EP2410279A1 - Low-maintenance heat exchanger comprising rotating scrapers - Google Patents

Abstract

The heat exchanger (7) has wipers centrally arranged in gas pipes, where the length of the wipers are similar to the length of the gas pipes. Each wiper is equipped with a blade fixed in a blade holder. The wiper has a shaft (13) at an end of the blade holder. The shaft is connected with a gear (5) such that the gear is driven by a motor.

Description

Low-maintenance heat exchanger, in particular for the exhaust gases of stationary internal combustion engines, combined heat and power plants, incinerators and / or heating systems and for vapors and / or gases in other processing processes.

Depending on the type of fuel is in exhaust gas heat exchangers or heat exchangers, are carried out by the heated or heated exhaust gases, the problem that the exhaust gas ducts are added with combustion or gas residues such as soot or sulfur residues. This clogging obstructs the flow of exhaust gas and reduces the heat exchange. The efficiency of the exhaust gas heat exchanger is reduced. Only through costly dismantling and subsequent cleaning measures, the exhaust gas heat exchanger can be cleaned again. Other measures for cleaning are the addition of the exhaust gas heat exchanger with additional mechanical cleaning elements.

That's how it describes DE 195 44 185 C2 a heat exchanger for flowing media combined into a tube bundle, mounted in tubesheets tubes which are interspersed in the longitudinal direction of wound around the pipe axis internals, the internals are designed as a limited elastic, freely arranged in the tube cross-section cleaning elements and at least on one side to a Tube bottom is associated with a resiliently supporting this tube plate at which the cleaning elements are fixed.

This measure is special in itself, but only insufficiently meets the increased requirements for maintaining high efficiency of the exhaust gas heat exchanger. The object of the invention is to provide a low-maintenance and self-cleaning heat exchanger for the exhaust gases of internal combustion engines, combined heat and power plants, incinerators and / or heating systems and for vapors and / or gases in other processing.

With the invention is achieved in the specified application, that a low-maintenance heat exchanger is provided, within which in a manifold and / or collecting parallel and within this collecting manifold and / or collecting housing extending evenly arranged gas transmission tubes centrically arranged scrapers are present. These scrapers extend over the length of the gas passage pipes. They have a knife holder and a knife. The knife extends to the inner wall or is arranged spaced from the inner wall. By a rotating movement of the scraper around the center of the tube of the gas passage tube can be removed with the knives, the combustion residues from the inner wall of the gas passage tubes. The heat-retaining layer of soot, sulfur residue or other residue is removed. As a result, the efficiency of the heat exchanger is improved. Elaborate cleaning of the heat exchanger by dismantling or by additional personnel expenses is eliminated. This rotating movement is made possible automatically by means of a gearbox. The transmission is advantageously driven by an electric motor.

The gas transmission tubes with the scraper can be used for all heat exchangers in which deposits are formed by the combustion gases and / or the combustion residues or gas residues.

Advantageous embodiments of the invention are shown in claims 2 to 11.

According to claim 2, the knife is mounted on the knife holder with an additional knife counterpart. This increases the stability of the scraper. The mechanical stress on the attachment of the knife to the knife holder is reduced.

The particular shape of the scraper and knife according to claim 3 allow a better removal and transport of the abrasion or the removed residues from the gas transmission tubes of the heat exchanger, whereby the efficiency of the heat exchanger increases and the exhaust gas flow is favored.

According to claim 4, the blades are arranged to the inner wall straight or angled, whereby the abrasion on the inner wall of the gas passage tubes is favored and reliable.

The distance of the knife to the inner wall according to claim 5 reduces the wear of the blades and jamming of the blades and thus increases the life of the scrapers.

Due to the different blade thicknesses according to claim 6, a swinging of the knife and the scraper is avoided. The durability is increased and the usage-related noise developments can be reduced.

Due to the rotatable according to claim 7 storage of scrapers on the transmission-free end stripping and rubbing takes place in a uniform high quality and reliability over the entire length of the scraper. Jamming or grinding is avoided. As a result, the efficiency is increased and the wear is reduced.

For easy cleaning and easy removal of the Abstreifrückstandes are according to claim 8 openings on the heat exchanger available. This avoids clogging by regular maintenance.

Due to the arrangement of the transmission with mutually combined spur gears according to claim 9, a uniform and low-maintenance drive of the scraper is possible. Thus, all scrapers are moved evenly and simultaneously. It is avoided that individual scrapers are not moved, whereby the reliability of the scrapers is increased.

By the gears with the timing belt and chainrings with the chains in the transmission according to claim 10 and spatially larger heat exchangers and / or heat exchangers can be equipped with large gas passage tubes with the scrapers. As a result, large complex Stirnradkonstruktionen and arrangements are avoided. A reliable function is also guaranteed.

By the sheets according to claim 11, the exhaust gases flowing through are swirled, whereby they remain longer in the exhaust gas heat exchanger and thus the process of heat exchange is more efficient. This increases the efficiency of the exhaust gas heat exchanger.

• Fig. 1 einen Abstreifer,
• Fig. 2 einen schraubenförmig verwundenen Abstreifer,
• Fig. 3 einen Detailausschnitt eines Abstreifers,
• Fig. 4 eine Antriebsseitenansicht eines
• Abgaswärmetauschers,
• Fig. 5 eine Längsseitenansicht eines Abgaswärmetauschers,
• Fig. 6 eine Schnittdarstellung des Getriebes eines Abgaswärmetauschers,
• Fig. 7 eine Schnittdarstellung eines Abgaswärmetauschers,
• Fig. 8 eine Schnittdarstellung eines Gasdurchleitungsrohres mit geradem Messer und
• Fig. 9 eine Schnittdarstellung eines Gasdurchleitungsrohres mit abgewinkeltem Messer,
• Fig. 10 eine Schnittdarstellung eines Abgaswärmetauschers mit quadratischen Querschnitt,
• Fig. 11 eine Schnittdarstellung eines Abgaswärmetauschers mit rechteckigem Querschnitt,
• Fig. 12 eine Darstellung eines Zahnriemengetriebes und
• Fig. 13 einen Detailausschnitt eines Abstreifers mit Blechfahnen.

Several embodiments of the invention are illustrated in the drawings and will be described in more detail below. Show it:

• Fig. 1 a scraper,
• Fig. 2 a helically wound scraper,
• Fig. 3 a detail of a scraper,
• Fig. 4 a drive page view of a
• Exhaust gas heat exchanger,
• Fig. 5 a longitudinal side view of an exhaust gas heat exchanger,
• Fig. 6 a sectional view of the transmission of a Exhaust gas heat exchanger,
• Fig. 7 a sectional view of an exhaust gas heat exchanger,
• Fig. 8 a sectional view of a gas transmission tube with straight knife and
• Fig. 9 a sectional view of a gas transmission tube with angled knife,
• Fig. 10 a sectional view of an exhaust gas heat exchanger with square cross-section,
• Fig. 11 a sectional view of an exhaust gas heat exchanger with rectangular cross-section,
• Fig. 12 a representation of a toothed belt drive and
• Fig. 13 a detail of a scraper with metal flags.

The exhaust gas heat exchanger 7 according to the invention has within a manifold 14 parallel to this manifold 14 Gasdurchleitungsrohre 1. Within the gas transmission pipes 1 are centrally located scraper 2. The scrapers 2 have, as in the FIGS. 1 . 2 . 3 . 8 and 9 in each case a knife 3 and in each case a knife holder 4. The knife 3 is screwed to the knife holder 4, welded and / or riveted. In addition, the knife 3 is screwed with a knife counter 4a on the knife holder a, welded and / or riveted. The scrapers 2 have at least the length of the gas passage tubes 1. The scrapers 2 have at one end of the knife holder 4, a shaft 13. This shaft 13 is rotatably mounted in a frontally arranged flat housing cover of the exhaust gas heat exchanger 7. The existing shaft 13 is connected to a transmission 5. The transmission 5 is located as in the FIG. 4 shown, on the front side arranged planar housing cover of the exhaust gas heat exchanger 7. The transmission 5 is driven by a motor 8, preferably by an electric motor. As in the FIGS. 4 and 5 shown, the engine 8 is located on the transmission 5. In addition the scrapers 2 are rotatably mounted on the gear housing 5 opposite the front side arranged planar housing cover, for. B. by a pin.

Like in the FIG. 6 illustrated, the transmission 5 consists of spur gears 6a, 6b. On the shafts 13 of the scrapers 2 are spur gears 6b. By one, as in the FIGS. 6 and 7 illustrated, star-shaped arrangement of the gas passage tubes 1, the scrapers 2 and the existing on the shafts 13 spur gears 6b are coupled together. The spur gears 6b are driven by the centrally arranged spur gear 6a.

The scraper 2 and the blade 3 extend inside and parallel to the inner wall of the gas passage pipe 1. As required, the scraper 2 and the blade 3, as in FIG. 2 shown helically wound in its course. As a result, the abraded combustion residues are continuously transported from the gas passage tubes 1. The knife 3 stands, as in the FIG. 8 represented perpendicular to the inner wall of the gas passage tube 1. The knife, however, as in FIG. 9 represented, depending on necessity in the region of the inner wall of the gas passage pipe 1 by 45 degrees in or against the direction of rotation of the scraper 2 angled or folded. The distance of the blade 3 to the inner wall of the gas passage tube 1 is z. B. the 0.0001 times the diameter of the gas passage tube 1. The knife 3 has a thickness of 0.1 mm.

As in FIG. 5 are shown, in the region of the exhaust gas feed 9 and in the region of the exhaust gas outlet 10 scraper residue collector 11 and a cleaning opening 12 for maintenance and cleaning work available.

The collecting housing 14, as in the FIGS. 10 and 11 shown, has a preferably square or rectangular cross-section. The gas passage pipes 1 are uniformly arranged in the collecting case 14. The scrapers are also driven via the shaft 13 and the spur gears 6a, 6b by the gear 5 and a motor 8 in the gas passage tubes 1. Here, the spur gears 6b are driven by the decentralized arranged spur gear 6a.

Depending on the dimensions of the heat exchanger 7 2 gears 15, 15b are arranged on the shafts 13 of the wiper. About this timing belt 16 are guided. Via a at least one centrally and / or decentrally arranged gear 15a, a toothed belt 16 is guided on the adjacent gears 15b. About other timing belt 16, the other gears 15 b can be driven. The transmission 5 can be driven via the motor 8. As a motor 8, a geared motor can be used. Likewise, 13 chainrings 15a, 15b are arranged on the shafts. The chainrings 15a, 15b are connectable via a chain 16. In this case, the chainrings 15b, starting from the central or decentralized chain blade 15a can be driven via the chain 16.

Regardless of how the gas passage pipes 1 are arranged in an exhaust gas heat exchanger 7, a cleaning of the gas passage pipes 1 is possible. In each gas passage pipe 1, the scrapers 2 are arranged. Depending on the arrangement of the gas transmission pipes 1, the scrapers 2 are connected to the chains 13 and arranged thereon with mutually engaging spur gears 6a, 6b, gears 15a, 15b with toothed belts 16 and / or chainrings 15a, 15b with chains 16. As a result, the scrapers 2 are driven uniformly via the motor 8. The motor 8 is preferably an electric motor.

To increase the efficiency of heat exchange on the knife counter 4a plate lugs 17 attached. The metal lugs cause turbulence in the exhaust gas, whereby the exhaust gas remains longer in the heat exchanger and thus is bound longer in the process of heat exchange. The metal lugs 17 are spaced from each other and advantageously riveted to the blade counter-holder 4a and are bent in the flow direction at an angle of approximately 30 degrees to the blade counter-holder 4a.

Compilation of the reference numerals

• 1 - gas passage pipe
• 2 - scraper
• 3 - knife
• 4 - knife holder
• 4a - knife counter holder
• 5 - Transmission
• 6a, 6b - spur gear
• 7 - Exhaust gas heat exchanger
• 8 - engine
• 9 - exhaust gas feed
• 10 - exhaust gas discharge
• 11 - Wiper residue collector
• 12 - cleaning opening
• 13 - wave
• 14 - Collecting tube, collecting housing
• 15a, 15b - gear, chainring
• 16 - Timing belt, chain
• 17 - sheet metal flags

Claims (11)

Low-maintenance heat exchanger for combustion exhaust gases, chemical vapors and / or chemical gases with a collecting pipe (14) and / or collecting housing (14) and evenly arranged gas supply pipes (1) extending inside and parallel to the inner wall of the collecting pipe (14) and / or collecting housing (14) wherein the exhaust gases are passed through the gas passage pipes (1) and a heat exchange liquid is passed and / or flows through the collecting pipe (14) and / or collecting housing (14), characterized
in that the scavenging tubes (2) have at least the length of the gas passage tubes (1) and consist of at least one knife holder (4) and at least one knife (3), wherein the Knife (3) is mounted on the knife holder (4) and that the scrapers (2) at one end of the knife holder (4) have a shaft (13) and rotatably mounted in a frontally arranged flat housing cover of the exhaust gas heat exchanger (7) and on the Shaft (13) are connected to a transmission (5) and that the transmission (5) with a motor (8) is drivable, wherein the transmission (5) on the frontally arranged flat housing cover of the exhaust gas heat exchanger (7) and the motor (8 ) is arranged on the transmission (5). Heat exchanger according to claim 1,
characterized,
that the knife (3) with a knife anvil (4a) on the knife holder (4) is attached. Heat exchanger according to claim 1,
characterized,
that the scrapers (2) with the knife holder (4) and the knife (3) and / or the scrapers (2) with the knife holder (4), the knife (3) and the knife counterpart (4b) inside and parallel to the inner wall surface of Gas transmission pipes (1) extend and / or helically wound in the course of the gas transmission pipes (1). Heat exchanger according to one of the preceding claims, characterized
in that the knives (3) are arranged perpendicularly to the inner wall of the gas-conducting tube (1) and / or bent at an angle between 0 and 80 degrees from the vertical of the inner wall of the gas-conducting tubes (1) in and / or against the direction of rotation of the scrapers (2). are arranged. Heat exchanger according to one of the preceding claims, characterized
in that the distance of the blade (3) to the inner wall of the gas-conducting tubes (1) corresponds to between 0.0001 and 0.5 times the diameter of the gas-conducting tubes (1). Heat exchanger according to one of the preceding claims, characterized
that the blade (3) have a thickness between 0.05 mm and 10 mm and the width of 1.01 times to 5 times the width of the knife holder (4). Heat exchanger according to one of the preceding claims, characterized
in that the wipers (2) are rotatably mounted on the flat housing cover arranged opposite the end face of the transmission (5). Heat exchanger according to one of the preceding claims, characterized
that in the area of the exhaust gas feed (9) and / or in the region of the exhaust gas discharge (10) at least one Abstreiferrückstandsammler (11) and / or a cleaning opening (12) is present. Heat exchanger according to one of the preceding claims, characterized
in that the gear mechanism (5) consists of spur gears (6a, 6b), with the spur gear (6a) arranged directly on the housing cover and / or on the central and / or decentrally arranged shaft (13) directly in a central and / or decentralized manner on the shafts (13) of the wiper (2) existing spur gears (6b) are driven by this centrally and / or decentralized spur gear (6a) and further on the shafts (13) existing spur gears (6b) of the scrapers (2) are drivable , Heat exchanger according to one of the preceding claims, characterized
in that the gear mechanism (5) consists of toothed wheels (15a, 15b), wherein at least one chainring (15a, 15b) and / or toothed wheel (15a, 15b) is arranged on the shafts (13), the chainrings (15a, 15b) and / or gears (15a, 15b) via at least one chain (16) and / or a toothed belt (16) are drivable and the chainrings (15b) and / or gears (15b) on the chainrings (15a) and / or the gears (15a) are drivable. Heat exchanger according to one of the preceding claims, characterized
in that on the knife holder (4), knife counterpart holder (4a) and / or knife (3) at least one sheet metal lug (17) is fixed, wherein the at least one metal lug (17) in the flow direction at an angle between 0 and 90 degrees to the knife holder (4), knife counter-holder (4a) and / or knife (3) is bent or folded.

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