阅读说明：本技术 一种用于超临界水热合成系统的快速急冷降压装置 (A quick rapid cooling pressure reduction device for supercritical hydrothermal synthesis system ) 是由 王树众 张熠姝 王栋 刘璐 张宝权 孙盼盼 于 2020-05-24 设计创作，主要内容包括：一种用于超临界水热合成系统的快速急冷降压装置,包括：顶盖,其上设置有减压阀接口、反应出水入口和反应出水出口；密封罐体,其内置外螺旋盘管和内螺旋盘管,外螺旋盘管位于内螺旋盘管的外围,入口与反应出水入口连接,出口与内螺旋盘管的入口连接,内螺旋盘管的出口与反应出水出口连接,外螺旋盘管的管内径大于或等于内螺旋盘管的管内径,密封罐体的罐体侧面设置有冷却水入口和冷却水出口,罐底设置有带排污阀的清洗排污口。优选地,本发明还可包括框式搅拌器,本发明将多功能集合于一体,简化连续式超临界水热合成的系统,提高系统的热经济性和稳定性,有效解决SCHS技术的防止团聚的问题,为大规模批量生产纳米材料提供了一定条件。(A rapid quenching pressure reduction device for a supercritical hydrothermal synthesis system, comprising: the top cover is provided with a pressure reducing valve interface, a reaction water outlet inlet and a reaction water outlet; the sealed tank body is internally provided with an outer spiral coil pipe and an inner spiral coil pipe, the outer spiral coil pipe is positioned on the periphery of the inner spiral coil pipe, an inlet is connected with a reaction water outlet, an outlet is connected with an inlet of the inner spiral coil pipe, an outlet of the inner spiral coil pipe is connected with a reaction water outlet, the inner diameter of the outer spiral coil pipe is larger than or equal to that of the inner spiral coil pipe, the side surface of the tank body of the sealed tank body is provided with a cooling water inlet and a cooling water outlet, and the tank bottom is provided with a cleaning drain outlet with a drain valve. Preferably, the invention can also comprise a frame type stirrer, integrates multiple functions, simplifies a continuous supercritical hydrothermal synthesis system, improves the thermal economy and stability of the system, effectively solves the problem of agglomeration prevention of the SCHS technology, and provides certain conditions for large-scale batch production of nano materials.)

1. A rapid quenching and pressure reduction device for a supercritical hydrothermal synthesis system is characterized by comprising:

the top cover (3) is provided with a pressure reducing valve interface (12), a reaction water outlet (13) and a reaction water outlet (2);

the sealed tank body (16) is internally provided with an outer spiral coil (7) and an inner spiral coil (8), the outer spiral coil (7) is positioned at the periphery of the inner spiral coil (8), an inlet is connected with a reaction water outlet (13), an outlet is connected with an inlet of the inner spiral coil (8), an outlet of the inner spiral coil (8) is connected with a reaction water outlet (2), the inner diameter of the outer spiral coil (7) is larger than or equal to that of the inner spiral coil (8), a cooling water inlet (19) and a cooling water outlet (6) are arranged on the side surface of the tank body of the sealed tank body (16), and a cleaning sewage outlet (11) with a sewage discharge valve (21) is arranged at the bottom of the tank.

2. The rapid quenching depressurization device for supercritical hydrothermal synthesis system of claim 1, further comprising: the frame type stirrer (1) is characterized in that a motor is positioned on a top cover (3), a stirring shaft penetrates through a sealed tank body (16) from top to bottom, and stirring blades are positioned in the middle of an outer spiral coil pipe (7) and an inner spiral coil pipe (8) so as to be in full contact with fluid of a cooling cavity (20) in the sealed tank body (16).

3. The rapid quenching and depressurizing device for supercritical hydrothermal synthesis system as claimed in claim 2, wherein the stirring blades of the frame stirrer (1) are as close as possible to the internal spiral pipe (18), and the spacing is in the range of 10-20 mm.

4. The rapid quenching and depressurizing device for supercritical hydrothermal synthesis system as claimed in claim 1, wherein the outer spiral coil (7) and the inner spiral coil (8) are distributed inside and outside in a staggered manner, are wound at equal intervals and in an inclined manner, and are fixed on the inner support bracket (10) and the outer support bracket (9) respectively through U-shaped bolts (17).

5. The rapid quenching and depressurizing device for supercritical hydrothermal synthesis system as claimed in claim 1, wherein the material of the outer spiral coil (7) and the inner spiral coil (8) is stainless steel 316L, carbon steel, low alloy steel, copper, aluminum, nickel, copper alloy, aluminum alloy or nickel alloy.

6. The rapid quenching and depressurizing device for supercritical hydrothermal synthesis system as claimed in claim 1 or 5, wherein the coil structures of the outer spiral coil (7) and the inner spiral coil (8) are light pipe, external thread coil or internal thread coil.

7. The rapid quenching and depressurizing device for supercritical hydrothermal synthesis system as claimed in claim 1, wherein the pipe inner diameter of the outer spiral coil (7) is 3-8 mm, the pipe inner diameter of the inner spiral coil (8) is 1-3 mm, the length of the outer spiral coil (7) is determined by calculating the heat exchange area required by system operation, and the length of the inner spiral coil (8) is determined by calculating the pressure drop required by system operation.

8. The rapid quenching and depressurizing device for supercritical hydrothermal synthesis system according to claim 1, wherein the cooling water inlet (19) is located at the lower portion of the sidewall of the sealed tank (16), the cooling water outlet (6) is located at the upper portion of the sidewall of the sealed tank (16) and is diagonally distributed with the cooling water inlet (19), the sidewall of the sealed tank (16) is further provided with an upper level meter interface (15), a lower level meter interface (18) and an overflow outlet (5), the overflow outlet (5) is located above the cooling water outlet (6) and has a caliber larger than that of the cooling water outlet (6), the upper level meter interface (15) and the lower level meter interface (18) are both located above the cooling water inlet (19) and below the cooling water outlet (6).

9. The rapid quenching and depressurizing device for supercritical hydrothermal synthesis system as claimed in claim 1, wherein the purge drain (11) and the purge valve (21) are distributed at the central axis of the tank and are communicated with the cooler cavity (20).

10. The rapid quenching and depressurizing device for supercritical hydrothermal synthesis system as claimed in claim 1, wherein the top cover (3) and the sealed tank (16) are fastened by a sealing gasket (14).

Technical Field

The invention relates to a device which is used in the technical fields of energy, chemical engineering, synthetic materials and the like and can quickly reduce the temperature and pressure and improve the efficiency, in particular to a quick quenching and pressure reduction device for a supercritical hydrothermal synthesis system.

Background

Supercritical Water (SCW) is a form of Water that exists in a specific manner above the critical state (T: 374.15 ℃, P: 22.12 MPa). In this form, the density of water becomes lower, the viscosity decreases, the diffusivity becomes higher, the ionic product increases by several orders of magnitude, and the number of hydrogen bonds increases greatly, which becomes a good reaction medium.

Supercritical hydrothermal synthesis (SCHS) refers to the fact that the solubility of metal salts and oxides thereof is extremely low in a supercritical water environment, and the metal salts and the metal oxides can be instantly saturated and precipitated. Chemical reactions occurring in the process include hydrolysis reaction, dehydration reaction, reduction reaction and the like, which can realize rapid nucleation and growth of crystal grains. The method has the advantages of extremely high nucleation rate, extremely high reaction rate, high product purity and low cost. Most importantly, the reaction medium of the method is water, the source is wide, other pollutants are not introduced in the reaction process, and the method is very green and environment-friendly and is widely favored by energy and environment-friendly industries.

The technological process of continuous supercritical hydrothermal synthesis consists of 3 parts, including material feeding/preheating system, mixing/reaction system and cooling/material recovering system. In the feeding/preheating system, the water-containing material is heated and pressurized to be above the critical point of water and then enters the mixing/reaction system, the material is fully reacted, and in the cooling/material recovery system, the outlet product after the reaction is finished can be discharged out of the system only by reducing the temperature and the pressure, which relates to the problem of reducing the temperature and the pressure of the material. The good quenching and pressure reduction device can affect the reliability of the supercritical system and is very important for the quality of the synthesized nano particles.

At present, the cooler that continuous supercritical hydrothermal synthesis adopted is mostly water cooler, also called shell-and-tube heat exchanger or shell and tube heat exchanger, and the pressure reduction adopts pressure regulating valve control more, and these rapid cooling pressure reduction devices have certain technical problem to include: (1) the heat exchange area is small, the cooling efficiency is limited, the cooling time of hot fluid is long, the temperature of an outlet product cannot be rapidly reduced, agglomeration is easy to occur, and the problems of blockage, siltation and the like in a cooler pipe are caused; (2) the system pressure drop is realized through one point, which causes excessive material flow rate, easily causes valve failure and serious abrasion and corrosion of elements in the valve; (3) the temperature reduction and the pressure reduction are carried out through two elements, the system is complex, and the temperature reduction and the pressure reduction speed can not be accurately controlled. The above problems are more pronounced especially for large-scale continuous mass production of nanoparticles.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a rapid quenching and pressure reducing device for a supercritical hydrothermal synthesis system, which is designed based on a countercurrent heat exchange and capillary pressure reducing method and technology and integrates two functions of quenching and pressure reducing. On one hand, the small-diameter spiral coil pipes which are closely distributed are arranged in the quenching and depressurizing tank body, so that the contact between the fluid and the wall surface is increased, the heat exchange area is expanded, the fluid is ensured to flow at a high flow speed, and the heat exchange time is shortened; secondly, a frame type stirrer is added to realize circumferential shearing of cold fluid in the tank, so that heat exchange is enhanced, and the quenching speed can be accurately controlled through motor frequency conversion of the stirrer; on the other hand, the fluid flows through the capillary tube to generate on-way resistance to realize pressure drop, and the pressure drop effect can be controlled in real time by controlling the length of the capillary tube. The whole device has obvious advantages, integrates multiple functions, simplifies a continuous supercritical hydrothermal synthesis system, improves the thermal economy and stability of the system, effectively solves the problem of agglomeration prevention of the SCHS technology, and provides certain conditions for large-scale batch production of nano materials.

In order to achieve the purpose, the invention adopts the technical scheme that:

a rapid quenching pressure reduction device for a supercritical hydrothermal synthesis system, comprising:

the top cover 3 is provided with a pressure reducing valve interface 12, a reaction water outlet 13 and a reaction water outlet 2;

the sealed tank body 16 is internally provided with an outer spiral coil 7 and an inner spiral coil 8, the outer spiral coil 7 is positioned on the periphery of the inner spiral coil 8, an inlet is connected with a reaction water outlet inlet 13, an outlet is connected with an inlet of the inner spiral coil 8, an outlet of the inner spiral coil 8 is connected with a reaction water outlet 2, the inner diameter of the outer spiral coil 7 is larger than or equal to that of the inner spiral coil 8, the side surface of the tank body of the sealed tank body 16 is provided with a cooling water inlet 19 and a cooling water outlet 6, and the tank bottom is provided with a cleaning sewage outlet 11 with a sewage discharge valve 21.

Preferably, the present invention may further comprise: the frame type stirrer 1 has a motor positioned on the top cover 3, a stirring shaft penetrating through the sealed tank 16 from top to bottom, and stirring blades positioned in the middle of the outer spiral coil 7 and the inner spiral coil 8 to be in full contact with fluid in the cooling cavity 20 in the sealed tank 16.

The stirring blades of the frame type stirrer 1 are as close as possible to the inner spiral coil 18, and the distance range is 10-20 mm.

The outer spiral coil pipe 7 and the inner spiral coil pipe 8 are distributed in an inner-outer staggered mode, are wound in an equidistant and inclined mode, and are fixed on the inner supporting support 10 and the outer supporting support 9 through U-shaped bolts 17 respectively.

The outer spiral coil pipe 7 and the inner spiral coil pipe 8 are made of stainless steel 316L, carbon steel, low alloy steel, copper, aluminum, nickel, copper alloy, aluminum alloy or nickel alloy.

The coil pipe structures of the outer spiral coil pipe 7 and the inner spiral coil pipe 8 are light pipes, external thread coils or internal thread coil pipes.

The pipe internal diameter of the outer spiral coil pipe 7 is 3-8 mm, the pipe internal diameter of the inner spiral coil pipe 8 is 1-3 mm, the length of the outer spiral coil pipe 7 is determined according to the calculation of the heat exchange area required by the operation of the system, and the length of the inner spiral coil pipe 8 is determined according to the calculation of the pressure drop required by the operation of the system.

The cooling water inlet 19 is positioned at the lower part of the side wall of the sealed tank body 16, the cooling water outlet 6 is positioned at the upper part of the side wall of the sealed tank body 16 and is distributed diagonally with the cooling water inlet 19, the side wall of the sealed tank body 16 is also provided with an upper liquid level meter interface 15, a lower liquid level meter interface 18 and an overflow outlet 5, the overflow outlet 5 is positioned above the cooling water outlet 6, the caliber of the overflow outlet is larger than that of the cooling water outlet 6, and the upper liquid level meter interface 15 and the lower liquid level meter interface 18 are both positioned above the cooling water inlet 19 and below the cooling water outlet 6.

The cleaning sewage draining port 11 and the sewage draining valve 21 are distributed on the central axis of the tank body and are communicated with the cooler cavity 20.

The top cover 3 and the sealed tank 16 are fastened through a sealing gasket 14.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention discloses a rapid quenching and depressurizing device for a supercritical hydrothermal synthesis system, which adopts a small-diameter spiral coil pipe wound at equal intervals and in an inclined manner, increases the contact between a hot fluid and a wall surface as well as cooling water, expands the heat exchange area, increases the convection heat exchange coefficient, accelerates the flow velocity of the fluid, can rapidly and efficiently complete the cooling process, and improves the conversion rate and the nucleation rate of nanoparticles.

(2) The invention discloses a rapid quenching and pressure reducing device for a supercritical hydrothermal synthesis system, which is provided with a frame type stirrer, realizes circumferential flow, thereby strengthening heat exchange, can realize accurate control of quenching speed through motor speed change and frequency conversion of the stirrer, shortens the whole heat exchange time, ensures that nucleation crystals are not easy to agglomerate, and produces nanoparticles with small particle size and high quality.

(3) According to the rapid quenching and pressure reducing device for the supercritical hydrothermal synthesis system, the hot fluid flows through the capillary tube to generate on-way resistance to realize pressure reduction, the pressure reducing effect can be controlled in real time by controlling the length of the capillary tube, the abrasion of elements caused by overhigh flow speed can be effectively avoided, and the system can be ensured to operate stably and reliably.

(4) The invention discloses a rapid quenching and depressurizing device for a supercritical hydrothermal synthesis system, which is characterized in that a spiral coil is arranged in the cooling/material recovery process of the supercritical hydrothermal synthesis system, the spiral coil on the front half section is quenched through heat exchange, and the spiral coil on the rear half section is depressurized through on-way resistance, so that multiple functions are integrated, the continuous supercritical hydrothermal synthesis system is simplified, the economy and the stability of the system are improved, the system optimization is realized, the problem of agglomeration prevention of an SCHS (small scale high speed hydrogen storage) technology is effectively solved, and a certain condition is provided for large-scale batch production of nano materials.

Drawings

FIG. 1 is a schematic diagram of a rapid quench pressure reduction apparatus of the present invention.

Wherein: 1 is a frame type stirrer; 2 is a reaction water outlet; 3 is a top cover; 4 is a fastening bolt; 5 is an overflow outlet; 6 is a cooling water outlet; 7 is an external spiral coil pipe; 8 is an external spiral coil pipe; 9 is an outer supporting bracket; 10 is an inner supporting bracket; 11 is a cleaning sewage draining outlet; 12 is a pressure reducing valve interface; 13 is a reaction water outlet inlet; 14 is a sealing gasket; 15 is an upper liquid level meter interface; 16 is a sealed tank body; 17 is a U-shaped bolt; 18 is a lower liquid level meter interface; 19 is a cooling water inlet; 20 is a cooling cavity; 21 is a blow-off valve.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The invention is described in further detail below with reference to the accompanying drawings:

as shown in FIG. 1, a rapid quenching and depressurizing device for supercritical hydrothermal synthesis system comprises a sealed tank 16 with a top cover 3, wherein the top cover 3 and the sealed tank 16 can be fastened by a sealing gasket 14, for example, the sealing gasket 14 can be symmetrically distributed on the contact surface of the top cover 3 and the sealed tank 16, so that the elements connected with each other are tightly attached to prevent external air from entering the device and affecting the air tightness of the device, and the horizontal line at the lower part in the figure is a welding line.

Wherein, the top cover 3 is provided with a pressure reducing valve interface 12, a reaction water outlet 13 and a reaction water outlet 2; the side surface of the sealed tank body 16 is provided with a cooling water inlet 19 and a cooling water outlet 6, the bottom of the tank is provided with a cleaning sewage outlet 11 with a sewage valve 21, and a cooling cavity 20 is formed in the tank. Wash drain 10 and blowoff valve 22 and can set up in jar body the central axis department, link up in jar, its process of enough control blowdown prevents to block up and deposit, and direct blowdown from the bottom easily dismantles and washs a jar body, avoids unnecessary manpower and materials.

The key technology of the invention is that an outer spiral coil 7 and an inner spiral coil 8 are arranged in a sealed tank body 16, the outer spiral coil 7 has larger coiling outer diameter and is positioned at the outer ring of the sealed tank body 16, the inner spiral coil 8 has smaller coiling outer diameter and is positioned at the inner ring of the sealed tank body 16, and the outer spiral coil and the inner spiral coil can be coaxial with the sealed tank body 16 in the longitudinal direction. The inlet of the outer spiral coil 7 is connected with the reaction water outlet 13, the outlet is connected with the inlet of the inner spiral coil 8, the outlet of the inner spiral coil 8 is connected with the reaction water outlet 2, and the inner diameter of the outer spiral coil 7 is larger than or equal to that of the inner spiral coil 8.

Wherein, the outer spiral coil pipe 7 and the inner spiral coil pipe 8 can be in an inner and outer staggered distribution form, namely, the inclination directions of the two are opposite to form a staggered effect. The two are coiled at equal intervals and in an inclined mode and are respectively fixed on the inner support bracket 10 and the outer support bracket 9 through the U-shaped bolts 17, so that the heat exchange area is increased, the convection heat exchange coefficient is increased, the heat exchange speed is accelerated, and the volume of the container is reduced.

In the invention, the materials, the tube types and the size parameters of the outer spiral coil 7 and the inner spiral coil 8 can be adjusted according to the actual engineering requirements. The material selection includes, but is not limited to, one or more of stainless steel 316L, carbon steel and low alloy steel, copper, aluminum, nickel, copper alloy, aluminum alloy, nickel alloy, and other commercially available metallic materials that are resistant to high temperatures and high pressures. In the aspect of pipe type, the spiral coil structure may be a light pipe, but is not limited thereto, and may also be an external thread coil or an internal thread coil. In the aspect of size, the inner diameter of the outer spiral coil 7 is generally 3-8 mm, the inner diameter of the inner spiral coil 8 is generally 1-3 mm, the length of the outer spiral coil 7 is determined according to the calculation of the heat exchange area required by the operation of the system, and the length of the inner spiral coil 8 is determined according to the calculation of the pressure drop required by the operation of the system.

According to the structure, the device can realize the parallel of countercurrent heat exchange, forced heat exchange and accurate pressure reduction. The hot fluid reacted under the supercritical high temperature and high pressure condition flows out of the reactor, enters the reaction water outlet 13, flows through the outer spiral coil 7 with a small caliber (3-8 mm), the flow speed is changed from slow to fast, and the retention time of the hot fluid is reduced. Cooling water enters the cooling cavity 20 from the cooling water inlet 19 and performs rapid and uniform countercurrent heat exchange with hot fluid in the outer spiral coil 7, so that the heat exchange efficiency is improved, the temperature of the hot fluid is rapidly reduced, the outer spiral coil 7 is transited to the inner spiral coil 8, the pipe diameter of the inner spiral coil 8 of the cooled hot fluid is smaller (1-3 mm) and the spiral bending positions are more, the friction resistance and the local resistance are greatly increased, and the pressure is rapidly reduced. Meanwhile, the pressure reduction effect can be controlled by controlling the length and the roughness of the inner spiral coil 8. The fluid which flows out of the inner spiral coil 8 after temperature and pressure reduction flows out of the reaction water outlet 2 after reaching a certain temperature and pressure, and the operation of the continuous hydrothermal synthesis system is completed. The cooling water after heat exchange flows out from the cooling water outlet 6, when the sealed tank body 16 needs to be cleaned, the cleaning water can be directly discharged from the cleaning sewage discharge outlet 11, the sewage discharge valve 21 can control the flow of the cleaning water, so that the blockage and deposition of impurities are prevented, and the long-term, stable and safe operation of the system is ensured.

In a more preferred embodiment of the present invention, a frame stirrer 1 is further included, and the frame stirrer 1 is generally composed of a motor, a stirring blade, and the like, wherein the motor is located on the top cover 3, the stirring shaft penetrates through the sealed tank 16 from top to bottom along the central axis, and the stirring blade is located in the middle of the outer spiral coil 7 and the inner spiral coil 8 so as to be in full contact with the fluid in the cooling cavity 20 in the sealed tank 16. The stirring blades of the frame stirrer 1 should be as close to the internal spiral coil 18 as possible, and the spacing is generally 10-20 mm. The motor of the frame type stirrer 1 drives the blades to circumferentially shear the cold fluid in the tank, so that forced convection can be increased, and the temperature of the hot fluid entering the inner spiral coil 8 can be further reduced due to the increased forced convection. The frequency conversion can be carried out by the motor of the frame type stirrer 1, the flow speed and the flowing state of cooling water are controlled, and the accurate control of the quenching speed is realized.

In a more preferred embodiment of the present invention, the cooling water inlet 19 is located at the lower portion of the sidewall of the sealed tank 16, and the cooling water outlet 6 is located at the upper portion of the sidewall of the sealed tank 16 and is diagonally distributed with respect to the cooling water inlet 19. The side wall of the sealed tank body 16 is also provided with an upper liquid level meter interface 15, a lower liquid level meter interface 18 and an overflow outlet 5, the overflow outlet 5 is positioned above the cooling water outlet 6, and the caliber of the overflow outlet is larger than that of the cooling water outlet 6, so that excessive cooling water can be prevented. The upper liquid level meter interface 15 and the lower liquid level meter interface 18 are both positioned above the cooling water inlet 19 and below the cooling water outlet 6, the flow direction of cold and hot fluid can be controlled through the diagonally distributed cooling water inlets and outlets, and pressure change can be accurately monitored in real time through the upper liquid level meter and the lower liquid level meter.

The above embodiments may be combined in any combination based on the key technology of the present invention.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.