A device for preventing the blockage of the waste heat boiler of a rotary hearth furnace

Abstract

The present invention discloses a device for preventing clogging of a rotary hearth furnace waste heat boiler. Two arc-shaped baffles are fixedly installed at intervals in a flue in front of the ZnCl2 melting zone of the waste heat boiler. A particle settling zone is formed between the two arc-shaped baffles. A flue gas inlet is provided at the bottom of the first arc-shaped baffle, and a flue gas outlet is provided at the top of the second arc-shaped baffle. A slag collection and discharge port is provided at the bottom of the particle settling zone. A material temporary storage chamber is sealed at the slag collection and discharge port. The material temporary storage chamber also has a discharge port. A first baffle plate and a second baffle plate are respectively installed on the slag collection and discharge port of the material temporary storage chamber. The first baffle plate and the second baffle plate are controlled to open or close by an electric mechanism. During collection, the first baffle plate is opened and the second baffle plate is closed. During discharge, the first baffle plate is closed and the second baffle plate is opened. The present invention has a simple structure and strong practicality. It prevents adhesion and deposition in the high-temperature melting zone of zinc chloride and reduces flue gas blockage.

Description

Technical Field

[0001] The invention belongs to the technical field of rotary hearth furnace waste heat boilers, and in particular relates to a device for preventing the rotary hearth furnace waste heat boiler from being blocked in a ZnCL2 melting zone. Background Art

[0002] During the production process, rotary hearth furnaces generate a large amount of high-temperature flue gas (950-1200°C). Currently, waste heat from this flue gas is recovered through traditional waste heat recovery methods. However, the flue gas from rotary hearth furnaces has a complex composition, containing a large amount of low-melting-point substances and fine dust particles, which can easily cause boiler blockage.

[0003] A Chinese patent (CN204573974U) for a waste heat boiler (HRSG) with a novel radiation chamber structure incorporates a radiation chamber within the HRSG. This allows the flue gas temperature to be lower than the melting point of the smoke before entering the convection tube bundle, allowing large quantities of smoke particles to settle within the radiation chamber, reducing the risk of smoke blocking the convection tube bundle. Most rotary hearth furnaces already have radiation chambers in the high-temperature zone, avoiding the melting and semi-melting regions of KCl and NaCl, partially addressing boiler blockage. However, due to the low efficiency of radiation heat transfer, it is difficult to address boiler blockage in the low-temperature region at the rear of the HRSG.

[0004] The main reason for the blockage of the rear section of the waste heat boiler is that the flue gas also contains fine particulate matter such as ZnCL2. As the flue gas is transported, collisions occur, and the particle size gradually increases. When flowing through the melting zone of ZnCL2 in the flue (that is, the area in the flue with a temperature of 250-350°C), sedimentation and adhesion occur, and long-term accumulation causes blockage. Summary of the Invention

[0005] The object of the present invention is to provide a device for preventing clogging of the waste heat boiler of a rotary hearth furnace. The device has a simple structure and achieves early enlargement and discharge of particulate matter through collision and other means, thereby preventing sedimentation in the molten area of zinc chloride and preventing clogging. It is used to solve the problem of clogging of the waste heat boiler of a rotary hearth furnace in the molten area of ZnCl2 in the steel industry.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical scheme: two arc-shaped baffles are fixedly installed at intervals in the flue in front of the melting zone of ZnCL2 in the waste heat boiler, the inner concave surfaces of the two arc-shaped baffles are arranged opposite to each other, and the area between the two forms a particulate matter settling area, wherein the lower part of the first arc-shaped baffle is provided with a flue gas inlet, and the upper part of the second arc-shaped baffle is provided with a flue gas outlet; a slag collection and discharge port is provided on the bottom side wall of the particulate matter settling area near the second arc-shaped baffle in the particulate matter settling area, and a material temporary storage chamber is sealed at the slag collection and discharge port, the slag collection and discharge port is the feed port of the material temporary storage chamber, and the material temporary storage chamber is also provided with a discharge port, and a first baffle plate and a second baffle plate are respectively installed on the slag discharge port and the discharge port of the material temporary storage chamber, and the first baffle plate and the second baffle plate are controlled to open or close by an electric mechanism. When in the material collection state, the first baffle plate is opened and the second baffle plate is closed; when in the discharge state, the first baffle plate is closed and the second baffle plate is opened.

[0007] Furthermore, the edge of the arc-shaped baffle is welded and fixed to the inner wall of the flue, and the arc-shaped baffle and the inner wall of the flue are also connected by an oblique support rod.

[0008] Furthermore, the curvature of the first arc-shaped baffle is 0.17 rad to 0.22 rad, and the curvature of the second arc-shaped baffle is 0.01 rad greater than that of the first arc-shaped baffle.

[0009] Furthermore, the height of the first arc-shaped baffle is 70-80% of the height of the cavity area, and the height of the second arc-shaped baffle is 1.05-1.15 times the height of the first arc-shaped baffle.

[0010] Furthermore, the thickness of the arc-shaped baffle is 15-25 mm, and the material of the arc-shaped baffle is TP347H stainless steel;

[0011] Furthermore, the length (d1) of the slag discharge port is 10-15% of the length of the cavity area, and the width (d2) of the slag discharge port is 5-10% of the width of the cavity area.

[0012] Furthermore, when the first baffle plate is in the open state, the angle between the first baffle plate and the bottom side wall of the flue is 160-170°.

[0013] The present invention utilizes two baffle structures with simple structures and convenient processing to solve the problem of blockage caused by the overlap of the flue gas settling zone of the waste heat boiler of the rotary hearth furnace and the ZnCl2 melting zone. This device is arranged at the front end of the ZnCl2 melting zone. The flowing flue gas first collides with the first arc-shaped baffle, and after being guided by the arc-shaped baffle, it enters the particle settling zone from the lower flue gas inlet, continues forward, and collides with the second arc-shaped baffle again. The flow direction continues to turn, and finally the flue gas is discharged from the upper flue gas outlet of the second arc-shaped baffle. In the aforementioned collision and turning process, the particulate matter mixed in the flue gas collides with the particulate matter in the flue gas that has not turned, which increases the collision chance and collision frequency, accelerates the growth of fine dust particles, and after multiple collisions and growth, the particles settle to the slag discharge port for discharge. The present invention has a simple and reasonable structure, strong practicality, economy and environmental protection; it avoids adhesion and deposition in the high-temperature melting zone of zinc chloride, and slows down the flue gas blockage. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a three-dimensional schematic diagram of the device of the present invention installed in front of the easily blocked temperature range of the waste heat boiler;

[0015] Figure 2 It is a main schematic diagram of the present invention.

[0016] Figure 3 It is a schematic top view of the present invention.

[0017] Figure 4 This is a schematic diagram of the states of the first baffle plate and the second baffle plate when the device of the present invention is in the collecting state.

[0018] Figure 5 It is a schematic diagram of the states of the first baffle plate and the second baffle plate when the device of the present invention is in the discharging state. DETAILED DESCRIPTION

[0019] like Figure 1-3 As shown, the present invention provides a device for preventing clogging of a rotary hearth furnace waste heat boiler. Two curved baffles are fixedly installed in the flue ahead of the ZnCl2 melting zone (direction of flue gas entry) in the waste heat boiler. Their concave surfaces face each other. The area between the two curved baffles forms a particle settling area 200. A flue gas inlet 11 is provided at the bottom of the first curved baffle 10, and a flue gas outlet 21 is provided at the top of the second curved baffle 20. A slag collection and discharge port 30 is provided on the bottom sidewall of the particle settling area 200, near the second curved baffle 20. A material temporary storage chamber 40 is hermetically connected to the slag collection and discharge port 30.

[0020] The temporary material storage chamber 40 is funnel-shaped. The collecting and discharging port 30 serves as the feed port of the temporary material storage chamber 40. The temporary material storage chamber 40 also has a discharge port. A first baffle plate 50 and a second baffle plate 60 are mounted on the discharge port 30 and the discharge port of the temporary material storage chamber 40, respectively. The first baffle plate 50 and the second baffle plate 60 are controlled by an electric mechanism, that is, the first baffle plate 50 and the second baffle plate 60 respectively control the opening or closing of the discharge port 30 and the discharge port of the temporary material storage chamber 40. When collecting particulate matter, the first baffle plate is opened and the second baffle plate is closed. During production, particulate matter falling in the particulate matter settling area 200 will enter the temporary material storage chamber 40 through the discharge port. After a period of time, the collected particulate matter will be discharged. In the discharge state, the first baffle plate 50 is closed and the second baffle plate 60 is opened, and the particulate matter is discharged from the temporary material storage chamber 40. By providing the temporary material storage chamber 40 and cooperating with the first baffle plate 50 and the second baffle plate 60, it is possible to ensure that the flue does not lose air during particle collection and discharge, thereby maintaining the pressure within the flue. Specifically, when the first baffle plate is in the open position, the angle β between it and the bottom sidewall of the flue is 160-170°. This prevents particles that have grown larger due to collisions in the flue gas from being entrained by subsequent flue gas flow as they settle to the bottom of the flue due to gravity. This angle also facilitates the opening and closing of the collection trough, facilitating ash discharge.

[0021] Preferably, the first curved baffle has a curvature of 0.17 rad to 0.22 rad, and the second curved baffle has a curvature of 0.01 rad greater than that of the first. The two curved baffles, each with a certain curvature, can block and guide the flue gas, allowing it to condense into large particles within the particle settling area 200 and fall to the slag discharge port.

[0022] The height of the first arc-shaped baffle is 70-80% of the height of the cavity area, and the height of the second arc-shaped baffle is 1.05-1.15 times the height of the first arc-shaped baffle.

[0023] Furthermore, the thickness of the arc baffle is 15-25 mm, and the material of the arc baffle is TP347H stainless steel. The arc baffle is made of TP347H stainless steel of appropriate thickness, which is resistant to high temperature and impact and has a long service life.

[0024] Preferably, the edges of the two curved baffles are welded to the inner wall of the flue, and the curved baffles are connected to the inner wall of the flue by an inclined support rod 70. The inclined support rod 70 is arranged on the concave side of the curved baffle to exert a reverse force on the curved baffle to offset the force of the flue gas on the baffle, thereby preventing the baffle from being damaged after long-term operation.

[0025] Furthermore, the length (d1) of the slag discharge port is 10-15% of the length of the cavity area, and the width (d2) of the slag discharge port is 5-10% of the width of the cavity area.

[0026] The present invention has a simple structure and is easy to operate. In the initial state, the device is in a collecting state, that is, the first baffle is open and the second baffle is closed. During production, fine particles such as zinc chloride entrained in the flue gas will grow into large particles in the particle settling area 200 in advance, fall to the slag discharge port under the action of gravity, and enter the material temporary storage chamber 40. During the production process, discharge is carried out every 2 hours, that is, the first baffle is closed and the second baffle is opened; the discharge time is 30 minutes. After the discharge is completed, it continues to reset to the collecting state.

[0027] The installation method of the device, the connection relationship between the components, and the processing method of the present invention are merely illustrated as an example and cannot be considered as protecting only the described scheme. Any technician familiar with this technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical scheme and inventive concept of the present invention, should be covered by the protection scope of the present invention.

Claims

1. A device for preventing the blockage of a rotary hearth furnace waste heat boiler, characterized in that: Two arc-shaped baffles are fixedly installed at intervals in the flue in front of the melting zone of ZnCL2 in the waste heat boiler, and the inner concave surfaces of the two arc-shaped baffles are arranged opposite to each other, and the area between the two forms a particulate matter settling area, wherein the lower part of the first arc-shaped baffle is provided with a flue gas inlet, and the upper part of the second arc-shaped baffle is provided with a flue gas outlet; a slag collection and discharge port is provided on the bottom side wall of the particulate matter settling area near the second arc-shaped baffle in the particulate matter settling area, and a material temporary storage chamber is sealed at the slag collection and discharge port, and the slag collection and discharge port is the feed port of the material temporary storage chamber, and the material temporary storage chamber is also provided with a discharge port, and a first baffle plate and a second baffle plate are respectively installed on the slag discharge port and the discharge port of the material temporary storage chamber, and the first baffle plate and the second baffle plate are controlled to open or close by an electric mechanism. When in a material collecting state, the first baffle plate is opened and the second baffle plate is closed; when in a discharging state, the first baffle plate is closed and the second baffle plate is opened; When the first baffle plate is in the open state, the angle between the first baffle plate and the bottom side wall of the flue is 160-170°.

2. The device for preventing the blockage of the waste heat boiler of a rotary hearth furnace according to claim 1, characterized in that: The edge of the arc-shaped baffle is welded and fixed to the inner wall of the flue, and the arc-shaped baffle and the inner wall of the flue are also connected by an oblique support rod.

3. The device for preventing the blockage of the waste heat boiler of a rotary hearth furnace according to claim 1, characterized in that: The curvature of the first arc-shaped baffle is 0.17 rad to 0.22 rad, and the curvature of the second arc-shaped baffle is 0.01 rad greater than that of the first arc-shaped baffle.

4. The device for preventing the blockage of the waste heat boiler of a rotary hearth furnace according to claim 1, characterized in that: The height of the first arc-shaped baffle is 70-80% of the height of the cavity area, and the height of the second arc-shaped baffle is 1.05-1.15 times the height of the first arc-shaped baffle.

5. The device for preventing the blockage of the waste heat boiler of a rotary hearth furnace according to claim 1, characterized in that: The thickness of the arc-shaped baffle is 15-25 mm, and the material of the arc-shaped baffle is TP347H stainless steel.

6. The device for preventing the blockage of the waste heat boiler of a rotary hearth furnace according to claim 1, characterized in that: The length (d1) of the slag discharge port is 10-15% of the length of the cavity area, and the width (d2) of the slag discharge port is 5-10% of the width of the cavity area.

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