Pipeline dissolution reaction device

Abstract

The utility model relates to a pipeline dissolution reaction device which comprises a slurry preheater, a dead steam preheater, a heater, a reactor and a flash evaporator. Except the slurry preheater, the number of the flash evaporators is consistent with that of the dead steam preheater, a discharge port of the reactor is connected with a feed port of the most upstream flash evaporator, a dead steam outlet of each stage of flash evaporator is connected with a steam inlet of the corresponding dead steam preheater, and a condensate water outlet of each dead steam preheater is connected with an inner cavity of the same stage of flash evaporator. According to the utility model, the problems of scabbing and blockage caused by the fact that the concentration of the slurry is increased to exceed the solubility of a medium after flash evaporation are solved.

Description

Technical Field

[0001] The utility model relates to a dissolution device in the technical field of metallurgy and chemical industry, in particular to a low-concentration pipeline dissolution reaction device. Background Art

[0002] High-pressure dissolution is the core process of alumina production. The pipeline dissolution device, also known as the pipeline dissolution reaction device, is the main equipment of the high-pressure dissolution procedure. Its application range has gradually expanded from high-pressure dissolution in alumina production to warm metallurgy, chemical industry and other fields.

[0003] The pipeline dissolution device in the prior art includes a slurry preheater, an exhaust steam preheater, a reactor, a flash evaporator, a condensed water self-evaporator, etc., wherein the exhaust steam preheater, the reactor and the flash evaporator are a multi-stage series structure, the flash evaporator heats the steam after the flash evaporation of the slurry into the exhaust steam preheater, and the condensed water of the exhaust steam preheater flows to the condensed water self-evaporator.

[0004] The existing problems with this type of pipeline reaction device are: 1. After the flash evaporation, the material concentration increases, and some even exceed its solubility. After the flash evaporation, precipitation will occur, which will cause crystallization blockage at the flash evaporator outlet, resulting in poor discharge of the flash evaporator, and the flashed exhaust steam will carry the slurry, affecting the normal operation of the system. During the gradual flash evaporation of the dissolution slurry of some alumina production enterprises, the sodium carbonate concentration often exceeds its solubility and blocks the flash evaporator outlet. Similar problems also occur during the alkaline lithium carbonate dissolution process using a pipeline dissolution device. 2. The existing pipeline reactor needs to be equipped with a multi-stage condensate self-evaporator to recover the heat in the condensate, and the condensate self-evaporator has a complex structure, occupies a large area, and has a high investment cost; 3. If the liquid level of the slurry in the flash evaporator is not well controlled, steam carrying is prone to occur, and the liquid level control operation in the flash evaporator is relatively difficult. Utility Model Content

[0005] The utility model aims to provide a pipeline dissolution reaction device to solve the technical problem that the concentration of slurry increases after flash evaporation and precipitates to block the discharge port of the flash evaporator, while avoiding the problem of increased equipment cost caused by the setting of the condensed water self-evaporator in the prior art.

[0006] In order to solve the above technical problems, the technical solution of the pipeline dissolution reaction device in the utility model is as follows:

[0007] A pipeline dissolution reaction device comprises a slurry preheater, an exhaust steam preheater, a reactor and a flash evaporator. The exhaust steam preheater is a structure connected in series of at least two stages, and the flash evaporator is a structure connected in series of at least two stages. The number of flash evaporators is consistent with the number of exhaust steam preheaters. The discharge port of the slurry preheater is connected to the feed port of the exhaust steam preheater at the most upstream, and the discharge port of the reactor is connected to the feed port of the flash evaporator at the most upstream. The exhaust steam outlets of the flash evaporators at each stage are respectively connected to the steam inlet of the corresponding exhaust steam preheater. Both the slurry preheater and the exhaust steam preheater are shell and tube heat exchangers. The flash evaporator and the exhaust steam preheater whose steam inlet is connected to the flash evaporator are defined as the same stage. The condensate outlet of the exhaust steam preheater is connected to the inner cavity of the flash evaporator at the same stage and / or the condensate outlet of the exhaust steam preheater is connected to the inner cavity of the flash evaporator at the next stage. The discharge port of the flash evaporator at the most downstream is connected to the shell inlet of the corresponding slurry preheater through a pipeline.

[0008] Furthermore, the pipeline dissolution device also includes a feeding trough and a discharging trough, the discharging trough is connected to the feeding port of the slurry preheater through a pipeline, and the shell layer outlet of the slurry preheater is connected to the discharging trough through a pipeline.

[0009] Furthermore, the exhaust steam preheater and the slurry preheater are in the form of indirect preheaters, and the indirect preheater is a tubular preheater, a shell-and-tube preheater or a plate preheater.

[0010] Furthermore, the slurry preheater is a tubular heat exchanger, the medium flowing through the inner tube is the unreacted material, and the slurry after heat exchange flows through the outer tube.

[0011] Furthermore, the exhaust steam preheater is a tubular heat exchanger, the medium flowing through the inner tube is the unreacted material, and the medium flowing through the outer tube is the exhaust steam flashed from the dissolved slurry.

[0012] Furthermore, the reactor is a tubular reactor, a tank reactor or a combination of tubular and tank reactors.

[0013] Furthermore, the reactor is a single reactor or a plurality of reactors connected in series.

[0014] Furthermore, there are n exhaust steam preheaters and n flash evaporators, where n is a positive integer not less than 2. Along the direction of the material, each exhaust steam preheater is respectively referred to as the nth exhaust steam preheater...the first exhaust steam preheater, and along the direction of the material, each flash evaporator is respectively referred to as the first flash evaporator, the second flash evaporator...and the nth flash evaporator. The condensate outlet of the first exhaust steam preheater is connected to the inner cavity of the first flash evaporator, the condensate outlet of the second exhaust steam preheater is connected to the inner cavity of the second flash evaporator...the condensate outlet of the nth exhaust steam preheater is connected to the inner cavity of the nth flash evaporator.

[0015] Furthermore, an additional steam heater is provided downstream of the first exhaust steam preheater, and the heat source of the additional steam heater is new steam, heat transfer oil or molten salt.

[0016] The beneficial effects of the utility model are as follows: in the utility model, the steam after the flash evaporator flashes the material enters the corresponding exhaust steam preheater to preheat the material, and the steam produces condensed water in the exhaust steam preheater. The condensed water with a lower temperature produced by the exhaust steam preheater is sent to the inner cavity of the corresponding flash evaporator, and the condensed water is mixed with the material, which has the following technical effects: 1. The temperature of the condensed water is relatively low, so the material can be cooled and the cooling effect of the flash evaporator is improved; 2. There is no need to set up a condensed water self-evaporator for treating the condensed water, which reduces the complexity and floor space of the equipment and reduces the equipment cost; 3. After the condensed water enters the flash evaporator and mixes with the material in the flash evaporator, the material concentration in the flash evaporator will not increase, so that the flash evaporator only plays a cooling role, and the material will not precipitate crystals to block the material outlet of the flash evaporator; 4. The condensed water is condensed from the steam in the flash evaporator, that is, the source of the condensed water is still the flash evaporator, and the addition of condensed water will not cause the problem of too high liquid level in the flash evaporator. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0018] Figure 1 This is a schematic structural diagram of Example 1 of a pipeline dissolution reaction device in the utility model;

[0019] Figure 2 This is a schematic diagram of the structure of Example 2 of a pipeline dissolution reaction device in the utility model;

[0020] Explanation of the reference numerals: 1. feeding trough; 2. discharging trough; 3. first slurry preheater; 4. third exhaust steam preheater; 5. second exhaust steam preheater; 6. first exhaust steam preheater; 7. additional steam heater; 8. tubular reactor; 9. first kettle reactor; 10. second kettle reactor; 11. third kettle reactor; 12. steam pipe; 13. condensate pipe; 14. first flash evaporator; 15. second flash evaporator; 16. third flash evaporator; 17. second slurry preheater. DETAILED DESCRIPTION

[0021] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. The accompanying drawings provide preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0022] It should be noted that, unless otherwise defined, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0023] Embodiment 1 of a pipeline reaction device in the utility model is as follows Figure 1 As shown:

[0024] It includes a feeding trough 1, a first slurry preheater 3, three-stage exhaust steam preheaters connected in series, an additional steam heater 7, a tubular reactor 8, three-stage reactors connected in series, three-stage flash evaporators connected in series and a discharge trough.

[0025] Along the material conveying direction, the three-stage exhaust steam preheaters connected in series are respectively called the third exhaust steam preheater 4, the second exhaust steam preheater 5 and the first exhaust steam preheater 6; the three-stage reactors connected in series are respectively called the first reactor 9, the second reactor 10 and the third reactor 11; the three-stage flash evaporators connected in series are respectively called the first flash evaporator 14, the second flash evaporator 15 and the third flash evaporator 16.

[0026] The slurry preheater, exhaust steam preheater and additional steam heater are all shell and tube heat exchangers, which belong to the prior art and their specific structures will not be described in detail.

[0027] The exhaust steam outlet of the first flash evaporator is connected to the steam inlet of the first exhaust steam preheater through the steam pipe 12, the exhaust steam outlet of the second flash evaporator is connected to the steam inlet of the second exhaust steam preheater, and the exhaust steam outlet of the third flash evaporator is connected to the steam inlet of the third exhaust steam preheater. The condensate outlet of the first exhaust steam preheater is connected to the inner cavity of the first flash evaporator through the condensate pipe 13, the condensate outlet of the second exhaust steam preheater is connected to the inner cavity of the second flash evaporator through the condensate pipe, and the condensate outlet of the third exhaust steam preheater is connected to the inner cavity of the third flash evaporator through the corresponding condensate pipe. In other words, the flash evaporator and the exhaust steam preheater whose steam inlet is connected to the flash evaporator are defined as the same level, and the condensate outlet of the exhaust steam preheater is connected to the inner cavity of the flash evaporator of the same level.

[0028] An additional steam heater 7 is provided downstream of the first exhaust steam preheater, a steam inlet of the additional steam heater is connected to a corresponding steam source, and a condensate outlet of the additional steam heater flows to a corresponding condensate tank.

[0029] In the utility model, the flow direction of the material, i.e., the slurry, is that the material is pumped out through the feeding trough, and then sequentially passes through the inner cavity of the first slurry preheater, the inner cavity of the third exhaust steam preheater, the inner cavity of the second exhaust steam preheater, the inner cavity of the first exhaust steam preheater, the inner cavity of the additional steam heater, the tubular reactor, the first reactor, the second reactor, the third reactor, the inner cavity of the first flash evaporator, the inner cavity of the second flash evaporator, the inner cavity of the third flash steam, and finally passes through the shell layer of the first slurry preheater and flows to the final discharge trough.

[0030] The steam of the additional steam heater comes from a new steam source, and the condensed water discharged from the additional steam heater can be collected by a condensed water tank.

[0031] The steam source of the first exhaust steam preheater comes from the first flash evaporator, and the condensed water produced by the first exhaust steam preheater flows back to the first flash evaporator; the steam source of the second exhaust steam preheater comes from the second flash evaporator, and the condensed water produced by the second exhaust steam preheater flows back to the second flash evaporator; the steam source of the third exhaust steam preheater comes from the third flash evaporator, and the condensed water produced by the third exhaust steam preheater flows back to the third flash evaporator.

[0032] The flash evaporator is used to cool the material, so the condensed water flowing back to the corresponding flash evaporator can improve the cooling effect of the flash evaporator on the material level; at the same time, the return of condensed water will cause the concentration of the corresponding material to not increase, avoiding the precipitation of crystals due to excessive concentration and blocking the material outlet of the flash evaporator; the condensed water comes from the steam of the corresponding flash evaporator, so it does not need to be deliberately controlled, and the liquid level in the flash evaporator will not be too high. It also avoids the problem of setting up a complicated condensed water self-evaporator to deal with the condensed water of each level of exhaust steam preheater.

[0033] In other embodiments of the present invention, the number of reactors can be increased or decreased as needed, such as one, two, four or other numbers; the number of exhaust steam preheaters and flash evaporators can also be increased or decreased as needed, such as two, four or other numbers.

[0034] Example 2 of a pipeline dissolution reaction device Figure 2 As shown:

[0035] The difference between Example 2 and Example 1 is that in this example, there are two slurry preheaters, which are a first slurry preheater and a second slurry preheater 17 .

[0036] The condensate outlet of the additional steam heater 7 is connected to the inner cavity of the first flash evaporator 14; the condensate outlet of the first exhaust steam preheater 6 is connected to the inner cavity of the second flash evaporator 15 through the corresponding condensate pipe 13, the condensate outlet of the second exhaust steam preheater 5 is connected to the inner cavity of the third flash evaporator 16 through the corresponding condensate pipe, and the condensate outlet of the third exhaust steam preheater 4 is connected to the inner cavity of the third flash evaporator 16 through the corresponding condensate pipe.

[0037] This is equivalent to the following: for the first exhaust steam preheater and the second exhaust steam preheater, the condensate outlets of the first exhaust steam preheater and the second exhaust steam preheater are respectively connected to the inner cavity of the next-stage flash evaporator; for the third exhaust steam preheater, its condensate outlet is connected to the inner cavity of the flash evaporator of the same stage.

[0038] In the above description of this specification, unless otherwise clearly specified and limited, the terms "fixed", "installed", "connected" or "connected" should be understood in a broad sense. For example, with regard to the term "connection", it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. Therefore, unless otherwise clearly defined in this specification, those skilled in the art can understand the specific meanings of the above terms in this utility model according to the specific circumstances.

[0039] According to the above description of this specification, those skilled in the art may also understand that the terms used below, such as "up", "down", "front", "back", "left", "right", "length", "width", "thickness", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", "center", "longitudinal", "lateral", "clockwise" or "counterclockwise", etc., which indicate the orientation or position relationship, are based on the orientation or position relationship shown in the drawings of this specification, and are only for the purpose of facilitating the explanation of the scheme of the utility model and simplifying the description, rather than explicitly or implicitly indicating that the device or element involved must have the specific orientation, be constructed and operate in a specific orientation. Therefore, the above-mentioned orientation or position relationship terms cannot be understood or interpreted as limitations on the scheme of the utility model.

[0040] In addition, the terms "first" or "second" used in this specification to refer to numbers or ordinals are only used for descriptive purposes and cannot be understood as explicitly or implicitly indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this specification, the meaning of "plurality" is at least two, such as two, three or more, etc., unless otherwise clearly and specifically defined.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A pipeline dissolution reaction device, comprising a slurry preheater, an exhaust steam preheater, a reactor and a flash evaporator, wherein the exhaust steam preheater is a structure of at least two stages connected in series, and the flash evaporator is a structure of at least two stages connected in series. The number of flash evaporators is consistent with the number of exhaust steam preheaters, the discharge port of the slurry preheater is connected to the feed port of the exhaust steam preheater at the most upstream, the discharge port of the reactor is connected to the feed port of the flash evaporator at the most upstream, and the exhaust steam outlets of the flash evaporators at each stage are respectively connected to the steam inlet of the corresponding exhaust steam preheater, characterized in that: Both the slurry preheater and the exhaust steam preheater are shell and tube heat exchangers. The flash evaporator and the exhaust steam preheater whose steam inlet is connected to the flash evaporator are defined as the same level. The condensate outlet of the exhaust steam preheater is connected to the inner cavity of the flash evaporator of the same level and / or the condensate outlet of the exhaust steam preheater is connected to the inner cavity of the flash evaporator of the next level. The discharge port of the most downstream flash evaporator is connected to the shell inlet of the corresponding slurry preheater through a pipeline.

2. The pipeline dissolution reaction device according to claim 1, characterized in that: The pipeline dissolution device also includes a feeding trough and a discharging trough. The discharging trough is connected to the feeding port of the slurry preheater through a pipeline, and the shell layer outlet of the slurry preheater is connected to the discharging trough through a pipeline.

3. The pipeline dissolution reaction device according to claim 1, characterized in that: The exhaust steam preheater and the slurry preheater are in the form of indirect preheaters, and the indirect preheater is a tubular preheater, a shell-and-tube preheater or a plate preheater.

4. The pipeline dissolution reaction device according to claim 1, characterized in that: The slurry preheater is a tubular heat exchanger, the medium flowing through the inner tube is the unreacted material, and the slurry after heat exchange flows through the outer tube.

5. The pipeline dissolution reaction device according to claim 1, characterized in that: The exhaust steam preheater is a tubular heat exchanger, the medium flowing through the inner tube is the unreacted material, and the medium flowing through the outer tube is the exhaust steam flashed from the dissolved slurry.

6. The pipeline dissolution reaction device according to claim 1, characterized in that: The reactor is a tubular reactor, a tank reactor or a combination of tubular and tank reactors.

7. The pipeline dissolution reaction device according to claim 1, characterized in that: The reactor is a single reactor or multiple reactors are connected in series.

8. The pipeline dissolution reaction device according to any one of claims 1 to 3, characterized in that: There are n exhaust steam preheaters and n flash evaporators, where n is a positive integer not less than 2. Along the material direction, each exhaust steam preheater is respectively referred to as the nth exhaust steam preheater...the first exhaust steam preheater. Along the material direction, each flash evaporator is respectively referred to as the first flash evaporator, the second flash evaporator...and the nth flash evaporator. The condensate outlet of the first exhaust steam preheater is connected to the inner cavity of the first flash evaporator, the condensate outlet of the second exhaust steam preheater is connected to the inner cavity of the second flash evaporator...the condensate outlet of the nth exhaust steam preheater is connected to the inner cavity of the nth flash evaporator.

9. The pipeline dissolution reaction device according to claim 8, characterized in that: An additional steam heater is arranged downstream of the first exhaust steam preheater, and the heat source of the additional steam heater is new steam, heat transfer oil or molten salt.

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