WO1988008822A1

WO1988008822A1 - Pressure vessel for compressed gases with a device for testing, storing and monitoring compressed gases such as ammonia, propane and similar

Info

Publication number: WO1988008822A1
Application number: PCT/EP1988/000418
Authority: WO
Inventors: Karl W. R. Lohr; Reinhard W. Ganske
Original assignee: Lohr Karl W R; Ganske Reinhard W
Priority date: 1987-05-15
Filing date: 1988-05-13
Publication date: 1988-11-17
Also published as: EP0396543A1; DE3716426C1

Abstract

A double-walled pressure vessel comprises an inner shell impermeable to compressed gases with a curved inner floor and an outer shell impermeable to compressed gases with a curved outer floor, and a double-walled stub-type access hole. A space is provided between the inner and outer shells and between the walls of the stub-type access hole. The stub-type access hole (2), a manometer well (3), an inspection pipe stub (4), a pump recirculation pipe stub (5), a gas displacement pipe stub (6), a thermometer well (7) and a level-indicating pipe (9) are arranged in the part of the floor (1) of the vessel subjected mainly to tensile stresses but to low flexural stresses. In addition to the stub-type access hole, all the other connecting pipe stubs are of double-walled design. Other double-walled pipe, namely a safety pipe (11), a rinsing pipe (12), a leak-detection pipe (13), an extraction pipe (14), an emergency extraction pipe (15), a filling pipe (16) and a leak space pipe (17) are provided in the region of the outer shell (10) subjected to low tensile stresses. All these pipe stubs are attached to the pressure vessel by liquid-tight and gas-tight welds. A space is left between the inner and outer walls of all pipe stubs, and all spaces communicate with one another.

Description

description

Pressure container for compressed gases with a device for testing, storing and maintaining compressed gases such as ammonia, propane and the like

Technical field

The invention relates to a double-walled pressure vessel made of a pressure-gas-resistant inner jacket with a curved inner bottom and a pressure-gas-tight outer jacket with a curved outer bottom, as well as with a double-walled manhole spigot, between the inner jacket with inner bottom and the outer jacket with outer bottom and between the walls of the double-walled manhole spigot a gap is provided.

Industrial applicability

To comply with the Federal Immission Control Act (BImSchG) for the purpose of reducing nitrogen oxide emissions in power plants, waste incineration plants and. . Large combustion plants ammonia (NH.,) Are used

4 NO + 4 NH ₃ + 0 ₂ - »4 N ₂ + δ H ₂ 0.

To increase the raw gas concentration from 1200 mg NO _____ / m ³ (NO_-k calculated as N0 ₉ •) to 200 mg NOΛ _, / m ³ in a smoke gas volume flow of, for example, 10 m ³ / h (= power plant output 330 MW _α] ) reduction, about 400 kg of ammonia are required per hour, ie 1 kg of NO _? _., which is reduced, requires 0.4 kg of ammonia. The high ammonia consumption as well as a The minimum stock level for Lo days generally requires a storage capacity of considerably more than 30 t of ammonia. Such large stores have so far rarely been set up outside of chemical plants.

Storage with ammonia is subject to the regulations of the Accident Ordinance from a certain storage quantity.

Ammonia is hazardous to health, very toxic, flammable and water-endangering (water hazard class 2). If it gets into the ground, there is a risk of groundwater contamination. Ammonia in water is lethal to fish at a concentration of 0.1 - 2.0 mg / C. ^'' The first effects in fish appear at 0.006 mg / t.

A monia clouds, released under pressure by an accident, originating from the liquid phase or from the gas phase, spread out like a heavy gas (heavier than air) on the ground in the direction of the wind and can even have a concentration of 2 even over distances of 800 , 1 vol%, measured at a height of one meter above the ground.

It follows from this that, in the interest of environmental protection, the ^" infrastructure of power plants and other large combustion plants must first and foremost be geared towards building and operating ammonia stores safely without endangering the environment.

In the storage of pressure-liquefied ammonia for the operation of DeNO systems in power plants and other large combustion plants, this environmentally protective precaution can lead to extremely economically burdensome costs and precautions which can be achieved by the system according to the invention to an economically acceptable level let reduce. State of the art

In DE-OS 32 18 653, full-fledged pressure vessels are considered to be a relatively thin-walled inner container and a relatively thick walled outer container described.

It is also known to store the compressed gases in single-walled pressure vessels underground or above ground within locally constructed concrete structures (containments), which are supposed to have a protective and containment function, in order to meet the safety requirements.

Containers according to DIN 4681, Part 2, are not suitable as double-walled containers for the testing, storage and maintenance of compressed gases because they have the following disadvantages and risks:

The deformation of the thin-walled outer casing, which is generally 4 mm thick, requires so much time after the earth-covered storage due to the gradual settlement of the freshly filled up soil that the leak detection liquid generally needs to be filled up within widely spaced intervals of the annular space / control space in the container (storage vessel) must be added frequently and until the deformation of the outer jacket has stabilized and the level in the control vessel remains constant. In the meantime, a false alarm can be triggered several times by falling liquid levels without a leak in the outer jacket.

Between the outer jacket and the inner jacket there are, for example, about 650 liters of leak detection liquid for a container of around 100 ³ contents with an approx. 4 mm ring gap, which, because it must be corrosion-preventing, frost-resistant and segregation-resistant, up to 80% glycol (water hazard class 2 ) contains and in the event of a malfunction, such as a leak due to corrosion of the outer casing, can get 100% into the groundwater (groundwater contamination).

The pressure test of the inner container - prescribed at certain recurring time intervals - requires an immense cost and time expenditure with considerable security risk during the outsourcing and opening of a container.

In the event of a leak in the inner container (pressure container), i.e. With this type of accident, is the thin-walled outer container not able to absorb the escaping compressed gas even temporarily? the system would have to be depressurized and drained immediately under the great risk of environmental damage.

All container sockets and the manhole must be attached to the top surface in the gas phase and there within a liquid-tight welded-on, aerated, walkable and gas-monitored dome shaft. This requires an expensive installation for submersible pumps that are known to be faulty limited lifespan or immersion pipes, for the storage of compressed gas, as well as complicated tank connections - problems with the drainage and the corrosion protection of the manhole are added.

Containers of this type cannot therefore be installed above ground: e.g. with a free end face, with a manhole in the end face, and they cannot be operated with a socket on their underside to remove the liquid phase «, the annular gap between the container shells does not control leaks in the socket or the manhole neck.

In the event of a leak in the liquid phase of a container stored in a concrete structure, the container empties completely (vapor pressure from post-evaporation). Two storage containers with a volume of 200 m ³ each require, for example, a collecting space of 2900 m ³ total volume within a concrete structure if this collecting space is completely covered (pore volume of the earth covering approx. 8%). This results in building base areas of 10 x 25 m with light heights of up to 7.5 m. '

It is obvious that such large structures with the required derten tightness immense costs in production and operation and cause the price of electricity (power plants) or Entsor¬ supply (incineration) economically hardly portable loading ^'burden.

Presentation of the invention

The object on which the invention is based is to design a pressure vessel of the type outlined at the outset in such a way that it and all the container connections, together with the leak detection space, can be permanently checked for leaks.

This object is achieved according to the invention in that the manhole connector, a manometer connector, a dip tube connector, a pump return connector, a gas pendulum connector, a thermometer connector and a level indicator connector are arranged in the part of the bottom of the pressure vessel which is predominantly stressed but largely free of bending, and in addition to the manhole connector All the other connecting sockets mentioned are double-walled, that further double-walled connecting sockets, namely a safety connection, a rinsing connection, a leak control connection, a removal connection, an emergency removal connection, a filling connection and a leakage connection connection in the low-tension area of the outer container shell it is provided that all nozzles are fixed to the pressure vessel in a liquid-tight and gas-tight manner by means of continuous, continuous weld seams, and that a gap space is free between the inner and outer walls of all nozzles is left, with all gap spaces of the pressure vessel being connected to one another.

Appropriate further developments of the pressure vessel according to the invention result from the subclaims.

The installation of an internal, remote-controlled quick closing valve in connection with the cut-out reinforcement plate designed as a block flange allows the double-walled connecting pieces designed in this way to be arranged below the liquid level while maintaining the offered security, whereby the installation of a pump is not necessary.

This not only saves the costs for the pump and the associated additional equipment, but also avoids procedural difficulties for the subsequent systems.

This inventive design of a pressure vessel makes it possible for the annular gap / annulus between the jackets and between the connecting piece and the manhole piece to be permanently checked for leak tightness during normal operation by means of an integrated liquid pressure testing device with a hydrostatic control device and to carry out a liquid pressure test at any time with the least amount of effort with the full prescribed test pressure, whereby during normal operation and the changing thermal and static influences the tension-compensating mobility of the inner container relative to the outer container (inner jacket and outer jacket) including all nozzles as well as the manhole remains.

The advantages which can be achieved with the construction of a double-walled pressure container according to the invention can be summarized as follows.

During storage (filling), storage and retrieval (removal), the stresses occurring in the components of the double-walled storage container are compensated by changing thermal and changing static loads, ie the tension-compensating mobility of the inner container relative to the outer container is completely retained. The execution of officially prescribed Pressure tests on the double-walled pressure vessel are possible in a cost-saving and risk-reducing manner without emptying / outsourcing the filling material. All connecting stubs, which communicate with the inner container are in communication, in the leak monitoring control of the intermediate space between the outer and Innenbehäl¬ retracted ter, ^'that is, they are continually monitored automatically über¬. Furthermore, a secure installation and safe operation of the pressure container according to the invention is guaranteed. All connections / pipe / jacket hole connections within the double-walled pressure vessel can also be arranged both in the liquid-carrying space on the underside of the vessel and in the vapor space on the top of the vessel, ie either completely covered with a front space which is kept free by a construction measure, or partially covered with ground one kept free by a construction measure

Forehead space or completely covered with earth with fittings arranged in the crown area within a simple armature that drains the rainwater, i.e. without having to provide a space for leakage gas, or completely above ground with nozzles provided in the front space and in the jacket area.

The arrangement of connection pieces / pipe / manhole connections in the liquid-carrying part of the double-walled pressure container according to the invention has the further advantage that one can work with a static inflow (NPSH) of the stored goods to the pump or evaporator systems and thereby complicate and expensive additional system elements can be saved, nevertheless a trouble-free operation of the pressure vessel is guaranteed in all weather conditions.

A thin-walled design of the inner jacket is made possible by particularly stress-relieved weldable weld seams. The stress-free annealing required for single-walled pressure vessels according to the rules of technology represents a very considerable cost and can be omitted for the inventive design of a pressure vessel. Even for larger storage quantities (container contents), double-walled pressure containers according to the invention can be erected "on the construction site" by prefabricating as many double-walled ring sections and the two double-bottom sections in the factory, transporting them to the construction site, preparing them and using relatively easy to carry out, fully auditable, ^post-7 - treatable, beschleifbaren ring welds zusammen¬ adds.

The invention is explained in more detail below using exemplary embodiments with reference to the accompanying drawing.

Brief description of the drawing

Show in the drawing?

1 is a side view of a pressure vessel with an exposed front wall part and a ground wall part installed on the ground,

2 shows an end face of the pressure container according to FIG. 1,

3 is a partial view of the pressure vessel of FIG. 1,

4 two possibilities I and II of connecting a manhole flange connector to the pressure vessel,

5.5a possible arrangements of the connecting piece on the pressure vessel according to FIG. 2,

6 the fixing of the individual connecting sections to the pressure vessel,

7 on an enlarged scale a connecting section of the container rings with a bridging ring,

8 shows another embodiment of the pressure vessel jacket, 9 and 10 the necessary positioning of the steel sheets of the outer and inner sheath for the simultaneous deformation and manufacture of the rings,

11 is a perspective view of the positioning of a washer strip,

12 shows the washer strip according to FIG. 11 after the longitudinal seams have been welded,

13 is a perspective view of the welded rings,

Fig. 14 shows an embodiment of the T-joint corresponding to the

Circle A and B in Fig. 1 and 2,

15 shows the design of the cut-out reinforcement ring as a block flange with an internal valve,

16 schematically shows the overall system,

17 and 17a are partial sectional views in which the possibilities for forming the gap space are shown.

Best way to carry out the invention

1, 2 and 3, in the part of a pressure vessel base 1 which is predominantly stressed but largely low in bending stress, there is a manhole connector 2, a manometer connector 3, a dip tube connector 4, a pump return connector 5, a gas pendulum connector 6, a thermometer connector 7 and a Ni - Veauanzeigerstutzen 9 arranged.

In the predominantly low-tension area of the pressure vessel outer casing 10, a safety connection 11, a flushing connection 12, a leak control connection 13, a removal connection 14, an emergency removal connection 15, a filling connection 16 and a leakage connection connection 17 are provided. In the further description, these individual nozzles are referred to as connecting nozzles.

4, the integration-welding of the manhole flange connection 2 with the relatively large nominal diameter DN 600 into the outer container jacket 10 and the inner container jacket J is shown in two embodiments I and II. According to embodiment I (left side, FIG. 4), the manhole spigot comprises a flange ring 18, an outer thick-walled dome neck 19 with a plurality of bores 20 for the passage of leakage detection liquid, an inner thin-walled dome neck 21 and a cut-out reinforcement plate 22.

In this embodiment, the dome neck parts 19, 21, 22 and the weld seams connecting them are designed and constructed in such a way that the leak detection fluid from the annular gap 5 between the outer container jacket 10 and the inner container jacket J reaches the annular space R unhindered and via the Boh ¬ stanchions 20 and the annular gap S and the dome neck parts 19, 21 remain constantly controlled.

In the embodiment II shown in FIG. 4 on the right side, the bores 20 are unnecessary, while saving the manufacturing costs, because the dome part 19 is only inserted into the outer casing 10 of the container as far as is necessary for a double-sided welding and one Correspondingly elongated dome part 21 is welded on both sides, in particular with the aid of the additional weld seams 23, to the cut-out reinforcing plate 22 so that the leak detection fluid reaches and controls the annular gap directly via the annular space R. In addition, embodiment II ensures that the dome neck parts 19 and 21 axially compensate each other in the event of changes in temperature and the resulting stresses can shift and this shift is compensated by the cut-out reinforcement plate 22. This is a very essential aspect of the invention.

5, 5a is the integration-welding of the double-walled rinsing pipe 12, pump pressure pipe 5, gas pendulum pipe 6, extraction pipe 6, which is relatively small in nominal size from DN 80/40 to 80/80, and which is shown in FIGS. 1, 2 14, filler neck 16, safety valve neck 11, leak control neck 13 and leakage neck 17 in the container outer jacket 10 and the container inner jacket J are shown in two embodiments III and IV, which correspond to the arrangement according to FIG. 4 with regard to the application of the weld seams and their mode of operation .

The nozzles according to embodiment III each comprise welding flanges 23 and 24, outer jacket tubes 25 and 26, an inner jacket tube 27, the annular gap R and a cutout reinforcing plate 28.

In the embodiment IV according to FIG. 5 a, it is analogous, as shown in FIG. 4, in which way the positioning and weld seam arrangement ensures a stress-compensating displacement of the inner jacket tube 27 relative to the outer jacket tube 25.

FIG. 6 shows the integration / welding of the double-walled emergency removal connection 15, thermometer connection 7, pressure gauge connection 3, dipstick connection 4 into the outer casing 10 and the inner casing J given in FIG shown, which corresponds in the application of the weld seams and in their mode of operation to the description of FIG. 4 of embodiment II. These sockets are formed from the welding neck flange 28, the outer jacket tube 29, the inner jacket tube 30, the annular gap R and the cutout reinforcing plate 31. According to FIG. 7, relatively narrow, thin-walled rings 34, which form the inner container casing, run concentrically with the relatively wide, thick-walled rings 32. These relatively narrow rings 34 are welded to one another by means of bridging rings 35 welded to them. The seams 36 between the relatively narrow rings 34 and the bridging rings 35 are continuously welded tightly in the fillet weld. The butt 33 is welded through. Inner floors (not shown) are welded to the end bridging rings 34 and are covered by outer floors.

According to FIG. 8 are concentric to the relatively wide and thick rings 32 relatively narrow, thin-walled ^'blade 39, the inner shell surface wel¬ J form. These rings 39 have a continuous round bead RS in the vicinity of their radially running outer edge, the inner curvature depth WT of which is equal to or greater than the sheet thickness DI of the rings 39. The relatively narrow rings 39 are in the weld seams by means of bridging rings 40 welded to them 41 tightly welded throughout.

It should be emphasized that a gap is provided between the inner and the outer jacket so that these jackets do not lie axially directly on top of one another, so that the inner jacket can "move" axially against the outer jacket. The cylindrical outer container shell, formed from the rings 32, and the cylindrical inner container shell J, formed from the rings 39 and 40, can be mutually opposed due to the described design of the rings 39, 40, the weld seams 41 and the intended gap move in the direction of the main axis of the container in such a way that thermally induced tensions are compensated or compensated.

9 and 10 show that the thin-walled sheet metal for the ring 39, which is beaded lengthwise in a previous known, not described working method, is placed directly on the thick-walled sheet metal for the ring 32 and in its position on both longitudinal sides by means of welded strips - sheets 42 and is fixed on its end face by means of direct section-by-point tack welds 43. Both the strip plates 42 and the tack welds 43 are removed after the round rolling has taken place, for example ground away. The roll W of a round rolling machine has two recesses E, which receive the bead RS according to FIG. 8 during the rounding process, with the effect that the preformed bead RS remains unchanged in cross section.

While in Fig. 11, the positioning and arrangement of an underlay sheet metal strip 44 a very small plate thickness of the rings is 3-9 shown prior to welding the longitudinal seams at the axially extending abutting ^edges', the position of the underlay sheet metal strip 44 ^"in the axially extending abutting edges of the rings 39 after welding the longitudinal seams in Fig. 12.

The arrangement of the rings 39 and 40 welded together is shown in perspective in FIG. 13.

The exact formation of the joint, as indicated in FIGS. 1 and 2 with circles A and B, is shown in section in FIG. 14, which is readily understandable.

15 shows the design of the cut-out reinforcement ring as a block flange. The installation of an internal remote-operated quick-closing valve is therefore possible without any problems.

A practical embodiment of the entire system with the double-walled pressure vessel described is shown in Fig. 16; there, by providing a further valve V, there is the possibility of localizing a possible leakage by pressurizing the intermediate space or annular space S. Via the leakage socket 17 shown at the bottom of the pressure vessel in FIG. 16 and one connected to it Valve W can selectively supply and discharge the leakage liquid.

17 and 17a show two essential features, namely the possibilities of how the gap space S can be achieved. 17, an inner tube 46 rolled or widened at one end is welded at the top to a nozzle tube 47 for the jacket nozzle, whereas its lower region is fixed to the inner wall with weld seams Sw, according to FIG. 17a, a corrugated tube 48 provided for the floor socket, which is welded to the latter in the upper region of the socket pipe 47, so that the gap S is also created here for the purpose of thrust compensation. "Even with a large nozzle length, there are no bending stresses on the Sw and S welds.

Claims

1. Double-walled pressure vessel made of a pressure-gas-resistant inner jacket with a curved inner floor and a pressure-gas-tight outer jacket with a curved outer floor, as well as with a double-walled manhole spigot, a gap being provided between the inner jacket with inner bottom and the outer jacket with outer bottom and between the walls of the double-walled manhole neck. characterized in that the manhole connector (2), a manometer connector (3), a Peil¬ pipe connector (4), a pump return connector (5), a gas pellet connector (6), a thermometer connector (7) and a level indicator connector (9 ) are arranged in the part of the bottom (1) of the pressure vessel which is predominantly stressed but largely bend-free, and in addition to the manhole connection all other connection connections mentioned are double-walled, that further double-walled connection connections, namely a safety connection (11) . Rinsing nozzle (12), a leak control nozzle (13), an extraction nozzle (14), a groove extraction nozzle (15), a filling nozzle (16) and a leakage socket (17) in the low-tension area of the outer container casing (10) are provided that all sockets are fixed liquid and gas-tight to the pressure vessel by means of continuous, continuous weld seams, and that between the inner and outer walls of all sockets one gap space is left open, all gap spaces of the pressure vessel being connected to one another.

2. Druckbeh lter according to claim 1, characterized in that the manhole socket (2) on its outer end face ei¬ NEN flange ring (18) angularly by means of two circumferential seams on an outer thick-walled dome neck (19) ange¬ welded and provided with several bores (20) for the passage of leak detection liquid, has an inner thin-walled dome neck (21) and on its inner end face a cut-out reinforcement plate (22) attached to the inner dome neck, the dome neck parts (19, 21, 22 ) and the welding seams connecting them are designed so that the leak detection liquid from the gap (S) between the outer container shell (10) and the inner container shell (J) is unhindered in an annular space (R) between the cut-out reinforcement plate and container outer jacket can reach (Fig. 4).

3. Pressure vessel according to claim 2, characterized in that the outer dome neck (19) is only inserted as far as in the container outer jacket (10), as is required for double-sided welding, and that the internal dσmhals which are also extended (21) is welded to the cut-out reinforcement plate (22) on both sides in a continuously sealed manner by means of weld seams (23).

4. Pressure vessel according to claim 1, characterized in that the double-walled, each consisting of an inner and outer Dom¬ neck (27.30? 25.26.29) connecting piece foresaw flanges (23.24.28 *), which on the outer dome necks (25, 26, 29) are welded by a circumferential ring seam and that each connecting piece on its side facing the pressure vessel interior has one on the inner or outer dome neck has fixed cut-out reinforcement plate (28, 31), the dome neck parts and the weld seams connecting them being designed in such a way that a leak detection fluid from the gap (S) between the outer container shell (10) and the inner container shell ( J) can pass freely into an annular space (R) between the cut-out reinforcement plate (28, 31) and the outer casing (10) of the container (Fig. 5,5a, 6).

5. Pressure vessel according to claim 1, characterized in that the outer jacket (10) consists of relatively wide and thick-walled rings (32), in which concentrically relatively narrow, thin-walled rings (34) are arranged, which the inner jacket form the pressure vessel (Fig. 7). •.

6. Pressure vessel according to claim 5, characterized in that the relatively narrow rings (34) are connected to these welded-on bridging rings (35).

7. Pressure vessel according to claim 5 or 6, characterized in that the connection points between the relatively narrow rings (34) and the bridging rings (35) are formed by continuous tight fillet welds (36), and that the joint (33) between adjacent Rings (32) of the outer jacket is welded through.

8. Pressure vessel according to claim 5 or 6, characterized gekenn¬ characterized in that at the ends of the pressure vessel ange¬ arranged bridging rings (35), the inner floors of the pressure vessel are welded.

9. Pressure vessel according to one of the preceding claims, characterized in that the relatively narrow thin-walled rings (39) forming the inner jacket of the pressure vessel have continuous round beads (RS) on their circumference, the inner curvature depth (WT) of which is equal to or greater than that Sheet thickness (DI) of the rings (39), these rings (39) being continuously sealed with bridging rings (40) by weld seams (41) (FIGS. 8 to 13). _First 8th

10. Pressure vessel according to one of claims 2 to 4, characterized in that the cut-out reinforcement plate (22) is designed as a block flange (45), whereby the installation of an internal remote-controlled safety shut-off valve such as a quick-release valve is possible (Fig. 15).