bypass designed in this way is also non-adjustable. It is desirable for a mixing system to have a variable bypass, with the bypass being automatically adjustable as a function of the mixture settings. The greater the flow of a substance for mixing in a mixing path of the mixing system, the less of the substance flows through a bypass and vice versa. Furthermore, more of the substance automatically flows in the mixing path for mixing purposes if less of the other substance, or substances, flows in this mixing path.
The object of the invention is to realize a mixing device with a bypass adjustment for mixing substances, especially liquids or gases at various temperatures.
The object is achieved in accordance with the invention by a mixing device with the features of the independent claims. The dependent claims relate to advantageous developments and embodiments of the invention.
The invention is based on the knowledge that the flow of a substance through an opening can be changed as a function of the size of the cross-section of the opening. Therefore, a mixing device is shown for mixing substances, especially liquids or gases at different temperatures, with a moveable, adjustable valve control disk and at least one fixed valve seat disk, with the valve seat disk having at least two opening groups, each of which consists of at least three through openings. Furthermore, a first opening is provided as an inlet opening or an outlet opening for a substance, a second opening is provided for connecting to a mixing path for the substances and a third opening is provided for bridging the mixing path. The valve control disk is provided on at least one side with a first recess and a second recess. By means of such recesses, a passage for substances between the openings, i.e. between the first, the second and the third opening, of the valve seat disk can be realized for each opening group of the valve seat disk. The valve control disk is arranged parallel to the valve seat disk so that at each opening group a flow is possible, via the first recess, between the first opening and the second opening and via a second recess a flow is possible between the first opening and the third opening. To form a passage, the first and second recesses are, for example, superimposed in each case over the first opening. To control the mixture, the valve control disk is to be adjusted relative to the valve seat disk so that for each group of openings the total superimposed surfaces of the first opening remain constant. In this way, the total surfaces, on which the first recesses are superimposed in each case, of the first openings of the complete group of openings remain constant and the total of the respective surfaces superimposed by the second recesses likewise remain constant. With this mixing device, a variable bypass can be realized in such a way that the passage of a substance in the bypass can be changed as a function of its passage in the mixing path. By adjusting the valve control disk, a passage cross-section, i.e. the superimposed surface of the first opening of the valve seat disk and of the first or second recess of the valve control disk can be changed and the relative proportion of substances to be mixed can thus be controlled. Furthermore, the bypass for the mixing path can be automatically adjusted as a function of the settings of the valve control disk. The valve control disk and the valve seat disk each usually consists of a round disk, with the valve control disk being rotatable relative to the valve seat disk to set the mixing device. It can also be designed in a different shape, e.g. as a rectangle, and the valve control disk can then be pulled or pushed relative to the valve seat disk.
According to an advantageous embodiment of the invention, the mixing device consists of a valve control disk and two valve seat disks, with the valve control disk being arranged between, and parallel to, the valve seat disks. The valve control disk is provided on each side with a first recess and a second recess. For each group of openings of the two valve seat disks, the first recess is provided to form a passage between the first opening and the second opening, with the second recess being provided to form a passage between the first opening and the third opening. Two of the second recesses in each case, each of which is arranged on both sides of the valve control disk, are connected to each other by a channel to enable a flow between the two valve seat disks. A mixing device designed in this way can be used on its own in a mixing system to create a mixing path, instead of using the two aforementioned mixing devices, each of which has only one valve seat disk.
Advantageously, the two valve seat disks are of identical construction and the first recesses and second recesses can be symmetrically arranged on both sides of the valve control disk. This enables the mixing device to be easily constructed and controlled.
According to an advantageous embodiment of the invention, the mixing device has at least two shut-off positions. If the mixing device is set to one of the shut-off positions, the mixing of the substances can be ended or avoided, i.e. the substances no longer flow in the mixing paths but instead they each flow completely in the bypasses. Because at least two shut-off settings are available in the mixing device, it is not necessary to set the mixing device to a specific state in order to separate the mixing of the substances. The mixing can be quickly or easily separated by setting the mixing device to a state corresponding to one of the shut-off positions of this mixing device.
In a mixing system, two mixing devices, each of which has only one valve seat disk, can be used to create a mixing path in such a way that a first mixing device can be provided as an inlet (supply valve) and a second mixing valve can be provided as an outlet (return valve), with the second openings of the first mixing device each being connected as an inlet opening and the second openings of the second mixing device each being connected as an outlet opening for a substance. To bridge the mixing path, the third openings of the first mixing device are each connected to the corresponding third openings of the second mixing device. A mixing path and its bypass can in this way be realized by using the two mixing devices. The mixing system can thus be cost effectively constructed because only two mixing devices/valves are used in this case. The substances to be mixed are fed from the second openings of the supply valve into the mixing path and then mixed together. The mixed substances are drawn off via the second openings of the valve seat disk and with the aid of the first recesses of the valve control disk through the first openings of the valve seat disk of the return valve. The substances supplied through the first openings of the supply valve but not fed in for mixing are passed, with the aid of the second recesses in each case, from the third openings of the supply valve through the bypass into the third openings of the return valve and are then passed on via the second recesses of the valve control disk through the first openings of the return valve for bridging the mixing path.
Alternatively, a mixing device which has one valve control disk and two valve seat disks can be used in the aforementioned mixing system for the creation of a mixing path. In this case, the mixing device is connected for the creation of a mixing path in such a way that the first valve seat disk is provided as an inlet (supply disk) and the second valve seat disk as an outlet (return disk) of the mixing path. The first openings and the third openings of the supply disk are each connected as the inlet opening for a substance. The second openings of the supply disk are each provided as a substance supply opening of the mixing path, with the second openings of the return disk each being provided as an outlet opening for a mixed substance. The first openings and the third openings of the return disk each also serve as an outlet opening. The mixture path is bridged in that the substances to be mixed are each fed to the third openings of the supply disk and then fed via two second recesses, which are located opposite each other on both sides of the valve control disk and connected by a channel, through the first and/or third openings of the return disk. A mixture path and one or more bypasses can thus be enabled by means of a single mixing device, without a further valve being required.
The invention is described in more detail in the following with the aid of the exemplary embodiments shown in the diagrams, in which;
At the inlet and outlet of the reaction module 8 are two actuating elements, each of which is based on two valves V1 and V2 or V3 and V4. Via valves V1 and V2, the reaction module 8 accepts its share of the hot and cold water supplied to it, in order to achieve a desired temperature by mixing. The mixed water is supplied via the mixing path 13 to the reactor 7 for temperature control of the chemical reaction and is then divided between valves V3 and V4 and is in each case returned to the circuits 21, 22.
A bridging consisting of a hot bypass B1 and a cold bypass B2 is formed for the mixing path 13. This ensures that the cryostats 9, 10 each receive a constant minimum flow. For each bypass, the reaction module 8 has a valve V5, V6, which is usually a manual rotary valve. Such valves can, however, not be automatically controlled according to a specific relative proportion in which the hot water and cold water are mixed, i.e. the flow of water through the bypass can, for example, only be manually controlled. Therefore, the bypasses B1, B2 are not variable. Even when the valve V5, V6 are each embodied as a multivalve together with the actuating elements V1, V2 and V3, V4, valves V5, V6 are still realized only once in the form of two fixed bores. Although in this case the number of valves that are used can be reduced, the bypass thus formed is still non-variable.
A shown in
Furthermore, due to the many valves, this microreaction system also requires a large number of stepper motors. Associated with this is the danger of the valve settings drifting relative to each other due to step losses in the stepper motors. The number of valves and stepper motors also results in a high space requirement and high costs.
The valve seat disk 2 has two groups of openings 11, 12 each of which is provided for the control and passage of hot water and cold water. Furthermore, each group of openings includes a first opening w1, k1, a second opening ma, mb for creating a mixing path 13 and a third opening w2, k2 for bridging the mixing path. The valve control disk 1 in
It can be seen from this table that by setting the valve control disk 1 the total flow of the hot water flowing in the mixing path 13 and in the bypass B1 or the total flow of the cold water flowing in the mixing path 13 and in the bypass B2 always remain constant because the total superimposed surfaces of the first opening w1, k1 of the valve seat disk 2, which in each case overlap the first recess wn1, kn1 and the second recess wn2, kn2, remain constant. The superimposed surfaces of the first opening w1, k1 can each be regarded as a passage cross-section for hot water and cold water. The size of the passage cross-section is to be set as the inlet opening for water, so that the hot water and the cold water can be mixed in a suitable proportion. For example, the more hot water flows through the total cross-section, i.e. the superimposed surface of the first recess wn1 and the first opening w1 in the mixing path 13, the less hot water flows through the total cross-section of the second recess wn2 and of the first opening w1 in the bypass B1.
Furthermore, the total amount of surface, which includes the total cross-section of the first recess wn1 and the first opening w1 and the total cross-section of the first recess kn1 and the first opening k1, also remains constant. Therefore, more hot water can, for example, automatically and simultaneously flow through the second opening ma for mixing in the mixing path 13 if the cold water flow through the other second opening mb is set smaller. The same applies also for the hot water and the cold water in the bypass sections B1 and B2.
Furthermore, there are two shut-off positions (see
The hot water and the cold water are supplied to the first openings vw1, vw2 of the supply valve 4 and then flow in each case via the first recesses vwn1, vkn1, through the second openings rma, rmb in the mixing path 13 on one hand, or via the third openings vw2, vk3 of the supply valve 4 in the bypass section B1, B2 on the other hand. The mixed water is drawn off via the second openings rma, rmb, the first recesses rwn1, rkn1 and the third opening rw1, rk1 of the return valve 5. Furthermore, the hot water and the cold water each flow through the bypass sections B1, B2 in the third openings and then on through the second recesses rwn2, rkn2 and the first openings rw1, rk1 of the return valve 5.
The combination of two such mixing devices in conjunction with the temperature-conditioning in the micro reaction system clearly shows the advantages of such a mixing device. With these mixing devices, it is possible to mix two separate water circuits and then divide them again into equal proportions.
a shows a side view of a cross-section of a valve control disk 1, with this valve control disk 1 being provided with trough-shaped recesses on both sides.
A valve control disk 1 of this kind can be formed from two valve seat disks, which are of similar design to the valve seat disks 2, 3 shown in
The hot water and the cold water in each case are supplied to the first openings vw1 vk1 and third openings vw2,vk2 of the first valve seat disk 2. The supplied hot water and the supplied cold water in each case flows on one hand via the first recesses vwn1, vkn1 of the valve control disk 1 and out from the second openings vma, vmb of the first valve seat disk 2 into the mixing path 13, and on the other hand via the second recesses vwn2, vkn2 and the channel 6 in the second recesses rwn2, rkn2 of the valve control disk 1 and then out from the first openings rw1, rk2 and the third openings rw2, rk2 of the second valve seat disk 3 into the circuits 21, 22.
The hot water and the cold water are mixed on the mixing path 13, in order to condition the reactor 7. The mixed water is in each case supplied through the second openings rma, rmb in the second valve see disk 3 and drawn off via the first recesses rwn1, rkn1 of the valve control disk 1 through the first openings rw1, rk1 of the second valve seat disk 3. Similar to the mixing device shown in
As shown in
Number | Date | Country | Kind |
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07018752.1 | Sep 2007 | EP | regional |