EP1767890B1 - Drop hammer - Google Patents

Abstract

The device has a longitudinal extended rotatable shaft (6), which is held by two supports, and a unit provided for rotation of the shaft. Several radial arms (9) are rigidly connected with a shaft at a distance from each other. A drop hammer (10) has a hammer head (11) and a hammer handle and is fixed at each radial arm at its outer end via a hammer joint (13). The hammer comprises of an anvil or striking handle and is designed with additional weight according to a specific equation.

Description

The invention relates to a monkey rapier comprising the features of the preamble of claim 1.

For example, a monkey rapper is off DE 35 00 431 A1 This knocking device is used for cleaning dust deposits on collecting electrodes and spray electrodes of dry-working electrostatic dust collectors.

The cleaning of the outer surfaces of heat exchanger tubes, such as finned tube walls and tube bundles of water-tube boilers, accumulated ashes and other deposits, is often accomplished by using mechanical knocking devices operating on the principle of the drop hammer. Such tapping devices usually consist of a series of drop hammers, each hitting an anvil or truncheon, which are connected to the pipes to be cleaned or at least in contact. The occurring periodic and sudden loading of the drop hammer, in particular its components hammer head, hammer handle and hammer joint, very often leads to damage to their high-stress points, especially on the hammer joint.

The object of this invention is now to provide a monkey rapper, on whose or their monkey the aforementioned disadvantages are avoided or whose mass distribution is arranged so low that in a stop on the anvil or the truncheon the load in the hammer joint against Zero goes and the tension in the hammer handle is minimized.

The above object is solved by the characterizing features of claim 1.

Advantageous embodiments of the invention can be found in the dependent claims.

• Weitgehende Reduzierung bis völlige Eliminierung der Rückschlagkraft im Hammergelenk zum Zeitpunkt des Hammerschlages auf den Amboss bzw. den Schlagstiel und somit minimale Belastung des Hammerstiels, des Hammergelenkes und der Hammerwelle,
• Die Lebensdauer des Fallhammers einschließlich des Hammergelenkes wird in wesentlichem Maße verlängert.

The solution according to the invention provides a monkey rapper having the following advantages:

• Extensive reduction to complete elimination of the recoil force in the hammer joint at the time of hammer impact on the anvil or the truncheon and thus minimal stress on the hammer handle, the hammer joint and the hammer shaft,
• The life of the drop hammer including the hammer joint is prolonged to a considerable extent.

Advantageously, the additional weight attached to the hammer head is attached to its side facing or away from the hammer joint, since sufficient space for attaching an additional weight is present on these sides and the mass distribution can also be effectively made here.

In the event that it is advantageous to concentrate the mass distribution within the drop hammer towards the hammer joint, the additional weight can also be attached to the hammer handle.

In an advantageous embodiment of the invention, the additional weight is screwed or welded to the hammer head or to the hammer handle. While the first variant offers the possibility of an easier exchange, the second variant has the advantage of a more durable connection.

Instead of attaching a separate additional weight on the monkey, it may be appropriate to form the additional weight of a monkey having a more weight and by mechanical processing of the drop hammer to achieve the required additional weight. This can for example be done by milling, grinding or the like of more or overweight material on the hammer head.

Embodiments of the invention with reference to the drawings and the description are explained in more detail below.

Fig. 1

eine Wärmeaustauscher-Rohreinheit, die mit einem Amboss bzw. Schlagstiel zur Klopfreinigung ausgebildet ist, schematisch und perspektivisch dargestellt,

Fig. 2

eine Mehrzahl von Wärmeaustauscher-Rohreinheiten, die mittels einer Fallhammer-Klopfvorrichtung gereinigt werden, in schematischer Darstellung,

Fig. 3

eine Fallhammer-Klopfvorrichtung während einer vollständigen Wellenumdrehung (360°), schematisch dargestellt,

Fig. 4

eine Detailansicht einer Fallhammer-Klopfvorrichtung, schematisch dargestellt

Fig. 5

wie Fig. 4, jedoch alternative Ausführung,

Fig. 6

wie Fig. 4, jedoch alternative Ausführung.

It shows:

Fig. 1

a heat exchanger tube unit, which is formed with an anvil or impact handle for knock cleaning, shown schematically and in perspective,

Fig. 2

a plurality of heat exchanger tube units that are cleaned by means of a monkey rapper, in a schematic representation,

Fig. 3

a monkey rapper during a complete shaft revolution (360 °), shown schematically

Fig. 4

a detailed view of a monkey rapper, shown schematically

Fig. 5

as Fig. 4 but alternative design,

Fig. 6

as Fig. 4 , but alternative design.

FIG. 2 shows a plurality of heat exchanger tube units 1, a single of which is shown in FIG FIG. 1 is shown. Such heat exchanger tube units 1 can be used for example as membrane tube walls or tube bundles in waste heat boiler. As in the operation of waste heat boiler formed with heat exchanger tube units 1 on the outer surfaces of the heat exchanger tube units 1 ash or other deposits accumulates, the heat transfer with increasing accumulation on the heat exchanger tube units 1 and circulating in the tubes 2 working medium decreases, it becomes necessary to eliminate the ash accumulation.

The cleaning of ash can, as in FIG. 2 illustrated schematically, done by a monkey rapper 16. In this case, by one of a drive means 7 driven and rotating shaft 6, which is held by at least two bearings 8, hammers 10 are raised and turned over or overturned. When reaching the tilting position of the case 10 drops from the highest to the lowest position and beats or taps on the anvil or truncheon 4 of the respective tube unit 1. The shaft 6 has according to the abzuklopfenden tube units 1 a number of radial arms 9, the Distance between each other are rigidly connected to the shaft 6, each arm 9 is fixed substantially at right angles to the shaft 6 rigidly at her with successively increasing circumferential angle a, based on the preceding, adjacent arm 9. The sequence of a shaft rotation of the knocking device 16 and the overturning of the drop hammer 10 above the shaft 6 and the subsequent falling and tapping of the drop hammer 10 against the striking surface or the exposed end 5 of the striker or anvil 4 shows FIG. 3 schematically on. The anvil or truncheon 4 is, as well as in FIG. 1 illustrated, attached to the manifold 3 in communication with it, which receives all the heat exchanger tubes 2 a heat exchanger tube unit 1. As drive means 7 known drives such as electric motor, hydraulic, pneumatic etc. operated drives or gear can be used.

The falling movement of the drop hammer 10 is in principle a rotary movement. The momentum of the drop hammer 10 when striking the anvil or striker 4 is equal to the sum of the momentum of the distributed mass Σm _i v _i at the drop hammer 10, wherein the velocity of the individual mass particles depends on the radius of rotation of the individual mass particles or increments. When the stop acts in the attachment point of the drop hammer 10, a force which is directed against the rotational movement of the drop hammer 10. The impact force acts on the drop hammer 10 with a torque that would generally result in a different movement of the drop hammer 10 after the stop, as a (retrograde) rotation of the drop hammer 10 to the hammer joint 13. Only by an additional force (kickback force) in Hammer joint 13 remains the hammer handle 12 of the drop hammer 10 is connected to the hinge and moves with the desired reverse rotation. The kickback force in the hammer joint 13 leads to a stress load in the hammer handle 12.

ausgebildet, wobei

m_z

die Masse des Zusatzgewichtes 14 in kg,

m_i

die Masse eines Massenteilchens bzw. -inkrementes bezüglich Hammerstiel 12 und Hammerkopf 11 in kg,

r_z

der Radius zwischen Mittelpunkt Hammergelenk 13 und Massenschwerpunkt des Zusatzgewichtes 14 in Meter,

r_a

der Radius zwischen Mittelpunkt Hammergelenk 13 und Schlagnormale N_s des Hammerkopfes 11 in Meter,

r_i

der Radius zwischen Mittelpunkt Hammergelenk 13 und Massenschwerpunkt des Massenteilchens bzw. -inkrementes bezüglich Hammerstiel 12 und Hammerkopf 11 in Meter ist.

To largely prevent tensions in the hammer handle 12, hammer head 11 and the hammer joint 13, which arise in an attack of the drop hammer 10 on the anvil 4 and often lead to damage - usually fractures - at the high-stress points, according to the invention the monkey 10 with an additional weight 14 according to the relationship $$m_z=\frac{{\displaystyle \mathrm{\Sigma }{m}_i}•r_i-r_A•{\mathrm{\Sigma }\mathit{m}}_i}{r_A-r_z}$$

trained, being

m _z

the mass of the additional weight 14 in kg,

m _i

the mass of a mass particle or increment with respect to hammer handle 12 and hammer head 11 in kg,

r _z

the radius between the center of the hammer joint 13 and the center of mass of the additional weight 14 in meters,

r _a

the radius between the center of the hammer joint 13 and the impact normal N _{s of} the hammer head 11 in meters,

_i

the radius between the center of the hammer joint 13 and the center of gravity of the mass particle or increment with respect to the hammer shank 12 and hammer head 11 is in meters.

The inventive design of the drop hammer 10 with an additional weight 14 according to the above relationship, the usually occurring kickback force within the drop hammer 10 and the hammer joint 13 can be reduced to a minimum or eliminated at best completely.

In FIGS. 4 to 6 Variants of the monkey rapper 16 according to the invention are illustrated, wherein the monkey 10 according to the FIG. 4 with an additional weight 14 is formed, which is attached to the hammer joint 13 remote from the side of the hammer head 11, whereas the monkey 10 according to the FIG. 5 is formed with an additional weight 14 which is attached to the hammer joint 13 facing side of the hammer head 11. The drop hammer 10 according to the FIG. 6 is formed with an additional weight 14, which additionally has a more or overweight proportion 15. This overweight portion 15 of the drop hammer 10 is worked by milling or abrading or the like. Up to the state until the drop hammer 10 is formed with the additional weight according to the above relationship.

LIST OF REFERENCE NUMBERS

1

Heat exchange pipe unit

2

heat exchanger tube

3

manifold

4

Anvil or truncheon

5

Striking surface or exposed end of the anvil or impact stem

6

wave

7

Means for driving the shaft

8th

shaft bearing

9

Radial arm

10

monkeys

11

hammerhead

12

Hammerstiel

13

hammer joint

14

additional weight

15

Over- or multi-load share of additional weight

16

Monkey tapping device

Claims (5)

1. A drop hammer rapping device for rapping and shaking heat exchanger tubes (2) for cleaning their outer surfaces, wherein the device comprises
   an elongated rotary shaft (6), which is retained by at least 2 bearings,
   a means (7) for rotating the shaft (6),
   a number of radial arms (9) which are rigidly connected to the shaft (6) at a certain distance from each other, wherein each arm (9) is rigidly secured essentially at right angles to the shaft (6) at a sequentially increasing peripheral angle related to the preceding adjacent arm (9),
   a drop hammer (10) which has a hammer head (11) and a handle (12) and is pivoted on each radial arm (9) at its outer end by a hammer joint (73), and
   an anvil or impact handle (4) which is secured to a header (3) of a tubular heat exchanger unit (1), or is in contact with it, and the drop hammer (10) strikes against its exposed end (5) when the shaft (6) rotates,
   characterised in that in order to reduce or eliminate a return stroke force generated in the hammer joint (13) during the hammer impact against the exposed end (5) of the anvil or impact handle (4), the drop hammer (10) is designed with an additional weight (14) according to the relation $$m_Z=\frac{{\mathrm{\Sigma }m}_i•r_i-r_A•{\mathrm{\Sigma }m}_i}{r_A-r_Z}$$

   

   
   where

   m_z is the mass of additional weight (14), in kg,

   m_i is the mass of a mass particle or increment related to handle (12) and hammer head (11), in kg,

   r_z is the radius between the centre of hammer joint (13) and the centre of gravity of additional weight (14), in metres,

   r_a is the radius between the centre of hammer joint (13) and the impact perpendicular N_s of hammer head (11), in metres,

   r_i is the radius between the centre of hammer joint (13) and the centre of gravity of the mass particle or increment relative to handle (12) and hammer head (11), in metres.
2. The drop hammer rapping device according to claim 1, characterised in that the additional weight (14) is fitted on the side of the hammer head (11) facing away or toward the hammer joint (13).
3. The drop hammer rapping device according to claim 1, characterised in that the additional weight (14) is fitted to the handle (12).
4. The drop hammer rapping device according to any one of claims 1 to 3, characterised in that the additional weight (14) is screwed or welded to the hammer head (11) or the handle (12).
5. The drop hammer rapping device according to any one of claims 1 to 3, characterised in that the additional weight (14) provides an extraweight and/or overweight portion (15) which is machined by mechanical machining for obtaining an additional weight (14).

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