Abstract
A device for tensioning a stuffing box packing includes a plurality of clamping elements, which press a stuffing box gland against the stuffing box packing and thus press the stuffing box packing against a superordinate assembly. At least two clamping elements are connected in a torque-transmitting manner such that rotation of one of the clamping elements causes rotation of the other clamping element or elements.
Claims
1. A device for tensioning a stuffing box packing, in particular a stuffing box packing of a rotary pressure filter, comprising the stuffing box packing, which is positioned against a superordinate assembly to be sealed by the stuffing box packing and does not belong to the device, a stuffing box gland which is positioned against a free side of the stuffing box packing, a plurality of clamping elements, which press the stuffing box the gland against the stuffing box packing and thus press the stuffing box packing against the superordinate assembly, wherein at least two clamping elements being connected in a torque-transmitting manner such that rotation of one of the clamping elements causes a rotation of the other clamping element or elements.
2. The device according to claim 1, wherein all the clamping elements of the device are connected to one another in a torque-transmitting manner such that rotation of one of the clamping elements causes rotation of all other clamping elements.
3. The device according to claim 2, wherein the clamping elements connected in a torque-transmitting manner are connected via at least one chain or belt.
4. The device according to claim 3, wherein all clamping elements are connected to one another via a single chain or a single belt.
5. The device according to claim 1, wherein the clamping elements are divided into at least two sub-groups, wherein clamping elements are only connected to clamping elements of the same sub-group in a torque-transmitting manner.
6. The device according to claim 1, wherein the clamping elements are designed as nuts which can be displaced on a stud screw.
7. The device according to claim 1, wherein at least one of the clamping elements are connected to a toothed ring such that rotation of the toothed ring causes rotation of the at least one clamping element connected thereto.
8. The device according to claim 1, wherein the device further comprises a motor which drives at least one of the clamping element.
9. The device according to claim 1, wherein the device comprises a measuring device which is designed to measure a force that is transmitted from the clamping elements to the stuffing box packing via the stuffing box gland.
10. The device according to 8 claim 9, wherein the device is designed to drive via the motor the at least one clamping element connected thereto if a predetermined threshold value of the force measured by the measuring device is reached or not attained.
11. The device according to claim 1, wherein a sliding element is arranged between the clamping elements and the stuffing box gland.
12. The device according to claim 1, wherein a gear, in particular a reduction gear, is arranged on at least one of the clamping elements.
13. The device according to claim 1, wherein the at least two clamping elements connected in a torque-transmitting manner are connected via at least one chain or belt.
Description
[0036] In the drawings:
[0037] FIG. 1 is a lateral sectional view of a section of a rotary pressure filter equipped with an embodiment of the inventive device;
[0038] FIG. 2 is a lateral sectional view of a further section of the rotary pressure filter and the inventive device according to FIG. 1;
[0039] FIG. 3 is a perspective elevation of the embodiment of the inventive device according to FIGS. 1 and 2;
[0040] FIG. 4 is a perspective elevation of a second embodiment of the inventive device;
[0041] FIG. 5 is a perspective elevation of a third embodiment of the inventive device;
[0042] FIG. 6 is a lateral sectional view of a detail of the embodiment according to FIG. 5.
[0043] In FIG. 1, an embodiment of the inventive device, which is installed in a rotary pressure filter 12, is designated 10 overall. A stud 18 is screwed into a threaded hole 14 of a housing 16 of the rotary pressure filter 12. The stud 18 has a shoulder 20 that is positioned against the housing 16 when the stud 18 is completely screwed in. A male thread 22 of the stud 18 projects through a through-hole 24 of a stuffing box gland 26. The stuffing box gland 26 is designed such that it presses against a stuffing box packing 28, which in this case comprises a plurality of stuffing box packing rings 30. On the side of the stuffing box packing 28 opposite the stuffing box gland 26, the former is positioned against a stuffing box packing shoulder 31. A clamping element 32 is screwed onto the male thread 22 of the stud 18 and is embodied here as a nut. The nut 32 comprises two gearwheels 34 and 36, also called roller chain wheels, the gearwheel 34 being located further away in an axial direction of the stud 18 and the nut 32 with respect to the stuffing box gland 26, i.e. further to the outside, than the gearwheel 36. The outer gearwheel 34 meshes with an outer chain 38, and the inner gearwheel 36 meshes with an inner chain 40.
[0044] It can be seen in FIG. 1 that the inner chain 40 connects the nut 32 shown in section in FIG. 1 to an inner gearwheel 36 of an adjacent clamping element 32. The outer chain 38 connects the nut 32 to a clamping element (not shown in FIG. 1) adjacent on the other side. Rotation of the nut 32 is transmitted from the two chains 38 and 40 in a synchronised manner to the adjacent clamping element 32 and to the clamping element (not shown) adjacent on the other side. When the nut 32 is rotated correspondingly on the stud 18, the latter is displaced on the male thread 22 of the stud 18 in the direction of the housing 16 of the rotary pressure filter 12. This displacement causes the nut 32 to exert force on the stuffing box gland 26 and, via the latter, to exert force on the stuffing box packing 28. The stuffing box packing 28 is then pressed towards the stuffing box packing shoulder 31, whereupon the stuffing box packing 28 bulges radially inwards against a filter drum 33.
[0045] When connecting the clamping elements 32 to the chains 38, 40, doing so should begin with an inner chain 40 for reasons of accessibility. To this end, a pair of clamping elements 32 should first be set to the same height, then the chain 40 should be placed over the clamping elements 32 and connected by means of a lock. After all of the inner chains 40 are assembled, the outer chains 38 can be assembled.
[0046] To reduce the coefficient of friction between the nut 32 and the stuffing box gland 26, a sliding element 42 in the form of a sliding disc is arranged between the nut 32 and the gland 26.
[0047] The nut 32 in this case has a through-hole 44. Through this through-hole 44, a depth gauge can measure how far the nut 32 is screwed onto the stud 18. To this end, both the stud 18, in particular the distance from the shoulder 20 to an opposite end of the stud 18, and a corresponding overall length of the nut 32 should have close tolerances and be known.
[0048] FIG. 2 shows a further section of the inventive device 10 or of the rotary pressure filter 12 according to the embodiment shown in FIG. 1. Therefore, please refer explicitly to the description of FIG. 1. Parts analogous to FIG. 1 are provided with the same reference numbers in FIG. 2 as in FIG. 1. A stud 18 can also be seen in FIG. 2 and is screwed into the housing 16 of the rotary pressure filter 12. A clamping element 46 is screwed onto the male thread 22 of the stud 18 and presses on the stuffing box gland 26 via a sliding ring washer 42. Analogously to the clamping element 32, the clamping element 46 is also designed as a nut, the part of the nut 46 opposite the part screwed onto the male thread 22 of the stud 18 projecting outwards through a protective cover 48 of the device 10.
[0049] At the outwardly projecting end of the nut 46, an interface 50 is provided, at which an operator of the device 10 can apply a tool, such as a torque wrench. Alternatively or additionally, a motor (not shown), such as an electric motor, can act on the interface 50.
[0050] As already described with reference to FIG. 1, a rotation of the nut 46 is transmitted to adjacent clamping elements via an outer chain 52 or an inner chain 54. For further support, the nut 46 is mounted in the protective cover 48 via a slide bearing bush 56.
[0051] The embodiment of the inventive device 10 described in FIGS. 1 and 2 is shown in FIG. 3 absent the other components of the rotary pressure filter 12. Here, the stuffing box packing 28 or its rings 30 can be seen, the stuffing box gland 26 resting against one side thereof. Distributed over the stuffing box gland 26 are twelve clamping elements 32, one of which is designed as a clamping element provided with an interface 50, in the sense of the clamping element 46 from FIG. 2. The clamping elements 32 and 46 are each connected in pairs via chains, as shown in FIGS. 1 and 2 by the outer chains 38 and 52 and the inner chains 40 and 54. In FIG. 3, two outer chains with the reference numbers 38 and 52 and two inner chains with the reference numerals 40 and 54 are provided by way of example.
[0052] It can be clearly seen in FIG. 3 that a rotation of the clamping element 46 is transmitted via the chains 38, 40, 52, 54 to each further clamping element 32 in a synchronised manner. At a point 58 of the device 10, no chain is provided between two adjacent clamping elements 32. On the one hand, this allows inclusion of a remainder of the difference of 360 minus the sum of the angular distances when using angular distances between the axes of the clamping elements 32 that do not add up to 360, and, on the other hand, it also allows free access to the rotary pressure filter 12 a flushing lance. A section of the protective cover 48 through which the clamping element 46 extends can also be seen in FIG. 3.
[0053] FIG. 4 shows a second embodiment 100 of the inventive device 10 according to FIGS. 1 through 3. Components in FIG. 4 similar to those of FIGS. 1 through 3 are shown with the same reference numbers, but increased by the number 100. With regard to the second embodiment 100, reference is explicitly made to the embodiment of the inventive device 10 according to FIGS. 1 through 3. In FIG. 4, thirty-two clamping elements 132 are evenly distributed across a stuffing box gland 126. A single continuous chain 160 is arranged on the clamping elements 132 such that it wraps alternately around a radially inner and a radially outer section of a clamping element 132 for the stuffing box gland 126.
[0054] Of course, the chain 160 could also be placed in a circular shape across all the radially outer sections of the clamping elements 132 for the stuffing box gland 126. However, the degree of wrap and thus the surface area of force transmission, i.e. the number of teeth of a wheel of a clamping element 132 that are engaged with the chain 160, is greater in the manner in which the chain 160 is placed as shown in FIG. 4.
[0055] FIG. 5 shows a further embodiment 200 of the inventive device 10 according to FIGS. 1 through 3 or the inventive device 100 according to FIG. 4. Components in FIG. 5 similar to those of FIGS. 1 through 4 are shown with the same reference numbers, but increased by the number 200 or increased by the number 100 with respect to FIG. 4. With regard to embodiment 200, reference is explicitly made to the embodiment of the inventive device 10 according to FIGS. 1 through 3 and the embodiment of the inventive device 100 according to FIG. 4. In FIG. 5, twenty-four clamping elements 232 are arranged on a stuffing box gland 226. As in the embodiments 10 and 100, the clamping elements 232 comprise gearwheels in this case, as well. The radially outer sections of the clamping elements 232 for the gland 226 are engaged with a toothed ring 262 that is designed as an internally toothed ring. One of the clamping elements 232 in FIG. 5 is provided with an interface 250, in the sense of the nut 46 from FIG. 2. A rotation of one of the clamping elements 232 is transmitted via the toothed ring 262 to all other clamping elements 232, so that they always rotate synchronously.
[0056] In FIG. 6, the embodiment 200 according to FIG. 5 is shown in section according to section line VI-VI. It can be seen that the gearwheel of the clamping element 232 is connected to the toothed ring 262.
[0057] In order to prevent the toothed ring 262 from separating from the gearwheels of the clamping elements 232, the toothed ring 262 has two radially inwardly projecting collars 264 and 266 that engage the gearwheels of the clamping elements 232. The collar 264 of the toothed ring 262 is arranged on a side of the gearwheel facing the stuffing box gland 226, and the collar 266 is arranged on an opposing side of the gearwheel facing away from the stuffing box gland 226.
