EP0406481B1 - Process and apparatus for the prevention or removal as appropriate of blockages in the outlet region of a cyclone heat-exchanger - Google Patents

Abstract

What is proposed is an apparatus for the prevention or removal of blockages in essentially vertically arranged enclosed spaces, such as, for example, cyclone heat exchangers (1-2) for the cement industry. In the region of the outlet (10, 11) of the closed space, there is a tool which can be introduced periodically from outside into the inner region of the flow-off by translational movement. The translational movement is executed violently by means of a pneumatic or hydraulic cylinder. The apparatus has a lance-shaped tool (20) which is equipped in the region of its free end with a boring head (36). An alternating to-and-fro rotational movement having an angle of rotation of less than 360 DEG can be superposed on the translational movement. The boring head (36) itself consists of an exchangeable cutter (37) having a plurality of tearing teeth (38) arranged above it. <IMAGE>

Description

The invention relates to a cyclone heat exchanger with a tool for preventing or removing blockages in the outlet area thereof, in which the essentially flour-shaped material flows vertically through the cyclone from top to bottom and can be removed in an outlet area narrowed with respect to the feed area, the tool is arranged at an acute angle in the outlet area of the cyclone and is formed from a lance which can be actuated by means of a cylinder and can be translationally inserted into the outlet area and at least one housing surrounding it.

Such a cyclone heat exchanger is known from DE-A-32 12 700.

The heat-saving technology of such a cyclone heat exchanger has long proven itself in the cement industry. Nevertheless, it is not uncommon for operational problems to occur due to clogging of the cyclone flour escapes. This is particularly common at the lowest level (transferring flour to the oven).

This is due to detachments from approaches that are caused by the effects of temperature and circulatory processes and which can block the discharge of flour from time to time. If such a case occurs, the furnace operation must be interrupted and the blockage removed by mining, the cleaning personnel being exposed to increased risks of burns despite protective clothing. Depending on the consistency of the approaches, clearing a cyclone blockage can take a long time. The shutdown and start-up of the incinerator causes an increase in energy consumption in any case, and the fireproof lining is also affected.

In the known cyclone heat exchanger, an apparatus for separating an agglomerated particulate material is provided. Provided on the outer wall of a container is a lance which can be passed through an opening in the wall and which has an actuating device for forcibly extending the lance from its retracted position outside the container into a position which moves into the container. The lance is along a line in the container movable, which runs downwards and forms an acute angle with the direction of flow of the material. The lance is provided with a tip in the area of its free end. A hydraulic cylinder is used as the actuating device, which introduces the lance into the area of the container at constant speed, the boundary edge being formed on the one hand by the wall and on the other hand by the upper part of the outlet. The lance can thus be inserted into the material accumulating in the outlet area. Since the lance only carries out a translational movement, it can happen here that the lance tip only digs a hole in the agglomerated baked material and the blockage cannot therefore be completely removed. Furthermore, the lance is not able to penetrate deeper into the outlet area (drain pipe) of the container in order to be able to specifically remove any blockages that may occur here.

Starting from DE-A 32 12 700, the invention is based on the object of designing a quasi-automatically mechanical tool for improving the cleaning of enclosed spaces, in particular the cyclone heat exchanger outputs. In addition, blockages should be able to be removed safely not only in the immediate outlet area of the cyclone but also in lower-lying areas of the drain pipe, without interfering with the operating process. A corresponding control system must also be provided, which automatically triggers the cleaning process upon detection of impending blockages.

• die Lanze wird mittels eines Hydraulik- oder eines Pneumatikzylinders stoßweise in den Auslaufbereich des Zyklon-Wärmetauschers eingeführt,
• der Stoßbewegung wird eine Rotationsbewegung überlagert, wobei die Rotationsbewegung alternierend mit einem Drehwinkel kleiner 360° durchführbar ist,
• die Mittellinie der Lanze entspricht etwa der Mittellinie des Auslaufbereiches des Zyklon-Wärmetauschers,
• die Lanze weist im Bereich ihres freien Endes einen Bohrkopf auf.

This task is solved by combining the following features:

• the lance is intermittently inserted into the outlet area of the cyclone heat exchanger by means of a hydraulic or pneumatic cylinder,
• a rotational movement is superimposed on the impact movement, the rotational movement being able to be carried out alternately with an angle of rotation of less than 360 °,
• the center line of the lance corresponds approximately to the center line of the outlet area of the cyclone heat exchanger,
• the lance has a drill head in the area of its free end.

The combination of the aforementioned features, in contrast to St.d.T. ensures that impending or existing blockages, in particular in the outlet area of cyclone heat exchangers, can be safely removed. The cleaning staff is therefore no longer exposed to increased dangers, rather it can be dispensed with entirely, since the tool can be easily controlled from the central control room. This measure prevents the entire system from being shut down and started up.

So that the tool has a corresponding freedom of movement, it is proposed to arrange the tool outside the space in such a way that it can be moved as far as possible into the area of the process. For this purpose it makes sense to bring the center line of the tool into line with the center line of the outlet area.

In order to be able to accommodate a rod magazine for total chute cleaning into the furnace (when the furnace is at a standstill), the entire device can be rotated about a swivel axis. The axis of rotation is defined by the pivot point on the lower mounting flange and a bracket attached to the casing tube.

The entire device is cooled with ambient air, which preferably feeds in a radial fan or is sucked in by the system vacuum. After cooling, the air leaves the device and enters the cyclone flour chute. When the cleaning device is in the rest position, it can be shut off to the hot area of the cyclone with an automatically operating slide. In this way, false air does not get into the furnace system unnecessarily and the components of the device are protected against damage.

By designing the lance tip as a drill head in connection with an alternating reciprocating rotary movement, a very strong milling or tearing movement is generated within the container outlet, which in conjunction with the intermittent translational movement of the lance leads to optimal tearing of blockages both in the outlet area of the Cyclone heat exchanger as well as in lower lying areas of the adjoining drain pipe.

The respective angle of rotation is preferably between 150 ° and 250 °. The drill head consists of at least one interchangeable cutting edge and a plurality of fangs arranged axially evenly distributed over the circumference thereof, the cutting edge being designed as a flat chisel according to a further concept of the invention. As a result of the reciprocating rotary movement, the cutting tip, which is kept flat in one plane, acts as a tearing tool and, in contrast to the pointed design according to DE-OS 32 12 700, can bring about a much better dissolution of caking.

According to a further embodiment of the invention, the lance is provided on the outer circumference with guide elements abutting the inner circumference of the housing (casing tube), which come to rest on the chute area of the cyclone heat exchanger outlet when the lance is extended and thus guide the lance. As already mentioned, the lance should not only clear the outlet area of the cyclone heat exchanger but also lower areas of the drain pipe of blockages. As the lance may be used for this latter purpose must be extended several meters, but the guidance takes place exclusively in the housing (casing tube), this results in a long lever mounted on one side, which is also still under the influence of the flowing material. If the lance were not operated as stated above, it could possibly be here happen that due to the long lever arm there is a bending of the lance, which may can lead to impairment when retracting into the housing. The angle of inclination of the chute is preferably selected so that it corresponds to the inclination of the housing, so that the lance can extend on this chute without any risk of being bent at any point.

Since temperatures of several hundred degrees C can prevail in the area of cyclone heat exchangers, a further criterion is specified here, which can lead to damage or influences on the operating sequence if the lance is operated within the cyclone heat exchanger for a longer period. In order to create optimal operating conditions here as well, it is still suggested inside the Lance, preferably in the area of the drill head, to provide a temperature sensor. This temperature sensor represents a safety device, which leads to an automatic extension of the lance into its rest position when a predetermined internal drill head temperature is exceeded.

A method for controlling the tool of a cyclone heat exchanger is characterized according to the invention in that the lance retraction process is started in dependence on the caking determined by means of a gamma emitter with associated receiver, in such a way that the drives for generating the intermittent translation and the superimposed rotational movement are activated and the lance is moved into the hot part of the cyclone heat exchanger, the working cycle of the lance being maintained until the temperature sensor detects an internal lance temperature above 150 ° C and the automatic extension of the lance into the colder area outside the cyclone heat exchanger brings about. The lance can preferably be automatically retracted into the hot area of the cyclone heat exchanger if the internal temperature is below 80 ° C.

This control device forms a safety device which, on the one hand, guarantees automatic operation and, on the other hand, virtually eliminates damage to the lance. Operational interruptions are only necessary if there are blockages in the tube of the cyclone that are lower than the maximum extension length of the lance itself. Here, however, there is also the option of decoupling the rotary drive and flanging extension rods onto the lance, so that areas that were previously inaccessible can also be detected.

Figur 1 -

Ansatzprofil bei Zyklon-Wärmetauscheranlagen mit Zyklonauslaufbereich

Figur 2 -

Gesamtkonzept einer Zyklonauslaufabreinigung

Figur 3 -

Darstellung der Lanze als Reinigungseinrichtung in der Seitenansicht

Figur 4 -

Schnitt durch die Figur 3 gemäß der Linie A-B

The invention is illustrated in the drawing using exemplary embodiments and is described as follows. Show it:

Figure 1 -

Approach profile for cyclone heat exchanger systems with a cyclone outlet area

Figure 2 -

Overall concept of a cyclone outlet cleaning

Figure 3 -

Representation of the lance as a cleaning device in a side view

Figure 4 -

Section through Figure 3 along the line AB

Figure 1 shows an approach profile, as is often the case when walking through cyclone heat exchangers. The lowest heat exchanger stage 1, 2 with the outlet areas 3, 4 and the rotary kiln 5 is shown. The heat exchangers 1, 2 represent enclosed rooms 6, 7 with corresponding gas outlets 8, 9, gas and material inlets 12, 12 'and corresponding ones Spouts 10.11 are provided. Depending on the materials used, a wide variety of chemical reactions take place, which lead to deposits 13 on the walls of the enclosed rooms 6, 7. Blockages in the outlet areas 10, 11 (drain pipes) can occur in that detachments of projections 13 take place in places, which can arise due to the effects of temperature and circulation processes and block the discharge of flour from time to time. If such a case occurs, the furnace operation must be interrupted. The corresponding blockage must be removed by cleaning personnel, the cleaning personnel being exposed to considerable dangers due to the still relatively high temperatures in the area of the cyclone.

FIG. 2 shows the tool 14 for essentially automatically removing or preventing blockages. The cyclone preheater 1 with its outlet area 10 (drain pipe) is shown in broken lines. The tool 14 is provided outside the cyclone 1 and is arranged on a lower fastening flange 15. The tool 14 can be pivoted about a fulcrum 16, which is defined on the one hand by the lower fastening flange 15 and on the other hand by a bracket 17. This measure ensures that, as a result of the swiveling away of the entire tool 14, in the event of a blockage 13 (FIG. 1) building up from the furnace in the direction of the cyclone heat exchanger 1, rod magazines can be introduced into the outlet area 10 (drain pipe). The tool 14 consists of an outer casing tube 18 (housing), a running tube 19, within which an impact and rotary tool 20 is arranged in the form of a lance. Connected to the lance 20 here is a pneumatic cylinder 21, which is arranged in the inner tube 22 such that it can be moved back and forth in a translatory and intermittent manner. With the help of Rotating device 23 and the rotary drive 24 is superimposed on the abrupt translational movement of the lance 20 a rotary movement (150 ° to 200 ° alternating). The rotary drive 24 is fastened on a motor console 25 on the housing 18. The power transmission is preferably carried out via a chain drive 26. The entire tool 14 is cooled with ambient air, which feeds a radial fan, not shown.

Alternatively, there is the possibility that air for cooling the lance 20 or the entire tool 14 is sucked in via the cooling air connection 27 by the negative pressure of the heat exchanger system. Furthermore, an automatically operated gate valve 28 is provided between the mounting flange 15 and the tool 14, which separates the tool 14 from the hot part of the heat exchanger system 1 in the rest position.

The area 29 is to be regarded as an intermediate piece between the cyclone 1 and the drain pipe 10. The center line 30 of the lance 20 corresponds approximately to the center line 31 of the drain pipe 10. The guide elements of the lance 20, not shown in this figure, come to rest on the chute area 32 of the intermediate piece 29, provided the lance 20 is inserted deeper into the drain pipe 10 thus prevent the lance 20 from bending too much. At the lower end of the intermediate piece 29, a device 33 for generating gamma rays with an associated receiver 34 is provided, which automatically starts the entire tool 14 as soon as ticks appear. Additional gamma emitters can also be provided in the drain pipe 10 in order to be able to react as quickly as possible to impending blockages.

Figure 3 shows the tool 14 in a side view. The housing 18, the lance 20 and the flange 15 and the bracket 17 can be seen, by means of which the entire tool 14 can be fastened to the cyclone heat exchanger 1 shown in FIG. The lance 20 is displaceable relative to the housing 18 by means of guide elements 35, which come to rest on the chute area 32 shown in FIG. A drill head 36 is provided on the lance tip, which is formed on the one hand from a flat chisel 37 and on the other hand from fangs 38. The wear elements 37 and 38 are displaceably displaced on the drill head 36. For the exchange, only the bolt or screw connection 39 has to be loosened, so that here the wear elements 37 and 38 can be easily changed outside the cyclone heat exchanger 1. At the upper end of the tool 14, the rotary drive (not shown here) is flanged in the area 25. The lines 40 and 41 serve on the one hand to act upon the pneumatic cylinder 21 and on the other hand to cool the entire tool 14 with ambient air. In the area of the drill head 36, a temperature sensor 42 is provided which, in order to avoid damage to the drill head 36 or the entire tool 14, causes the lance 20 to automatically move into the colder area outside the cyclone heat exchanger at an internal lance temperature above 150 ° C. 1 is retracted. If the temperature has dropped below 80 ° C. again, the lance 20 can be moved back into the cyclone heat exchanger 1 or its region 29 or the drain pipe 10 if necessary.

Figure 4 shows a section along the line a-b. The housing 18, the lance 20 with the guide elements 35 and the pneumatic cylinder 21 can be seen.

Claims (14)

1. Cyclone heat exchanger (1, 2) with a tool for suppressing or removing blockages in the outlet region (10, 11) of the former (1, 2), in which the material substantially in the form of meal flows vertically downwards through the cyclone and can be discharged in an outlet region (10, 11) which is narrowed compared with the feed region, the tool being arranged in the outlet region (10, 11) of the cyclone at an acute angle and consisting of a lance (20), which can be actuated by means of a cylinder (21) and translatorily introduced into the outlet region (10, 11), and of at least one casing (18) surrounding the lance, characterised by the combination of the following features:

   - the lance (20) is introduced in jerks by means of a hydraulic or pneumatic cylinder (21) into the outlet region (10, 11) of the cyclone heat exchanger (1, 2),

   - a rotational movement is superimposed on the jerky movement, it being possible for the rotational movement to take place alternatingly over an angle of rotation less than 360°,

   - the centre line (30) of the lance (20) corresponds approximately to the centre line (31) of the outlet region (10, 11) of the cyclone heat exchanger (1, 2), and

   - the lance (20) has a drilling head (36) in the region of its free end.
2. Cyclone heat exchanger according to Claim 1, characterised in that the rotational drive (23, 24) is arranged on the free end (25) of the casing (18).
3. Cyclone heat exchanger according to Claims 1 and 2, characterised in that the casing (18) is rotatable outside the former (1, 2) about a pivoting axis (16).
4. Cyclone heat exchanger according to Claim 3, characterised in that the range of rotation is defined by a lower fixing flange (15) and a bracket (17) fixed to the casing (18).
5. Cyclone heat exchanger according to Claims 1 to 4, characterised by a fan, in particular a radial fan, for cooling the lance (20) and/or the components located within the casing (18), the air used for cooling leaving the casing (18) in the direction of the outlet region (10, 11).
6. Cyclone heat exchanger according to Claim 5, characterised in that the air for cooling the lance (20) and/or the components located within the casing (18) is drawn in at the cooling air branch (27) by the reduced pressure in the cyclone (1, 2).
7. Cyclone heat exchanger according to Claims 4 to 6, characterised in that, between the fixing flange (15) and the casing (18), there is an automatically actuatable isolation valve (28) which separates the casing (18) and the lance (20) in the rest position from the hot part of the cyclone (1, 2).
8. Cyclone heat exchanger according to Claims 1 to 7, characterised in that the angle of rotation of the drilling head (36) is between 150° and 250°.
9. Cyclone heat exchanger according to Claims 1 to 8, characterised in that the drilling head (36) is designed to be replaceable and is formed by at least one cutting edge (37) and a plurality of tearing teeth (38) arranged axially on top thereof in a uniform distribution around the circumference.
10. Cyclone heat exchanger according to Claim 9, characterised in that the cutting edge (37) is formed as a flat chisel.
11. Cyclone heat exchanger according to Claims 1 to 10, characterised in that the lance (20) is provided on the outer circumference with guide elements (35) which bear against the inner circumference of the casing (18) and, when the lance (20) is moved out, come into contact with the chute region (32) of the cyclone heat exchanger (1) and thus guide the lance (20).
12. Cyclone heat exchanger according to Claims 1 to 11, characterised in that a temperature sensor (42) is provided in the interior of the lance (20) in the region of the drilling head (36).
13. Method of controlling the tool of a cyclone heat exchanger (1, 2) according to Claims 1 to 12, characterised in that the step of introducing the lance (20) is started as a function of the encrustations detected by means of a gamma-ray emitter (33) with an associated receiver (34), in such a way that the drives for generating the jerky translatory movement and the superimposed rotational movement are activated and the lance (20) is introduced into the hot part of the cyclone heat exchanger (1), the working cycle of the lance (20) being maintained until the temperature sensor (42) detects an internal lance temperature above 150°C and causes the lance (20) to be moved out automatically into the colder region outside the cyclone heat exchanger (1).
14. Method according to Claim 13, characterised in that, at an internal temperature below 80°C, the lance (20) is automatically reintroduced into the hot region of the cyclone heat exchanger (1).

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