A kiln head boiler inlet temperature boosting device

Abstract

The application discloses a kiln head boiler inlet temperature lifting device, which comprises a grate cooler and a waste heat boiler; the first end side of the grate cooler is provided with a kiln cylinder body and a third air pipe, and the tail end of the grate cooler is further provided with a hot air branch pipe; the hot air branch pipe is connected to the third air pipe from the tail end of the grate cooler. By increasing the hot air branch pipe, a hot air branch pipe air path is further arranged at the tail end of the grate cooler on the basis of the original division of the secondary air, the third air and the waste heat boiler, and is directly connected to the third air pipe; under the premise that the total air supply amount of the grate cooler and the air intake amount of the waste heat boiler are not changed, the zero pressure surface of the grate cooler will be changed, and is shifted to the head position of the grate cooler and is far away from the waste heat boiler; the change can make the hot air temperature entering the waste heat boiler through the grate cooler higher.

Description

Technical Field

[0001] This invention relates to a kiln head boiler, specifically to a kiln head boiler inlet temperature enhancement device, belonging to the field of waste heat power generation technology in the cement industry. Background Technology

[0002] After completing the grate cooler upgrade, our company found that although the clinker power consumption and standard coal consumption decreased significantly, it also resulted in a substantial decline in power generation. Firstly, this led to an increase in purchased electricity, increasing electricity costs. Secondly, the generator unit's capacity could not be fully utilized, wasting the equipment's potential.

[0003] Currently, there are three main directions for optimizing waste heat power generation technology in the cement industry: first, optimizing the heat exchange of the grate cooler itself (such as modifying the grate cooler, optimizing the grate gap and cooling fan airflow); second, modifying the heating surface of the waste heat boiler (such as increasing the heat exchange area); and third, research on adding a supplementary combustion furnace at the kiln head to increase the boiler temperature. However, all of these approaches suffer from high investment, slow returns, and non-compliance with environmental emission standards. Therefore, further improvements are needed. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a kiln head boiler inlet temperature enhancement device to adjust the zero pressure surface position, increase the kiln head boiler temperature, significantly increase power generation, and reduce clinker costs.

[0005] The technical solution adopted in this invention is as follows: a kiln head boiler inlet temperature raising device, including a grate cooler and a waste heat boiler; the grate cooler has a kiln cylinder and a tertiary air duct on one side of its front end, and a hot air branch pipe is also provided at the rear end of the grate cooler; the hot air branch pipe draws air from the rear end of the grate cooler to the tertiary air duct.

[0006] Furthermore, the hot air branch pipe is equipped with a butterfly valve for controlling the air volume; one end of the hot air branch pipe is connected to a bypass pipe; the bypass pipe is located at the tail end of the grate cooler.

[0007] Furthermore, the bypass pipeline is connected to the kiln head dust collector; the waste heat boiler is connected to both the kiln head exhaust fan and the kiln head dust collector.

[0008] Furthermore, the other end of the hot air branch pipe is connected to the kiln head hood end of the tertiary air pipe; several temperature sensors are respectively installed on the kiln head hood end and the hot air branch pipe.

[0009] Furthermore, the air inlet of the tertiary air duct is provided with a horn-shaped opening; and an air regulating damper is provided at the horn-shaped opening.

[0010] Furthermore, the tertiary air duct is connected to the hinge support via a sliding support; the hot air branch duct is provided with a second sliding support, a fixed support, and a third sliding support.

[0011] Furthermore, the second sliding support and the fixed support are respectively welded to the hot air branch pipe; the third sliding support is in contact with the hot air branch pipe.

[0012] Furthermore, the outer casing of the hot air branch pipe is provided with at least two non-metallic expansion joints.

[0013] Furthermore, a second butterfly valve is installed in the bypass pipeline; the butterfly valve, the damper, and the temperature sensor are respectively connected to the control back-end terminal.

[0014] Furthermore, a dust collection box is provided on the outer side of the hot air branch pipe; the hot air branch pipe is divided into a front section and a rear section at the position of the dust collection box; the dust collection box is provided with connection holes opposite to the front and rear sections respectively; sealing rings are provided on the outer periphery of the front and rear sections respectively; a top cover is provided on the surface of the dust collection box; an anode electrode and a cathode electrode are respectively provided on the two inner walls of the dust collection box other than the connection holes.

[0015] Furthermore, the connecting hole is provided with a raised edge relative to the sealing ring; an inner edge is provided inside the raised edge; a plurality of screws are uniformly surrounded on the raised edge; a wedge-shaped pressure block is provided at the bottom of the screws; the wedge-shaped pressure block abuts against the sealing ring and makes close contact with the inner edge surface.

[0016] Furthermore, the dust removal box is equipped with an adsorption column inside; the top cover is provided with corresponding adsorption holes relative to the adsorption column; the adsorption holes are provided with plugs; the adsorption holes are connected to the negative pressure dust suction pipe; and multiple elongated through holes are opened around the bottom of the adsorption column.

[0017] This invention offers the following advantages: By adding a hot air branch pipe, in addition to the existing distinction between secondary air, tertiary air, and waste heat boiler, a hot air branch pipe is added at the tail end of the grate cooler and directly connected to the tertiary air duct. Without changing the total air supply of the grate cooler or the air intake of the waste heat boiler, the zero-pressure surface of the grate cooler will change, shifting towards the head of the grate cooler and away from the waste heat boiler. This change allows for a higher temperature of the hot air entering the waste heat boiler from the grate cooler. This invention can solve the problem of increasing power generation for similar cement enterprises, forming a replicable technical solution of "grate cooler induced draft - zero-pressure surface adjustment - increased kiln head boiler temperature - increased power generation". Attached Figure Description

[0018] Figure 1 This is a front view structural diagram of the present invention.

[0019] In the diagram, A1 represents the initial position of the zero-pressure surface; A2 represents the adjusted position of the zero-pressure surface.

[0020] Figure 2 This is a schematic diagram of the butterfly valve opening control.

[0021] Figure 3 This is a schematic diagram of the air temperature at the tertiary air duct during operation.

[0022] Figure 4 When broadcasting a radio station during runtime.

[0023] Figure 5 This is a schematic diagram of the internal structure of the dust collector.

[0024] Figure 6 This is a magnified view of part C.

[0025] Wherein: 1 is the grate cooler, 2 is the kiln body, 3 is the tertiary air duct, 5 is the hot air branch pipe, 6 is the butterfly valve, 7 is the bypass pipe, 8 is the waste heat boiler, 9 is the air regulating damper, 10 is the sliding support, 11 is the hinge support, 12 is the second sliding support, 13 is the fixed support, 14 is the third sliding support, 15 is the non-metallic expansion joint, 16 is the dust collector box, 16-1 is the connection hole, 17 is the sealing ring, 18 is the top cover, 19 is the anode electrode, 20 is the cathode electrode, 21 is the raised edge, 22 is the inner edge, 23 is the wedge-shaped pressure block, 24 is the adsorption column, 25 is the adsorption hole, and 26 is the screw. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0027] See Figure 1-6 This application discloses a kiln head boiler inlet temperature enhancement device, including a grate cooler 1 and a waste heat boiler 8; the grate cooler 1 has a kiln cylinder 2 and a tertiary air duct 3 on one side of its front end, and a hot air branch pipe 5 is also provided at the rear end of the grate cooler 1; the hot air branch pipe 5 draws air from the rear end of the grate cooler 1 to the tertiary air duct 3.

[0028] Furthermore, the hot air branch pipe 5 is equipped with a butterfly valve 6 for controlling the air volume; one end of the hot air branch pipe 5 is connected to the bypass pipe 7; the bypass pipe 7 is located at the tail end of the grate cooler 1.

[0029] Furthermore, the bypass pipeline 7 is connected to the kiln head dust collector; the waste heat boiler 8 is connected to the kiln head dust collector.

[0030] Specifically, the waste heat boiler used in this embodiment is an AQC boiler.

[0031] Furthermore, the other end of the hot air branch pipe 5 is connected to the kiln head hood end of the tertiary air pipe 3; and several temperature sensors are respectively installed on the kiln head hood end and the hot air branch pipe 5.

[0032] Furthermore, the air inlet of the tertiary air duct 3 is provided with a horn-shaped opening; and the horn-shaped opening is provided with an air regulating damper 9.

[0033] Furthermore, a second butterfly valve is installed in the bypass line 7. During normal operation, the second butterfly valve in the bypass line 7 should remain closed.

[0034] Specifically, before the modification, when the grate cooler was running normally, the cooling fan supplied air from the bottom, with a total air volume of Q, which was divided into three outlets: 1. Secondary air: Goes into the kiln, with an air volume of Q2 and an air pressure of P2; 2. Tertiary air: to the tertiary air duct, the air volume is Q3, and the air pressure is P3; 3. Air intake from AQC boiler: The air volume is Q4 and the air temperature is T from the AQC boiler at the kiln head.

[0035] Secondary and tertiary air are drawn to the kiln tail by the high-temperature fan at the kiln tail, and air from the AQC boiler is drawn to the kiln head dust collector by the kiln head exhaust fan. Q = Q2 + Q3 + Q4. At this time, the pressure surface of the grate cooler is close to the tail of the grate cooler (pressure surface 1). All the air on the right side of the pressure surface enters the AQC boiler, and all the air on the left side of the pressure surface enters the kiln and the tertiary air duct.

[0036] After the improvement: A hot air duct is drawn from the tail end of the grate cooler and connected to the tertiary air duct. The total air supply volume Q of the grate cooler remains unchanged and is divided into 4 outlets: 1. Tail end of the grate cooler: to the tertiary air duct, air volume is q1, air pressure is p1; 2. Secondary air: Goes into the kiln, with an air volume of q2 and an air pressure of p2; 3. Tertiary air: to the tertiary air duct, the air volume is q3, and the air pressure is p3; 4. Air intake from AQC boiler: Air volume is q4 and air temperature is T from AQC boiler at the kiln head.

[0037] Q = q1 + q2 + q3 + q4. In actual operation, p1 > p3. Therefore, when the newly added butterfly valve opens, part of the air from the tail end of the grate cooler goes to the tertiary air duct through the newly added pipe, with an air volume of q1. The size of q1 can be adjusted according to the valve opening. Because the operating conditions of the high-temperature fan and the kiln head exhaust fan remain unchanged, the air volume of q4 remains unchanged. At this time, Q4 = q4, Q2 + Q3 = q1 + q2 + q3. The larger q1 is, the closer the pressure surface of the grate cooler is to the head of the grate cooler. At this time, the pressure surface of the grate cooler will shift to the left (pressure surface 2). After the action of the cooling fan, the air temperature inside the grate cooler gradually decreases from the head to the tail end. Therefore, the closer the pressure surface of the grate cooler is to the head, the higher the air temperature T entering the AQC boiler.

[0038] According to the above formula, in actual operation, since the total air supply Q of the grate cooler is constant, and the air volume q4 entering the AQC boiler through the kiln head exhaust fan is also constant, the sum of the original q2 and q3 must decrease to satisfy the premise that the total air volume Q remains constant after the introduction of the new q1. Therefore, it can be seen that after adopting this method, the air volume of the kiln shell 2 and the tertiary air duct 3 will decrease, resulting in a pressure reduction at the head of the grate cooler, ultimately causing the zero-pressure surface to shift to the left (with...). Figure 1 (For example).

[0039] After the zero-pressure surface shifts to the left, the range of high-temperature airflow increases, which raises the average air temperature in the middle and rear sections of the grate cooler. As shown in the figure, the AQC boiler can take in more high-temperature hot air, thereby increasing the air temperature entering the waste heat boiler and improving power generation efficiency.

[0040] Furthermore, the tertiary air duct 3 is connected to the hinge support 11 via a sliding support 10; the hot air branch duct 5 is provided with a second sliding support 12, a fixed support 13 and a third sliding support 14.

[0041] Specifically, in this embodiment, the hot air branch pipe 5 is made of Q235B material and its pipe wall thickness is 6mm.

[0042] For the tertiary air duct, its surface is surrounded by reinforcing ribs formed by 80*10 flat steel bars; the length of the flat steel bars is 150m.

[0043] Furthermore, the second sliding support 10 and the fixed support 13 are respectively welded to the hot air branch pipe 5; the third sliding support 14 is in contact with the hot air branch pipe 5.

[0044] Furthermore, the hot air branch pipe 5 is fitted with at least two non-metallic expansion joints 15.

[0045] The non-metallic expansion joint 15 adopts a 1600mm specification, with an axial compensation of 150mm and a radial compensation of 60mm. It is pre-stretched by 30mm at 20℃, and its overall length is 780mm.

[0046] In practice, the direct benefits are as follows: 2000kw of additional power is generated per hour, and based on the purchased electricity price of 0.6115 yuan, the electricity cost is saved by 2000 * 0.6115 = 1223 yuan per hour. Calculations show that if the temperature of the tertiary air drops by 180 degrees, 1.12 tons of standard coal per hour will be needed to replenish the heat, which is equivalent to an increase of 1.76 tons of alternative fuel per hour. Based on the current price of alternative fuel of 379 yuan per ton, the increase in alternative fuel cost per hour is: 1.76 * 379 = 667.04 yuan. Net profit per hour: 1223 - 667.04 = 555.96 yuan; The overall cost per ton of clinker decreased by: 555.96 / 240 = 2.32 yuan / ton; Based on an annual operating period of 180 days, the annual revenue is calculated as follows: 555.96 * 24 * 180 / 10000 = 2,401,700 yuan.

[0047] Taking the butterfly valve 6 with an opening of 50-70% as an example, the temperature of the tertiary air (left side of the zero-pressure surface) drops by 150-200℃, which can cause the temperature on the right side of the zero-pressure surface to rise significantly, and the power generation can increase by 1500-2000 kWh / h.

[0048] Furthermore, a dust collection box 16 is provided on the outer side of the hot air branch pipe 5; the hot air branch pipe 5 is divided into a front section and a rear section at the position of the dust collection box 16; the dust collection box 16 is provided with connecting holes 16-1 respectively for the front section and the rear section; sealing rings 17 are provided on the outer periphery of the front section and the rear section of the branch pipe respectively; a top cover 18 is provided on the surface of the dust collection box 16; an anode electrode 19 and a cathode electrode 20 are respectively provided on the two inner walls of the dust collection box 16 other than the connecting holes.

[0049] Furthermore, the connecting hole 16-1 is provided with a protruding edge 21 relative to the sealing ring 17; an inner edge 22 is provided inside the protruding edge 21; a plurality of screws 26 are evenly surrounded on the protruding edge 21; a wedge-shaped pressure block 23 is provided at the bottom of the screws 26; the wedge-shaped pressure block 23 abuts against the sealing ring 17 and makes close contact with the surface of the inner edge 22.

[0050] Specifically, the screw 26 is rotatably connected to the wedge-shaped pressure block 23, meaning that the screw 26 can rotate freely while the wedge-shaped pressure block 23 is circumferentially fixed. When the screw 26 rotates, it will naturally drive the wedge-shaped pressure block 23 to move up and down.

[0051] Furthermore, the dust collection box 16 is also provided with an adsorption column 24 inside; the top cover is provided with corresponding adsorption holes 25 relative to the adsorption column 24; a plug is provided in the adsorption hole; the adsorption hole is connected to the negative pressure dust collection pipe; and multiple elongated through holes are opened around the bottom of the adsorption column 24.

[0052] Specifically, the sealing rings 17 of the front and rear sections of the branch pipe are aligned with the connecting holes 16-1 on the front and rear sides of the dust collector housing 16, so that the sealing rings 17 can be inserted into the flange 21 and the sealing rings 17 and the inner edge 22 are close together; then, the screw 26 on the flange 21 is rotated, so that the wedge-shaped pressure block 23 at its end gradually descends or rises. As the wide end of the wedge-shaped pressure block 23 goes deeper, it can squeeze the sealing rings 17, so that they are in close contact with the surface of the inner edge 22 to form a seal.

[0053] As hot air passes through the dust collector 16, the presence of the anode electrode 19 and cathode electrode 20 allows the anode motor 19 to adsorb dust particles in the hot air. When the power is off, the anode electrode 19 loses its adsorption force, and the dust falls to the bottom of the dust collector 16 under gravity. At this point, simply connecting the external negative pressure pipe to the adsorption hole 25 and removing the plug from the adsorption hole 25 will generate negative pressure within the adsorption column 24, ultimately removing the dust from the bottom of the dust collector 16.

[0054] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A device for raising the inlet temperature of a kiln head boiler, comprising a grate cooler (1) and a waste heat boiler (8); wherein the grate cooler (1) has a kiln shell (2) and a tertiary air duct (3) on one side of its head end, characterized in that: The tail end of the grate cooler (1) is also provided with a hot air branch pipe (5); the hot air branch pipe (5) draws air from the tail end of the grate cooler (1) to the tertiary air pipe (3).

2. The kiln head boiler inlet temperature raising device according to claim 1, characterized in that: The hot air branch pipe (5) is equipped with a butterfly valve (6) for controlling the air volume; one end of the hot air branch pipe (5) is connected to the bypass pipe (7); the bypass pipe (7) is located at the tail end of the grate cooler (1).

3. The kiln head boiler inlet temperature raising device according to claim 2, characterized in that: The bypass pipeline (7) is connected to the kiln head dust collector; the waste heat boiler (8) is connected to the kiln head dust collector.

4. The kiln head boiler inlet temperature raising device according to claim 2, characterized in that: The other end of the hot air branch pipe (5) is connected to the kiln head hood end of the tertiary air pipe (3); several temperature sensors are respectively installed on the kiln head hood end and the hot air branch pipe (5).

5. The kiln head boiler inlet temperature raising device according to claim 4, characterized in that: The air inlet of the tertiary air duct (3) is provided with a horn-shaped opening; the horn-shaped opening is provided with an air regulating damper (9).

6. The kiln head boiler inlet temperature raising device according to claim 5, characterized in that: The bypass pipeline (7) is equipped with a second butterfly valve; the butterfly valve (6), the air damper (9) and the temperature sensor are respectively connected to the control back-end terminal.

7. The kiln head boiler inlet temperature raising device according to claim 1, characterized in that: The tertiary air duct (3) is connected to the hinge support (11) via a sliding support (10); the hot air branch pipe (5) is provided with a second sliding support (12), a fixed support (13) and a third sliding support (14); the hot air branch pipe (5) is covered with at least two non-metallic expansion joints (15); the second sliding support (10) and the fixed support (13) are respectively welded to the hot air branch pipe (5); the third sliding support (14) is in contact with the hot air branch pipe (5).

8. The kiln head boiler inlet temperature raising device according to claim 1, characterized in that: A dust collector housing (16) is also provided on the outside of the hot air branch pipe (5); the hot air branch pipe (5) is divided into a front section and a rear section at the position of the dust collector housing (16); the dust collector housing (16) is provided with connecting holes (16-1) respectively relative to the front section and the rear section; sealing rings (17) are provided on the outer periphery of the front section and the rear section of the branch pipe respectively; a top cover (18) is provided on the surface of the dust collector housing (16); an anode electrode (19) and a cathode electrode (20) are respectively provided on the two inner walls of the dust collector housing (16) other than the connecting holes.

9. The kiln head boiler inlet temperature raising device according to claim 8, characterized in that: The connecting hole (16-1) is provided with a raised edge (21) relative to the sealing ring (17); an inner edge (22) is provided inside the raised edge (21); a plurality of screws (22) are evenly surrounded on the raised edge (21); a wedge-shaped pressure block (23) is provided at the bottom of the screw (22); the wedge-shaped pressure block (23) abuts against the sealing ring (17) and makes close contact with the surface of the inner edge (22).

10. The kiln head boiler inlet temperature raising device according to claim 9, characterized in that: The dust removal box (16) is also equipped with an adsorption column (24); the top cover is provided with corresponding adsorption holes (25) relative to the adsorption column (24); the adsorption holes are provided with plugs; the adsorption holes are connected to the negative pressure dust suction pipe; and multiple elongated through holes are opened around the bottom of the adsorption column (24).

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