JP2014231946A - Dust scraping-off device of exhaust gas cooling tower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust scraping-off device of an exhaust gas cooling tower capable of surely and efficiently scraping off dust firmly stuck to outer peripheries of heat exchange pipes.SOLUTION: An exhaust gas cooling tower 2 in which a plurality of heat exchange pipes 4 in which a refrigerant is circulated, are arranged in parallel with each other, and an exhaust gas is circulated at outer peripheries of the heat exchange pipes 4, includes scraper bodies 5A, 5B scraping off dust stuck to the outer peripheries of the heat exchange pipes 4, an endless ring-shaped chain 6 to which the scraper bodies 5A, 5B are mounted on one place in the longitudinal direction, and a motor 75 rotating the chain 6 forward and backward to reciprocate the scraper bodies 5A, 5B in the longitudinal direction along the heat exchange pipes 4.

Description

  The present invention relates to a dust scraping device for an exhaust gas cooling tower, and more particularly to a dust scraping device for an exhaust gas cooling tower provided in an exhaust gas flow path of a vacuum refining furnace.

  A vacuum smelting furnace that removes impurities in a vacuum state from the molten metal with scrap is provided with an exhaust gas cooling tower in the exhaust gas flow path to reduce the temperature of the exhaust gas flowing into the subsequent dust collector to an appropriate value. Yes. As such an exhaust gas cooling tower, for example, as shown in Patent Document 1, an indirect cooling type exhaust gas cooling tower in which exhaust gas is circulated on the outer periphery of a heat exchange pipe through which a refrigerant such as cooling air is circulated is used. ing. In this case, since dust in the exhaust gas adheres to the outer periphery of the heat exchange pipe, a dust scraping device including a scraper for periodically scraping and removing the dust is often provided.

JP 2000-18886

  By the way, since scraps in recent years contain a lot of high-grade steel sheets such as galvanized steel sheets, they contain a lot of Zn and Pb evaporated in the exhaust gas. It adheres firmly as dust. Therefore, a dust scraping device that can reliably and efficiently scrape dust firmly adhered to the outer periphery of the heat exchange tube is desired.

  Therefore, the present invention solves such a problem, and provides a dust scraping device for an exhaust gas cooling tower that can reliably and efficiently scrape dust firmly adhered to the outer periphery of a heat exchange tube. Objective.

  In order to achieve the above object, according to the first aspect of the present invention, an exhaust gas in which a plurality of heat exchange tubes (4) for circulating a refrigerant are arranged in parallel so that the exhaust gas is circulated on the outer periphery of these heat exchange tubes (4). In the cooling tower (2), the scraper body (5A, 5B) for scraping off the dust adhering to the outer periphery of the heat exchange pipe (4) and the endless where the scraper body (5A, 5B) is attached at one place in the longitudinal direction Ring-shaped connecting band (6) and moving drive means for reciprocally moving the scraper body (5A, 5B) in the longitudinal direction along the heat exchange pipe (4) by rotating the connecting band (6) forward and backward. (75).

  In the first invention, since the scraper body is attached to the endless connection band, when the connection band is rotated forward and reverse, the scraper body is strongly pulled in any direction along the heat exchange tube. As a result, the dust firmly deposited and adhered to the outer periphery of the heat exchange pipe is scraped off powerfully and reliably.

  In the second invention, the ring-shaped ends of the connecting band (6) are respectively suspended on the suspension members (71, 72), and these suspension members (71, 72) have a predetermined tension applied to the connection band (6). So as to be separated from each other.

  In the second aspect of the invention, since the tension is applied to the connection band, the scraper body is pulled more strongly by the connection band without slack, and the dust adhered to the outer periphery of the heat exchange tube is more strongly and reliably scraped. Be dropped.

  The reference numerals in the parentheses indicate the correspondence with specific means described in the embodiments described later.

  As described above, according to the dust scraping device of the exhaust gas cooling tower of the present invention, dust firmly adhered to the outer periphery of the heat exchange pipe can be scraped reliably and efficiently.

It is side surface vertical sectional drawing of an exhaust gas cooling tower. It is a front vertical sectional view of an exhaust gas cooling tower. It is a top view of the scraper body provided in the exhaust gas cooling tower.

  The embodiment described below is merely an example, and various design improvements made by those skilled in the art without departing from the gist of the present invention are also included in the scope of the present invention.

  FIG. 1 shows a side vertical sectional view of the exhaust gas cooling tower, and FIG. 2 shows a front vertical sectional view thereof. In FIG. 1, an exhaust gas cooling tower 2 in which exhaust gas flows in a direction indicated by a white arrow is provided with an exhaust gas cooling tower 2 in the middle, and the lower part of the exhaust gas cooling tower 2 is dust that branches downward from the exhaust gas pipe 1. Located in the discharge pipe 3.

  Inside the exhaust gas cooling tower 2, heat exchange pipes 4 are formed in four rows in the longitudinal direction of the exhaust gas pipe 1, with the lower ends folded into a U shape and opened at both upper ends. As shown in FIG. 2, a large number are arranged at predetermined intervals so as to cross the exhaust gas pipe 1. Cooling air as a refrigerant is circulated through each heat exchange pipe 4 via a pipe line (not shown).

  An air circulation gap S is formed between the U-shaped inner space of these heat exchange pipes 4 and the heat exchange pipes 4 adjacent to each other, and the exhaust gas flowing through the exhaust gas pipe 1 passes through the air circulation gap S. In the meantime, the temperature is lowered by exchanging heat with the cooling air. And when Zn and Pb are contained in the exhaust gas, they accumulate as dust such as zinc oxide and lead oxide on the outer periphery of the heat exchange tube 4 as the temperature of the exhaust gas decreases, and adhere firmly.

  For such a heat exchange pipe 4, scraper bodies 5 </ b> A and 5 </ b> B constituting a dust scraping device are provided in each of the pair of front and rear heat exchange pipes 4 in the longitudinal direction of the exhaust gas pipe 1. FIG. 3 shows a plan view of the scraper bodies 5A and 5B. Both scraper bodies 5A and 5B have the same structure, and a pair of parallel scraping plates 51 extending left and right so as to cross the exhaust gas pipe 1, and a number of scrapes spanned obliquely and in parallel between the scraping plates 51. It consists of a plate 52. These scraping plates 51 and 52 are located in the air circulation gap S formed between the heat exchange tubes 4 and are close to the outer periphery of the heat exchange tube 4.

  Both ends of the scraping plate 51 are connected to each other by end plates 53, and parallel brackets 54 erected outward from each end plate 53 are connected to the chain 6 as a connecting band disposed in the vertical direction. As a result, the scraper bodies 5A and 5B are attached to the chain 6. The chains 6 are respectively provided at the left and right positions of the exhaust gas cooling tower 2 (FIG. 2). Each chain 6 is formed in an endless ring shape, and its upper end and lower end are respectively suspended by sprockets 71 and 72 as suspension members provided at the upper left and right positions and the lower left and right positions of the exhaust gas cooling tower 2. It is not always necessary to use a chain as the connection band, but a chain is suitable when used in a high load state.

  The left and right sprockets 71 provided on the upper side are fixed to both ends of a common shaft body 73 that is horizontally disposed through the cover body 711 covering these, and the sprocket 74 is located at an intermediate position on the shaft body 73. The sprocket 74 is connected to a sprocket 76 provided on the output shaft of the motor 75 by a chain (not shown). Thereby, when the motor 75 is rotated forward and backward, the shaft body 73 and the chain 6 are rotated forward and backward accordingly.

  As shown in FIG. 1, the scraper bodies 5A and 5B are attached to the opposite positions of the chain 6, and when one moves to the upper end position, the other moves to the lower end position. The shaft body 73 is provided with a limit switch knocker 77 (FIG. 2) at an intermediate position. When the scraper bodies 5A and 5B reach the upper end position and the lower end position, respectively, the limit switch (not shown) is connected to the motor 75. A reverse command is output.

  Each of the left and right sprockets 72 provided on the lower side is housed in a bracket body 8 provided with a horizontal shaft body 81 that rotatably supports this, and each bracket body 8 is biased downward by a spring member 82. Has been. As a result, the lower sprocket 72 housed in the bracket body 8 is always urged downward, which is a direction away from the upper sprocket 71. Accordingly, a predetermined tension is always applied to the left and right chains 6. The means for urging the lower sprocket 72 is not limited to the spring member 82, and the upper sprocket 71 or the upper and lower sprockets 71, 72 may be urged away from each other.

  In the dust scraping device 2 having such a structure, when dust adheres to the outer periphery of the heat exchange tube 4, the chain 6 is rotated by the motor 75, and the scraper bodies 5 </ b> A and 5 </ b> B are moved up and down along the heat exchange tube 4. Move in the direction. As a result, the scraping plates 51 and 52 of the scraper bodies 5A and 5B are moved in the air flow gap S, and the scraping plates 51 and 52 that move in the vicinity of the outer periphery of the heat exchange tube 4 are used as heat exchange tubes. The dust adhering to the outer periphery of 4 is scraped off. At this time, the scraper bodies 5A and 5B are attached to the endless chain 6 suspended by the upper and lower sprockets 71 and 72 and given a predetermined tension. Is also pulled strongly by the slackless chain 6 that receives the driving force of the motor 75. As a result, the dust firmly deposited and adhered to the outer periphery of the heat exchange pipe 4 is scraped off powerfully and reliably and falls into the dust discharge pipe 3 and discharged.

DESCRIPTION OF SYMBOLS 1 ... Exhaust gas pipe line, 2 ... Exhaust gas cooling tower, 4 ... Heat exchange pipe, 5A, 5B ... Scraper body, 6 ... Chain (connection zone), 75 ... Motor (moving drive means).

Claims (2)

In the exhaust gas cooling tower in which a plurality of heat exchange tubes for circulating the refrigerant are arranged in parallel and exhaust gas is circulated on the outer periphery of these heat exchange tubes, a scraper body that scrapes off dust adhering to the outer periphery of the heat exchange tube; An endless ring-shaped connecting band in which the scraper body is attached at one position in the longitudinal direction, and the connecting band is rotated forward and backward to reciprocate the scraper body in the longitudinal direction along the heat exchange pipe. A dust scraping device for an exhaust gas cooling tower provided with a moving drive means. The ring-shaped ends of the connection band are respectively suspended by suspension members, and the suspension members are urged in directions away from each other so as to apply a predetermined tension to the connection band. Dust scraping device for exhaust gas cooling tower.

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