Patent Grant
11112062
The invention relates to a safety system having a valve block to which at least one gas safety valve is connected in a preferably detachable manner, having at least one controllable valve in or at the valve block and having at least one pressure accumulator holding the gaseous pressure medium. The pressure accumulator is also connected to the valve block in a detachable manner.
Such a safety system can be found in different hydraulic supply systems and is known for instance from the product catalog “Speichertechnik” (storage technology) No. D 3.553.4/03.16 by HYDAC INTERNATIONAL. The known solution is used for filling and testing hydro-storage facilities having a back-up version. For this purpose, the known valve block has various fluid ports, in particular for the connection of a filling and testing device, a pressure gauge, downstream nitrogen cylinders, a pressure accumulator in the form of a hydraulic accumulator and at least one gas safety valve. During operation of the valve block, the gas end of the hydraulic accumulator, preferably in the form of a piston accumulator, is permanently connected to the gas safety valve. The liquid end of the hydraulic accumulator, which is separated from the gas end by a separating element, such as a separating piston movable longitudinally in a storage housing, is connected to a hydraulic supply system, for instance in the form of a conventional hydraulic circuit. Further, a shut-off valve is in the valve block, which shut-off valve in its open position opens the fluid path between the possibly connected, downstream nitrogen cylinders and the hydraulic accumulator for a gas-conveying connection to the nitrogen gas and which shut-off valve in its closed position, blocks this fluid path.
When removing the gas safety valve from the valve block, for instance, in the context of maintenance or repair work, then the pressurized working gas has to be completely vented from the safety system every time. The individual connected hydraulic accumulator and/or the individual connected nitrogen cylinders have to be closed, and at least parts of a connected hydraulic system must be depressurized accordingly. Upon subsequent recommissioning of the safety system, including the assigned gas safety valve and correspondingly connected pressure accumulators, the above-mentioned decommissioning steps have to be reversed.
Based on this prior art, the invention addresses the problem of providing a safety system having improved functionality and conserving resources.
A safety system according to the invention solves this problem.
A particularly high level of safety is achieved because, according to the invention, a gas-conveying connection routed at least partially within the valve block between the connected pressure accumulator and the connected gas safety valve can be opened or blocked by the valve. The individual gas safety valve can be removed from the valve block, if necessary, provided that the assigned valve in or at the valve block is brought into its blocking position and is safely separated from the gas end of the connected gas pressure accumulator. The gas pressure accumulator is composed of a hydraulic accumulator or a gas reservoir, such as a nitrogen cylinder or any other at least partially gas-holding pressure vessel, such as a storage tank or the like.
The safety system according to the invention provides the option of shutting off the gas safety valve connected to the valve block of the safety system via an assigned controllable valve without suffering substantial gas losses at the end of the pressure accumulator system connected to the valve block and without depressurizing any components of the hydraulic system.
The required removal of a gas safety valve from the valve block of the safety system required during repair and/or maintenance work can be performed quickly and inexpensively. Any time-consuming emptying and filling procedures at the gas end of a connected system having the pressure accumulator can be omitted, which conserves resources. This ability is without parallel in the prior art.
Pressure accumulators according to the invention include all containers, such as pressure vessels, hydraulic accumulators, gas cylinders, in particular nitrogen cylinders, and the like, suitable and used for receiving a fluid, in particular a gas. The accumulator used in the safety system according to the invention is not limited to the usual language definitions in individual areas.
In a preferred embodiment of the safety system according to the invention, the pressure accumulator is a pressure vessel, which is or can be filled exclusively with the gaseous pressure medium, such as a nitrogen cylinder or a hydraulic accumulator. The hydraulic accumulator, in particular may be designed as a bellows, membrane, storage or piston, whose separator accommodated in a storage housing separates a gas end from a liquid end. In this way, various types of pressure accumulators, which are only connected to one valve block, can be safely operated and controlled based on only one safety system, which is regularly the case, when at least one hydraulic accumulator is connected as a pressure accumulator to a hydraulic system at one end of the valve block. Additional nitrogen cylinders are connected as storage or downstream cylinders at the same or another end of the valve block, which cylinders can, for an established fluid supply, be used to recharge the hydraulic accumulator at its gas end even in operation or increase its prestress at its gas end in operation.
In a further preferred embodiment of the safety system according to the invention, at least two gas safety valves are connected to the valve block. A safety device ensures that the gas-conveying connection to each connected pressure accumulator is interrupted before a gas safety valve is removed from the valve block. The connection leading to at least one other gas safety valve is maintained such that a permanent gas-conveying connection between this individual pressure accumulator and this other gas safety valve is established during the replacement of the one gas safety valve and its re-commissioning. In this way, the operation of a hydraulic, at least partially gas-conveying plant can be maintained, even if a gas safety valve is removed from the valve block, because the gas safety valve remaining at the valve block for safety reasons fully takes over the addressed safety functions.
The safety system according to the invention, in particular, ensures that during commissioning and continuous operation of a hydraulic supply system, the gas safety valve set to maximum response pressure remains permanently connected to the gas end of the pressure accumulator. The pressure accumulator liquid end remains connected to a hydraulic system or equipment, for instance in the form of a hydraulic accumulator. In particular, for a plurality of gas safety valves used at the valve block, for cleaning and/or maintenance of such a gas safety valve, the gas safety valve can be removed from the valve block, while the other gas safety valve remaining at the valve block takes over the safety function described for the hydraulic supply system and its equipment. Generally, such gas safety valves are composed of pressure relief valves, whose gas outlet end leading to the environment is covered by a mesh grid or a sieve to protect any persons in the vicinity from being affected by the outflow of compressed gas of high pressure in the event of a safety incident.
In a preferred embodiment of the safety system according to the invention, the safety device is based on a mechanical locking system, a mechanical control system, an electrical monitoring system or a chip-controlled actuation system for the relevant controllable valve. Due to the design of the safety device that is based on the requirements of and adapted to the particular application, a secure shut-off of the pressure accumulator, having a low susceptibility to failure and fault, is ensured in operation, for instance, before an assigned gas safety valve is removed. Mechanical systems for locking or controlling the valve have the advantage of high robustness and low maintenance requirements. An electrical or chip-controlled system for monitoring or actuation offers the advantage of a small footprint and the option of remote monitoring when using suitable data transmission.
In a further preferred embodiment of the safety system according to the invention, two, preferably manually operated, ball valves are provided to implement a mechanical locking system, which ball valves are each connected to an assigned gas safety valve in a gas-conveying manner and which ball valves bear control disks ensuring in the mutually locked state that a first ball valve in its open position connects the assigned gas safety valve to the pressure accumulator via a gas-conveying connection and a second ball valve in its blocking position blocks an assigned other connection to the relevant pressure accumulator for the removal of the assigned gas safety valve from the valve block, for instance, for replacement or maintenance purposes.
The control disks are an integral part of a mechanical lock of the actuating elements of the ball valves and preferably are arranged at an outer end of the valve block. Once a ball valve is blocked to remove the assigned gas safety valve, the assigned control disk is interlocked with at least one control disk of a further gas safety valve that the further gas safety valve is blocked in the open, safe operating position and held securely. Thus, when dismounting and removing one gas safety valve, at least one further functional gas safety valve is connected to the valve block in its open position, which then performs solely the safety function.
In a further preferred embodiment of the invention, one of the control disks can, starting from a common opening direction, be actuated in the direction of a closed position of the ball valve by two hand levers of the ball valves. The outer peripheral end of that one control disk has a cutout, which interacts with a correspondingly shaped cutout at the outer periphery of the other control disk such that a rotational movement of the respective ball valve is enabled or blocked by the assigned hand lever. Particularly preferably, the respective cutout has an arcuate contour with a curvature comparable to the outer circumference of the control disk. The other control disk engages with a cutout shaped in that way such that the assigned hand lever is blocked in the selected position, and an unintentional or deliberate change of this position is not possible.
The gas safety valves have a basic cylindrical shape and are arranged at an underside of the valve block. The hand levers for actuating the assigned ball valves are preferably arranged at an end of the valve block accessible to an operator. As a rule a vertical direction indicates the open position and a horizontal direction indicates the closed position of the assigned ball valve. Particularly preferably, the cutouts in adjacent hand levers are arranged such that in the open position of the two hand levers, the cutouts are arranged next to each other and opposite from each other such that upon movement of one hand lever into the closed position, the assigned control disk is moved into the cutout at the other control disk of the other hand lever, thereby blocking its movement in the closed position as well.
Preferably, two or more gas safety valves are arranged next to each other, at the valve block, forming a row. Accordingly, two or more hand levers having assigned control disks are arranged next to each other, at the side of the valve block, forming a row.
It is also advantageous that the control disk interacts with a stop limit at the valve block, such that the hand lever can be pivoted from an opening direction parallel to the longitudinal direction of the relevant gas safety valve by 90° to a blocking position transverse to this longitudinal orientation and vice versa. This interaction results in the advantage of error-free operation when pivoting the relevant hand lever in one of its positions.
In a further preferred embodiment of the safety system according to the invention, a 3-way ball valve is used as a controllable valve to implement a mechanical control system. This ball valve in its one control position connects a gas safety valve via a connection to the pressure accumulator in a gas-conveying manner and decouples another gas safety valve from the pressure accumulator by blocking an assigned further connection. In a further control position, the other gas safety valve is connected to the pressure accumulator via the other connection in a gas-conveying manner, and the one gas safety valve is decoupled by blocking the one connection. By using only one 3-way ball valve, two separate ball valves for the two gas safety valves can be dispensed with. Regardless of the control position of the 3-way ball valve, one gas safety valve is then connected to the pressure accumulator, and one gas safety valve is disconnected therefrom, i.e. at least one gas safety valve always takes over the safety function of the pressure accumulator.
In a further preferred embodiment of the safety system according to the invention, the open and closed positions of the controllable valve are monitored by sensors for the implementation of an electric monitoring system. A higher-level control only permits the hydraulic supply system to operate, if the sensor system detects that the relevant gas-conveying connection between the gas safety valve and pressure accumulator via the controllable valve is actually open and communicates this fact to the controller. This arrangement results in the advantage that an opening or locking of the gas-conveying connection can be “automatically” detected. By an additional optical display, for instance attached to an outside of the valve block, an operator can be notified of the enabling for the removal of the gas safety valve when the other gas safety valve performs the safety function.
In a further preferred embodiment of the safety system according to the invention, a control chip is provided for the implementation of a chip-controlled actuation system. This chip-controlled actuation system permits the operation of the control system of the hydraulic supply system if deployed there, but stops the supply system if it is removed. Upon its deployment at the controllable valve, it decouples the relevant assignable gas safety valve from the pressure accumulator at the gas end by blocking the assigned connection. Conversely, an operation of the hydraulic supply system is only possible when the control chip returns the gas safety valve back to its open position after removal, and this chip re-deployed at the controller permits the resumption of the operation of the connected hydraulic system.
It is also advantageous that the valve block has at least one further supply port, to which at least one further pressure accumulator, preferably a gas pressure accumulator, can be connected. In its open position, the further pressure accumulator is connected to the relevant pressure accumulator, preferably to the gas end of a hydraulic accumulator, in a gas-conveying manner via a check valve arranged within the valve block. In particular, gas can then be taken from the gas supply of the storage cylinder via the further supply port and directed to the gas end of the hydraulic accumulator in order to increase the working capacity of this hydraulic accumulator.
It is also advantageous that the valve block has at least one further port, to which a filling and testing device can be connected. This filling and testing device is connected directly to the pressure accumulator via a filling and test port in the valve block in a gas-conveying manner, preferably is connected to the gas end of a hydraulic accumulator in the form of a piston accumulator. This filling and test port is connected to a further connection between the further pressure accumulator and the pressure accumulator via a check valve, which opens in the direction of the respective controllable valves. Characteristics of the gas, such as temperature and pressure of the gas volume, can be monitored and recorded by the filling and testing device.
If a hydraulic supply system is connected to the above-mentioned hydraulic accumulator in a conventional manner at its liquid end, the safety system according to the invention ensures that in case of malfunction, for instance caused by a fire, no unintentional pressure increases can occur at the gas end of hydraulic accumulator. No unintentional pressure increases occur because the open valve device or the ball valve in the open position ensures that gas can be directly vented to the outside if the pressure at the hydraulic accumulator end exceeds the maximum pressure set at the relevant gas safety valve. In this way, excessive pressure at the liquid end of the hydraulic accumulator and at the end of the supply system, which could result in the bursting of system parts, is immediately vented. The operators at the system components of the supply system are then not exposed to hazards. The safety system further ensures that manual maloperation, which could result in an unwanted shutdown of the function of the gas safety valve, is impossible.
Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the drawings, discloses preferred embodiments of the present invention.
Referring to the drawings that form a part of this disclosure and that are schematic and not to scale:
A third hand lever 20 is arranged at the outside of the valve block 10 spaced apart from the hand levers 16, 18 arranged next to each other. The third hand lever 20 can be used to actuate a ball of a further or third ball valve 54 (see
Each annular control disk 30a, 30b for the hand levers 16, 18 has a segmented, concave-shaped cutout 32a, 32b having an arcuate contour. The two cutouts 32a, 32b are arranged opposite one another in the opened control positions of the two hand levers 16, 18 shown in
Further two pin-like projecting stop limits, 15a, 15b are provided at the valve block 10, each defining the rotational movement of the respective assigned hand levers 16, 18 by 90° in the open and the closed control positions and interacting with stop lugs arranged adjacent to the cutouts 32a, 32b of the respective control disks 30a, 30b. The pertinent stop limit is common in ball valves, i.e. they will not be discussed further in this context. In particular, individual details have been omitted in the figures for purposes of clarity.
In the valve block 10, a plurality of interconnected fluid connections are formed between the first valve port 36, the second valve port 38, the supply port 22, the pressure port 26, the filling and testing port 24, the measuring port 48 and the pressure gauge port 34. Typically, the connections are introduced as drilled holes in the valve block 10 made of a metal material. From the first valve port 36, a first connection section 21 leads to a first intersection point 23. From the second valve port 38 a second connection section 25 leads to a second intersection point 27. The first intersection point 23 and the second intersection point 27 are arranged in a third connection section 29, which extends in the interior of the valve block 10 from the measurement connection 48 to a third intersection point 31.
A fourth connection section 33 extends from the supply port 22 to the pressure port 26. The third intersection point 31 and a fourth intersection point 35 are arranged in the fourth connection section 33. The fourth intersection point 35 is the end of a filling and test connection 37 beginning at the filling and test port 24. A fifth intersection point 39, which represents the end of a fifth connection section 41 beginning at the first intersection point 23, is arranged in the filling and test connection 37. A sixth intersection point 43 is arranged between the first valve port 36 and the first intersection point 22 in the first connection section 21, which sixth intersection point constitutes the end of a sixth connection section 45 beginning at the pressure gauge connection 34.
Further, there is a first line section 47 between the first gas safety valve 12 and the first valve port 36, a second line section 49 between the second gas safety valve 14 and the second valve port 38, third line sections 51, 51a, 51b between the further pressure accumulators 40a, 40b and the supply port 22, a fourth line section 53 between the pressure accumulator or gas storage cylinder 42 and the pressure port 26, fifth line sections 55a, 55b, 55c between the measuring device 28 and the measuring port 48 and continuing from the measuring device 28, and sixth line sections 57a, 57b between the pressure gauge 44 and the pressure gauge port 34.
In the connections leading from the gas safety valves 12, 14 to the pressure accumulator 42, the first ball valve 50 is arranged in the first connection section 21, and the second ball valve 52 is arranged in the second connection section 25. The third ball valve 54 is arranged between the third intersection point 31 and fourth intersection point 35 in the fourth connection section 33 leading to the pressure accumulator 42 and parallel thereto a check valve 56 is installed in the fifth connecting section 41 between the first intersection point 23 and fifth intersection points 39. The check valve opens in the direction of the first intersection point 23. The individual ball valves 50, 52, 54 are actuated individually by hand using the assigned hand levers 16, 18, 20. The filling and test connection 37 leads directly from the fourth intersection point 35 adjacent to the pressure port 26 to the filling and test port 24.
As soon as the pressure at the gas end 45 of the pressure accumulator 42 increases due to an impermissible pressure increase, for instance caused by a technical fault in the hydraulic supply system 43, such as a fire, beyond a maximum pressure at the gas end 45 of the pressure accumulator 42, which maximum pressure is preset by the set pressure of the gas safety valves 12, 14, that increased pressure causes their triggering. Gas can then flow from the gas end 45 of the pressure accumulator 42 when the valves in the form of ball valves 50, 52 are open through the gas safety valves 12, 14, until their set pressure of, for instance, 330 bar again is reached or if the pressure has fallen below that value. This safety function is also implemented when the gas ends of the further pressure accumulators 40a, 40b are separated from the gas end 45 of the pressure accumulator 42 by closing the further third ball valve 54. In this case, the pressure compensation uses the check valve 56, which opens in the direction of the two gas safety valves 12, 14 and insofar opens the assigned connections in the valve block 10, which regularly vent working gas in the form of nitrogen gas, for the purpose of pressure reduction. For the sake of completeness, the piston 49 of the pressure accumulator 42 designed as a piston accumulator separates the gas end 45 from the liquid end 47 leading to the supply system 43. In the exemplary embodiment of the safety system shown in
The circuit diagram shown in
In the diagram shown in
In the circuit diagram shown in
In the embodiments of the safety system shown in
In the exemplary embodiment shown in
Once a gas safety valve 12, 14 is to be removed from the valve block 10, it must first be ensured that the relevant gas-conveying connection has been disconnected or shut off by the gas safety valve 12, 14 using the valve ports 36, 38 and the respective assigned ball valve 50, 52 or 58 and the pressure port 26 of the pressure accumulator 42. This is achieved by actuating the assigned hand lever 16, 18 and an assigned mechanical locking of the control disks 30a, 30b formed at the hand levers 16, 18 or via an appropriate setting of one of the two control positions of the 3-way ball valve 58. In the valve solution using a ball valve 58, an externally actuated control would also be conceivable, for instance. In the form of an electric, hydraulic or pneumatic motor control. Alternatively, or additionally, the blocking of the gas connection from the gas safety valve 12, 14 to the relevant pressure accumulator 42 can be monitored using at least one monitoring device 60, 62. The monitoring devices 60, 62 generate appropriate control and/or monitoring signals for a higher-level control device (not shown). Correspondingly, the active replacement of a gas safety valve 12, 14 by hand can be monitored at the valve block 10, and the valves 50, 52, 58 can be brought into the opening or closing control position as required.
As soon as the fourth connection section 33 is shut off from the pressure accumulator 42 to the gas safety valves 12, 14 using the third ball valve 54, the gas end 45 of the relevant pressure accumulator 42 can be checked and optionally refilled using a filling and testing device 28 (not shown) to be connected to the filling and test port 24. If refilling or adding working gas from the gas supply of the further pressure accumulators 40a, 40b is required, the third ball valve 54 is permanently opened, so that the working gas can flow from the gas supply of the further pressure accumulators 40a, 40b to the supply port 22 via the third line sections 51, 51a, 51b, further to the pressure port 26 via the fourth connection section 33 and further to the pressure accumulator 42 via the fourth line section 53, if necessary. The assigned pressure curve can be monitored using the pressure gauge 44 connected to the pressure gauge port 34.
Furthermore, the pressure in the safety system can be monitored electrically using the pressure transducer 28. If the gas supply in the respective further pressure accumulators 40a, 40b also has to be filled, assuming that the further pressure accumulators 40a, 40b are also connected to the valve block 10 via the port 22, this happens simultaneously with the gas end 45 of the relevant pressure accumulator 42 for an open ball valve 54 and, if required, for a closed ball valve 54 using the check valve 56. The pertinent filling using the port 24 then continues until the self-adjusting pressure equilibrium between the further pressure accumulators 40a, 40b, the refilling device at the port 24 and the relevant pressure accumulator 42 causes the non-return valve 56 to increasingly reach its closed position.
An alternative embodiment of the safety system according to the invention is shown in
In the first variant of the safety system shown in
The second variant of the safety system illustrated in
While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2017 007 628.6 | Aug 2017 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2018/071644 | 8/9/2018 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2019/034529 | 2/21/2019 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4076176 | Torrence | Feb 1978 | A |
| 20150184805 | Lee | Jul 2015 | A1 |
| Number | Date | Country |
|---|---|---|
| 244 387 | Apr 1987 | DE |
| 10 2010 008 636 | Aug 2011 | DE |
| 10 2014 013 098 | Dec 2015 | DE |
| 2 857 727 | Apr 2015 | EP |
| 3 024 204 | Jan 2016 | FR |
| WO-2011101293 | Aug 2011 | WO |
| Entry |
|---|
| International Search Report (ISR) dated Dec. 4, 2018 in International (PCT) Application No. PCT/EP2018/071644. |
| Number | Date | Country | |
|---|---|---|---|
| 20200149683 A1 | May 2020 | US |
