SI20221A - Three-way control valve with exclusive operation - Google Patents

Abstract

In a three-way valve both valve plates are flexibly positioned on the control axis. The upper plate features a built-in spring, which pushes both plates together in the closing direction. In the central position of the control axis both plates are tightly closed. If the control axis is moving up, the lower plate remains firmly closed due to the spring force, while the upper one is opening and vice-versa. This way one valve and one motor drive can control two circuits, while one circuit is open by any percentage, the other remains firmly closed. If a security function is activated, the control axis moves towards the upper position and first tightly closes the lower plate and subsequently the security plate. The plate geometry is chosen in such a way, that the media does not enter the plates when they are moving relatively one against the other and does not cram the gaps in the guides. On the outlet side there is an axial flow controller, which controls the throughput and at the same time eases the pressure on both plates.

Description

Exclusive three-way control valve

The subject of the invention is a three-way control valve with integrated flow regulator. If one inlet direction is open, the other inlet direction is completely closed. In normal operation, both directions can be closed simultaneously. In the event of a power failure, both directions are closed tightly. It is especially suitable for installation in domestic district heating stations, because with one valve and one motor drive, two circuits can be controlled, heating and consumable water.

This invention solves the following technical problems.

Problem 1. Regulate two circuits with one valve and one motor actuator, with one circuit open and the other closed tightly and vice versa.

Problem 2. In the event of a power failure, when the safety spring in the motor drive pushes the valve axis to the extreme position, both directions must be tightly closed.

Problem 3. The built-in flow controller must regulate the flow individually. Because the maximum flow rate is not always the same in both directions.

Problem 4. The relative movement of the axle and valve plate must not cause the medium to be pumped through the sliding of the internal sliding surfaces. The fine debris that the medium (water) carries with it could clog the narrow gaps and block the valve.

Problem 5. The flow of the media should not be affected by the external inlet openings of the moving valve plates. Accident can clog the slit and block operation.

Problem 6. In the event of a leakage of the flow regulator, which at the same time relieves both valve plates, the pressure of the medium must be applied to the valve plates in the direction of closure.

The well-known three-way valves work in such a way that both directions can be opened at the same time. Only when one direction is fully open is the other completely closed. It is not possible to secure both directions simultaneously.

Problem Solving 1-6

Problem 1. In the three-way valve, both valve plates are movably mounted on the steering axis. An upper spring is fitted with a spring which pushes the two plates together in the direction of closure. In the middle position of the steering axis, both plates are tightly closed. If the steering axle is moving upwards, the lower plate remains, under the influence of the force of the spring, it remains tightly closed and the upper one opens. And vice versa. In this way, two valves can be controlled with one valve and one motor actuator, with one circuit open open and the other closed tightly. The advantage is about half the cost and less space consumption, which is essential for small compact district heating stations.

Problem 2. If a power failure occurs, the safety function is activated. The steering axle moves towards the final upper position and closes the lower plate first, then completely opens the upper plate for a short time. But the axis continues to travel one more stroke and with the third safety plate closes the direction of the upper plate as well. This provides the security function required by the regulations.

Problem 3. The impulse (V +) for the flow controller can only be taken before the bottom plate. Otherwise, in the case of a safety closure, when the safety plate is closed, the flow regulator would remain open and both plates unburdened. As each valve plate in its direction is also a throttle for piloting the flow controller, limiting the maximum stroke of each plate individually, can arbitrarily limit the flow in a particular direction. However, the stroke limitation may not work in the event of a safety closing. Therefore, the stroke limitation is performed by measuring the position of the steering axis and the corresponding parameter in the digital controller program that determines the position of the steering axis.

Problem 4. The surface by which the upper plate slides after the lower plate extension is equal to the surface of the steering axis that slides along the inside of the lower portion of the lower plate extension. This prevents the media from being pumped into the two plates completely. The interior is filled with medium only once, that is, at first filling and never again. The medium and the dirt are no longer entering the interior.

Problem 5. The bottom plate has a tubular extension that extends into the top plate. The slit between the extension and the top plate is closed with a felt or rubber scraper. Thus, the bottom plate does not even have a slit facing the flow of media from the opposite direction. The upper plate, however, has a slit that is protected by a scraper and is far from the jet of media from the lower plate. This greatly reduces the possibility of entry of dirt and blocking of operation.

Problem 6. Both plates are mounted in such a way that they are closed by the spring force and the pressure of the medium, and the force of the motor drive opens. This prevents the possibility of leakage if the flow regulator is leaky and the plates are not unloaded.

Description of the design solution

Figure 1

The common housing (1) has a three-way control valve (26) and an axial flow regulator (27). The three-way control valve has three seats, namely the lower seat (25), the upper seat (2) and the safety seat (7), and the three valve plates, namely the lower plate (24), the upper plate (3) and the safety plate (5). The plates are movably mounted on the steering axle (21). The lower plate is sealed against the axle by a gasket (23) and secured against intrusion by a scraper (22). The lower plate has a tubular extension (14) extending into the inside of the upper plate (3). The lower part (15) of the tubular extension (14) has the same diameter (D1) inside as the steering axle (21) and the outer diameter (D2) on the upper part (11). In this way, the movement of the steering axis (21) does not cause the medium to be pumped from the outside into the plates. In the upper plate (3) there is a spring (10) which, through the bracket (9) and the tubular extension (14), presses on the lower plate (24) and has a force sufficient to close the two plates tightly. The entrance to the inside of the top plate is protected by a scraper (12). Protective

j the plate (5) is screwed into the upper part of the upper plate and sealed with the seal (4). The safety seat is freely inserted into the housing and sealed with a gasket (6). The steering axle (21) has a nut (8) at the top, which with the underside can press the lower plate with the upper side and the upper plate.

The medium can enter the housing from two directions A or B. When it enters the lower chamber (20) from the lower chamber (20), it flows past the lower plate into the middle chamber (19) and past the plate (18) through the axial flow regulator (27). The media in the lower chamber acts through the impulse hole (V +) to one side of the diaphragm (16) in the flow regulator (27), and the pressure of the medium from the middle chamber acts through the impulse hole (V-) to the other side of the diaphragm and tries together with the control open the flow regulator (27) to the spring (17). When the medium enters from direction B, it flows past the guard plate into the upper chamber (13), then past the upper plate into the middle chamber and then exits through the flow regulator in the direction C.

When the steering axle (21) is in the middle position and the nut (8) does not touch any plate, both plates are tightly closed. They are closed by the spring force (10) and the pressure difference between the lower and middle chambers, or the upper and middle chambers. If the steering axle (21) moves downwards from the middle position, the nut (8) presses against the lower plate (24). The spring (10) is compressed and the lower plate can move away from the seat for the entire stroke. Keeping the top plate tightly closed. If the steering axle moves upwards from the middle position, it presses on the guard plate and pulls the top plate (3) up with it. The upper plate squeezes the spring (10) and the lower plate is closed tightly. When the upper plate (3) reaches full travel, the steering axis stops. However, if both directions are required, the steering axle continues to move upwards for one stroke, the spring is further compressed and the guard plate (5) is closed tightly.

For correct operation, the steering axle (21) must always be in the correct position. The position of the steering axle is measured by a suitable stroke meter (M) and adjusted by means of a regulator (R), which operates depending on the regulated parameters. The flow restriction may be different for each direction (A or B). It is achieved by properly limiting the travel of the lower and upper plates. However, when it is necessary to secure both directions, there is no restriction on the stroke of the upper plate.

Claims (7)

Patent claims 1. Exclusive three-way control valve characterized by the fact that two valve plates, the lower plate (24) and the upper plate (3) are mounted in the common housing (1) on the steering axle (21) and are mounted inside the upper plate a spring (10) that presses the upper plate towards the upper seat (2) and at the same time presses the lower plate (24) against the lower seat (25) through the bracket (9) and the tubular attachment (14) with the lower plate sealed against the steering axis (21) ) with gasket (23) and in the middle position of the steering axis the nut (8) does not touch any plate and therefore both plates are pressurized to the seats by the force of the spring and the pressure of the media, and close when the steering axis (21) moves out of the middle of the up position, the nut (8) presses on the upper plate (3) and opens it, while keeping the lower plate (24) under the force of the spring (10) remains tightly closed, but when the steering axis (21) moves from the middle position of the movement down then the nut (8 ) presses through the tubular attachment (14) to the lower plate (24) and opens it, while keeping the upper plate (3) under tight force of the spring (10). A three-way control valve according to claim 1, characterized in that a safety plate (5) is sealed on the upper side of the upper plate (3), which is sealed with a seal (4) and a safety seat is attached above it in the housing (1). (7), which is sealed with a seal (6) wherein, in the middle position of the steering axis (21), the distance between the safety plate (5) and the safety seat (7) is approximately twice the maximum travel of the upper plate (3) and is in the upper upper position of the steering axle (21) the safety plate (5) is pressed against the safety seat (7) and thus tightly closed, while the lower plate is tightly closed by the force of the spring (10). (24) 3. Three-way control valve according to claim 1, characterized in that the diameter (D1) of the steering axis (21) in the region of the lower plate (24) and the seal (23) is approximately equal to the outer diameter (D2) of the upper part (11) of the tubular fitting (14), which slides the scraper (12), which prevents the entry of dirt into the interior of the top plate (3). 4. Three-way control valve according to claim 1, characterized in that a scraper (22) is installed in the lower plate (24) before the seal (23), which prevents it from entering the seal (23). 5. Three-way control valve according to claim 1, characterized in that the lower plate (24) and the upper plate (3) are mounted on the steering axis (21) such that, in addition to the spring force (10), the lower plate also closes the pressure difference of the medium between lower (20) and middle (19) chamber, and closes the upper plate (3) in addition to the spring force (10) also the difference in pressure of the medium between the upper (13) and the middle (19) chamber, and the medium flows from the direction (A) through the lower the chamber (20) past the lower plate (24) into the middle chamber (19) and flows the medium from the direction (B) past the safety plate (5) through the upper chamber (13) and then past the upper plate (3) into the middle chamber (19) . 6. Three-way control valve according to claim 1, characterized in that an axial flow regulator (27) is mounted in the housing (1) on the outlet side, so that the medium flows from the middle chamber (19) through the axial flow regulator (27) and then exits the housing in the direction (C), and the pressure of the medium in the lower chamber (20) acts through the impulse hole (V +) to one side of the diaphragm (16), and the pressure of the medium from the middle chamber (19) through the impulse hole (V-) to the other side of the diaphragm (16) and, together with the control spring (17), tries to open the axial flow regulator (27), which regulates the flow and relieves both plates of pressure. Three-way control valve according to claim 1, characterized in that the travel of the lower plate (24) and the upper plate (3) is arbitrary by means of the stroke meter (M) and the regulator (R), so that the flow from the direction (A) can be set to another value than flow from direction (B), wherein the travel of the steering axle (21) is measured and adjusted by means of a stroke meter (M) connected to a regulator (R) in which the set stroke limits are stored. Three-way control valve according to claim 7, characterized in that in the event of the safety function being activated, when the control axis (21) has to reach the extreme upper position and close the safety plate (5) tightly, the stroke of the upper plate (3) does not work.