A system for utilizing waste heat from a calcining and cooling kiln

Abstract

The utility model discloses a kind of calcination cooling kiln waste heat utilization systems, belong to industrial waste heat recovery technical field. Including waste heat collection unit, heating unit, material drying unit and closed loop reflux pipeline, the waste heat collection unit inlet is communicated with calcination cooling kiln high-temperature water outlet, the waste heat collection unit outlet is communicated with the heating unit inlet by heating branch, the waste heat collection unit outlet is communicated with the material drying unit inlet by drying branch, the heating unit outlet and the material drying unit outlet are all communicated with the closed loop reflux pipeline inlet, the closed loop reflux pipeline outlet is communicated with the calcination cooling kiln cold water inlet. The utility model is by constructing closed loop heat cycle network, and waste heat is used for building heating and material drying, realizes the goal of more than 100,000 yuan of annual power saving.

Description

Technical Field

[0001] This utility model relates to the field of industrial waste heat recovery technology, specifically to a waste heat utilization system for a roasting and cooling kiln. Background Technology

[0002] A roasting and cooling kiln is an industrial equipment that integrates the functions of roasting and cooling materials. It is widely used in industries such as metallurgy, chemical industry, and building materials, and plays a key role, especially in processes that require rapid cooling after high-temperature treatment.

[0003] The cooling section of the roasting cooling kiln is located at the rear of the cylinder and uses air cooling, water cooling, or indirect cooling methods to rapidly cool the high-temperature materials after roasting, avoiding changes in material properties or overheating of the equipment due to slow cooling. The cooling water temperature in the cooling section can reach 70-80℃. This high-temperature water is usually recycled after being cooled by a cooling tower, resulting in direct waste of the 70-80℃ residual heat, which is not effectively utilized. Utility Model Content

[0004] This invention provides a waste heat utilization system for a roasting cooling kiln, which can solve the problems of waste heat waste and ineffective utilization in existing roasting cooling kilns.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A waste heat utilization system for a calcining cooling kiln includes a waste heat collection unit, a heating unit, a material drying unit, and a closed-loop reflux pipeline. The inlet of the waste heat collection unit is connected to the high-temperature water outlet of the calcining cooling kiln. The outlet of the waste heat collection unit is connected to the inlet of the heating unit via a heating branch. The outlet of the waste heat collection unit is connected to the inlet of the material drying unit via a drying branch. The outlets of the heating unit and the material drying unit are both connected to the inlet of the closed-loop reflux pipeline. The outlet of the closed-loop reflux pipeline is connected to the cold water inlet of the calcining cooling kiln.

[0007] As a further embodiment of this utility model: the waste heat collection unit includes a hot water pump and a three-way electric diverter valve. The inlet of the hot water pump is connected to the high-temperature outlet of the calcining cooling kiln, and the outlet of the hot water pump is connected to the inlet of the three-way electric diverter valve. The two outlets of the three-way electric diverter valve are respectively connected to the heating branch and the drying branch. The heating branch delivers hot water to the heating unit, and the drying branch delivers the remaining hot water to the material drying unit.

[0008] As a further embodiment of this utility model: the heating unit includes a heating inlet pipe, radiators and a heating outlet pipe, a number of the radiators are connected in parallel between the outlet of the heating inlet pipe and the inlet of the heating outlet pipe, the inlet of the heating inlet pipe is connected to the heating branch, and the outlet of the heating outlet pipe is connected to the inlet of the closed loop return pipe.

[0009] As a further embodiment of this utility model: an electric thermostatic valve is installed at the inlet of each group of radiators.

[0010] As a further embodiment of this utility model: the material drying unit includes a drying inlet pipe, a plate heat exchanger, and a drying outlet pipe. The drying inlet pipe is connected between the drying branch and the hot water inlet of the plate heat exchanger. The drying outlet pipe is connected between the condensate outlet of the plate heat exchanger and the inlet of the closed-loop return pipe. The plate heat exchanger is installed above the tailings conveyor belt.

[0011] As a further embodiment of this utility model: the material drying unit further includes a hot air conveying pipe, which is connected to the hot air outlet of the plate heat exchanger, and the hot air outlet of the hot air conveying pipe is directly opposite the tailings conveying belt.

[0012] As a further embodiment of this utility model: the closed-loop reflux pipeline includes a reflux inlet pipe, an expansion tank, and a reflux outlet pipe. The outlet of the heating unit and the outlet of the material drying unit are both connected to the inlet of the reflux inlet pipe. The outlet of the reflux inlet pipe is connected to the inlet of the expansion tank. The outlet of the expansion tank is connected to the inlet of the reflux outlet pipe. The outlet of the reflux outlet pipe is connected to the cold water inlet of the calcining cooling kiln.

[0013] As a further embodiment of this utility model: a Y-type filter is connected to the inlet of the return inlet pipe, and the outlet of the heating unit and the outlet of the material drying unit are respectively connected to the two inlets of the Y-type filter.

[0014] As a further embodiment of this utility model, it also includes an intelligent control unit, which includes a PLC controller that is communicatively connected to the waste heat collection unit, the heating unit, and the material drying unit.

[0015] As a further embodiment of this utility model, the intelligent control unit also includes a first temperature sensor installed at the high-temperature outlet of the calcining cooling kiln, a second temperature sensor installed at the outlet of the heating unit, and a third temperature sensor installed at the outlet of the material drying unit.

[0016] The beneficial effects of this utility model are:

[0017] This invention features a waste heat collection unit, a heating unit, a material drying unit, and a closed-loop return pipeline. The inlet of the waste heat collection unit is connected to the high-temperature outlet of the calcining cooling kiln, and the outlet of the waste heat collection unit is connected to the inlet of the heating unit via a heating branch. The outlet of the waste heat collection unit is connected to the inlet of the material drying unit via a drying branch. Both the outlets of the heating unit and the material drying unit are connected to the inlet of the closed-loop return pipeline, and the outlet of the closed-loop return pipeline is connected to the cold water inlet of the calcining cooling kiln. The waste heat collection unit extracts hot water at 70-80°C from the calcining cooling kiln and supplies it to the heating unit and the material drying unit. The heating unit absorbs the heat from the hot water to provide heating for indoor spaces such as office buildings and workshop duty rooms. The material drying unit absorbs the heat from the hot water and converts it into hot air to dry the material on the tailings conveyor belt. Finally, the closed-loop return pipeline recycles the mixed return water flowing from the heating unit and the material drying unit back into the calcining cooling kiln for reuse. This invention, by constructing a closed-loop heat circulation network, utilizes waste heat for building heating and material drying, achieving annual electricity savings of over 100,000 yuan. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings.

[0019] Figure 1 This is a structural block diagram of a waste heat utilization system for a roasting cooling kiln according to this utility model;

[0020] Figure 2 This is a schematic diagram of a waste heat utilization system for a roasting cooling kiln according to the present invention;

[0021] Figure 3 This is a schematic diagram of the heat circulation of a waste heat utilization system for a roasting and cooling kiln according to this utility model.

[0022] In the diagram: 1. Waste heat collection unit; 11. Hot water pump; 12. Three-way electric diverter valve; 2. Heating unit; 21. Heating inlet pipe; 22. Radiator; 23. Heating outlet pipe; 24. Electric thermostatic valve; 3. Material drying unit; 31. Drying inlet pipe; 32. Plate heat exchanger; 33. Drying outlet pipe; 34. Hot air delivery pipe; 4. Closed-loop return pipeline; 41. Return inlet pipe; 42. Expansion tank; 43. Return outlet pipe; 44. Y-type filter; 5. Heating branch; 6. Drying branch; 7. Intelligent control unit; 71. Temperature sensor No. 1; 72. Temperature sensor No. 2; 73. Temperature sensor No. 3. Detailed Implementation

[0023] The technical solutions in the embodiments of this utility model are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or a specific orientational structure and operation. Therefore, they should not be construed as limitations on this utility model.

[0025] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] Please see Figure 1 As shown, this utility model embodiment provides a waste heat utilization system for a roasting cooling kiln, including a waste heat collection unit 1, a heating unit 2, a material drying unit 3, a closed-loop return pipeline 4, and an intelligent control unit 7. The intelligent control unit 7 includes a PLC controller, and the waste heat collection unit 1, the heating unit 2, and the material drying unit 3 are all communicatively connected to the PLC controller.

[0027] Please see Figure 1 As shown, the inlet of the waste heat collection unit 1 is connected to the high-temperature outlet of the calcining cooling kiln, and the outlet of the waste heat collection unit 1 is connected to the inlet of the heating unit 2 through the heating branch 5. The heating unit 2 is used to provide heating to the office building and workshop duty room. The outlet of the waste heat collection unit 1 is connected to the inlet of the material drying unit 3 through the drying branch 6. The waste heat collection unit 1 is used to dry the tailings / materials. The outlets of the heating unit 2 and the material drying unit 3 are both connected to the inlet of the closed-loop return pipeline 4. The outlet of the closed-loop return pipeline 4 is connected to the cold water inlet of the calcining cooling kiln. The closed-loop return pipeline 4 realizes water circulation and saves water resources.

[0028] Please see Figure 2 As shown, in this embodiment, the waste heat collection unit 1 includes a hot water pump 11 and a three-way electric diverter valve 12. The hot water pump 11 has a flow rate of 50 m³ / h. 3The hot water pump 11 has its inlet connected to the high-temperature outlet of the calcining cooling kiln via a stainless steel pipe. The centerline of the hot water pump 11 is 0.5-1.0m lower than the centerline of the cooling kiln outlet to ensure gravity-flow injection. The outlet of the hot water pump 11 is connected to the inlet of a three-way electric diverter valve 12. The installation position of the three-way electric diverter valve 12 is ≤2m away from the outlet of the hot water pump 11 to reduce heat loss. The two outlets of the three-way electric diverter valve 12 are connected to the heating branch 5 and the drying branch 6, respectively. Both heating branch 5 and drying branch 6 use insulated pipes. The heating branch 5 delivers 60-75℃ hot water to the heating unit 2, and the drying branch 6 delivers the remaining hot water to the material drying unit 3. The three-way electric diverter valve 12 is electrically connected to a PLC controller, which can adjust the opening of the three-way electric diverter valve 12 to prioritize the heating needs in winter.

[0029] Please see Figure 2 As shown, in this embodiment, the heating unit 2 includes a heating inlet pipe 21, radiators 22, and a heating outlet pipe 23. Several sets of radiators 22 are connected in parallel between the outlet of the heating inlet pipe 21 and the inlet of the heating outlet pipe 23. These sets of radiators 22 are placed in areas requiring heating, such as office buildings and workshop duty rooms. The inlet of the heating inlet pipe 21 is connected to the heating branch line 5. Hot water flows through the radiators 22, and the radiators 22 absorb heat energy to raise their temperature for indoor heating. The outlet of the heating outlet pipe 23 is connected to the inlet of the closed-loop return pipe 4. An electric thermostatic valve 24 is installed at the inlet of each set of radiators 22, and the electric thermostatic valve 24 is communicatively connected to the PLC controller.

[0030] Please see Figure 2 As shown, in this embodiment, the material drying unit 3 includes a drying inlet pipe 31, a plate heat exchanger 32, a hot air conveying pipe 34, and a drying outlet pipe 33. The drying inlet pipe 31 is connected between the drying branch 6 and the hot water inlet of the plate heat exchanger 32. The drying outlet pipe 33 is connected between the condensate outlet of the plate heat exchanger 32 and the inlet of the closed-loop return pipe 4. The plate heat exchanger 32 is installed above the tailings conveyor belt. The hot air conveying pipe 34 is connected to the hot air outlet of the plate heat exchanger 32, and the hot air outlet of the hot air conveying pipe 34 faces the tailings conveyor belt. The plate heat exchanger 32 absorbs heat from the hot water and converts it into hot air to dry the material on the tailings conveyor belt.

[0031] Please see Figure 2As shown, in this embodiment, the closed-loop reflux pipeline 4 includes a reflux inlet pipe 41, an expansion tank 42, and a reflux outlet pipe 43. The outlets of the heating unit 2 and the material drying unit 3 are both connected to the inlet of the reflux inlet pipe 41. The outlet of the reflux inlet pipe 41 is connected to the inlet of the expansion tank 42. The highest water level of the expansion tank 42 is 2m higher than the highest point of the system, maintaining a static pressure of 0.4MPa. The outlet of the expansion tank 42 is connected to the inlet of the reflux outlet pipe 43, and the outlet of the reflux outlet pipe 43 is connected to the cold water inlet of the calcining cooling kiln. Furthermore, a Y-type filter 44 is connected to the inlet of the reflux inlet pipe 41, and the outlets of the heating unit 2 and the material drying unit 3 are respectively connected to the two inlets of the Y-type filter 44.

[0032] Please see Figure 2 As shown, in this embodiment, the intelligent control unit 7 further includes a first temperature sensor 71 located at the high-temperature outlet of the calcining cooling kiln, a second temperature sensor 72 located at the outlet of the heating unit 2, and a third temperature sensor 73 located at the outlet of the material drying unit 3. All three temperature sensors are communicatively connected to the PLC controller. If the temperature of the first temperature sensor 71 is lower than a preset value, the PLC controller shuts down the entire system. If the temperature of the second temperature sensor 72 is lower than the preset value, the PLC controller increases the flow rate of hot water entering the heating unit 2. If the temperature of the third temperature sensor 73 is higher than the preset value, the PLC controller decreases the flow rate of hot water entering the material drying unit 3.

[0033] The working principle of this utility model:

[0034] Please see Figure 3 As shown, when the PLC controller starts the system, the hot water pump 11 draws high-temperature hot water from the outlet of the calcining and cooling kiln. The hot water is then distributed to the heating branch 5 and the drying branch 6 via a three-way electric diversion valve 12 according to a preset ratio. The hot water in the heating branch 5 enters the heating unit 2, where the radiators 22 absorb the heat energy and raise the temperature for indoor heating. The hot water in the drying branch 6 enters the material drying unit 3, where the plate heat exchanger 32 absorbs the heat and converts it into hot air to dry the material on the tailings conveyor belt. Finally, the mixed return water flowing from the heating unit 2 and the material drying unit 3 is collected in the expansion tank 42. After pressure stabilization in the expansion tank 42, it re-enters the calcining and cooling kiln for reuse. In winter, the intelligent control unit 7 controls the hot water primarily for heating the heating unit 2; in summer, the intelligent control unit 7 controls the hot water primarily for drying the material in the material drying unit 3.

[0035] The preferred embodiments of this utility model have been described in detail above and should not be considered as limiting the scope of this utility model. All equivalent changes and improvements made within the scope of the claims of this utility model should still fall within the patent coverage of this utility model.

Claims

1. A waste heat utilization system for a roasting and cooling kiln, characterized in that: It includes a waste heat collection unit (1), a heating unit (2), a material drying unit (3), and a closed-loop return pipeline (4). The inlet of the waste heat collection unit (1) is connected to the high-temperature water outlet of the calcining cooling kiln. The outlet of the waste heat collection unit (1) is connected to the inlet of the heating unit (2) through the heating branch (5). The outlet of the waste heat collection unit (1) is connected to the inlet of the material drying unit (3) through the drying branch (6). The outlets of the heating unit (2) and the material drying unit (3) are both connected to the inlet of the closed-loop return pipeline (4). The outlet of the closed-loop return pipeline (4) is connected to the cold water inlet of the calcining cooling kiln.

2. The waste heat utilization system for a calcination cooling kiln according to claim 1, characterized in that: The waste heat collection unit (1) includes a hot water pump (11) and a three-way electric diverter valve (12). The inlet of the hot water pump (11) is connected to the high-temperature outlet of the calcination cooling kiln, and the outlet of the hot water pump (11) is connected to the inlet of the three-way electric diverter valve (12). The two outlets of the three-way electric diverter valve (12) are respectively connected to the heating branch (5) and the drying branch (6). The heating branch (5) delivers hot water to the heating unit (2), and the drying branch (6) delivers the remaining hot water to the material drying unit (3).

3. The waste heat utilization system for a calcination cooling kiln according to claim 1, characterized in that: The heating unit (2) includes a heating inlet pipe (21), radiators (22) and a heating outlet pipe (23). Several sets of radiators (22) are connected in parallel between the outlet of the heating inlet pipe (21) and the inlet of the heating outlet pipe (23). The inlet of the heating inlet pipe (21) is connected to the heating branch (5), and the outlet of the heating outlet pipe (23) is connected to the inlet of the closed-loop return pipe (4).

4. The waste heat utilization system for a calcination cooling kiln according to claim 3, characterized in that: An electric thermostatic valve (24) is installed at the inlet of each radiator (22).

5. The waste heat utilization system for a calcination cooling kiln according to claim 1, characterized in that: The material drying unit (3) includes a drying inlet pipe (31), a plate heat exchanger (32), and a drying outlet pipe (33). The drying inlet pipe (31) is connected between the drying branch (6) and the hot water inlet of the plate heat exchanger (32). The drying outlet pipe (33) is connected between the condensate outlet of the plate heat exchanger (32) and the inlet of the closed-loop return pipe (4). The plate heat exchanger (32) is installed above the tailings conveyor belt.

6. The waste heat utilization system for a calcination cooling kiln according to claim 5, characterized in that: The material drying unit (3) further includes a hot air conveying pipe (34), which is connected to the hot air outlet of the plate heat exchanger (32), and the hot air outlet of the hot air conveying pipe (34) is directly opposite the tailings conveying belt.

7. The waste heat utilization system for a calcination cooling kiln according to claim 1, characterized in that: The closed-loop return pipeline (4) includes a return inlet pipe (41), an expansion tank (42), and a return outlet pipe (43). The outlet of the heating unit (2) and the outlet of the material drying unit (3) are both connected to the inlet of the return inlet pipe (41). The outlet of the return inlet pipe (41) is connected to the inlet of the expansion tank (42). The outlet of the expansion tank (42) is connected to the inlet of the return outlet pipe (43). The outlet of the return outlet pipe (43) is connected to the cold water inlet of the calcining cooling kiln.

8. A waste heat utilization system for a calcination cooling kiln according to claim 7, characterized in that: A Y-type filter (44) is connected to the inlet of the return inlet pipe (41), and the outlet of the heating unit (2) and the outlet of the material drying unit (3) are respectively connected to the two inlets of the Y-type filter (44).

9. A waste heat utilization system for a calcination cooling kiln according to claim 1, characterized in that: It also includes an intelligent control unit (7), which includes a PLC controller that is communicatively connected to the waste heat collection unit (1), the heating unit (2), and the material drying unit (3).

10. A waste heat utilization system for a calcination cooling kiln according to claim 9, characterized in that: The intelligent control unit (7) also includes a first temperature sensor (71) installed at the high temperature outlet of the roasting cooling kiln, a second temperature sensor (72) installed at the outlet of the heating unit (2), and a third temperature sensor (73) installed at the outlet of the material drying unit (3).

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