A combined storage and transport container for blades of a fluid flow machine such as a steam turbine has a parallelepiped configuration and is made in two longitudinally extending mating halves which when fitted together establish a cavity within which the blade is supported against movement. The container halves are cast from a synthetic resin preferably expanded polyurethane or polystyrene. The cavity is wider than the blade and a plurality of replaceable support members are arranged in longitudinal spaced relation along the blade to fill the space between opposing surface portions of the blade and of the cavity.
Field of Search:
1. A reusable combined storage and transport container for blades or a fluid flow machine, said container having a parallelepiped configuration and being constituted by two longitudinally extending halves cast from an expandable synthetic resin which when fastened together establish a cavity for receiving the blade but which is larger in certain directions than corresponding surface portions of the blade thus leaving a space therebetween to facilitate placement of the blade in and its removal from the cavity, and a plurality of replaceable support members arranged in longitudinal spaced relation along the blade in said space and which fill out the corresponding portions thereof between the surface of the blade and the corresponding surface portions of the cavity.
The present invention relates to an improvement in a storage and transport container for the blades of fluid flow machines.
In steam turbines of large unit capacity, particularly the slow-running, half-speed turbines of nuclear power stations, the final row of the low-pressure section comprises large, heavy blades which can weigh 100 kg, and more. Because of their dimensions, low-pressure rotors fitted with such blades can no longer be transported complete with their blades from the manufacturer to the power station since they greatly exceed the permitted loading gauge. The rotor and blades therefore have to be shipped separately and assembled on site.
Such blades are expensive and often difficult to replace. In order to avoid damage as much as possible, both to the balde itself and to the root fixing, they must be packed very carefully and protected against external influences. Hitherto they have been packed in heavy wooden crates. The risk of the blades damaging each other during packing and shipment was reduced by fixing the blades in position by means of wooden struts and using wood wool or similar material as packing. It was nevertheless still quite possible for the blades to be damaged during shipment or when being unpacked.
The principal object of the present invention is to provide an improved container structure for storing and transporting blades which is light in weight, can easily be stacked, in which the blades can be held securely without the need for additional material and which wherever possible can easily be adapted to blades of different shapes.
This object is achieved in that the container which has a rectangular configuration consists of two half-parts of castable synthetic resin which, when put together, form a cavity to receive the blade which is supported in the container at least at two points.
Various advantages are obtained in this way: because of the rectangular shape of the containers they can be stacked well, making full use of available space. The low weight of the material facilitates handling and reduces transport costs. A saving in cost of up to 50 percent can be achieved, compared with the form of packing customary hitherto. Each container can be separately labelled or numbered, thus simplifying the whole organization of storage, e.g., searching for a particular replacement blade.
The foregoing as well as other objects and advantages inherent in the invention will become more apparent from the following detailed description of a preferred embodiment thereof and the accompanying drawing the single FIGURE of which is a view of the improved rectangular blade container structure in perspective with one-quarter broken away to show the interior thereof with the blade securely in place and supported at multiple points to prevent damage to it.
With reference now to the drawing, the container structure is seen to have a generally rectangular (parallelepiped) configuration consisting of two elongated halves 1 and 2 which are mated together along a common contact surface indicated generally at 3. The half-part 2 has been sectionalized to reveal the cavity 4 into which the blade 5 has been set and supported firmly against any movement by means of three set-in support members 6 arranged longitudinally along the blade in contact therewith. However, a pair of spaced support members would be sufficient.
It would also be possible in principle to support the blade along its entire length, in which case a blade can be used as a mould for the container casting process. The blade can be put in and taken out more easily, however, if there are spaces round the blade. On the other hand, supporting the blade at only a few points has some disadvantage that the supports are more subject to compression and wear. This can be remedied by making the support pieces 6 replaceable. In this way it is possible not only to change damaged supports, but also to use the container for blades of different shapes by fitting supports which are suitable for a given blade, thus greatly simplifying storage.
It is desirable to provide means whereby the two half parts 1 and 2 of the container can quickly be brought together in the right position. Such means can be complementary mating means on the two halves, for example, dowels or a key arrangement 7 as shown in the drawing. When the blade is in place the two parts are fixed together, by means of clamping bolts, for example, or still better, with straps. So that the straps do not damage the edges of the container it is advisable to round off the longitudinally extending edges thereof to provide longitudinally spaced bearing points 8. A groove passing round the two halves can also be provided to receive the straps so that these do not interfere with storage of the containers.
Any plastics material which is castable and light in weight is suitable for the containers. Of particular advantage are expandable plastics because these can have an extremely low specific weight, as in the case of polyurethane or polystyrene, for example.
It should also be mentioned that two or more blades can also be fitted in one container, although the container will then be correspondingly heavier and less easy to handle. With certain blade shapes it is also possible to make the parts of the container identical or symmetrical.