Reaction device hydrothermal recovery system and metal oxide preparation system and method

Abstract

The invention discloses a reaction device water heat recovery system and a metal oxide preparation system and method, and relates to the technical field of metal oxide preparation waste heat recovery, the reaction device water heat recovery system comprises a first heat exchange device, and the first heat exchange device is provided with a first heat exchange channel and a second heat exchange channel; the first heat exchange channel can receive damp and hot tail gas, the second heat exchange channel is used for receiving a fluid medium, the damp and hot tail gas in the first heat exchange channel can transfer heat to the fluid medium in the second heat exchange channel to heat the fluid medium in the second heat exchange channel, the fluid medium is introduced into the reaction device, and therefore waste heat in the damp and hot tail gas is recycled. Energy saving of the system is achieved, water vapor in damp and hot tail gas in the first heat exchange channel is condensed to form condensate water, the condensate water enters the reaction device, water resources in the damp and hot tail gas are recycled, and water saving of the system is achieved; the metal oxide preparation system comprises a reaction device and a reaction device hydrothermal recovery system.

Description

Technical Field

[0001] The present invention relates to the technical field of waste heat recovery in the preparation of metal oxides, and particularly to a gas heat exchange device, a waste heat recovery system, a metal oxide preparation system and a method. Background Art

[0002] Metal oxide materials (such as zinc oxide, titanium dioxide, iron oxide, etc.) play an important role in fields such as coating pigments, environmental catalysis, and magnetic materials due to their excellent electrochemical activity, catalytic performance, and stability. Their properties are closely related to the microscopic morphology, grain size, and purity, and the above characteristics are directly affected by the preparation process. Among many synthesis methods, the oxidation precipitation method has attracted much attention due to its advantages such as simple process, low cost, and easy large-scale production. In this method, water, metal, and seeds are placed in an oxidation reactor to first carry out a precipitation reaction, and then an oxidation reaction. Air and high-temperature water vapor generated by a boiler are respectively introduced into the oxidation reaction device to increase the temperature of the reaction system and catalyze the reaction. However, the tail gas after the reaction contains high-temperature water vapor and air. Usually, factories will directly discharge these hot and humid tail gases into the atmosphere, wasting a large amount of heat and resulting in high energy consumption of the oxidation reaction system. Summary of the Invention

[0003] The purpose of the present invention is to provide a gas heat exchange device, a waste heat recovery system, a metal oxide preparation system and a method to solve the problems existing in the above-mentioned prior art, and to be able to recover and utilize the waste heat in the hot and humid tail gas to achieve system energy conservation.

[0004] To achieve the above purpose, the present invention provides the following solutions:

[0005] The present invention provides a hydrothermal recovery system for a reaction device, including a first heat exchange device. The first heat exchange device has a first heat exchange channel and a second heat exchange channel. The first inlet of the first heat exchange channel is used to communicate with the first outlet of the reaction device and can receive hot and humid tail gas. The first outlet of the first heat exchange channel is communicated with the first inlet of the reaction device. The second heat exchange channel is used to receive a fluid medium. The first outlet of the second heat exchange channel is used to communicate with the second inlet of the reaction device to introduce the fluid medium into the reaction device. The hot and humid tail gas in the first heat exchange channel can transfer heat to the fluid medium in the second heat exchange channel to heat the fluid medium in the second heat exchange channel, and the water vapor in the hot and humid tail gas in the first heat exchange channel condenses to form condensed water after heat exchange. The condensed water can enter the reaction device through the first heat exchange channel.

[0006] In some embodiments, a second heat exchange device is further included. The second heat exchange device has a third heat exchange channel and a fourth heat exchange channel. The third inlet and the third outlet of the third heat exchange channel are used for communicating with a pulp storage device. The fourth inlet of the fourth heat exchange channel is used for introducing a fluid medium, and the fourth outlet of the fourth heat exchange channel is used for outputting the fluid medium. The slurry in the third heat exchange channel can transfer heat to the fluid medium in the fourth heat exchange channel.

[0007] In some embodiments, a fluid medium storage device is further included for storing the heated fluid medium. The fluid medium storage device can communicate with the first inlet of the second heat exchange channel to introduce the heated fluid medium into the second heat exchange channel; the fluid medium storage device can communicate with the third inlet of the reaction device to introduce the heated fluid medium into the reaction device.

[0008] In some embodiments, the first heat exchange channel has a first high-temperature section and a first low-temperature section arranged in sequence from the first inlet to the first outlet. The second heat exchange channel has a second high-temperature section and a second low-temperature section. The second high-temperature section is used for connecting with the fluid medium storage device to receive the heated fluid medium, and the second low-temperature section is used for receiving the unheated fluid medium. The high-temperature and humid tail gas in the first high-temperature section is used for secondary heating of the heated fluid medium in the second high-temperature section, and the low-temperature and humid tail gas in the first low-temperature section is used for heating the unheated fluid medium in the second low-temperature section.

[0009] In some embodiments, an unheated fluid medium storage device is further included. The unheated fluid medium storage device communicates with the second low-temperature section to introduce the unheated fluid medium, and the unheated fluid medium storage device communicates with the fluid medium storage device to introduce the unheated fluid medium into the fluid medium storage device.

[0010] In some embodiments, the second heat exchange channel is arranged inside the first heat exchange channel. A first atomizer is arranged in the second high-temperature section. The fluid medium storage device communicates with the first atomizer, and the first atomizer is used for atomizing the heated fluid medium and introducing it into the second high-temperature section; a second atomizer is arranged in the second low-temperature section. The unheated fluid medium storage device communicates with the second atomizer, and the second atomizer is used for atomizing the second fluid medium and introducing it into the second low-temperature section.

[0011] In some embodiments, the fluid medium includes water and / or air.

[0012] The present invention also provides a metal oxide preparation system, which includes a reaction device and the hydrothermal recovery system of the reaction device described in any one of the above. The first outlet of the reaction device is used to communicate with the first inlet of the first heat exchange channel and can introduce the humid and hot tail gas into the first heat exchange channel. The second inlet of the second heat exchange channel is used to introduce a fluid medium. The second outlet of the second heat exchange channel is communicated with the first inlet of the reaction device to provide the heated fluid medium to the reaction device. The first outlet of the first heat exchange channel is communicated with the second inlet of the reaction device to introduce the condensed water into the reaction device.

[0013] In some embodiments, a gas distributor is provided at the second inlet of the reaction device. The second outlet of the second heat exchange channel is communicated with the gas distributor, and the gas distributor can disperse the heated fluid medium into the reaction device.

[0014] The present invention also provides a metal oxide preparation method based on the metal oxide preparation system, including the following steps:

[0015] Add a solid medium and a fluid medium into the reaction device and start the oxidation reaction;

[0016] Introduce the humid and hot tail gas generated during the reaction into the first heat exchange channel. The humid and hot tail gas in the first heat exchange channel transfers heat to the fluid medium in the second heat exchange channel. The water vapor in the humid and hot tail gas in the first heat exchange channel condenses to form condensed water, and the condensed water is introduced into the reaction device.

[0017] The present invention has achieved the following technical effects compared with the prior art:

[0018] The hydrothermal recovery system, metal oxide preparation system and method provided by the present invention connect the first outlet of the reaction device with the first heat exchange channel, introduce the humid and hot tail gas generated by the reaction device into the first heat exchange channel of the first heat exchange device, introduce the fluid medium into the second heat exchange channel. In the first heat exchange device, the heat of the humid and hot tail gas in the first heat exchange channel can be transferred to the fluid medium in the second heat exchange channel, and by connecting the second heat exchange channel with the first inlet of the reaction device, the heated fluid medium is introduced into the reaction device, thereby recovering and utilizing the heat in the humid and hot tail gas to heat the fluid medium, introducing the heated fluid medium into the reaction device, recovering the waste heat in the humid and hot tail gas, realizing the energy saving of the system, and introducing the condensed water formed by condensing the water vapor in the humid and hot tail gas into the reaction device, recovering and utilizing the water resources in the humid and hot tail gas, realizing the water saving of the system.

[0019] Further, by using the third inlet and the third outlet of the third heat exchange channel of the second heat exchange device to communicate with the slurry storage device, the fourth inlet of the fourth heat exchange channel is used to introduce a fluid medium, and the fourth outlet of the fourth heat exchange channel is used to output the fluid medium. The slurry in the third heat exchange channel can transfer heat to the fluid medium in the fourth heat exchange channel to heat the fluid medium in the fourth heat exchange channel, thereby recycling the heat generated by the high-temperature slurry in the slurry storage device and further realizing system energy conservation.

[0020] Furthermore, by using the second high-temperature section of the second heat exchange channel to receive the heated fluid medium and the second low-temperature section to receive the unheated fluid medium, the high-temperature and humid exhaust gas in the first high-temperature section of the first heat exchange channel is used to secondary heat the heated fluid medium in the second high-temperature section, and the low-temperature and humid exhaust gas in the first low-temperature section is used to heat the unheated fluid medium in the second low-temperature section. By corresponding the temperature of the fluid medium with the temperature of the humid exhaust gas, the heat in the humid exhaust gas can be utilized at multiple levels, making full use of the heat in the humid exhaust gas and further realizing system energy conservation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 Schematic diagram of a metal oxide preparation system in an embodiment of the present invention;

[0023] Figure 2 Schematic diagram of a metal oxide preparation system in another embodiment of the present invention;

[0024] Figure 3 Comparison chart of steam consumption per ton of product corresponding to three implementation schemes in the third embodiment of the present invention;

[0025] In the figure: 1: reaction device; 2: pipeline connecting the fluid medium storage device and the first heat exchange device; 3: pipeline connecting the second heat exchange channel and the reaction device; 4: pipeline connecting the heat supplement device and the reaction device; 5: slurry storage device; 6: fluid medium storage device; 7: first heat exchange device; 2-1: third valve; 2-2: third flowmeter; 2-3: fourth pressure conveying equipment; 3-1: first valve; 3-2: first flow connection; 3-3: first pressure conveying equipment; 3-4: air distributor; 4-1: fifth valve; 4-2: fifth flowmeter; 5-1: slurry discharge valve; 5-2: slurry storage device; 6-2: second heat exchange device; 6-3: second pressure conveying equipment; 6-4: fluid medium measuring device; 6-5: third pressure conveying equipment; 6-6: unheated fluid medium storage device; 6-7: fifth pressure conveying equipment; 6-8: fifth pressure conveying equipment; 7-2: first atomizer; 7-3: induced draft fan; 7-4: condensate storage device; 7-5: condensate pump; 7-6: fourth valve; 7-7: fourth flowmeter; 7-8 second valve; 7-9: second flowmeter;

[0026] In the figure: The first heat exchange device has a first inlet: 71; a first outlet: 72; a second inlet: 73; a second outlet: 74;

[0027] The reaction device has a first inlet: 11; a first outlet: 12; a second inlet: 13; a second outlet: 14; a third inlet: 15; a fourth inlet: 16. Specific embodiments

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] The object of the present invention is to provide a gas heat exchange device, a waste heat recovery system, a metal oxide preparation system and a method to solve the problems existing in the above-mentioned prior art, be able to recover and utilize the waste heat in the humid and hot tail gas, and achieve system energy conservation.

[0030] To make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0031] Embodiment 1

[0032] This embodiment provides a hydrothermal recovery system for a reaction device 1, as Figures 1 - 2As shown in the figure, it includes a first heat exchange device 7. The first heat exchange device 7 has a first heat exchange channel and a second heat exchange channel. The first inlet 71 of the first heat exchange channel is used to communicate with the first outlet 12 of the reaction device 1 and can receive the humid and hot tail gas. The first outlet 72 of the first heat exchange channel communicates with the first inlet 11 of the reaction device 1. The second heat exchange channel is used to receive the fluid medium. The first outlet 1 of the second heat exchange channel communicates with the second inlet 13 of the reaction device 1 to introduce the fluid medium into the reaction device 1. The humid and hot tail gas in the first heat exchange channel can transfer heat to the fluid medium in the second heat exchange channel to heat the fluid medium in the second heat exchange channel. Moreover, the water vapor in the humid and hot tail gas in the first heat exchange channel condenses after heat exchange to form condensed water, and the condensed water can enter the reaction device 1 through the first heat exchange channel. Thus, the heat in the humid and hot tail gas is recycled to heat the fluid medium, and the heated fluid medium is introduced into the reaction device 1 to recover the waste heat in the humid and hot tail gas, achieving the energy conservation of the system. And the condensed water formed by condensing the water vapor in the humid and hot tail gas is introduced into the reaction device 1 to recycle the water resources in the humid and hot tail gas, achieving the water conservation of the system.

[0033] In another embodiment of this embodiment, as Figure 2 shown, the second outlet 74 of the first heat exchange channel is connected to the atmosphere, and the low-temperature non-condensable humid and hot tail gas after heat exchange is discharged through the second outlet 74.

[0034] In another embodiment of this embodiment, as Figure 2 shown, an induced draft fan 7-3 is provided at the second outlet 72 of the first heat exchange channel, and a speed regulating device is also provided on the induced draft fan 7-3. Starting the induced draft fan 7-3 can keep the first heat exchange channel in a slightly negative pressure state, so that the humid and hot tail gas generated in the reaction device 1 can enter the first heat exchange channel as soon as possible. When the reaction device 1 is in a slightly positive pressure state, the speed of the induced draft fan 7-3 is increased through the speed regulating device to further accelerate the speed of the humid and hot tail gas entering the first heat exchange channel.

[0035] In another embodiment of this embodiment, as Figure 2 shown, a condensed water storage device 7-4 and a condensate pump 7-5 are provided on the pipeline connecting the first outlet 72 of the first heat exchange channel and the first inlet 11 of the reaction device 1. The condensed water flowing out from the first outlet 72 of the first heat exchange channel is first stored in the condensed water storage device 74, and when it is necessary to introduce the condensed water into the reaction device 1, the condensate pump 7-5 is started to introduce the condensed water into the reaction device 1 through the first inlet 11 of the reaction device 1.

[0036] In another embodiment of this embodiment, as Figure 2As shown in the figure, a first valve 3-1, a first flowmeter 3-2 and a first pressurized conveying device 3-3 are provided on the pipeline connecting the second outlet 74 of the second heat exchange channel and the second inlet 13 of the reaction device 1. The first pressurized conveying device 3-3 is turned on and the first valve 3-1 is opened to allow the fluid medium to flow into the reaction device 1. The first flowmeter 3-2 is used to calculate the flow rate of the fluid medium flowing into the reaction device 1. The opening and closing of the first pressurized conveying device 3-3 and the first valve 3-1 are controlled by the first flowmeter 3-2 in a linked manner to meet the different flow rate requirements of the fluid medium in different reaction stages.

[0037] In another embodiment of this example, as Figure 2 shown, the hydrothermal recovery system of the reaction device 1 further includes a second heat exchange device 6-2. The second heat exchange device 6-2 has a third heat exchange channel and a fourth heat exchange channel. The third inlet and the third outlet of the third heat exchange channel are used to communicate with the slurry storage device 5. The fourth inlet of the fourth heat exchange channel is used to introduce the fluid medium, and the fourth outlet of the fourth heat exchange channel is used to output the fluid medium. The slurry in the third heat exchange channel can transfer heat to the fluid medium in the fourth heat exchange channel to heat the fluid medium in the fourth heat exchange channel, thereby recovering and utilizing the heat generated by the high-temperature slurry in the slurry storage device 5, and further realizing system energy conservation.

[0038] In another embodiment of this example, as Figure 2 shown, the hydrothermal recovery system of the reaction device 1 further includes a fluid medium storage device 6 for storing the heated fluid medium. The fluid medium storage device can communicate with the second inlet 73 of the second heat exchange channel to introduce the heated fluid medium into the second heat exchange channel. The fluid medium storage device 6 can communicate with the third inlet 15 of the reaction device 1 to introduce the heated fluid medium into the reaction device 1. By utilizing the heat generated by the high-temperature slurry in the slurry storage device 5, the fluid medium is heated, and the heated fluid medium is introduced into the first heat exchange channel, and the heat of the humid and hot tail gas is used to secondary heat the heated fluid medium. The heated fluid medium can also be introduced into the reaction device 1 to provide the heated fluid medium for the reaction in the reaction device 1.

[0039] In another embodiment of this example, as Figure 2 shown, the fourth inlet and the fourth outlet of the fourth heat exchange channel are used to communicate with the fluid medium storage device 6. The fourth heat exchange channel can transport the heated fluid medium to the fluid medium storage device 6. A second pressurized conveying device 6-3 is provided on the pipeline connecting the fluid medium storage device 6 and the fourth inlet of the fourth heat exchange channel to transport the fluid medium in the fluid medium storage device 6 into the fourth heat exchange channel and transport the heated fluid medium in the fourth heat exchange channel to the fluid medium storage device 6.

[0040] In another implementation of this embodiment, Figure 2 As shown, a second valve 7-8, a second flow meter 7-9 and a third pressurized delivery device 2-3 are provided on the pipeline connecting the fluid medium storage device 6 and the first inlet 71 of the second heat exchange channel. The third pressurized delivery device 2-3 and the second valve 7-8 are opened to allow the fluid medium to flow into the second heat exchange channel, and the second flow meter is used to calculate the flow rate of the fluid medium entering the second heat exchange channel. The opening and closing of the third pressurized delivery device 2-3 and the second valve 7-8 are controlled by the second flow meter 7-9 in linkage to meet the different flow requirements of the fluid medium in different reaction stages.

[0041] In another implementation of this embodiment, Figure 2 As shown, a third valve 2-1, a third flow meter 2-2 and a fourth pressurized delivery device 6-5 are provided on the pipeline connecting the fluid medium storage device 6 and the third inlet 15 of the reaction device 1. The fourth pressurized delivery device 6-5 is opened and the second valve is opened to allow the fluid medium to pass into the reaction device 1, and the third flow meter 2-2 is used to calculate the flow rate of the fluid medium passing into the second heat exchange channel. The opening and closing of the fourth pressurized delivery device 6-5 and the third valve 2-1 are controlled by the third flow meter 2-2 to meet the different flow requirements of the fluid medium in different reaction stages.

[0042] In another embodiment of the present embodiment, the first heat exchange channel has a first high temperature section and a first low temperature section arranged in sequence from the first inlet 71 to the first outlet 72, and the second heat exchange channel has a second high temperature section and a second low temperature section. The second high temperature section is used to connect to the fluid medium storage device to receive the heated fluid medium, and the second low temperature section is used to receive the unheated fluid medium. The high temperature and humid hot exhaust gas in the first high temperature section is used to secondary heat the heated fluid medium in the second high temperature section, and the low temperature and humid hot exhaust gas in the first low temperature section is used to heat the unheated fluid medium in the second low temperature section. By making the temperature of the fluid medium correspond to the temperature of the humid hot exhaust gas, the heat in the humid hot exhaust gas can be utilized at multiple stages, and the heat in the humid hot exhaust gas can be fully utilized to further achieve energy saving of the system.

[0043] In another implementation of this embodiment, Figure 2 As shown, the hydrothermal recovery system of the reaction device 1 also includes an unheated fluid medium storage device 6-6, which is connected to the second low-temperature section to allow the introduction of unheated fluid medium to adjust the temperature of the fluid medium introduced into the second heat exchange channel at different reaction stages. The unheated fluid medium storage device 6-6 is connected to the fluid medium storage device 6 to allow the introduction of unheated fluid medium into the fluid medium storage device 6 to ensure that there is sufficient fluid medium in the fluid medium storage device 6.

[0044] In another implementation of this embodiment, Figure 2 As shown, a fourth valve 7-6, a fourth flow meter 7-7 and a fifth pressurizing and conveying device 6-7 are arranged on the channel connecting the unheated fluid medium storage device 6-6 and the second low-temperature section. The fifth pressurizing and conveying device 6-7 is opened and the fourth valve 7-6 is opened to allow the unheated fluid medium to pass into the second heat exchange channel. The fourth flow meter 7-7 is used to calculate the flow rate of the unheated fluid medium passing into the second heat exchange channel. The opening and closing of the fifth pressurizing and conveying device 6-7 and the fourth valve 7-6 are controlled by the fourth flow meter 7-7 in linkage to meet the different flow requirements of the fluid medium in different reaction stages.

[0045] In another implementation of this embodiment, Figure 2 As shown, a fluid medium measuring device 6-4 is arranged in the fluid medium storage device 6, and a sixth pressurizing conveying device 6-8 is arranged on the pipeline connecting the unheated fluid medium storage device 6-6 and the fluid medium storage device 6 to pass unheated fluid medium into the fluid medium storage device 6, and the fluid medium measuring device 6-4 is linked with the fifth pressurizing conveying device 6-7 to control the flow rate of the unheated fluid medium passed into the fluid medium storage device 6 according to the amount of the heated fluid medium.

[0046] In another implementation of this embodiment, Figure 2 As shown, the second heat exchange channel is arranged in the first heat exchange channel, the first atomizer 7-2 is arranged in the second high temperature section, the fluid medium storage device 6 is connected with the first atomizer 7-2, the first atomizer 7-2 is used to atomize the heated fluid medium and pass it into the second high temperature section; the second atomizer 7-7 is arranged in the second low temperature section, the unheated fluid medium storage device 6-6 is connected with the second atomizer 7-7, the second atomizer 7-7 is used to atomize the second fluid medium and pass it into the second low temperature section, by atomizing the heated fluid medium and the unheated fluid medium, the fluid medium can flow along the second heat exchange channel and enter the reaction device.

[0047] In another implementation of this embodiment, the fluid medium includes water and / or air.

[0048] In another implementation of this embodiment, Figure 2 As shown, the second inlet 73 of the second heat exchange channel is also connected to the atmosphere to allow air to flow into the second heat exchange channel.

[0049] In another implementation of this embodiment, Figure 2 As shown, the second outlet 74 of the second heat exchange channel is also connected to the fluid medium storage device 6 so that the fluid medium that has not entered the reaction device 1 can return to the fluid medium storage device 6 .

[0050] In another embodiment of this example, the first heat exchange device 7 is a plate heat exchanger. The humid and hot tail gas in the first heat exchange channel heats the mixture of atomized water and air in the second heat exchange channel, and the heated mixture of atomized water and air is introduced into the reaction device 1 to participate in the reaction.

[0051] In another embodiment of this example, a mixture of atomized hot water and air is introduced into the second high-temperature section of the second heat exchange channel. The mixture of atomized hot water and air exchanges heat with the humid and hot tail gas in the first high-temperature section of the first heat exchange channel. A mixture of atomized cold water and air is introduced into the second low-temperature section. The mixture of atomized cold water and air exchanges heat with the humid and hot tail gas in the first low-temperature section of the first heat exchange channel, thereby achieving a hierarchical utilization of the heat energy in the humid and hot tail gas.

[0052] In another embodiment of this example, the second heat exchange device 6-2 is a shell-and-tube heat exchanger. The slurry flows through the shell side, and water flows through the tube side. The heat of the slurry in the shell side is transferred to the water in the tube side, thereby heating the water and realizing the utilization of the heat energy in the slurry.

[0053] In another embodiment of this example, the temperature of the humid and hot tail gas in the first high-temperature section is 70-87 °C, the temperature of the hot water in the second high-temperature section is 65-85 °C, the temperature of the humid and hot tail gas in the first low-temperature section is less than 70 °C, the temperature of the cold water in the second low-temperature section is 15-25 °C, and the temperature of the heat-exchanged low-temperature non-condensable humid and hot tail gas discharged through the first heat exchange channel is less than 45 °C.

[0054] Example Two

[0055] This example provides a metal oxide preparation system, as Figure 2 shown, which includes a reaction device 1 and a hydrothermal recovery system for the reaction device 1. The first outlet 12 of the reaction device 1 is used to communicate with the first inlet 71 of the first heat exchange channel and can introduce the humid and hot tail gas into the first heat exchange channel. The second inlet 73 of the second heat exchange channel is used to introduce a fluid medium. The second outlet 3 of the second heat exchange channel is communicated with the first inlet 11 of the reaction device 1 to provide the heated fluid medium to the reaction device 1. The first outlet 72 of the first heat exchange channel is communicated with the second inlet 13 of the reaction device 1 to introduce the condensed water into the reaction device 1.

[0056] In another embodiment of this example, as Figure 2 shown, a gas distributor 3-4 is provided at the second inlet 13 of the reaction device 1. The second outlet 3 of the second heat exchange channel is communicated with the gas distributor 3-4, and the gas distributor 3-4 can uniformly disperse the heated fluid medium into the reaction device 1.

[0057] In another embodiment of this example, as Figure 2As shown, the atomized water and air mixture heated in the second inlet 73 of the second heat exchange channel is introduced into the slurry in the reaction device 1 through the air distributor 3-4, so that the high-temperature and high-humidity atomized water and air mixture are evenly dispersed into the slurry, supplement heat and oxygen, and maintain conditions such as the pH value required for the reaction. The unreacted atomized water and air mixture escapes from the slurry and becomes the humid and hot tail gas.

[0058] In another embodiment of this embodiment, as Figure 2 shown, the metal oxide preparation system further includes a slurry storage device 5. The second outlet 14 of the reaction device 1 is communicated with the slurry storage device 5, and a slurry discharge valve 5-1 is provided on the communication pipeline. After the reaction is completed, the slurry discharge valve 5-1 is opened to discharge the high-temperature slurry in the reaction device 1 into the slurry storage device 5, and the fluid medium is heated by the second heat exchange device 6-2.

[0059] In another embodiment of this embodiment, as Figure 2 shown, it further includes a heat supplement device 4. The heat supplement device 4 is communicated with the fourth inlet 16 of the reaction device 1. A fifth valve 4-1 and a fifth flowmeter 4-2 are provided on the pipeline connecting the heat supplement device 4 and the fourth inlet 16 of the reaction device 1. When the temperature in the reaction device 1 does not meet the process requirements, the fifth valve 4-1 is opened to allow the water vapor in the heat supplement device 4 to be introduced into the reaction device 1 to supplement heat to the reaction device 1 to increase the temperature in the reaction device 1.

[0060] Embodiment Three

[0061] This embodiment provides a method for preparing metal oxide based on a metal oxide preparation system, including the following steps:

[0062] Open the fourth pressure conveying device 6-5 and the second valve to allow the hot water in the fluid medium storage device 6 to be introduced into the reaction device 1. Close the third valve 2-1 and the fourth pressure conveying device 6-5 when the flow rate displayed by the third flowmeter 2-2 reaches the process requirements.

[0063] Add an excessive amount of metal into the reaction device 1. The excessive metal can increase the reaction rate, improve the purity of the metal oxide slurry, and add other reaction substances into the reaction device 1.

[0064] In another embodiment of this embodiment, the metal oxide is iron oxide. Add an excessive amount of iron sheet into the reaction device 1, and add iron yellow seeds with a solid content of 1.2%, and control the initial pH of the reaction solution to be 4.0.

[0065] Turn on the induced draft fan 7-3 at the second outlet 73 of the first heat exchange channel of the first heat exchange device 7 to keep the first heat exchange channel in a slightly negative pressure state, so that the hot and humid exhaust gas generated in the reaction device 1 enters the first heat exchange channel, and the atomized water and air mixture is introduced into the second heat exchange channel. The hot and humid exhaust gas in the first heat exchange channel transfers heat to the atomized water and air mixture in the second heat exchange channel to achieve heat recovery and utilization of the hot and humid exhaust gas. The water vapor in the hot and humid exhaust gas condenses to form condensed water, which is stored in the condensed water storage device 7-4, so that it can be introduced into the reaction device 1 when water is added to the reaction device 1 next time, thereby achieving water resource recovery and utilization in the hot and humid exhaust gas.

[0066] The first pressurized conveying device 3-3 is turned on and the first valve 3-1 is opened to allow the heated atomized water and air mixture to be introduced into the reaction device 1. The flow rate of the atomized water and air mixture introduced into the reaction device 1 is calculated using the first flow meter 3-2. The opening and closing of the first pressurized conveying device 3-3 and the first valve 3-1 are controlled by the first flow meter 3-2 to meet the different flow requirements of the fluid medium in different reaction stages.

[0067] When the temperature in the reaction device 1 is insufficient, the fifth valve 4 - 1 is opened to allow the water vapor in the heat supplement device 4 to flow into the reaction device 1 , thereby supplementing heat into the reaction device 1 to increase the temperature in the reaction device 1 .

[0068] In another embodiment of the present embodiment, the slurry temperature change process setting system in the reaction device 1 is as follows: 0-8 hours, the temperature rises to 70°C; 8-12 hours, the temperature rises to 70°C; 12-30 hours, the temperature rises to 80-82°C; after 30 hours, the temperature rises to 85-88°C. According to the process setting temperature, the third pressurizing and conveying equipment 2-3 is opened in time and the second valve is opened to allow the hot water to be atomized and then passed into the second high temperature section of the second heat exchange channel, or the fifth pressurizing and conveying equipment 6-7 is opened and the fourth valve 7-6 is opened to allow the cold water to be atomized and then passed into the second low temperature section of the second heat exchange channel.

[0069] In another implementation of this embodiment, the flow rate regulation system of the first flow meter 3-2 is as follows: 0-8 hours, flow rate 300Nm 3 / h (standard cubic meter per hour, standard state refers to temperature 0℃, one standard atmospheric pressure); 8-12 hours, flow rate 600Nm 3 / h; 12-30 hours, flow rate 600Nm 3 / h; after 30 hours, flow rate 750-800Nm 3 / h.

[0070] After the reaction is completed, open the slurry discharge valve 5-1 to discharge the high-temperature slurry in the reaction device 1 into the slurry storage device 5, and heat the water in the fluid medium storage device 6 through the second heat exchange device 6-2 to realize the recovery and utilization of the heat energy of the high-temperature slurry. The hot water in the fluid medium storage device 6 is used to add hot water into the reaction device 1 before the next reaction starts.

[0071] Examine the implementation schemes under 3 different conditions respectively, record the temperature of the slurry in the reaction device, the flow rate of the steam input by the heat supplement device, and the flow rate of the atomized water and air mixture introduced into the reaction device. After the reaction is completed, test the solid content of the slurry in the slurry storage device, and calculate the product yield and the steam consumption per ton of product.

[0072] Scheme (1): The traditional production process scheme corresponding to when the second heat exchange device 6-2 and the first heat exchange device are not turned on, neither recovering and utilizing the heat and water resources in the wet and hot tail gas nor the heat in the high-temperature slurry;

[0073] Scheme (2): The production process scheme corresponding to when the second heat exchange device 6-2 is not turned on and only the first heat exchange device 7 is turned on, only recovering and utilizing the heat and water resources in the wet and hot tail gas and not recovering and utilizing the heat in the high-temperature slurry;

[0074] Scheme (3): The production process scheme corresponding to when both the second heat exchange device 6-2 and the first heat exchange device 7 are turned on, recovering and utilizing the heat and water resources in the wet and hot tail gas, as well as the heat in the high-temperature slurry.

[0075] The data obtained from different implementation schemes are shown in Table 1.

[0076] Table 1 Index parameters corresponding to different implementation schemes

[0077] Index parameters Scheme (1) Scheme (2) Scheme (3) Steam consumption of the reaction device 12 hours ago (tons) 8.4 8.3 4.6 Steam consumption of the reaction device 12 hours later (tons) 18.7 11.4 12.1 Single - cumulative steam consumption of the reaction device (tons) 27.1 19.7 16.7 Single - cumulative reaction time of the reaction device (hours) 52.5 62.3 61.7 Solid content of the slurry after reaction (g / 100ml) 7.9 8.7 9.0 Single - product output of the reaction device (tons) 7.1 7.8 8.1 External - supplied steam consumption per ton of product (tons / ton) 3.8 2.5 2.1 Steam saving rate per ton of product (%) 0 34.2 44.7

[0078] The comparison of the steam consumption per ton of product corresponding to the three implementation schemes is as Figure 3 shown. From Table 1 and Figure 3 it can be seen that under other same conditions, compared with Scheme (1), the production process scheme (Scheme (2)) that recovers and utilizes the heat and water resources in the wet and hot tail gas and does not recover and utilize the heat in the high-temperature slurry can achieve the energy-saving effect of saving 1.3 tons of steam per ton of product, and the steam saving rate per ton of product can reach 34.2%; compared with Scheme (1), recovering and utilizing the heat and water resources in the wet and hot tail gas, as well as the heat in the high-temperature slurry (Scheme (3)), can achieve the energy-saving effect of saving 1.7 tons of steam per ton of product, and the steam saving rate per ton of product can reach 44.7%. Therefore, the present invention has remarkable energy-saving and water-saving effects and is easy to be industrially transformed and applied.

[0079] In the present invention, specific examples are used to illustrate the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A water heat recovery system for a reaction device, characterized in that: The invention comprises a first heat exchange device, which has a first heat exchange channel and a second heat exchange channel, wherein the first inlet of the first heat exchange channel is used to be connected with the first outlet of the reaction device and can receive the humid hot exhaust gas, the first outlet of the first heat exchange channel is connected with the first inlet of the reaction device, the second heat exchange channel is used to receive the fluid medium, the first outlet of the second heat exchange channel is used to be connected with the second inlet of the reaction device to introduce the fluid medium into the reaction device, the humid hot exhaust gas in the first heat exchange channel can transfer heat to the fluid medium in the second heat exchange channel to heat the fluid medium in the second heat exchange channel, and the water vapor in the humid hot exhaust gas in the first heat exchange channel is condensed to form condensed water after heat exchange, and the condensed water can enter the reaction device through the first heat exchange channel.

2. The water heat recovery system of the reaction device according to claim 1, characterized in that: It also includes a second heat exchange device, which has a third heat exchange channel and a fourth heat exchange channel. The third inlet and the third outlet of the third heat exchange channel are used to communicate with the slurry storage device, the fourth inlet of the fourth heat exchange channel is used to allow fluid medium to enter, and the fourth outlet of the fourth heat exchange channel is used to output fluid medium. The slurry in the third heat exchange channel can transfer heat to the fluid medium in the fourth heat exchange channel.

3. The water heat recovery system of the reaction device according to claim 2, characterized in that: Also included is a fluid medium storage device for storing heated fluid medium, wherein the fluid medium storage device can be communicated with the first inlet of the second heat exchange channel to pass the heated fluid medium into the second heat exchange channel; The fluid medium storage device can be communicated with the third inlet of the reaction device to introduce the heated fluid medium into the reaction device.

4. The water heat recovery system of the reaction device according to claim 3, characterized in that: The first heat exchange channel has a first high temperature section and a first low temperature section arranged in sequence from the first inlet to the first outlet, and the second heat exchange channel has a second high temperature section and a second low temperature section. The second high temperature section is used to connect with the fluid medium storage device to receive the heated fluid medium, and the second low temperature section is used to receive the unheated fluid medium. The high temperature and humid hot exhaust gas in the first high temperature section is used to secondary heat the heated fluid medium in the second high temperature section, and the low temperature and humid hot exhaust gas in the first low temperature section is used to heat the unheated fluid medium in the second low temperature section.

5. The water heat recovery system of the reaction device according to claim 4, characterized in that: It also includes an unheated fluid medium storage device, which is connected to the second low-temperature section to allow the unheated fluid medium to pass through, and the unheated fluid medium storage device is connected to the fluid medium storage device to allow the unheated fluid medium to pass through the fluid medium storage device.

6. The water heat recovery system of the reaction device according to claim 5, characterized in that: The second heat exchange channel is arranged in the first heat exchange channel, a first atomizer is arranged in the second high temperature section, the fluid medium storage device is communicated with the first atomizer, and the first atomizer is used to atomize the heated fluid medium and pass it into the second high temperature section; a second atomizer is arranged in the second low temperature section, the unheated fluid medium storage device is communicated with the second atomizer, and the second atomizer is used to atomize the second fluid medium and pass it into the second low temperature section.

7. The water heat recovery system of the reaction device according to claim 5, characterized in that: The fluid medium includes water and / or air.

8. A metal oxide preparation system, characterized in that: It comprises a reaction device and a water heat recovery system for the reaction device as described in any one of claims 1 to 7, wherein the first outlet of the reaction device is used to be connected with the first inlet of the first heat exchange channel and can introduce hot and humid exhaust gas into the first heat exchange channel, the second inlet of the second heat exchange channel is used to introduce fluid medium, the second outlet of the second heat exchange channel is connected with the first inlet of the reaction device to provide the heated fluid medium to the reaction device, and the first outlet of the first heat exchange channel is connected with the second inlet of the reaction device to introduce the condensed water into the reaction device.

9. The metal oxide preparation system according to claim 8, characterized in that: An air distributor is provided at the second inlet of the reaction device, and the second outlet of the second heat exchange channel is communicated with the air distributor, and the air distributor can disperse the heated fluid medium into the reaction device.

10. A method for preparing metal oxide based on a metal oxide preparation system, characterized in that: The steps include: Adding solid medium and fluid medium into the reaction device to start oxidation reaction; The hot and humid exhaust gas generated during the reaction process is introduced into the first heat exchange channel. The hot and humid exhaust gas in the first heat exchange channel transfers heat to the fluid medium in the second heat exchange channel. The water vapor in the hot and humid exhaust gas in the first heat exchange channel condenses to form condensed water, which is introduced into the reaction device.

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