CH637460A5 - Mounting device for an exhaust gas pipe measurement probe - Google Patents

Description

The invention relates to a holding device for a measuring probe that can be inserted into an exhaust pipe through a measuring bore.

In the flue gases from fireplaces, certain characteristic values must be measured at intervals to meet legal requirements. These parameters are e.g. the temperature of the exhaust gases and their content of C02 and soot to determine the soot number. For each of these measurements, a special measuring probe must be inserted through the measuring hole into the exhaust pipe. A relatively short piece of pipe, which is provided at one end with a slightly conical external thread, has so far served as the holding device for these measuring probes. The operator screws this piece of pipe with the thread by hand into the measuring bore of the exhaust pipe. The pipe section cuts its holding thread in the measuring bore itself. The respective measuring probe is then inserted through the pipe section into the interior of the exhaust pipe and fixed using an adjusting screw. The disadvantage here is that an exact positioning of the pipe section relative to the exhaust pipe is either not at all or is very difficult to achieve. It is important that the respective probe runs as precisely as possible at right angles to the longitudinal axis of the exhaust pipe. Even if this should initially succeed with relatively great effort on the part of the operator, each measuring probe represents a relatively long lever arm, via which torques are introduced into the pipe section and its screw connection to the exhaust pipe during the measuring operation. In practice, these torques often lead to loosening of the pipe section in the exhaust pipe. As a result, the measuring probe changes its position in an extremely unfavorable manner, as a result of which the measured values are falsified. It is particularly aggravating that the measuring point on the exhaust pipe is difficult to reach in many cases because B. is arranged relatively high. In addition, there are the connecting hoses or connecting cables from the respective measuring probe to the measuring device, which also introduce forces and movements into the pipe section serving as a holding device and its conical screw connection to the exhaust pipe. These difficulties are particularly disadvantageous when the exhaust pipe z. B. in gas fireplaces consists of aluminum sheet. Aluminum sheet is relatively soft and all the more

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less able to offer a sufficiently tight fit to the threaded tube piece for holding the measuring probe. In practice, especially with exhaust pipes made of aluminum sheet, these pipe sections serving as holders tear out relatively frequently. As a result, the quality and speed of the measurement process suffer in all cases.

The invention has for its object to provide an improved holding device for the measuring probe.

This object is achieved according to the invention in that the holding device has a base plate which can be fixed on the exhaust pipe, and that on the base plate a guide piece receiving the measuring probe in a through hole is axially movable and gas-tightly pressed against the edge of the measuring bore via a sealing body is.

To a certain extent, the base plate forms the stable mounting base for the holding device. The guide piece is arranged in a clearly defined manner relative to the base plate and, with its through hole, ensures very precise and precise guidance of the respective measuring probe. The measuring probe is expediently arranged with a sliding fit in the through-bore of the guide piece, so that even if the measuring probe is set differently axially, a gas exchange between the measuring probe and the guide piece cannot take place. By pressing the sealing body of the guide piece against the edge of the measuring bore, an undesired gas exchange between the interior of the exhaust pipe and its surroundings can also be prevented at this point.

It is particularly advantageous that the measuring probe, including the holding device, can be changed very quickly and precisely. For this purpose, the holding device can remain unchanged in its previously centered position, so that after the introduction of a new measuring probe, its exact positioning at right angles to the longitudinal axis of the exhaust pipe is again automatically ensured. The operator is therefore completely relieved of the corresponding controls and can concentrate solely on the measuring process.

According to one embodiment of the invention, the sealing body is formed in the shape of a truncated hollow cone. This sealing body partially penetrates the measuring bore and lies with its conical outer part on the edge of the measuring bore. This edge can come into sealing contact with the sealing body either with a sharp edge or over a large area with a complementary conical surface to the sealing body.

According to another embodiment of the invention, the guide piece is provided with a clamping screw for fixing the measuring probe. This means that the respective measuring probe can be quickly and precisely determined in its respective operating position.

According to one embodiment of the invention, the guide piece is screwed into a threaded hole in the base plate. With this screwing in, a sufficient sealing pressure between the guide piece and the edge of the measuring bore can be achieved in any case. This holding device remains in its once selected position until all the necessary measuring probes have been used through the guide piece.

According to another embodiment of the invention, the guide piece is mounted in a bearing bush connected to the base plate. The bearing bush can be screwed into a threaded hole in the base plate. Base plate and bearing bush then form a rigid unit of the holding device.

According to a further embodiment of the invention, a compression spring is arranged between the guide piece and the bearing bush. This compression spring can be pretensioned if necessary and in all cases ensures that the guide piece is automatically and sufficiently pressed against the edge of the measuring bore. With this construction there is no separate one

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Operation for establishing the gas-tight connection between the guide piece and the edge of the measuring bore. In this case, when the holding device is attached, the sealing body of the guide piece is first inserted into the measuring bore. Then, against the force of the compression spring, the base plate is pressed into contact with the exhaust pipe and fixed in this working position.

According to a further embodiment of the invention, the guide piece rests in a rest position with a stop ring on an end face of the bearing bush. This defined rest position of the individual parts of the holding device facilitates quick and accurate mounting of the holding device on the exhaust pipe.

According to another embodiment of the invention, a drill bushing can be screwed into the threaded bore of the base plate for the initial production 15 of the measurement bore in the exhaust pipe. This is particularly advantageous if the edge of the measuring bore is in a special way, e.g. complementary conical to the conical sealing body of the guide piece.

20 According to one embodiment of the invention, a clamping strap, which is provided with a quick-release fastener and surrounds the exhaust pipe, is connected to the base plate. This enables a quick and safe assembly of the holding device. Particularly favorable installation conditions result if the ends of the tensioning strap are attached to opposite side surfaces of the base plate.

According to a further embodiment of the invention, the base plate is provided with two cylindrical support skids arranged at a distance from one another and parallel to one another. 30 The support skids can be very securely attached to the exhaust pipe parallel to the longitudinal axis of the exhaust pipe and fixed there. The measuring probe is in the middle between the two support runners. passed through.

According to legal regulations, the flue gas flow from certain combustion systems, e.g. B. to measure the temperature of the flue gases, the carbon dioxide content and the soot number. These measurements are to be carried out in the connecting piece or in the exhaust pipe between the fireplace and the chimney behind the heat exchanger in the core of the smoke gas flow. To do this, the core flow must first be found within the flue gas flow. The center of this core flow has the highest temperature in the cross-sectional area of the exhaust pipe. Flue gas samples for determining the carbon dioxide content and the soot number of the 45 flue gases are to be taken at right angles to the flue gas flow and preferably from the center of the core flow.

This results in the need to design the holding device according to the invention in such a way that the measuring probe can be aligned 50 to the center of the core flow of the flue gas flow.

For this purpose, an embodiment of the invention is proposed in which the guide piece is connected to a joint piece articulated on the base plate. When the base plate is fixed to the exhaust pipe for all measurements, the joint piece permits an articulated movement of the measuring probe containing a temperature measuring device through the interior of the exhaust pipe. A temperature measuring device is expediently used, which permits a point-like temperature measurement. This enables z. B. Thermocouples. To locate the center of the core flow with its maximum temperature, the measuring probe can be moved on the one hand in the axial direction relative to the guide piece and on the other hand thanks to the joint piece.

According to one embodiment of the invention, the joint 65 piece is pivotable about an axis running parallel to a longitudinal axis of the exhaust pipe. The measuring probe can thus be pivoted in a transverse plane of the exhaust pipe, so that it is no longer necessary to pay attention to it during the measuring process.

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that the longitudinal axis of the measuring probe is in the required manner in a plane perpendicular to the longitudinal axis of the exhaust pipe. This is guaranteed automatically.

According to a further embodiment of the invention, opposite pivot pins of the joint piece are each guided in an elongated hole in the base plate. This results in safe guidance and support of the joint piece on the base plate.

According to another embodiment of the invention, the elongated holes extend at least approximately in a plane parallel to the longitudinal axis of the exhaust pipe. The elongated holes are then particularly easy to manufacture.

According to one embodiment of the invention, one of the pivot pins protrudes from the associated elongated hole with a threaded end carrying a locking nut. This allows the measurement probe to be fixed in the pivot position in which the center of the core flow was found. After the temperature measurement, all other measurements can also be carried out in this prescribed favorable position without the operator having to determine the center of the core flow again before each further measurement process.

Functional safety is provided if the joint piece is guided in an opening in the base plate.

To avoid damage to the measuring probe through the edge of the measuring bore, the joint piece is provided with stop faces to limit its swiveling movement. The stop surfaces can preferably interact with support surfaces on the base plate. This construction is particularly simple and reliable.

A particularly good seal between the sealing body and the edge of the measuring bore is obtained if an area of the sealing body which comes into sealing contact with the edge of the measuring bore is spherical.

Preferably, either the guide piece or a bore bushing for the initial production of the measuring bore in the exhaust pipe can be screwed into a threaded bore of the joint piece.

The invention is explained in more detail below with reference to the drawings in several exemplary embodiments. Show it:

Figure 1 is a side view of a holding device with exhaust pipe and measuring probe.

FIG. 2 shows the holding device according to FIG. 1 in its rest position;

3 shows the top view of a base plate according to FIGS. 1 and 2;

Figure 4 shows a longitudinal section through the base plate with screwed drill bushing.

5 shows a longitudinal section through the base plate with a screwed-in guide piece;

6 shows an arrangement with a conical edge of the measuring bore;

7 shows a cross section through an exhaust pipe with another holding device and a measuring probe;

8 shows a schematic longitudinal section through an exhaust pipe with core flow;

9 shows a part of the holding device according to FIG. 7 in a perspective representation;

10, 11 and 12 are views of a base plate of the holding device according to FIG. 7;

13, 14 and 15 are views of a joint piece of the holding device according to FIGS. 7 and

16 shows a partial cross section through an exhaust pipe with another holding device.

In Fig. 1, an exhaust pipe 10 is provided with a cylindrical measuring bore 11, with the edge 13 of which is a frustoconical sealing body 15 of a guide piece 17 in sealing contact. The guide piece 17 has a through bore 19 in which a measuring probe 20 is arranged with a sliding fit.

A stop ring 21 is screwed onto an external thread at the upper end of the guide piece 17. A clamping screw 23 for fixing the measuring probe 20 relative to the guide piece 17 is screwed through the stop ring 21 and the upper neck of the guide piece 17.

In the area of the measuring bore 11, a base plate 27 is placed on the outside of the exhaust pipe by means of support skids 25 and 26. On opposite side surfaces 29 and 30 of the base plate 27, ends 33 and 34 of a tensioning band 37 provided with a quick-release fastener 35 are fastened by means of screws 31.

A bearing bush 40 is screwed with a threaded end 41 into a threaded bore 43 of the base plate 27. In a bore 45 of the bearing bush 40, a cylindrical extension 47 of the sealing body 15 is guided in the radial direction at the bottom. At the upper end of the bearing bush 40 there is an inward shoulder 49 which guides the guide piece 17 in the radial direction.

In the space between the guide piece 17 and the bore 45, a prestressed compression spring 50 is arranged, which is supported on the one hand on the shoulder 49 and on the other hand on the cylindrical extension 47. The compression spring 50 thus presses the sealing body 15 into sealing contact with the edge 13 of the measuring bore 11.

Fig. 2 shows the individual parts of the holding device in its rest position. The compression spring 50 has pushed the guide piece 17 down until the stop ring 21 according to FIG. 2 has come to rest on an end face 53 of the bearing bush 40.

To assemble the holding device according to FIG. 2, the conical lower end of the sealing body 15 is first inserted into the measuring bore 11 (FIG. 1) and then the base plate 27 with the bearing bush 40 attached to it is pressed down until the supporting runners 25, 26 rest axially parallel on the exhaust pipe 10. The two free ends of the tensioning band 37 are then connected to one another in the region of the quick-release fastener 35 and tensioned by the quick-release fastener 35. Here, with increasing tension of the pressure spring 50, a relative movement between the guide piece 17 and the unit consisting of the base plate 27 and the bearing bush 40 has taken place into the relative position shown in FIG. 1. The holding device is thus mounted and the measuring probe 20 can pass through the through hole 19 into the interior of the exhaust pipe

10 will be introduced. The measuring probe 20 will finally be fixed in its desired axial position by the clamping screw 23.

3 shows further details of the base plate 27. Two threaded bores 55 for the screws 31 are provided on each of the side surfaces 29, 30.

4, a drill bushing 57 is screwed into the threaded bore 43 of the base plate 27, the central bore 59 of which leads a drill (not shown) for the initial production of the measurement bore 11 (FIG. 1).

FIG. 5 shows another embodiment insofar as a guide piece 60 is screwed directly into the threaded bore 43 of the base plate 27 and is pressed into the measuring bore 11 with a truncated cone-shaped sealing body 61. A through bore 63 of the guide piece 60 accommodates a measuring probe, not shown, with a sliding fit, which can be fixed in the respective working position by means of the clamping screw 23.

6, the edge of the measuring bore 11 in the exhaust pipe 10 is complementarily conical to the sealing body 15, so that there is a relatively large-area contact between the sealing body 15 and the measuring bore

11 results in the sealed working position shown in FIG. 6.

7 to 16, the same parts as in the previous figures are provided with the same reference numbers.

7, the threaded end 41 is screwed into a threaded bore 65 (FIG. 9) of a joint piece 66. The

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Joint piece 66 is guided with lateral pivot pins 67 and 68 (FIG. 15) in elongated holes 69 and 70 (FIG. 12) of the base plate 27. The joint piece 66 is further guided laterally in a recess 71 of the base plate 27. The joint piece 66 has stop surfaces 72 and 73 to limit its pivoting movement. The stop surfaces 72, 73 cooperate with support surfaces 74 and 75 on the base plate 27 and allow the measuring probe 20 a pivoting angle 76 shown in FIG. 7. This prevents the part of the measuring probe 20 protruding from the sealing body 15 at the edge 13 the measuring bore 11 is damaged.

Nevertheless, the swivel angle 76 is sufficient to find a center 77 of a core flow 78 of the flue gases in the exhaust pipe 10 in any case - possibly with superimposed axial movement of the probe 20.

8 shows that the center 77 of the core flow 78 does not always coincide with a longitudinal axis 79 of the exhaust pipe 10. Rather, the core flow according to FIG. 8 generally forms wavy, so that the operator must search for the center 77 in the cross section of the exhaust pipe 10 containing the measuring bore 11. This is done as follows:

First, the sealing body 15 is inserted into the measuring bore 11, the tightening strap 37 is closed by means of the quick-release fastener 35, and in this way the base plate 27 is fixed relative to the exhaust pipe 10. The guide piece 17 moves relative to the bearing bush 40 against the force of the compression spring 50. The measuring probe 20 is then inserted through the through hole 19 into the interior of the exhaust pipe 10. At this stage, the measuring probe 20 is provided with a thermocouple, which allows a point-like temperature measurement. The measuring probe 20 is moved in the axial direction relative to the guide piece 17 and, if necessary, additionally pivoted by pivoting the joint piece 66 relative to the base plate 27 until the hottest point, namely the center 77 of the core flow 78, is found .

In this measuring position, the measuring probe is fixed on the one hand by tightening the clamping screw 23 and on the other hand by tightening a locking nut 80 (FIG. 9). The locking nut 80 sits on a threaded extension 81 (FIG. 15) of the pivot pin 68 and interacts with an outer surface 82 of the base plate 27.

When the temperature of the flue gases in the center 77 of the core flow 78 has been measured in the measurement position described above, the clamping screw 23 is loosened and the probe 20 removed from the holding device. Instead, another measuring probe, not shown in the drawing, is quickly and easily inserted up to the center 77 through the holding device. This can e.g. be facilitated by a scale on the measuring probe, which is read above the stop ring 21. With this additional measuring probe z. B. a flue gas sample can be taken from the center 77.

In FIG. 9, the bearing bush 40 together with the guide piece 17 and measuring probe 20 has been omitted to clarify the illustration.

10, 11 and 12 show the base plate 27 in its 20 different views.

13, 14 and 15 represent different views of the joint piece 66. An angle 83 is entered in FIG. 13, which the stop surfaces 72 and 73 each include with the horizontal.

15 illustrates that longitudinal axes of the pivot pins 67 and 68 define an axis 84 about which the joint piece 66 can be pivoted.

16 shows only a part of the holding device for clarification. The guide piece 17 has at the lower end 30 of the cylindrical extension 47 a spherical sealing body 85, which cooperates with the edge 13 of the measuring bore 11 in any pivoting position of the guide piece 17 in a well-sealing manner.

Instead of the bearing bush 40 35, a drill bush corresponding to the drill bush 57 in FIG. 4 or directly a guide piece corresponding to the guide piece 60 in FIG. 5 can also be screwed into the threaded bore 65.

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3 pages of drawings

Claims (23)

637 460 1. Holding device for a measuring probe insertable through a measuring bore into an exhaust pipe, characterized in that that it has a base plate (27) which is connected to the exhaust pipe 5 2. Holding device according to claim 1, characterized in that the sealing body (15; 61) is formed as a truncated cone. 3. Holding device according to claim 1 or 2, characterized in that the guide piece (17; 60) is provided with a clamping screw (23) for fixing the measuring probe. 4. Holding device according to one of claims 1 to 3, characterized in that the guide piece (60) is screwed into a threaded bore (43) of the base plate (27). 5. Holding device according to one of claims 1 to 3, 20 characterized in that the guide piece (17) is mounted in a bearing bush (40) connected to the base plate (27). 6. Holding device according to claim 5, characterized in that the bearing bush (40) is screwed into a threaded bore (43) of the base plate (27). 7. Holding device according to claim 5 or 6, characterized in that a compression spring (50) is arranged between the guide piece (17) and the bearing bush (40). 30th 8. Holding device according to one of claims 5 to 7, characterized in that the guide piece (17) lies in a rest position with a stop ring (21) on an end face (53) of the bearing bush (40). 9. Holding device according to claim 4 or 6, characterized in that a drill bushing (57) can be screwed into the threaded bore (43) of the base plate (27) for the initial production of the measuring bore (11) in the exhaust pipe (10). 10. Holding device according to one of claims 1 to 9, characterized in that the base plate (27) is connected to a tensioning strap (37) provided with 40 a quick-release fastener (35) and encompassing the exhaust pipe (10). (10) can be fixed, and that a guide piece (17; 60) accommodating the measuring probe (20) in a through hole (19; 63) can be moved axially on the base plate (27) and gas-tight to the edge via a sealing body (15; 61) (13) the measuring bore 11. Holding device according to claim 10, characterized in that ends (33, 34) of the tensioning band (37) on opposite side surfaces (29, 30) of the base plate (27) are fastened 45. (11) is supported in a compressible manner. 10th 12. holding device according to one of claims 1 to 11, characterized in that the base plate (27) is provided with two cylindrical support skids (25, 26) arranged at a distance from one another and parallel to one another. 50 13. Holding device according to one of claims 1 to 3, 5, 7, 8, 10 to 12, characterized in that the guide piece (17) is connected to a joint piece (66) articulated on the base plate (27). 14. Holding device according to claim 13, characterized in that the joint piece (66) is pivotable about an axis (84) running parallel to a longitudinal axis (79) of the exhaust pipe (10). 15. Holding device according to claim 14, characterized in that opposite pivot pins (67,68) of the 60 joint piece (66) are each guided in an elongated hole (69,70) of the base plate (27). 15 PATENT CLAIMS 16. Holding device according to claim 15, characterized in that the elongated holes (69, 70) extend at least approximately in a plane parallel to the longitudinal axis (79) of the exhaust pipe (10). 17. Holding device according to claim 15 or 16, characterized in that one of the pivot pins (68) protrudes from the associated elongated hole (70) with a threaded extension (81) carrying a locking nut (80). 18. Holding device according to one of claims 13 to 17, characterized in that the joint piece (66) is guided in a recess (71) of the base plate (27). 19. Holding device according to one of claims 14 to 18, characterized in that the joint piece (66) is provided with stop faces (72, 73) to limit its pivoting movement. 20. Holding device according to claim 19, characterized in that the stop surfaces (72, 73) interact with support surfaces (74, 75) on the base plate (27). 21. Holding device according to one of claims 13 to 20, characterized in that a region of the sealing body (85) which comes into sealing contact with the edge (13) of the measuring bore (11) is spherical. 22. Holding device according to one of claims 13 to 21, characterized in that the guide piece (60) is screwed into a threaded bore (65) of the joint piece (66). 23. Holding device according to one of claims 13 to 21, characterized in that a drill bushing (57) can be screwed into a threaded bore (65) of the joint piece (66) for the initial production of the measuring bore (11) in the exhaust pipe (10).