EP4334659B1 - Testing method for a knocking device, and testing apparatus for a knocking device - Google Patents

Description

The invention relates to a test method for a tapping device arranged in a wall, i.e. several tapping tappets arranged in a wall, which are aligned with a tapping tappet longitudinal axis extending transversely to the wall and to each other along a horizontal plane. The tapping tappets are deflected from a rest position to a deflection position by a strike of a striking cylinder. A distance laser acting as a distance laser is assigned to the striking cylinder for carrying out a measurement.

Such a knocking device is used for cleaning a surface, a wall or the like, in particular a metal wall, e.g. the wall of a heat exchanger inside a boiler housing of a waste incineration plant.

State of the art

Today's waste incineration plants have a boiler for heat recovery in which steam or boiling water is generated, which is then used to generate electricity or in another thermal way.

Steam or hot water is generated via heat exchangers located inside the boiler or boiler housing Such heat exchangers usually comprise convexly curved tube bundles through which water or steam flows and which open into a box-shaped collector at a lower end. The fire arranged below the collector and the resulting rising heat use the hot flue gas from combustion to transfer the heat to the water in the heat exchangers, which then heats up, evaporates or even overheats. The heat transfer in the tube bundles of the heat exchangers takes place primarily through convection.

The effectiveness, i.e. the performance, of such heat exchangers can be greatly reduced by deposits of fly ash carried in the flue gas. The resulting contamination or slagging reduces the heat transfer to the water or steam and thus leads to a reduced efficiency of the heat exchanger and thus of the entire system.

The effectiveness of heat exchangers can be improved by cleaning the system and its surfaces, even during operation. Various methods are used for this. Today, water spray systems, soot blowers or tapping devices are used to clean the walls and surfaces of the heat exchangers.

In the case of vertically extending boiler walls of waste incineration plants, the heat exchangers are usually designed as vertically hanging tube bundles that extend vertically in the flues, shafts or secondary flues. Tapping devices are regularly used to clean such hanging tube bundles. These cause the dirty tube bundles to vibrate with an impulse so that the residues deposited on the surface fall off. This impulse is transmitted via a tapping ram preferably transferred to the collector, on which a blow is exerted on the outside by the wall holding the tappet, for example by a striking cylinder.

A method according to the preamble of claim 1 is described in EP 2 119 997 B1 revealed.

In the method described in this document, the vibration of the boiler wall with the heat exchangers accommodated therein is measured during an impact of the impact cylinder on the tappet by means of a vibration analysis.

Disadvantages of the state of the art

To carry out this process, the known method requires a laser and a reflection element associated with this laser at each impact point. Since each system has hundreds of impact points, a lot of material and, above all, assembly time is required. The most important point of the known patent is that the measurement must be carried out at the same time as the impact and as quickly as possible afterwards.

Consequently, complex high-speed measurements are required, which enable vibration analysis. Since this is a dynamic measuring method, it is relatively complex, also because very large amounts of data must be recorded, e.g. up to 10,000 measuring points per second for one measurement. This flood of measurement data must also be stored in a powerful data recording device.

Finally, during the development of the invention, it became clear that only minimum and maximum deflections, frequencies and oscillation periods are in the foreground of the analysis. In fact, the distance between the impact cylinder and the ram face (= impact surface) can vary greatly. This can have different causes. For example, the collector in the boiler may have shifted due to jamming, deposits blocking the guide, welding distortion after commissioning when the heat exchanger gets warm or thermal expansion between cold and warm operation. Possible causes are also wavy boiler walls, inaccurate manufacture of welded structures, wear on the tappet or swapping the tappet types.

During the development of the invention, it was shown that the optimal distance between the face of the ram and the face of the impact cylinder, which meet during impact, is approximately 65 mm. The impact cylinder can usually compensate for a distance deviation of +/- 25 mm. However, if the distance is greater than 90 mm, the impact cylinder can be damaged because the impact cylinder's firing pin extends too far. If the distance is less than 40 mm, the impact energy is insufficient because the impact cylinder's firing pin needs at least 40 mm to reach sufficient speed.

In practice, these dimensional deviations of the tappets and the problems they cause are not known at all. The high number of tappets (hundreds per system) and the many causes result in a considerable amount of work when inspecting the system.

Task

Based on the generic state of the art, the invention is therefore based on the object of at least partially avoiding the disadvantages described above and, in particular, of providing a particularly simple and durable testing method.

invention

This problem is already solved by the independent claims. Preferred, but not mandatory, features are set out in the subclaims.

In the most abstract embodiment of the test method, an actual distance is measured directly on the front face of a tappet to be tested immediately before a blow is made as part of the distance measurement with the laser. This front face or impact surface is therefore the surface on which the impact pin of the impact cylinder strikes. This recorded actual distance is then compared with one or more reference values in a distance comparison and finally, depending on the distance comparison, in particular if a desired tolerance range is present, a blow is made on the tappet being tested or, if the actual distance is outside the tolerance range, no blow is made and the tappet in question is marked for further processing.

This method can therefore effectively prevent damage to or even destruction of the impact cylinder caused by the firing pin being extended too far due to an actual distance or actual distance that is too great.

A reflection element protruding to the side of the tappet for reflecting the laser beam, as was sometimes used in the prior art and only allows for a different measurement, is no longer necessary. Instead, the impact surface on the front of the tappet can be measured quickly and precisely.

In contrast to the known dynamic methods, the invention thus provides a static measurement of the vertical distance from the distance laser to the front impact surface of the impact ram, which enables a very precise measurement of the actual distance.

The method according to the invention is thus characterized in that the at least one distance laser measures the distance directly to the front impact surface of the tappet to be tested, in particular before but also after the impact is triggered, and an impact of the impact cylinder on this tappet is only carried out if the distance is within a predetermined tolerance range.

In contrast to the dynamic measuring methods known from the prior art, the invention is therefore a static test or measuring method, which is therefore much simpler and for which a much simpler apparatus is required, which is consequently also significantly more cost-effective.

The knocking device is preferably arranged in a wall, in particular a metal wall of a boiler housing or boiler, in which heat exchangers extending with vertical tubes with collectors arranged at the lower end are arranged.

In a preferred device for carrying out the method according to the invention, the impact cylinder and the associated laser or distance laser are arranged on a movable carriage in front of the wall in which the tapping rams are arranged. Due to this design, the impact cylinders do not have to be moved manually and can preferably move automatically or manually driven along a horizontal row of impact cylinders in the wall from impact cylinder to impact cylinder.

This mobile driving, impact or knocking carriage can also accommodate several impact cylinders with associated distance lasers, e.g. one above the other, which are assigned to a respective row of knocking tappets at different heights in the wall. This means that even if one of the two knocking tappets arranged one above the other fails, one of the knocking tappets can still be operated if the other is no longer usable.

The invention also relates to a testing device for testing a tapping device with several tapping rams arranged in at least one row of tapping rams on a horizontal plane in a wall, in particular a boiler wall. A tapping carriage with at least one impact cylinder can be adjusted relative to the tapping rams of the row of tapping rams via a drive and can be positioned in front of a tapping ram to be tested, and the impact cylinder comprises a relatively movable impact bolt for executing an impact on the tapping ram. Finally, a distance laser is provided.

To avoid impacts of the firing pin on tapping rams from too great a distance, the distance laser is assigned to the impact cylinder and the tapping carriage includes a drive with a control system to position the tapping carriage directly in front of a tapping ram to be tested and to use the distance laser to measure an actual distance directly to a front impact surface of the tapping ram.

Depending on the result of the measurement of this actual distance and a subsequent test with comparison values, the tapping carriage is automatically moved further by means of the drive and a blow of the striking pin of the striking cylinder is triggered or prevented and the respective striking cylinder is marked, for example, as for maintenance or replacement.

It is within the scope of the invention that the distance laser assigned to a striking cylinder or a striking pin and the striking cylinder itself are arranged on a carriage, which can also be referred to as a "knocking carriage".

Preferably, the distance laser (range laser) assigned to the impact cylinder is arranged immediately to the side of the firing pin of the impact cylinder, e.g. on a side plate next to the impact cylinder or on a housing enclosing the impact cylinder.

However, it is understandable to the person skilled in the art that in a simplified embodiment of the method according to the invention it is also possible for the distance laser to be arranged on a carriage separate from the tapping device, e.g. a measuring carriage, so that the measurement can be carried out separately.

Preferably, the tappets to be tested extend with a respective tappet longitudinal axis along the tappet in a stationary, preferably cylindrical housing which accommodates them in a relatively movable manner, extending transversely to the surface of the wall in which they are arranged.

Typically, the individual tappets are arranged at a distance from one another along a first horizontal plane in the wall, which according to the invention is referred to as the first row of tappets on a first plane.

Embodiments of the method provide for the arrangement of a further second or third row of tappets of knock tappets, which are also arranged horizontally to one another in a plane with their respective tappet longitudinal axis extending transversely in the wall, whereby this second or also third and fourth row of tappets thus formed is arranged vertically offset from another horizontal row of tappets.

This second horizontal row of knocking rams is associated with a second impact cylinder on the movable carriage or knocking carriage, which is also vertically offset and associated with a second distance laser corresponding to the second plane, so that the two knocking rams can be associated in pairs vertically one above the other with a distance or distance laser associated with each of them on the carriage. This configuration enables a large number of knocking rams to be tested particularly quickly.In the following detailed description of the figures, reference is made to the accompanying drawings, which form part of this description of the invention and in which, by way of illustration, specific embodiments are shown with which the invention can be practiced. In this regard, directional terminology such as "top", "bottom", "front", "back", "front", "rear", etc. is used with reference to the orientations of the figure(s) described. Since components of embodiments can be positioned in a number of different orientations, the directional terminology is for illustrative purposes and is in no way limiting. It should be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description is not to be taken in a limiting sense.

In this description, the terms "connected", "attached" and "integrated" are used to describe both a direct and an indirect connection, direct or indirect connection and direct or indirect integration.

Unless otherwise stated, the indefinite article and the definite article do not refer only to a single component, but are to be understood as "at least one". The terminology includes the words mentioned above, variations thereof and similar meanings. Furthermore, it should be understood that the terms "about", "substantially" and similar terms in connection with the dimensions and a characteristic of a component of the invention do not describe the described dimension and characteristic as a strict limit or parameter and do not exclude minor variations thereof which are functionally similar. At a minimum, description parts with numerical parameters also include variations of these parameters according to the mathematical and manufacturing principles in the state of the art, e.g. rounding, deviations and other systematic errors, manufacturing tolerances, etc.

In the figures, identical or similar elements are provided with identical reference symbols wherever appropriate.

Reference lines are lines that connect the reference symbol to the part in question. On the other hand, an arrow that does not touch a part refers to an entire unit to which it is directed.

The representations in the figures are not necessarily to scale. Certain areas may be shown exaggeratedly large to illustrate details. In addition, the drawings may be simplified and do not contain every detail that may be present in practical implementation.

The method is described below by way of example using the figure. All features of the respective embodiments are disclosed independently and independently of other features of the respective embodiment. Likewise, the features mentioned above and those described further can each be used individually or in combination in any desired manner. The embodiments shown and described are not to be understood as an exhaustive list, but rather are exemplary in nature for describing the invention.

The single figure shows an enlarged isometric side view of a beating carriage 3 arranged in front of a boiler wall 2 of a waste incineration plant 2, which can be moved over two tracks designed as double-1 supports, namely a lower track 4 and an upper track 6 in front of the stationary boiler wall 2 by means of a drive coupled to a control system. The control system and the drive make it possible to drive the beating carriage 3 to any point along the tracks and to stop it.

Extending transversely to the boiler wall 2, two rows of tappets are arranged vertically spaced from one another, namely a lower row of tappets 8 and an upper row of tappets 10. Each row of tappets 8, 10 comprises a plurality of tappets 12, here cylindrical, arranged horizontally spaced from one another, which are each accommodated in a relatively movable manner in a stationary outer tappet housing accommodated in the boiler wall 2. Inside the boiler, the tappets of the tappets 12 strike a collector (not shown) of a heat exchanger at the lower end of vertically extending heat exchanger tubes or tube bundles.

Two impact cylinders 14, 16 are arranged on the tapping carriage 3, namely a lower impact cylinder 14 and an upper impact cylinder 16, each of which is assigned to one of the two rows of tapping rams 8, 10, so that the respective relatively movable impact cylinder 14, 16 can strike the relevant tapping ram 12 with its front impact surface when the drive of the tapping carriage 3 is positioned via the control in front of the relevant tapping ram 12 within the row of tapping rams 8, 10. In this case, the vertical distance between the relatively movable impact bolts of the impact cylinders is between 200 and 400 mm.

Distance lasers 18, 20 are arranged on the sides of the impact cylinders 14, 16 on a surrounding housing of the tapping carriage 3, each of which is assigned to a striking pin of an impact cylinder 14, 16, but is positioned laterally offset from the corresponding impact cylinders 14, 16. These distance lasers 18, 20 measure the actual distance to the respective impact surface or front surface of the relevant tapping ram 12, in each case before the associated impact cylinder 14, 16 is positioned in front of the relevant tapping ram 12 and can execute a blow.

By arranging such distance lasers 18, 20 on both sides of the impact cylinder 14, 16, the processing speed can be increased because the measurement can then be carried out in both directions of movement in front of the impact cylinder 14, 16.

The distance lasers 18, 20 arranged laterally next to the impact cylinders 14, 16 can therefore measure the distance to the impact surface either during the movement of the tapping carriage 3 or during a short stop in front of the tapping rams 12. the tappet 12 measure.

If the distance comparison shows that the actual distance is within a permitted range, the relevant impact cylinder can execute an impact on the relevant tappet 12.

If the distance comparison produces a result that is outside a defined tolerance range, i.e. the deviation is too large, then a message will be sent to a PLC control system, for example. If the deviation from the tolerance range is still acceptable, then a warning message will simply be sent that maintenance of the tappet will soon be necessary. In the case of extreme values, however, the relevant knock tappet 12 can also be removed from the program immediately. In this case, the carriage skips the impact point and moves to the next tappet.

As a rule, up to 10 different types of tappets are installed in the system, which then have different lengths so that dimensional deviations between the collector, boiler wall and carriage can be compensated within an acceptable range. The tappet carriage 3 stops in front of each tappet 12 and either the upper or lower impact cylinder is activated. The actuated impact cylinder 14, 16 generates an impact that is transferred to the movable tappet 12. The tappet 12 in turn transfers this impact to the heat exchanger in the combustion chamber. The impact and the vibrations cause the deposits to fall off the heat exchanger.

The invention relates to an automatic testing method for a knocking device, wherein in a wall 2 several knocking tappets 12 are arranged transversely to the wall and are aligned with each other along a horizontal plane. A striking cylinder 14, 16 moves these knocking tappets through a from a rest position into a deflected position. A distance measurement to the tappet 12 is carried out via a distance laser 18, 20.

In order to avoid damage to the impact cylinders 14, 16 due to the relatively movable impact piston being extended too far, it is proposed that, for distance measurement, an actual distance is measured directly on a front impact surface of a tappet 12 to be tested immediately before a blow is made, that this actual distance is compared with one or more reference values in a distance comparison and that, depending on the distance comparison, either a blow is made on the tappet 12 to be tested or no blow is made and the tappet in question is marked for further processing.

List of reference symbols

2

Boiler wall

3

Knocking cart

4

lower lane

6

upper carriageway

8

lower tappet row

10

upper tappet row

12

Tappet

14

lower impact cylinder

16

upper impact cylinder

18, 20

Distance laser

Claims (5)

1. Test method for a knocking device designed for cleaning a surface, a wall or the like, in particular a, in particular a metal wall, e.g. a boiler wall in the interior of a boiler housing of a waste incineration plant,

   wherein in the wall a plurality of knocking tappets (12) extend transversely to the wall and are spaced apart from one another along a horizontal plane,

   wherein the knocking tappets (12) are deflected from a rest position into a deflected position by an impact of an impact cylinder (14, 16),

   and wherein a distance laser (18, 20) is associated with the impact cylinder (14, 16) for carrying out a distance measurement to the knocking tappet (12),

   CHARACTERIZED IN

   that, for distance measurement directly onto an end face of a knocking tappet (12) to be tested, an actual distance is measured immediately before the execution of an impact,

   in that this actual distance is automatically compared with one or more reference values in a distance comparison,

   and in that, depending on the distance comparison, the impact cylinder (14, 16) either executes an impact on the knocking tappet (12) to be tested

   or no impact is performed, and the relevant knocking tappet (12) is recognized for further processing.
2. Testing device for testing a knocking device with a plurality of knocking tappets (12) arranged in at least one row of knocking tappets (8, 10) on a horizontal plane in a wall,

   wherein a knocking carriage (3) with at least one impact cylinder (14, 16) is adjustable relative to the knocking tappets (12) of the rows of knocking (8, 10) and can be positioned in front of a knocking tappet (12) to be tested,

   wherein the impact cylinder each comprises a relatively movable firing pin (14, 16) for striking the knocking tappet (12),

   and a distance laser (18, 20) is provided,

   CHARACTERIZED IN

   that the distance laser (18, 20) is assigned to the impact cylinder,

   in that the knocking carriage (3) comprises a drive with a control system to measure an actual distance to an end-face impact surface with the distance laser (18, 20) and, depending on this measurement, triggers or prevents the firing pin of the impact cylinder from striking.
3. Testing device according to claim 2,
   CHARACTERIZED IN
   that the tapping cylinder (14, 16) and the distance laser (18, 20) are arranged on a movable tapping carriage (3) in front of the wall.
4. Testing device according to claim 2,
   CHARACTERIZED IN
   that the impact cylinder (14, 16) and the distance laser (18, 20) are arranged on separate movable carriages in front of the wall.
5. Testing device according to one of the claims 2 to 4,
   CHARACTERIZED IN

   that knocking tappets (12) extend in a first horizontal row of tappets,

   and in that further knocking tappets (12) extend transversely through to the wall and along a second horizontal row of tappets, which are arranged vertically offset from the first horizontal plane,

   in that the impact cylinder is assigned as the first impact cylinder (14) to the first horizontal plane of knocking tappets (12),

   and in that a second impact cylinder (16) with a second distance laser (18, 20) is assigned to the second horizontal row of knocking tappets (12),

   so that the two knocking tappets (12) are arranged on the tapping carriage (3) vertically in pairs one above the other, each associated with a Distance laser (18, 20).

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