EP1198693B1 - Water lance blower for cleaning heat exchangers, especially of a combustion chamber heating surface - Google Patents

Abstract

The invention relates to a water lance blower that is separately controlled by servomotors (30; 31) with resolvers (32; 33). The conventional linear unit (10) which can be horizontally displaced and whose height can be adjusted is guided on a vertically arranged linear unit (9) via a cross slide (11). Said linear unit (10) is fastened to the boiler wall via an auxiliary frame (1) and via two fastening brackets (5; 6), whereby the cardan joint (13) placed on the linear unit (9) is designed as a closed double frame structure (14) and the outer frame (15) is connected, in its upper area, via a spacer (17) with ribs (18) to the linear unit (9) via two flanges (19; 20), whereby the connecting flange for receiving a pin (23) has a recess (21) so that an upper and lower pivot is created, and the pin (23) is fastened to the inner frame (16) via an additional spacer (22). Said frame (16) receives, in the middle thereof, the blast pipe guide bush (24) via a transversal pin (25). The blast pipe guide bush comprises, on both sides, connection pieces (26; 27) which each receive expansion bellows (28; 29).

Description

The invention relates to a water lance blower for cleaning heat exchangers, in particular a combustion chamber heating surface in steam boilers According to the preamble of claim 1. Such a water lance blower is from DE-A-196 37 700 known.

According to DE 41 42 448 a water lance blower for cleaning heat exchangers is already known, which is attached to the mouth of the blowpipe via a universal joint in a hatch of the combustion chamber wall and in which the rear part of the blowpipe is arranged in a guide which is mounted on a vertical spindle is vertically displaceable, the vertical spindle being horizontally displaceable on a horizontal spindle at the top and bottom. The horizontal spindles are stored at their ends in a box, fastened there and are operatively connected to one another on one side.
The guide is formed from a housing that is not rotatably seated on the vertical spindle and carries on the side a fork-shaped holder, in which a gimbal-shaped cage is arranged, which is provided with a sleeve in its inner part and receives the blow tube axially displaceably therein.
The horizontal spindles of this water lance blower are surrounded by a bellows to protect the spindles from dirt.

The disadvantage of this water lance blower is that the lower horizontal spindle is driven by a roller chain from the upper horizontal spindle. Due to the existing manufacturing tolerance for a roller chain and the change in length of the roller chain that occurs during operation, readjustment for the lower horizontal spindle in both side boxes is necessary.
The fastening for the lower spindle always had to be loosened, readjusted, aligned exactly parallel to the upper spindle and then tightened again.
Furthermore, the horizontal and vertical swiveling of the blowpipe towards the middle position during operation is not recognizable, and control of the automatically running cleaning processes is therefore not possible.
The change of the bellows on the horizontal spindles that wear out relatively quickly makes it necessary to remove the spindles from the boxes.

Also known is a water lance blower located in a hatch of the combustion chamber wall inserted via a special box, with separate nozzles provided, guided over two horizontal and one vertical spindle and adjusted by means of a fork-shaped bracket with an angle scale and plug-in notch is (DE 196 37 700).

Both conventional water lance blowers have two horizontal and one vertical spindles moved by asynchronous motors, the vertical spindle holding the cardan joint for the blowpipe guide via a fork-shaped holder.
The control of both blowers is only possible via asynchronous motors by means of incremental encoders after the reference points of the blow pattern have been specified by pulse counting. Due to the cycle times of the programmable logic controller (PLC) and play in the spindle nuts, the process is fraught with inaccuracies. The design of the fan is complex and relatively expensive. The attachment or guidance of the blow pipe over the fork-shaped receptacle is unstable. In addition, this blower can only be adapted to a limited extent to various boiler designs, especially in confined spaces. The blowing angle is max. Limited to 60 °. The blower can only be transported as a complete construction.

A design of the nozzle head and the nozzle is described in DD 205 976. The integration of an axially displaceable blow pipe for cleaning DD 235 103 shows heat exchangers in the combustion chamber wall.

All water lance blowers shown have in common that a cleaning of the nozzle head in case of contamination that comes from the steam boiler over the Hatch occur in the area of the nozzle head or nozzle, largely unsatisfactory he follows.

Known is a water lance blower for cleaning heat exchangers, in which the housing of the blower and the receptacle of the gimbal are formed from one part, a feather key, which is T-shaped, in a special way via a flange and a shaft with the housing is connected (DE 42 39 410 A1).
The design of this water lance blower is complicated. This results in malfunctions in operation due to contamination and the undesired escape of residual water after the fan is switched off.

In addition, an arrangement for cooling a water lance blower is known, in which the blower head of the blower is formed from two blowing nozzles which are at an angle to one another (DD 268 759 A1).
An expanding jacket tube is arranged around the two angle nozzles, through which cooling air is blown. The expanding cooling air jet causes insufficient cooling of the nozzles. In particular, the nozzle center is not exposed to cooling air at all. Deposits cannot be effectively removed with it.

Furthermore, a steam nozzle is known in which the steam is applied Nozzle is cooled by radial air slots by means of air (DE-PS 202 062). The Forming an effective protective veil around the nozzle is with radial slots not possible. The nozzle is also rigid and not movable.

The invention has for its object to develop a water lance blower which is easily transportable in individual parts, easy to assemble and to repair, precise control and high repetition accuracy the blow pattern allows without causing increased production costs than contamination of the nozzle head as possible, even under operating conditions to prevent or constant cleaning without complex measures to achieve, so that at no time a reduction in the emerging Nozzle jet occurs through caking and the cooling effect on the To improve nozzle.

This is according to the invention through a water lance blower according to claim 1 reached.

The linear units are interchangeable in size depending on the boiler and can also be arranged at an angle depending on the space available.
The bellows attached to the fittings are connected to the blowpipe.
The profile for fastening the linear units to the boiler wall is preferably designed as a U-profile with a flange.

Another special feature of the invention is that a targeted use of the pressure difference between the boiler house and the combustion chamber takes place via the recesses of the connecting piece arranged in a circle around the nozzle and its integration into the front universal joint. This pressure difference is used in a particularly advantageous manner via the recessed extension of the connecting piece, that the air flow without significantly changing its direction, on the one hand flows around the nozzle in a veil-like manner and on the other hand via the conically enlarged inlet and the recesses the flow rate of the distributor is increased.
This has the consequence that largely no dirt can be deposited in the first place and any existing deposits can be effectively cleaned off without the use of additional media. In this sense, there is no unnecessary turbulence caused by the equalization of the air flow, which would reduce the effect. In addition, the nozzle is exposed to considerably less high combustion temperatures of the boiler, since there is a strong cooling due to the veil-like air flow. The distributor ring has circular cutouts.

By installing a swirl device in the inlet area of the blowpipe guide the water jet largely freed from turbulence, so that by the interaction of a directed water jet according to the invention and a bundling air flow a maximum gain and concentration the blasting and cleaning effect is achieved.

Fig. 1 -

den Bläser inkl. Befestigung im Querschnitt

Fig. 2 -

den Bläser mit Befestigung im Längsschnitt

Fig. 3 -

den Bläser mit Servomotoren in der Draufsicht

Fig. 4 -

das hintere Kardangelenk mit Doppelrahmenkonstruktion im Querschnitt

Fig. 5 -

die Blasrohrführung mit Anschlußstück für den Faltenbalg

Fig. 6 -

den Blasrohrkopf mit vorderem Kardangelenk und Verbindungsstück im Längsschnitt

Fig. 7 -

das Verbindungsstück im Längsschnitt

Fig. 8 -

das Verbindungsstück im Querschnitt

Fig. 9 -

der Entdraller im Längsschnitt

Fig. 10 -

der Entdraller im Querschnitt

The invention will be explained in more detail below using an exemplary embodiment. Show:

Fig. 1 -

the wind player incl. fastening in cross section

Fig. 2 -

the wind section with a longitudinal section

Fig. 3 -

the blower with servo motors in top view

Fig. 4 -

the rear universal joint with a double frame construction in cross section

Fig. 5 -

the blowpipe guide with connector for the bellows

Fig. 6 -

the blowpipe head with front universal joint and connecting piece in longitudinal section

Fig. 7 -

the connector in longitudinal section

Fig. 8 -

the connector in cross section

Fig. 9 -

the swirl in longitudinal section

Fig. 10 -

the swirler in cross section

The blower is constructed via the auxiliary frame 1 by means of a U-profile 2 and mounting flange 3 on the boiler wall 4 and via the mounting brackets 5; 6 tied to the wall box 7 (Fig. 1 and 2). The mobility of the blow pipe 8 is on the one hand via a vertical and a horizontal linear unit 9; 10, which are connected to one another via a cross slide 11, and on the other hand via a front and a rear universal joint 12; 13 accomplished. While the front universal joint 12 is used in a round shape with a small gap width, the rear joint 13 is designed as a closed double frame construction 14 with an outer frame 15 and an inner frame 16.
The outer frame 15 is over the spacer 17 and ribs 18 and flange 19; 20 connected to the vertical linear unit 9.
The inner frame 16 is connected to the outer frame 15 via the recess 21 and spacer 22 with vertical bolts 23.
The blowpipe guide 24 (FIG. 4) is held in the center via the horizontal bolt 25 in the inner frame 16. The blow pipe guide 24 has connecting pieces 26 on both sides; 27 for receiving a respective bellows 28; 29, which are connected at their other ends to the blowpipe 8 and thus keep the permanently sliding guide of the blowpipe 8 clean even in the event of heavy dust and dirt accumulation (FIG. 5).
Each linear unit 9; 10 is via a servo motor 30; 31 driven.
The servomotors 30; 31 are on the resolvers 32; 33 with the respective control unit 34; 35 connected.

The nozzle head 36 attached to the blow tube sleeve 24 has the nozzle 37 in its head region (FIG. 6).
The connecting piece 40 is fastened / fitted via its ring-shaped thickening 39 in the front universal joint 12 and is characterized by a cylindrical part 46, an adjoining conical extension 38 and an enlarged cylindrical part 49 (FIG. 7). In the area of the enlarged cylindrical part 49, the connecting piece 40 has a distributor ring 42 with recesses 41, which engages in a recess 43 of the nozzle head 36 and is fastened to it.

The swirl device 44 arranged in the inlet area of the blow tube sleeve 24 has Installation plates 45 for rectifying the water jet flow (Fig. 9 and 10).

The mode of action is as follows:

The water lance blower (WLB) is used to remove dirt from heating surfaces in combustion plants. The water introduced suddenly cools the incrustations on the hot tube bundles, causing the slag to flake off.
To clean the heating surfaces, the water is pumped at high pressure through a blow pipe, at the end of which there is a nozzle, not shown. The blow pipe is clamped in the rear part in an axis system, which is able to approach any XY coordinate within the mechanical limits. By storing the blowpipe in the front area, the water jet can coat a cone / pyramid of up to ± 100 °, based on the axial center of the lance, over the solution according to the invention.

The axes are moved by servo drives, which are characterized by their positioning accuracy compared to other systems. After referencing via an external limit switch - after switching on the supply voltage - all travel commands relating to acceleration, braking, speed and positioning are monitored and controlled via a position measuring system (resolver) integrated in the motor. Deviations from the target position (even after positioning) are automatically tracked. This is called position control. This system suppresses inaccuracies in the movement that z. B. result from mechanical aging.
In order to optimize the cleaning of the heating surfaces, any movement can be programmed - so-called blow figures. These are stored in the control units of the axes. After initiating the program, the WLB works through the blow figure independently. The interdependency of the X and Y axes and the valve for switching the water jet on and off are controlled directly from the program. Commands from higher-level control systems are not required during the blow program. At the end of the program, a ready message is issued.

In order to achieve a constant cleaning of the nozzle head 36 and to prevent contamination without complex measures, according to the invention, the pressure difference between the boiler house and the combustion chamber through the recesses 41 of the distributor ring 42 leads air 50 around the nozzle 37 in a veil-like manner with a strong increase in their flow speed , In this way, the formation of deposits and caking in the form of dust particles from the combustion chamber is largely avoided without any aids and additional media and, on the other hand, any deposits that may still exist are cleaned.
This is done without unnecessarily redirecting the flow direction of the air 50 and without swirling it.
By installing a swirl device 44 with mounting plates 45 in the inlet area of the blowpipe sleeve 24, the water jet is formed in such a way that it is atomized as a laminar flow in the nozzle 37, so that effective cleaning can take place even in large steam generators with considerable diameters.

1. Der konstruktive Aufbau des Wasserlanzenbläsers wird erheblich vereinfacht, da

• eine horizontale Spindel
• beide Kastenprofile
• das Gehäuse

entfallen.

2. Durch die Verwendung von Lineareinheiten anstatt herkömmlicher Spindeln ist der Bläser

• einfacher an die jeweiligen Platzverhältnisse anzupassen
• drehbar (schräg) anzuordnen
• demontierbar zu transportieren
• einfacher auf- und abzubauen
• problemlos reparierbar

3. Durch die Entwicklung einer konstruktiv neuen Ausbildung des hinteren Kardangelenkes als geschlossene Doppelrahmenkonstruktion und einer veränderten Aufhängung entsteht ein exakt zu führendes symmetrisches System, welches sehr stabil und beweglich ist.

4. Der dadurch zu erreichende Hub wird stark vergrößert, so daß der Bewegungswinkel bis auf max. 100 ° ansteigt.

5. Durch den Einsatz von Servomotoren mit Resolver und die Verwendung neuer Steuereinheiten, jeweils getrennt für jede Lineareinheit, entsteht

• ein Regelkreis ohne Ungenauigkeiten mit sehr hoher Wiederholungsgenauigkeit des Blasbildes.
• Die Steuergeräte der verschiedenen Lineareinheiten kommunizieren miteinander.
• Ein Nachlauf der Bläser entfällt.
• Eine zentrale digitale Kontrolle von der Leistungsstufe bis zum Sollwertgenerator ist möglich.
• Ein integriertes Steuern von Bewegungen und ein Regeln von Geschwindigkeiten ist in einem Gerät möglich.
• Der Verkabelungsaufwand ist gering.

6. Die Angabe von Referenzpunkten, die Inkrementalgeber, die Impulszählung und die bisherigen Asynchronmotoren können entfallen.

7. Ohne zusätzliche Medienbereitstellung ist eine einfache und wirkungsvolle Freihaltung der Düse von Verunreinigungen sowie eine damit einhergehende Kühlung des Düsenkopfes möglich.

The following advantages are achieved by the invention:

1. The design of the water lance blower is considerably simplified because

• a horizontal spindle
• both box profiles
• the housing

omitted.

2. By using linear units instead of conventional spindles, the blower is

• easier to adapt to the available space
• can be rotated (diagonally)
• removable to transport
• easier to assemble and disassemble
• easily repairable

3. The development of a constructively new design of the rear universal joint as a closed double-frame construction and a modified suspension result in a symmetrical system that can be guided exactly, which is very stable and movable.

4. The stroke to be achieved thereby is greatly increased, so that the movement angle up to max. 100 ° increases.

5. The use of servo motors with resolvers and the use of new control units, each separately for each linear unit, creates

• a control loop without inaccuracies with very high repeat accuracy of the blow pattern.
• The control units of the various linear units communicate with each other.
• There is no need to run the wind.
• Central digital control from the power level to the setpoint generator is possible.
• Integrated control of movements and regulation of speeds is possible in one device.
• The wiring effort is low.

6. The specification of reference points, the incremental encoder, the pulse count and the previous asynchronous motors can be omitted.

7. Without additional media provision, it is possible to keep the nozzle free of contaminants in a simple and effective manner and to cool the nozzle head as a result.

List of the reference numerals used

1

subframe

2

U-profile

3

mounting flange

4

boiler wall

5

mounting bracket

6

mounting bracket

7

wall box

8th

blowpipe

9

vertical linear unit

10

horizontal linear unit

11

cross slide

12

front universal joint

13

rear universal joint

14

Double frame construction

15

outer frame

16

inner frame

17

spacer

18

ribs

19

flange

20

flange

21

recess

22

spacer

23

vertical bolt

24

blowpipe sleeve

25

cross bolt

26

connector

27

connector

28

bellow

29

bellow

30

servomotor

31

servomotor

32

resolver

33

resolver

34

control unit

35

control unit

36

nozzle head

37

jet

38

conical extension

39

ring-shaped thickening

40

joint

41

recess

42

distribution ring

43

collection

44

Entdraller

45

Mounting plate

46

cylindrical part

49

enlarged cylindrical part

50

air

Claims (7)

1. Water-lance blower for cleaning heat exchangers, in particular a combustion-chamber generator surface in steam boilers, which can be mounted on the combustion-chamber wall with the opening of blast pipe (8) via a front universal joint (12) into a hatch or a wall casing (7) and of which the rear part of blast pipe (8) is connected in a guide, the height of which can be adjusted vertically and which can be moved horizontally by a known linear unit via a connection to a rear universal joint (13), the inner section of which is a blast-pipe guide (24), in which the blast pipe (8) can be displaced axially; the blast pipe (8) containing a nozzle (37) and nozzle hood (36), characterized in such a way,
   that the linear unit (10) is controlled separately via servo motors (30, 31) with resolvers (32, 33) and can be adjusted vertically and moved horizontally, and is guided via a cross support (11) to a vertically aligned linear unit (9), which can be mounted on the chamber wall via a subframe (1) and two mounting brackets (5, 6), in which the rear universal joint (13), which is connected to the vertical linear unit (9) is executed as a closed double-frame construction (14), while the upper area of the outer frame (15) is connected by means of a separator (17) with ribs (18) to vertically aligned linear unit (9) via two flanges (19, 20), in which flange (20) has a groove (21) to accommodate bolt (23), providing an upper and lower point of rotation, while bolt (23) is secured via another separator (22) to the inner frame (16) of double-frame construction (14), the centre of which accommodates blast-pipe guide (24) via a transverse bolt (25), which guide has connection components (26, 27) on either end, each of which accommodates an expansion bellows (28, 29),
   that a joining piece (40) is connected between nozzle hood (36) and front universal joint (12), which has a conical extension (38) in the area of nozzle (37) fitted into nozzle hood (36), a circular enlargement (39) in the internal area of front universal joint (12) fitted into this and in the front area of nozzle hood (36) a grooved (41) distribution ring (42) located on this, which is preferably screwed to nozzle hood (36).
2. Water-lance blower in accordance with Claim 1, characterized in such a way that different sizes of linear units (9, 10) can be exchanged depending on the combustion chamber.
3. Water-lance blower in accordance with Claim 1 or 2, characterized in such a way that linear units (9, 10) are arranged diagonally, different from their horizontal and vertical positions, having been adjusted to the constraints of the available space.
4. Water-lance blower in accordance with one or more of Claims 1 through 3, characterized in such a way that expansion bellows (28, 29) arranged on connection components (26, 27) are connected to blast pipe (8).
5. Water-lance blower in accordance with one or more of Claims 1 through 4, characterized in such a way that a U-shaped profile (2) has been executed in order to connect linear units (9, 10) to the combustion-chamber wall.
6. Water-lance blower in accordance with one or more of Claims 1 through 5, characterized in such a way that distribution ring (42) has circular grooves (41).
7. Water-lance blower in accordance with one or more of Claims 1 through 6, characterized in such a way that an unwinder (44) with built-in panels (45) is arranged in the area of entry of the blast-pipe guide.

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