The invention relates to a draining or venting device for a compensator. Moreover, the invention relates to a heat exchanger with a compensator and a draining or venting device for the compensator.
Compensators are required when, as a result of temperature or pressure stress, system components that are connected to one another expand or move relative to one another to different degrees. According to the prior art, these differences in the expansion of components can be accommodated by compensators. Compensators are used as equalizers of expansion or motion on equipment such as heat exchangers, pipelines, pumps, motors, turbines and machinery.
A compensator is generally formed as a tubular element with a corrugated or folded structure that has at least one formation that runs around the periphery, for example in the form of a corrugation or a fold. The corrugation can be made, for example, in the form of a ring that is open to the inside and that runs around the periphery of the compensator. A compensator can have a single corrugation or several corrugations or folds. Similarly to an accordion and as a result of its corrugated or folded structure, the compensator can be pulled apart or pressed together. Compensators can be formed from elastomer materials such as rubber, or from metal. In the case of a metal design, compensators with one or more peripheral formations or corrugations can also be referred to as metal bellows compensators.
Especially for a horizontal arrangement of such a compensator, the corrugations or formations enclose spaces in which liquid or gas collects that cannot be drained by gravity. Among others, this constitutes a safety risk when the system is to be maintained and dangerous gases or liquids remain in the formation or the corrugation of the compensator. Moreover, it is desirable to completely remove all fluids from a system from time to time, since in the operation of a system, substances can collect that can have an adverse effect on the processes taking place in the system.
In order to solve this problem, it would be possible in the respective corrugation or fold of the compensator to form a closable drain or vent opening. In compensators with a wall thickness of less than 2 mm, this is, however, technically difficult to do. Moreover, in general, manufacturers of compensators do not guarantee compensators that are provided with holes.
One object of this invention is therefore to provide a device with which complete or substantially complete residual draining or residual venting of a compensator is possible without violating the compensator wall in the region of the corrugation or the fold.
Upon further study of the specification and appended claims, other objects and advantages of the invention will become apparent, for example, a method of producing the device, a heat exchange incorporating the device as well as a method of using the heat exchanger.
These objects are achieved with a draining or venting device for a compensator that has a central, especially cylindrical, interior space and at least one peripheral formation, especially a corrugation which surrounds the interior space of a formation, the draining or venting device having a suction means for sucking a fluid out of the interior space of the formation, and a connecting line that establishes a flow connection between the interior space of the formation and the suction means, the connecting line running through the central interior space of the compensator and running through a through opening, especially a through hole, in one wall of a component that is connected to the compensator.
Accordingly, a draining or venting device for a compensator is provided that has a central, preferably cylindrical, interior space and at least one peripheral formation, for example a corrugation, that surrounds the interior of the formation, whereby the draining or venting device has: a suction means for sucking a fluid out of the interior space of the formation, and a connecting line that establishes a flow connection between the interior space of the formation and the suction means, the connecting line running through the central interior space of the compensator and running through a through opening, for example a through hole, in one wall of a component that is connected to the compensator. The advantage of this device is that the connecting line is routed through the central interior space of the compensator and runs to the outside via a through opening in an adjacent component. It is therefore unnecessary to make an opening in the compensator itself. Damaging the compensator by making a drain or vent hole is thus avoided. Thus, notch stresses in the compensator wall are avoided that would adversely affect the expansion behavior of the compensator. Since the compensator wall is intact, the guarantee of the manufacturer for the compensator remains in effect. By already applying a low vacuum that overcomes the gradient and the pressure loss of the connecting line, the fluid can be removed from the interior space of the formation by way of the connecting line.
The fluid that can be removed from the compensator can be a gas or a liquid. If the compensator has several formations such as corrugations, with several interior spaces of the formations, for each formation a flow connection to a suction means can be created. Preferably, the suction means comprises an electrically-driven pump. In general, however, it is also conceivable for a liquid in the interior space of the formation to be removed by a gradient using the siphon principle.
In the device according to the invention, the connecting line preferably projects into the interior space of the formation of the compensator. This has the advantage that a fluid located in the interior space of the formation can also be removed with a low vacuum. If a passage between the central interior space of the compensator and the interior space of the formation is too narrow to route a corresponding pipeline through, it is also possible to have the connecting line leading from the central interior space of the compensator in front of this passage. The connecting line then does not project into the interior space of the formation, but rather ends in front of the passage. By applying a corresponding vacuum or negative pressure, however, gaseous fluids can also be removed.
If a liquid is to be removed from the interior space of the formation, the device according to the invention preferably has a heating means for vaporizing the liquid located in the formation. The vaporized liquid can then also be removed using a line that ends in front of the passage. The heating means is preferably an electrical heating means such as, for example, a heating mat that is located on the outside of the formation.
The device according to the invention is preferably made such that (a) a first, inner part of the connecting line is formed by a pipeline that runs through the central interior space of the compensator and extends as far as or into the through opening, and (b) a second, outer part of the connecting line that leads to the suction means and can be flow-connected, via a pipe socket that is connected from the outside to the through opening, to the first, inner part of the connecting line. In the operation of the compensator, the pipe socket is preferably sealed by a blind flange. If the compensator is to be drained when out of operation, the second, outer part of the connecting line that leads to the suction means is connected to the pipe socket. In general, however, a configuration is also conceivable in which the inner part and the outer part of the connecting line are continuously connected and—by way of a valve in the connecting line—a flow connection between the interior space of the formation and the suction means is established or blocked. This can be a manually operated valve.
Preferably, the through opening is located in one wall of a tubular connecting part that is connected to the compensator and to the aforementioned first, inner part of the connecting line that runs through the central interior space of the compensator and extends as far as or into the through opening as a prefabricated unit. This simplifies installation of the draining or venting device at the system site. The connecting part then need be connected only to the corresponding system component, for example a jacket part, and the inner part of the connecting line must be connected to the outer part of the connecting line and thus must be flow-connected to the suction means.
In the device according to the invention, a first part of the connecting line that runs into the central interior space of the compensator, preferably the aforementioned first, inner part of the connecting line, has a diameter of less than 20 mm, preferably of less than 10 mm. This makes it possible to use the device according to the invention also for equipment or machinery in the interior of which there is less room for the connecting line. One example of this is the jacket space of heat exchangers with a straight tube bundle where there is too little room between the outer pipe circle and the inside of the jacket.
The draining or venting device according to the invention can be used for all types of compensators that have one or more formations in which fluids collect, which cannot be drained solely by gravity, during operation of the compensator. This is especially the case for a horizontal arrangement of a compensator in which at least one part of the formation or the interior space of the formation is underneath the lowest or above the highest wall section of a component that is connected to the compensator. The device according to the invention is preferably suited for compensators with corrugations in which the respective corrugation in the form of a ring runs around the essentially tubular body of the compensator, or else for compensators with corrugations that likewise run around an essentially tubular body of the compensator and have an essentially circular or elliptical cross-section. Since these corrugations can have large interior spaces of the corrugations, considerable amounts of fluids can collect here that cannot be drained by gravity. Preferably, the device according to the invention is intended for compensators that have a corrugation made of metal, preferably high-grade steel, with a wall thickness in the range from roughly 0.5 to 1.5 mm. In them, the arrangement of a venting or draining means on the wall of the corrugation is not possible.
The device according to the invention offers major advantages for heat exchangers, for example straight tube heat exchangers, in which the compensator connects the jacket parts of the heat exchanger to one another. As mentioned above, in these heat exchangers, there is little room in the jacket space, since the pipes border the jacket there, and there is little room between the pipes of the individual pipe circles. The part of the connecting line that runs into the central interior space of the compensator or into the jacket space of the heat exchanger can, however, be made very thin so that it has enough room between the outer pipe circle and the inside of the jacket. With the device according to the invention, even horizontally installed heat exchangers, which due to large temperature differences between the medium flowing in the jacket space and the medium flowing in the pipe space require a compensator that is located between the jacket parts, can thus be completely drained.
Preferably, the device according to the invention is used for a straight tube heat exchanger that is used in a synthesis gas or hydrogen facility, for example, as a preheater in which a feedstock, for example water or natural gas, is preheated in indirect heat exchange with hot synthesis gas. Due to the high temperature differences between the feedstock that flows through the jacket space and the hot synthesis gas that flows through the pipes, a compensator on the jacket is necessary. The latter can be completely drained, for example of natural gas, using the device according to the invention so that maintenance efforts such as welding can be done without danger to the maintenance personnel.
The device according to the invention can also be used for floating head heat exchangers with a straight tube bundle, a floating head with an attached pipe socket with a compensator, as is described in the patent application “Heat Exchanger with Straight Tube Bundle and Floating Head” (applicant file number 102007017227.5).
The invention as well as further details of the invention are explained in more detail below based on the embodiments shown in the drawings. Here:
To facilitate an understanding of the Figures, the following table presents a list explaining by order of number of the components.
In the region of the tubes 3, the jacket 2 of the heat exchanger 1 is formed from tubular jacket parts 13 and 14 that are connected to one another by way of a compensator 15. The compensator 15 is made in one layer and has a formation or corrugation 16 that runs around the periphery of the compensator 15. The compensator 15 is made of high-grade steel (chromium-nickel steel). As can be seen from
If the tubes 3 undergo lengthwise expansion differently than the jacket parts 13 and 14 during operation of the heat exchanger 1 from
The heat exchanger 1 shown in
As
In the region of the through hole 40, a pipe socket 44 is attached to the outside of the connecting part 10 and is connected coaxially to the straight section 35 of the pipeline 30. In the operation of the heat exchanger 1, the pipe socket 44 is sealed with a blind flange 49 as is shown at top right in
When the heat exchanger 1 is not in operation, a pipeline 47 can be connected to the pipe socket 44 by way of a flange 46. The pipeline 47, as also shown in
During operation of the heat exchanger 1 as a feedstock preheater in a hydrogen plant, natural gas that is routed through the jacket space 10 travels through the gap 23 into the interior 25 of the corrugation. Since part of the peripherally running interior space 25 of the corrugation, as shown in
In order to remove the remaining residues of the natural gas from the interior 25 of the corrugation, the pipeline 47 is connected to the pipe socket 44 shown in
In contrast to the embodiment that is shown, it is also possible to connect the pipeline 47 permanently to the pipe socket 44 and to provide it with a valve that is closed in the operation of the heat exchanger 1 and that in the case of necessary venting of the compensator 15 is opened for connection to the pump 50. If the compensator, in contrast to the embodiment that is shown, has several corrugations 16, each corrugation 16 can be provided with a corresponding pipeline 30 and a corresponding number of through holes 40 and pipe sockets 44 can be provided on the jacket of the heat exchanger 1. In this case, the respective pipe sockets 44 can be located distributed over the periphery at the same axial height on the connecting part 19 or 20 or else on the jacket parts 13 and 14 of the heat exchanger 1.
For purposes of ventilation, a vacuum is also produced here using the pump 50 and sucks out the residue of the first medium, here natural gas, from the interior 25′ of the corrugation. In order to reduce the lateral flow of air out of the central interior space 17′ of the compensator 15′ into the pipeline 30′, the line end 36′ should be located as near as possible to the gap 23′. Moreover, it is possible to make the end 36′ as a nozzle with an elongated gap, which is not shown, however.
With reference to
The draining device shown in
In the operation of the heat exchanger 1, water flows from the jacket space 10 through the gap 23 into the interior space 25 of the corrugation. In one region of the interior space 25 of the corrugation, which, as shown in
A residue of liquid fluid that remains underneath the lower end 136 of the pipeline 130 in the interior space 25 of the corrugation is vaporized using the heating means 160. The vapor is likewise sucked out by way of the pipeline 130 and the pump 150.
As indicated in
A venting device as is explained with reference to
Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
In the foregoing and in the examples, all temperatures are set forth uncorrected in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.
The entire disclosures of all applications, patents and publications, cited herein and of corresponding German application No. 102008026596.9, filed Jun. 3, 2008 are incorporated by reference herein.
The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
Number | Date | Country | Kind |
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102008026596.9 | Jun 2008 | DE | national |