Kiln hood monitoring device

Abstract

This prevents dust from accumulating and accumulating in the inspection hatch inside the kiln hood, improving the visibility of the window panel. [Solution] A kiln hood monitoring device for monitoring a cement kiln from the kiln hood on the front side of the kiln, comprising: a cylindrical body provided in the kiln hood and forming an inspection opening that communicates with the inside of the kiln hood; a window plate attached to the end of the cylindrical body, which allows the inside of the kiln hood to be viewed from the outside through the inspection opening; and one or more gas supply pipes connected to the cylindrical body that inject gas into the inspection opening to generate a spiral airflow along the inner surface of the cylindrical body.

Description

Technical Field

[0001] The present invention relates to a monitoring device inside a kiln hood provided in cement manufacturing equipment.

Background Art

[0002] Generally, in cement manufacturing equipment, when firing cement raw materials in a cement kiln, the inside of the cement kiln is monitored through a monitoring device provided in the kiln hood on the front side of the kiln of the cement kiln. At this time, the monitoring device is provided with a cylindrical body, and a transparent window plate is provided at the end of this cylindrical body. Through this window plate, cement clinker and the like led out from the cement kiln are observed from the inspection port formed inside the cylindrical body as a viewing window.

[0003] In this case, in order to maintain the visibility from the viewing window, in Patent Document 1, water vapor is injected into the viewing hole, which is the viewing window, from a steam pipe to prevent dust deposition, or blowing fan air of a clinker cooler is blown in from an air introduction pipe to blow off dust, or air is extracted from inside the viewing hole by an air venting device to prevent fogging of the glass plate provided on the viewing window.

[0004] Further, Patent Document 2 relates to the exhaust gas treatment of cement firing equipment. In this exhaust gas treatment system, a dust removal nozzle is provided in an extraction duct for extracting extraction gas of cement firing equipment, and a swirling flow is ejected from the downstream side of the extraction gas toward the exhaust duct through this dust removal nozzle to remove dust deposited in the extraction duct.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

[0006] In the method for cleaning the peephole of a cement kiln described in Patent Document 1, when water vapor is injected into the peephole from a steam pipe or air is blown in from a fan, these water vapors and blown air do not flow smoothly throughout the entire peephole, and airflow may stagnate in part of the peephole. As a result, a large amount of dust may remain inside the peephole, adhering to the peep plate or accumulating inside the inspection opening, causing condensation on the glass plate and reducing visibility. On the other hand, when air is released through the air vents, a large amount of dust tends to remain inside the viewing hole.

[0007] Furthermore, Patent Document 2 attempts to remove dust accumulated inside the extraction duct by using a swirling flow from a dust removal nozzle while simultaneously drawing in the extracted gas from the extraction duct with an induced fan installed downstream of the extraction duct. However, since the dust removal nozzle is located on the side toward which the high-temperature extracted gas drawn in by the induced fan is directed, there is a problem with heat resistance. In addition, this exhaust gas treatment system has installation space issues.

[0008] In these cases, if dust or other particles adhere to or accumulate on the viewing windows inside the inspection ports, it becomes necessary to frequently clean the inside of these inspection ports and viewing windows manually in order to ensure stable operation of the cement manufacturing equipment and to check the conditions inside the furnace.

[0009] This invention has been made in view of these circumstances, and aims to improve the visibility of the window panel by preventing the accumulation and retention of dust in the inspection opening inside the kiln hood. [Means for solving the problem]

[0010] The kiln hood monitoring device of the present invention is a kiln hood monitoring device for monitoring a cement kiln from the kiln hood on the front side of the kiln, and is characterized by comprising: a cylindrical body provided in the kiln hood and forming an inspection opening that communicates with the inside of the kiln hood; a window plate attached to the end of the cylindrical body and allowing the inside of the kiln hood to be viewed from the outside through the inspection opening; and one or more gas supply pipes connected to the cylindrical body that inject gas into the inspection opening to generate a spiral airflow along the inner circumferential surface of the cylindrical body.

[0011] By injecting gas into the cylindrical body from the gas supply pipe to generate a spiral airflow, the swirling flow circulates throughout the entire inner surface of the inspection port. This creates a higher pressure inside the inspection port than on the cement kiln side, removing dust that would otherwise accumulate inside the port by blowing it towards the cement kiln, and also preventing dust from entering from the cement kiln side. In this case, the swirling flow follows the inner surface of the inspection port, reliably preventing dust from remaining, and preventing dust from adhering, solidifying, or accumulating on the window panel, thus ensuring the transparency of the window panel. This allows for good visibility from the window panel, enabling observation of the inside of the kiln hood from the outside, and accurate measurement of temperatures at necessary locations, while properly firing the cement raw materials to produce the desired cement clinker. In addition, it prevents the intrusion of high-temperature heat from the cement kiln side, and the spiral airflow cools the cement kiln-facing side of the window panel, preventing damage such as cracking of the window panel. Furthermore, by installing multiple gas supply pipes and generating airflow from these pipes, a swirling flow is reliably created across the entire inner surface of the cylinder, allowing dust inside the inspection port to be removed in a short time.

[0012] In the kiln hood monitoring device of the present invention, it is desirable that a movable shielding plate for opening and closing the inspection port is provided inside the window plate in the cylindrical body.

[0013] By blocking the inspection opening with a movable shielding plate, dust from the cement kiln side onto the window panel is prevented, keeping the window panel clean and improving visibility when the movable shielding plate is open. Since the movable shielding plate can be opened and closed as needed, it can be used to block access from the cement kiln side under normal circumstances and opened only when necessary, thus reliably protecting the window panel. For example, even in the event of sudden draft changes during operation that cause red-hot dust to be blown out, the adhesion and accumulation of red-hot dust on the window panel is prevented, thus preventing damage to the window panel. Furthermore, when attaching or detaching the window panel, a movable barrier plate can be used to separate the cement kiln side from the window panel, allowing for safe maintenance such as replacing or cleaning the window panel. [Effects of the Invention]

[0014] According to the present invention, by generating a swirling airflow along the inner surface of the cylindrical body, dust adhesion and accumulation on inspection openings and window panels are prevented, the transparency of the window panels is maintained well, and monitoring work inside the kiln hood can be performed easily and accurately. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram showing a cement manufacturing facility to which a kiln hood monitoring device according to one embodiment of the present invention is applied. [Figure 2] This is a schematic, enlarged side view showing the area around the kiln hood in the cement manufacturing facility shown in Figure 1. [Figure 3] Figure 2 is a front view of the kiln hood. [Figure 4] This is a longitudinal cross-sectional view showing one embodiment of a kiln hood monitoring device. [Figure 5] This is a cross-sectional view taken along line AA in Figure 4. [Figure 6] This is a cross-sectional view taken along the line BB in Figure 4. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described below with reference to the drawings.

[0017] Figure 1 shows an embodiment of cement manufacturing equipment. This cement manufacturing equipment 1 includes a raw material storage warehouse 2 for storing limestone, clay, silica, iron raw materials, etc. separately as cement raw materials, a raw material mill and dryer 3 for pulverizing and drying these cement raw materials, a preheater 4 for preheating the powdery cement raw materials obtained by this raw material mill, a cement kiln (rotary kiln) 5 for firing the cement raw materials preheated by the preheater 4, a clinker cooler 6 for cooling the cement clinker after being fired in the cement kiln 5, and the like.

[0018] The cement kiln 5 is a cylindrical rotary kiln that is horizontal and slightly inclined downward from the kiln tail part 5a toward the kiln front part 5b, and rotates around its axis core. And the cement raw materials in the raw material storage warehouse 2 are pulverized and dried by the raw material mill and dryer 3, sent to the preheater 4 and preheated, and then supplied to the kiln tail part 5a of the cement kiln 5. In the cement kiln 5, while sending the cement raw materials supplied to the kiln tail part 5a to the kiln front part 5b, they are heated and fired to about 1450 °C by the burner 7 in the kiln front part 5b during the sending process to generate cement clinker, and this cement clinker is sent out from the kiln front part 5b to the clinker cooler 6. The cement clinker is cooled to a predetermined temperature by the clinker cooler 6 and then sent to the finishing process. In addition, reference numeral 9 in Figure 1 indicates a calciner connected to the cement kiln 5 together with the preheater 4, and the cement raw materials preheated by the preheater 4 are calcined by the burner 10.

[0019] Meanwhile, the exhaust gas generated in the cement kiln 5 is sent to the preheater 4 via the rising duct 15 at the kiln end 5a of the cement kiln 5. It is then drawn in by an induced fan 16 located between the preheater 4 and the raw material mill and dryer 3, causing it to flow from bottom to top, opposite to the flow of the cement raw material, before being introduced into the raw material mill and dryer 3. The raw material mill and dryer 3 simultaneously crush and dry the cement raw material by receiving the exhaust gas from the cement kiln 5. This exhaust gas from the raw material mill and dryer 3 is released into the atmosphere through a chimney (exhaust gas outlet of the present invention) 18, as indicated by the arrow in Figure 1, via an electrostatic precipitator 17.

[0020] Reference numeral 21 indicates a kiln hood located at the front 5b of the cement kiln 5. As shown in Figures 2 and 3, this kiln hood 21 is provided to surround the cement kiln 5 while supporting it rotatably, and is connected to the clinker cooler 6, surrounding the cement clinker being discharged from the cement kiln 5 and guiding it to the clinker cooler 6. The kiln hood 21 is equipped with the aforementioned burner 7 and a monitoring device 22 for monitoring the inside of the cement kiln 5.

[0021] The monitoring device 22 is installed so that the front part 5b of the cement kiln 5 can be monitored from outside the kiln hood 21. It is installed on the wall 21a of the kiln hood 21 and, as shown in Figures 4 to 6, comprises a cylindrical body 23 for forming an inspection opening 23a, a window plate 24 attached to the cylindrical body 23 and covering the inspection opening 23a, a plurality of gas supply pipes 25 for injecting gas into the cylindrical body 23, and a movable shielding plate 26 for opening and closing the inside of the cylindrical body 23. Outside the window plate 24, a radiation thermometer 27 (see Figure 2) or the like is provided that can measure the temperature of the front part 5b of the cement kiln 5 via the window plate 24.

[0022] The cylindrical body 23 is provided horizontally along the wall 21a of the kiln hood 21 so as to protrude outward. The wall 21a of the kiln hood 21 is constructed of refractory material, and a hole 28 is formed in the wall 21a so as to communicate with the inside of the cylindrical body 23. The internal space of this cylindrical body 23 serves as an inspection opening 23a, and a window plate 24 is attached to the protruding end of the cylindrical body 23. The window panel 24 is made of heat-resistant transparent glass or the like and is airtightly fixed to the cylindrical body 23.

[0023] The gas supply pipe 25 is installed at an intermediate position along the length of the cylindrical body 23, perpendicular to the center C1 of the cylindrical body 23 (inspection port 23a), and offset (eccentrically) from the center C1. In other words, even if the center C2 of the gas supply pipe 25 is extended, it does not intersect with the center C1 of the cylindrical body 23, but extends to the side of the center C1 of the cylindrical body 23. In the example shown in Figure 5, four gas supply pipes 25 are arranged at 90° intervals around the circumference of the cylindrical body 23. Gas such as air is supplied to these gas supply pipes 25 from the blower 29.

[0024] As a result, gas is continuously or intermittently injected into the cylindrical body 23 from the gas supply pipe 25. Because the gas supply pipe 25 is positioned eccentrically with respect to the center C1 of the cylindrical body 23, a spiral airflow is generated inside the cylindrical body 23 along the inner surface of the cylindrical body 23, as indicated by the arrows in Figures 4 and 5. This airflow flows toward the opposite side of the window plate 24, that is, toward the kiln hood 21, because the end of the cylindrical body 23 is closed by the window plate 24. Normally, when the cement kiln 5 is in operation, gas is constantly ejected from each gas supply pipe 25 and flows spirally through the cylindrical body 23 toward the kiln hood 21.

[0025] Furthermore, a housing portion 31 is integrally formed between the window plate 24 and the gas supply pipe 25 in the cylindrical body 23, extending radially outward from the cylindrical body 23 so as to bulge a part of the peripheral wall of the cylindrical body 23, and a movable shielding plate 26 is housed within this housing portion 31 so as to be movable in its planar direction. The flattened space 31a for housing this movable shielding plate 26 is formed by widening a part of the inner circumferential surface of the cylindrical body 23 in a groove-like manner, and is also formed to extend into the housing portion 31.

[0026] Furthermore, the movable shielding plate 26 is integrally provided with a long, rod-shaped handle portion 32, and a shaft portion 33 fixed to a part of this handle portion 32 is rotatably supported on the side of the housing portion 31. In this case, the movable shielding plate 26 is formed in a disc shape, and the handle portion 32 is fixed so as to protrude radially outward from it. By operating the end of the handle portion 32 that protrudes on the opposite side of the shaft portion 33 from the movable shielding plate 26, the movable shielding plate 26 can be moved back and forth between a blocking position S, which is positioned inside the cylindrical body 23 and blocks the inspection opening 23a within the flattened space 31a, and a retracted position T, which is moved away from the inspection opening 23a and housed inside the housing portion 31, as shown by the arrow in Figure 6.

[0027] The radiation thermometer 27 is positioned outside the kiln hood 21, facing the window plate 24, and is capable of measuring the temperature near the front 5b of the cement kiln 5 through the window plate 24. As a monitoring device 22, multiple cylindrical bodies 23 similar to those described above are installed on the wall 21a of the kiln hood 21, allowing for monitoring of multiple locations within the kiln hood 21. The cement kiln 5 is positioned approximately 5m away from the front wall 21a of the kiln hood 21. Furthermore, as shown in Figure 3, if multiple cylindrical bodies 23 are provided in the kiln hood 21, it is possible to place radiation thermometers 27 opposite all of the cylindrical bodies 23, but it is also possible to place radiation thermometers 27 only on the required number of cylindrical bodies 23.

[0028] In the cement manufacturing facility 1 configured in this way, the cement raw materials sent from the preheater 4 are fired in the cement kiln 5 using the burner 7, and the fired cement clinker is guided from the front part 5b of the cement kiln 5 to the clinker cooler 6. The monitoring device 22 can monitor the front section 5b of the cement kiln 5 and the cement clinker guided from the front section 5b to the clinker cooler 6, and can also measure the temperature near the front section 5b of the cement kiln 5 using the radiation thermometer 27.

[0029] In this monitoring device 22, when air or other gas is supplied from the gas supply pipe 25, the gas supply pipe 25 is positioned eccentrically with respect to the center C1 of the cylindrical body 23, which generates a spiral flow within the cylindrical body 23, causing the gas to flow inward towards the kiln hood 21. Therefore, if dust has accumulated on the inner surface of the cylindrical body 23, it can be blown into the kiln hood 21 by the spiral flow. In addition, the pressure inside the cylindrical body 23 is increased by this airflow, preventing dust from the kiln hood 21 from entering the cylindrical body 23.

[0030] Therefore, by continuously supplying gas from the gas supply pipe 25, the adhesion and accumulation of dust inside the cylindrical body 23 is suppressed. In addition, since gas is constantly supplied to the cylindrical body 23 from the outside, high-temperature gas from the cement kiln 5 is prevented from entering the cylindrical body 23, the temperature inside the cylindrical body 23 can be kept low, the surface temperature of the glass window plate 24 is reduced, fogging is prevented, and cracks and other damage can also be prevented. For example, it was confirmed that the surface temperature of the window plate 24 was 170°C when no gas was supplied from the gas supply pipe 25, but it dropped to 130°C when air was supplied.

[0031] Since the window panel 24 is kept clean, the temperature can be accurately measured by the radiation thermometer 27, and consequently, the firing temperature in the cement kiln 5 can be properly controlled, enabling the production of cement clinker with uniform quality. Furthermore, dust accumulation inside the cylindrical body 23 is prevented, and the inside of the cylindrical body 23, which is the inspection port 23a, and the window plate 24 can be kept clean. As a result, the frequency of cleaning work is reduced, workers are less likely to come into contact with high-temperature environments, making it safer and improving the working environment.

[0032] Furthermore, the monitoring device 22 is equipped with a movable shielding plate 26 that can be opened and closed inside the cylindrical body 23. Therefore, when inspection work by the radiation thermometer 27 is not required, the movable shielding plate 26 can be used to block the inside of the cylindrical body 23, thereby isolating the area around the window plate 24 from the atmosphere inside the kiln hood 21. As a result, by blocking the inside of the cylindrical body 23 during the operation of the cement kiln 5, even if a sudden pressure change on the cement kiln 5 side causes red-hot dust to be blown out, the movable shielding plate 26 prevents it from reaching the window plate 24. In addition, the movable shielding plate 26 also prevents the blowing of high heat due to the firing process of cement raw materials in the cement kiln 5, thereby preventing damage to the glass window plate 24. Even when the inside of the cylindrical body 23 is blocked by the movable shielding plate 26, the supply of gas from the gas supply pipe 25 is kept continuous, thereby maintaining the inside of the cylindrical body 23 in a clean state at all times.

[0033] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, although the cylindrical body 23 is provided horizontally, it may also be provided with a downward slope towards the inside of the kiln hood 21, which would make it less likely for dust to accumulate inside. Although the gas supply pipe 25 is installed perpendicular to the cylindrical body 23, it may also be installed at an angle, for example, with the tip connected to the cylindrical body 23 inclined toward the kiln hood 21 (moving away from the kiln hood 21 as it moves away from the cylindrical body 23). Furthermore, the number of gas supply pipes 25 is not limited to four as in this embodiment; a spiral flow can be formed with just one pipe. Furthermore, although the movable shielding plate 26 is configured to be opened and closed manually by an operator using the handle 32, it may also be opened and closed using a drive source such as a motor. [Explanation of Symbols]

[0034] 1. Cement manufacturing equipment 2. Raw material storage 3. Raw material mill and dryer 4 Preheater 5. Cement Kiln 5a Kiln butt 5b Kiln front 6. Clinka Cooler 7 Burners 21 Kilnhood 22 Monitoring equipment 21a Wall 23 Cylinder 23a Inspection hatch 24 Window board 25 Gas supply pipe 26 Movable shield plate 27 Radiation thermometer 28 Hole 31 Housing Section 31a Flattened space 32 Handle section 33 Shaft section

Claims

1. A kiln hood monitoring device for monitoring a cement kiln from the kiln hood on the front side of the kiln, comprising: a cylindrical body provided in the kiln hood and forming an inspection opening communicating with the interior of the kiln hood; a window plate attached to the end of the cylindrical body, allowing the interior of the kiln hood to be viewed from the outside through the inspection opening; and one or more gas supply pipes connected to the cylindrical body, which inject gas into the inspection opening to generate a spiral airflow along the inner circumferential surface of the cylindrical body.

2. The kiln hood monitoring device according to claim 1, characterized in that a movable shielding plate for opening and closing the inspection port is provided inside the window plate in the cylindrical body.

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