Waste heat utilization device of hybrid drive type rotary kiln

Abstract

The invention discloses a waste heat utilization device of a hybrid drive type rotary kiln, and relates to the technical field of rotary kilns. The invention aims to solve the problems that the waste heat of the rotary kiln cannot be reasonably utilized and the cost of equipment is reduced and the efficiency is improved. After the waste heat is recycled, the medium contains higher internal energy, then the medium blows the steam turbine, and the steam turbine drives the hydraulic equipment connected in parallel to work, so that the inherent hydraulic equipment is replaced, the rotary kiln is driven to rotate by the energy of the waste heat, the energy-saving effect is achieved, and the waste heat can be recycled continuously.

Description

Technical Field

[0001] The present invention belongs to the technical field of rotary kilns, and particularly relates to a waste heat utilization device for a hybrid drive type rotary kiln. Background Art

[0002] In the current process of dezincing in a rotary kiln, the slag cooling method adopts the water quenching method. This cooling method cannot recover and utilize the large amount of heat existing in the slag, and a wet demisting system is required to purify the water vapor generated during the water quenching process. Therefore, such a process will waste a large amount of energy.

[0003] With the increasing support for the concept of energy conservation and environmental protection, how to recover and utilize the heat in the molten slag is the mainstream direction of future technological development. Most of the existing technologies deal with the waste heat of the molten slag by preparing steam, but the operating cost and economic efficiency of the rotary kiln equipment have not been reduced, and there are many heat sources in the metallurgical plant that can utilize and prepare steam. When there is an excess of steam, the heat in the molten slag will still be directly discarded, so continuous waste heat recovery cannot be achieved. To sum up, currently, it is necessary to solve the problem that the waste heat of the rotary kiln cannot be reasonably utilized and the equipment cost is reduced and efficiency is increased.

[0004] The information disclosed in this background art section is only intended to enhance the overall understanding of the present invention and should not be regarded as an admission or any form of suggestion that this information constitutes the prior art already known to those of ordinary skill in the art. Summary of the Invention

[0005] The purpose of the present invention is to solve the problem that the waste heat of the rotary kiln cannot be reasonably utilized and the equipment cost is reduced and efficiency is increased, and to provide a waste heat utilization device for a hybrid drive type rotary kiln.

[0006] The first aspect of the present invention provides a waste heat utilization device for a hybrid drive type rotary kiln, including a rotary kiln body, a speed reduction mechanism, a hydraulic motor, a hydraulic system, a driving device, and a waste heat recovery power system;

[0007] The hydraulic system includes a first hydraulic pump and a first valve connected by a pipeline, and a second hydraulic pump and a second valve connected by a pipeline. The first valve and the second valve are connected to the hydraulic motor through parallel pipelines;

[0008] The waste heat recovery power system includes a first high-pressure storage tank, a flow pump, a heat exchanger, a second high-pressure storage tank, a flow valve, and a steam turbine connected in sequence through pipelines;

[0009] The heat exchanger is used to recover the heat in the molten slag of the rotary furnace;

[0010] The driving device is used to drive the first hydraulic pump to work;

[0011] The steam turbine is used to drive the second hydraulic pump to work;

[0012] The hydraulic motor drives the rotary kiln body to rotate through the speed reduction mechanism.

[0013] In an embodiment of the present invention, the medium in the heat exchanger is carbon dioxide.

[0014] In an embodiment of the present invention, the carbon dioxide in the first high-pressure storage tank, the heat exchanger, and the second high-pressure storage tank is in a supercritical state.

[0015] In an embodiment of the present invention, the waste heat recovery power system includes a low-pressure storage tank and a high-pressure pump; the low-pressure storage tank is connected to the outlet of the steam turbine and the inlet of the high-pressure pump through a pipeline, and the outlet of the high-pressure pump is connected to the first high-pressure storage tank through a pipeline.

[0016] In an embodiment of the present invention, the heat exchanger includes a shell and heat exchange tubes. The top of the shell is provided with a feed inlet for pouring molten slag. The heat exchange tubes are located inside the shell and are connected to the first high-pressure storage tank and the second high-pressure storage tank.

[0017] In an embodiment of the present invention, the slag discharge port at the bottom of the rotary kiln body is vertically opposite to the feed inlet.

[0018] In an embodiment of the present invention, a hydraulic pressure regulating device is provided between the first hydraulic pump and the first valve.

[0019] In an embodiment of the present invention, a hydraulic pressure regulating device is provided between the second hydraulic pump and the second valve.

[0020] In an embodiment of the present invention, the driving device uses an electric motor, a fuel engine, or a hybrid engine.

[0021] In an embodiment of the present invention, the speed reduction mechanism includes a gear and a toothed ring that mesh with each other. The gear is fixedly connected to the output shaft of the hydraulic motor, and the toothed ring is coaxially sleeved on the rotary kiln body.

[0022] Compared with the prior art, the technical effects achieved by the present invention are as follows:

[0023] 1. When enough heat can be absorbed from the molten slag, there is no longer a need for the driving device to consume energy to work. Instead, the waste heat of the molten slag is used as energy, and the rotary kiln body is driven to rotate through the steam turbine, the second hydraulic pump, and the hydraulic motor. Therefore, the effects of energy saving and increased economic benefits are achieved.

[0024] 2. The produced molten slag can be used continuously to heat the medium, thereby continuously driving the rotation of the rotary kiln body, ensuring the utilization efficiency of the molten slag waste heat and enriching the utilization ways of the molten slag waste heat. Description of the Drawings

[0025] Figure 1 is of the waste heat utilization device of the hybrid drive type rotary kiln according to an embodiment of the present invention;

[0026] Figure 2 is a schematic structural diagram of the waste heat recovery system according to an embodiment of the present invention.

[0027] Main reference numeral description:

[0028] 1. Rotary kiln body; 2. Reduction mechanism; 21. Gear; 22. Tooth ring; 3. Hydraulic motor; 41. First valve; 42. Second valve; 5. Hydraulic pressure regulating device; 61. First hydraulic pump; 62. Second hydraulic pump; 7. Driving device; 8. Waste heat recovery power system; 81. First high-pressure storage tank; 82. Flow pump; 83. Heat exchanger; 831. Shell; 8311. Feed inlet; 832. Heat exchange tube; 84. Second high-pressure storage tank; 85. Flow valve; 86. Steam turbine; 87. Low-pressure storage tank; 88. High-pressure pump. Detailed Embodiment

[0029] Unless otherwise clearly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "having" etc. will be understood to include the stated elements or components, without excluding other elements or other components.

[0030] The technical solutions of the present invention are described below through specific embodiments. It should be understood that one or more steps mentioned in the present invention do not exclude the existence of other methods and steps before and after the combined steps, or other methods and steps can be inserted between these clearly mentioned steps. It should also be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. Unless otherwise specified, the numbers of each method step are only for the purpose of identifying each method step, rather than limiting the arrangement order of each method or limiting the implementation scope of the present invention. The change or adjustment of their relative relationship can also be regarded as the implementable scope of the present invention under the condition of no substantial change in technical content.

[0031] There is no specific limitation on the sources of the raw materials and instruments used in the embodiments, and they can be purchased in the market or prepared according to the conventional methods well-known to those skilled in the art.

[0032] Such as Figures 1 to 2As shown, the waste heat utilization device of the hybrid drive rotary kiln according to the preferred embodiment of the present invention includes a rotary kiln body 1, a speed reduction mechanism 2, a hydraulic system, a driving device 7, and a waste heat recovery power system 8.

[0033] The rotary kiln body 1 is a common prior art device in the metallurgical industry. During the rotation of its kiln barrel, heat is transferred to the material to achieve metallurgical processing.

[0034] The hydraulic system includes a first hydraulic pump 61, a hydraulic pressure regulating device 5, and a first valve 41 connected in sequence through pipes, and a second hydraulic pump 62, a hydraulic pressure regulating device 5, and a second valve 42 connected in sequence through pipes. The first valve 41 and the second valve 42 are connected to the hydraulic motor 3 through parallel pipes. Both the first hydraulic pump 61 and the second hydraulic pump 62 can drive the hydraulic motor 3 to operate. The hydraulic pressure regulating device 5 is used to regulate the output pressure of the hydraulic oil, thereby changing the working condition of the hydraulic motor 3. The opening and closing states of the first valve 41 and the second valve 42 determine which branch controls the operation of the hydraulic motor 3.

[0035] The speed reduction mechanism 2 includes a meshing gear 21 and a gear ring 22. The gear 21 is fixedly connected to the output shaft of the hydraulic motor 3, and the gear ring 22 is coaxially sleeved on the rotary kiln body 1. Therefore, the hydraulic motor 3 drives the rotary kiln body 1 to rotate through the speed reduction mechanism 2.

[0036] The driving device 7 uses an electric motor, a fuel engine, or a hybrid engine. Preferably, an electric motor is used. The output shaft of the driving device 7 is drivingly connected to the first hydraulic pump 61 to drive the first hydraulic pump 61 to work.

[0037] The waste heat recovery power system 8 includes a first high-pressure storage tank 81, a flow pump 82, a heat exchanger 83, a second high-pressure storage tank 84, a flow valve 85, and a steam turbine 86 connected in sequence.

[0038] The first high-pressure storage tank 81 is used to store the medium. The flow pump 82 is used to transport the medium in the first high-pressure storage tank 81 to the heat exchanger 83 and control the flow rate of the medium. The heat exchanger 83 is used to extract heat from the slag of the rotary furnace body. The heat exchanger 83 specifically includes a housing 831 and heat exchange tubes 832. The heat exchange tubes 832 are installed inside the housing 831. The heat exchange tubes 832 are connected to the first high-pressure storage tank 81 and the second high-pressure storage tank 84. A feed port 8311 for pouring slag is provided at the top of the housing 831, and the slag discharge port at the bottom of the rotary kiln body 1 is vertically opposite to the feed port 8311, so that the discharged slag can directly fall into the inside of the heat exchanger 83 and contact the heat exchange tubes 832, thereby completing the heat conduction with the medium inside the heat exchange tubes 832. The second high-pressure storage tank 84 is used to store the high-temperature medium from the heat exchanger 83. The flow valve 85 is used to release the medium in the second high-pressure storage tank 84 to the steam turbine 86.

[0039] The medium is preferably carbon dioxide, and the carbon dioxide in the first high-pressure storage tank 81, the heat exchanger 83, and the second high-pressure storage tank 84 is in a supercritical state. The supercritical state refers to carbon dioxide existing in a liquid form after exceeding specific temperature and pressure conditions. Supercritical carbon dioxide is a very dense fluid with liquid characteristics, such as high density, high heat transfer efficiency, and strong work capacity. It also has gas characteristics, such as low viscosity, strong fluidity, and small system circulation losses.

[0040] The medium that absorbs heat in the heat exchanger 83 will increase its internal energy and pressure potential energy. Subsequently, the carbon dioxide released to the steam turbine 86 through the flow valve 85 will leave the supercritical state, and the contained pressure potential energy will be released, thus violently impacting the impeller of the steam turbine 86 and causing the impeller to rotate. The output shaft of the steam turbine 86 can then do work. The output shaft of the steam turbine 86 is drivingly connected to the second hydraulic pump 62 to drive the second hydraulic pump 62 to operate.

[0041] The waste heat recovery power system 8 further includes a low-pressure storage tank 87 and a high-pressure pump 88. The low-pressure storage tank 87 is connected to the outlet of the steam turbine 86 and the inlet of the high-pressure pump 88 through pipelines. The inlet of the high-pressure pump 88 is connected to the first high-pressure storage tank 81 through a pipeline. Therefore, the pipeline of the waste heat recovery power system 8 forms a closed loop. The carbon dioxide discharged from the steam turbine 86 enters the low-pressure storage tank 87, and the carbon dioxide re-enters the first high-pressure storage tank 81 through the high-pressure pump 88. Thus, the carbon dioxide forms a cycle in the pipeline, and no carbon dioxide needs to be supplemented during the process, nor is there any loss of carbon dioxide.

[0042] The specific working process is as follows: First, the first valve 41 is opened and the second valve 42 is closed. The driving device 7 consumes energy to do work, drives the hydraulic motor 3 to operate through the first hydraulic pump 61, and finally drives the rotary kiln body 1 to rotate. After working for a period of time, when enough molten slag can be generated in the rotary kiln body 1, the first valve 41 is controlled to close and the second valve 42 is opened to discharge the molten slag and conduct heat exchange at the heat exchanger 83. The medium absorbs heat and releases energy to drive the steam turbine 86 to rotate. The steam turbine 86 drives the hydraulic motor 3 to operate through the second hydraulic pump 62, and finally drives the rotary kiln body 1 to rotate. Thus, it is no longer necessary for the driving device 7 to consume energy to work, but rather a working process is formed that uses the waste heat of the molten slag as the energy source to finally drive the rotary kiln body 1 to rotate.

[0043] The foregoing description of the specific exemplary embodiments of the present invention is for purposes of illustration and exemplification. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many modifications and variations are possible in light of the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical applications, so that those skilled in the art can implement and utilize the various different exemplary embodiments of the present invention, as well as various different selections and modifications. The scope of the present invention is intended to be defined by the claims and their equivalents.

Claims

1. A waste heat utilization device for a hybrid drive rotary kiln, characterized in that, It includes a rotary kiln body, a speed reduction mechanism, a hydraulic motor, a hydraulic system, a driving device and a waste heat recovery power system; The hydraulic system includes a first hydraulic pump and a first valve connected by a pipeline, and a second hydraulic pump and a second valve connected by a pipeline. The first valve and the second valve are connected to the hydraulic motor through parallel pipelines; The waste heat recovery power system includes a first high-pressure storage tank, a flow pump, a heat exchanger, a second high-pressure storage tank, a flow valve and a steam turbine connected in sequence through pipelines; The heat exchanger is used to recover the heat in the molten slag of the rotary furnace; The driving device is used to drive the first hydraulic pump to work; The steam turbine is used to drive the second hydraulic pump to work; The hydraulic motor drives the rotary kiln body to rotate through the speed reduction mechanism; 2. The waste heat utilization device of the hybrid drive rotary kiln according to claim 1, wherein, The medium in the heat exchanger is carbon dioxide; 3. The waste heat utilization device of the hybrid drive rotary kiln according to claim 2, characterized in that, The carbon dioxide in the first high-pressure storage tank, the heat exchanger and the second high-pressure storage tank is in a supercritical state; 4. The waste heat utilization device of the hybrid drive rotary kiln according to claim 1, characterized in that, The waste heat recovery power system includes a low-pressure storage tank and a high-pressure pump; the low-pressure storage tank is connected to the outlet of the steam turbine and the inlet of the high-pressure pump through a pipeline, and the outlet of the high-pressure pump is connected to the first high-pressure storage tank through a pipeline; 5. The waste heat utilization device of the hybrid drive rotary kiln according to claim 1, characterized in that, The heat exchanger includes a housing and heat exchange tubes. The top of the housing is provided with a feed inlet for pouring molten slag. The heat exchange tubes are located inside the housing and are connected to the first high-pressure storage tank and the second high-pressure storage tank; 6. The waste heat utilization device of the hybrid drive rotary kiln according to claim 5, characterized in that, The slag discharge port at the bottom of the rotary kiln body is vertically opposite to the feed inlet; 7. The waste heat utilization device of the hybrid drive rotary kiln according to claim 1, characterized in that, A hydraulic pressure regulating device is provided between the first hydraulic pump and the first valve; 8. The waste heat utilization device of the hybrid drive rotary kiln according to claim 1, characterized in that, A hydraulic pressure regulating device is provided between the second hydraulic pump and the second valve; 9. The waste heat utilization device of the hybrid drive rotary kiln according to claim 1, characterized in that, The driving device adopts an electric motor, a fuel engine or a hybrid engine; 10. The waste heat utilization device of the hybrid drive rotary kiln according to claim 1, wherein The speed reduction mechanism includes a gear and a gear ring that mesh with each other. The gear is fixedly connected to the output shaft of the hydraulic motor, and the gear ring is coaxially sleeved on the rotary kiln body.

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