Efficient evaporation system based on flow state conversion

Abstract

The invention discloses an efficient evaporation system based on flow state conversion, and relates to the technical field of chemical engineering. A feed liquid inlet of the graphite evaporator is provided with a nozzle used for atomizing and dispersing feed liquid to generate 300-800 [mu] m liquid drops, a graphite corrugated plate is arranged below the nozzle and used for impacting the liquid drops to form 50-200 [mu] m micro-drops or 0.1-0.5 mm liquid films, the wave height of the graphite corrugated plate is 3-5 mm, the wave pitch is 8-12 mm, the surface roughness Ra is 6.3-12.5 [mu] m, and the wave inclination angle is 45 + / -5 degrees. The internal structure of the evaporator is optimized, the flowing path of the feed liquid in the evaporator is improved, the'fluid column 'form of the feed liquid is broken, and the'fluid column' form is changed into'liquid drops, liquid lines or liquid films', so that a flash evaporation efficiency mechanism is effectively released, the'feed liquid flash evaporation 'release space is effectively enlarged by strengthening the feed liquid into the'liquid drops, liquid lines or liquid films' form, and the flash evaporation efficiency is improved. Conditions are created for efficient and energy-saving operation of an evaporation system, the material circulation amount is reduced, the flash evaporation area is increased, and the evaporation efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of chemical technology, specifically to a high-efficiency evaporation system based on fluid transformation. Background Technology

[0002] Given the diverse properties of chemical feedstocks during evaporation and concentration, evaporation processes for heat-sensitive or easily crystallizing materials must be limited to specific temperature ranges. Strict control of material temperature below these limits necessitates the use of exceptionally high flow rates to achieve the desired evaporation intensity. However, this exceptional flow rate raises the question of how to effectively utilize the heat from the "fluid column" and achieve flash evaporation. Clearly, the heat utilization of the "fluid column" is extremely limited; multiples of circulation volume, sometimes even tens of times higher, are used solely to utilize the limited sensible heat of the feedstock to achieve the evaporation process objective. This is obviously a high-energy-consumption, low-efficiency process. Consequently, in an evaporation project with an evaporation intensity of 4000 kg / h, the material circulation volume reaches a staggering 1200 m³ / h. 3 / h, which is at least tens of times the circulation rate compared to conventional process designs.

[0003] The "high-flow circulation, heating process avoiding boiling" process is indeed beneficial for temperature-controlled evaporation of heat-sensitive and easily crystallizing materials, effectively avoiding and preventing blockage caused by the heat-sensitive denaturation or crystallization of materials during system operation. However, the drawbacks of the "high-flow circulation" heating method are also obvious. First, the direct result of high-flow circulation is that the temperature difference between the liquid and the feed during circulation is extremely small, which is not conducive to the full utilization of equipment performance. Second, because of the "high-flow" circulation, the liquid is in the form of a "fluid column," and the probability of flash evaporation during the circulation process is extremely low. The only opportunity for continuous flash evaporation is limited to the surface area of ​​the liquid within the evaporator, thus greatly reducing evaporation efficiency. Third, high-flow circulation requires a high-power circulation pump, which undoubtedly increases the system's energy consumption and operating costs.

[0004] Therefore, we propose a high-efficiency evaporation system based on fluid regime transformation to address the problems mentioned above.

[0005] The information disclosed above in this background section is only for enhancing the understanding of the background section of this invention, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a high-efficiency evaporation system based on fluid state transformation to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a high-efficiency evaporation system based on fluid transformation, comprising a raw material tank, a material conveying pump, a graphite preheater, a graphite heater, a forced circulation pump, a graphite evaporator, a graphite condenser, a secondary steam condensate tank I, a secondary steam condensate tank II, and a secondary steam condensate conveying pump. The feed inlet of the graphite evaporator is equipped with a nozzle for atomizing and dispersing the feed liquid to generate 300-800μm droplets. Below the nozzle is a graphite corrugated plate for impacting the droplets to form 50-200μm microdroplets or 0.1-0.5mm liquid films. The graphite corrugated plate has a wave height of 3-5mm, a wave pitch of 8-12mm, a surface roughness Ra of 6.3-12.5μm, and a corrugation angle of 45°±5°.

[0008] Preferably, the raw material tank, the first secondary steam condensate tank, the second secondary steam condensate tank, and the graphite evaporator are all equipped with level gauges, and the graphite evaporator is equipped with a hydrometer.

[0009] Preferably, the top of the secondary steam condensate tank is equipped with a vent valve.

[0010] Preferably, the secondary steam condensate tank is connected to a vacuum unit.

[0011] Preferably, the material in the raw material tank is pressurized by the material conveying pump and then sequentially enters the graphite preheater tube side, the graphite heater tube side, and the graphite evaporator, forming a closed loop of graphite evaporator-graphite reboiler-graphite heater-graphite evaporator under the drive of the forced circulation pump.

[0012] Preferably, the secondary steam generated by the graphite evaporator enters the graphite condenser from the top of the graphite evaporator, and then enters the secondary steam condensate tank one and the secondary steam condensate tank two.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] This invention optimizes the internal structure of the evaporator, improves the flow path of the liquid within the evaporator, breaks the "liquid fluid column" morphology, and transforms the "fluid column" morphology into "droplets, liquid lines, or liquid films," thereby effectively releasing the flash evaporation efficiency mechanism. By strengthening the measures to make the liquid appear as "droplets, liquid lines, or liquid films," the release space of "liquid flash evaporation" is effectively expanded, creating conditions for the efficient and energy-saving operation of the evaporation system, reducing the material circulation volume, increasing the flash evaporation area, and improving evaporation efficiency.

[0015] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the system structure of the present invention;

[0017] Figure 2 This is a schematic diagram of a conventional system structure.

[0018] In the diagram: G01, raw material tank; G02, secondary steam condensate tank one; G03, secondary steam condensate tank two;

[0019] P01, Material conveying pump; P02, Forced circulation pump; P03, Secondary steam condensate conveying pump;

[0020] E01, Graphite heater; E02, Graphite preheater; E03, Graphite condenser;

[0021] V01, graphite evaporator; V02, graphite corrugated plate; V03, nozzle. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1

[0024] Please see Figure 1 A high-efficiency evaporation system based on fluid transformation, the main equipment of which includes raw material tank G01, material transfer pump P01, graphite preheater E02, graphite heater E01, forced circulation pump P02, graphite evaporator V01, graphite condenser E03, secondary steam condensate tank one G02, secondary steam condensate tank two G03, and secondary steam condensate transfer pump P03.

[0025] The feed inlet of the graphite evaporator V01 is equipped with a nozzle V03 for atomizing and dispersing the feed liquid to generate 300-800μm droplets. Below the nozzle V03, a graphite corrugated plate V02 is arranged to impact the droplets to form 50-200μm microdroplets or 0.1-0.5mm liquid films. The graphite corrugated plate V02 has a wave height of 3-5mm, a wave pitch of 8-12mm, and forms a capillary effect. The surface roughness Ra is 6.3-12.5μm, and the corrugation inclination angle is 45°±5° to promote nucleated boiling.

[0026] Specifically, the raw material tank G01, the secondary steam condensate tank 1 G02, the secondary steam condensate tank 2 G03 and the graphite evaporator V01 are all equipped with level gauges, and the graphite evaporator V01 is equipped with a hydrometer.

[0027] Specifically, a vent valve is installed on the top of the secondary steam condensate tank 2G03.

[0028] Specifically, the secondary steam condensate tank G02 is connected to a vacuum unit.

[0029] Working principle:

[0030] I. Heat Source Circulation System: Steam Heating Stage

[0031] 1. Saturated steam (shell side pressure 0.3-0.5MPa) first enters the shell side of the graphite heater E01, and after exchanging heat with the tube side material, it condenses into condensate containing 5-8% flash steam.

[0032] 2. The condensate continues to flow through the shell side of the graphite preheater E02 to preheat the feed material;

[0033] 3. Finally, the condensate is discharged from the system through a steam trap.

[0034] II. Material Handling Process: Material Preheating and Circulation

[0035] 1. The material in raw material tank G01 is pressurized by material conveying pump P01 and then enters the graphite preheater E02 tube side, graphite heater E01 tube side, and graphite evaporator V01 in sequence;

[0036] The graphite evaporator V01 breaks down the feed liquid: the nozzle V03 atomizes and disperses the feed liquid to produce droplets of 300-800μm. After the droplets hit the graphite corrugated plate V02, they undergo droplet impact → spreading into a film → edge contraction → filament breakage → secondary atomization to form microdroplets of 50-200μm or liquid films of 0.1-0.5mm. The traditional columnar flow is 8-15mm; the innovative atomized flow is 50-200μm, increasing the specific surface area by 400 times.

[0037] 2. A closed-loop circulation is formed under the drive of the forced circulation pump P02, consisting of graphite evaporator V01 → graphite reboiler → graphite heater E01 → graphite evaporator V01.

[0038] 3. Evaporation and concentration control: The material continuously boils in the graphite reboiler at an operating temperature of 60-80℃ and a vacuum degree of -0.08 to -0.095MPa. The concentrated liquid is discharged through the interlock control of the density meter at the bottom of the graphite evaporator V01.

[0039] III. Secondary Steam Treatment: Condensation and Vacuum Maintenance

[0040] 1. The secondary steam generated by evaporation enters the graphite condenser E03 from the top of the graphite evaporator V01, and then enters the secondary steam condensate tank 1 G02 and the secondary steam condensate tank 2 G03.

[0041] 2. Dual-tank alternating operation mechanism:

[0042] When the liquid level in the secondary steam condensate tank reaches a certain height (liquid level ≥ 80%), shut off the valve between the secondary steam condensate tanks to ensure the normal operation of the system and the negative pressure of secondary steam condensate tank 1 G02. Open the top vent valve of secondary steam condensate tank 2 G03 and discharge it through the secondary steam condensate transfer pump P03. When the liquid level reaches a low level (liquid level ≤ 15%), close the secondary steam condensate transfer pump P03 and the top vent valve of secondary steam condensate tank 2 G03, and open the valve between the two tanks.

[0043] 3. Vacuum system linkage: The vacuum unit continuously pumps non-condensable gases to maintain an absolute pressure of 8-15 kPa; it adopts a pressure-level dual signal interlock: when the level of any condensate tank exceeds the limit, the valve status is immediately switched.

[0044] Traditional processes limit the boiling point rise to within 1.5°C to prevent the decomposition of heat-sensitive materials, but this necessitates maintaining an ultra-low temperature difference ΔT ≤ 2°C and increases the required heat exchange area by 5 to 8 times for the same evaporation rate. This invention, through fluid morphology modification, allows the boiling point rise to be increased to 6–7°C. The expanded temperature difference range increases the single-effect evaporation rate from 4000 kg / h in traditional processes to 6000–8000 kg / h. The required heat exchange area is reduced from 500 m² to only 110 m², a reduction of 78%.

[0045] This invention establishes a dynamic temperature difference model through the design of the temperature difference between the hot and cold media, proving that the optimal performance range is: heating section ΔT = 15-20℃, compared to 8-10℃ in the traditional process; flash section ΔT = 6-7℃, compared to 1.5-2℃ in the traditional process.

[0046] This invention establishes a three-dimensional flash evaporation model of "droplet-liquid line-liquid surface", which increases the flash evaporation contact area from 2.3㎡ to 67.5㎡, increases the density of vaporization core points from 50 / ㎡ to 2200 / ㎡, and shortens the evaporation time from 8.2s to 0.35s.

[0047] The following is a comparison of the key equipment parameters of this invention and traditional processes.

[0048] Equipment type Traditional crafts Innovative process of this invention Decrease Circulation pump power 640kW 110kW 82.8％ heat exchanger area 500㎡ 110㎡ 78％ Total weight of equipment 68 tons 19 tons 72％

[0049] The following is a comparison of the measured comprehensive benefits of the present invention and traditional processes for treating a certain concentration project (evaporation rate of 4000 kg / h).

[0050] parameter Traditional crafts Innovative process of this invention Increase Steam consumption 1.5t / h 0.62t / h 82.8％ Power consumption 703kWh 118kWh 83％ Area 210㎡ 85㎡ 59.5％ Water vapor consumption per ton 0.29t 0.155t 46.5％ Equipment investment ¥5.8 million ¥2.2 million 62％ Maintenance cycle 3 months 8 months 2.67 times

[0051] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0053] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0054] The embodiments of the present invention are given for the purposes of illustration and description. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made by those skilled in the art to the above embodiments within the scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-efficiency evaporation system based on fluidized bed conversion, comprising a raw material tank (G01), a material transfer pump (P01), a graphite preheater (E02), a graphite heater (E01), a forced circulation pump (P02), a graphite evaporator (V01), a graphite condenser (E03), a secondary steam condensate tank one (G02), a secondary steam condensate tank two (G03), and a secondary steam condensate transfer pump (P03), characterized in that: The graphite evaporator (V01) is equipped with a nozzle (V03) at the feed inlet to atomize and disperse the feed liquid into droplets of 300-800 μm. Below the nozzle (V03) is a graphite corrugated plate (V02) to impact the droplets and form microdroplets of 50-200 μm or liquid films of 0.1-0.5 mm. The graphite corrugated plate (V02) has a wave height of 3-5 mm, a wave pitch of 8-12 mm, a surface roughness Ra of 6.3-12.5 μm, and a corrugation angle of 45°±5°.

2. The high-efficiency evaporation system based on fluid regime transformation according to claim 1, characterized in that: The raw material tank (G01), secondary steam condensate tank one (G02), secondary steam condensate tank two (G03) and graphite evaporator (V01) are all equipped with level gauges, and the graphite evaporator (V01) is equipped with a hydrometer.

3. The high-efficiency evaporation system based on fluid regime transformation according to claim 1, characterized in that: The top of the secondary steam condensate tank (G03) is equipped with a vent valve.

4. The high-efficiency evaporation system based on fluid regime transformation according to claim 1, characterized in that: The secondary steam condensate tank (G02) is connected to a vacuum unit.

5. The high-efficiency evaporation system based on fluid regime transformation according to claim 1, characterized in that: The material in the raw material tank (G01) is pressurized by the material conveying pump (P01) and then enters the tube side of the graphite preheater (E02), the tube side of the graphite heater (E01), and the graphite evaporator (V01) in sequence. Under the drive of the forced circulation pump (P02), a closed loop is formed from graphite evaporator (V01) to graphite reboiler to graphite heater (E01) to graphite evaporator (V01).

6. The high-efficiency evaporation system based on fluid regime transformation according to claim 1, characterized in that: The secondary steam generated by the graphite evaporator (V01) enters the graphite condenser (E03) from the top of the graphite evaporator (V01), and then enters the secondary steam condensate tank one (G02) and the secondary steam condensate tank two (G03).

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