WO2022007378A1

WO2022007378A1 - Apparatus and process for continuously preparing titanium oxychloride solution

Info

Publication number: WO2022007378A1
Application number: PCT/CN2021/070360
Authority: WO
Inventors: 梁立德; 周士钊; 韦贝佩; 冯俊艳; 陈丹; 苏尔田; 周方超
Original assignee: 广西七色珠光材料股份有限公司
Priority date: 2020-07-10
Filing date: 2021-01-05
Publication date: 2022-01-13
Also published as: CN111672346A

Abstract

The present invention relates to the field of chemical industry, and specifically relates to an apparatus and process for continuously preparing a titanium oxychloride solution. The apparatus comprises: a titanium tetrachloride flowmeter, a Venturi mixer, a pure water flowmeter, a falling film absorber, a hydrochloric acid absorption tower, a U-shaped tube, a heat exchanger, a liquid preparation circulation pump, a liquid preparation circulation tank, an absorption circulation pump, a tail gas fan, a hydrochloric acid circulation tank, and a hydrochloric acid circulation pump. The apparatus and process can continuously produce and prepare a titanium oxychloride solution having an adjustable concentration and an adjustable temperature, and reaction heat generated by continuous and mixed reactions can be removed, thereby avoiding bumping caused by a large amount of released heat. The whole system of the apparatus runs under a negative micro-pressure, and therefore, there is no potential safety hazard of gas leakage. The apparatus can continuously suction and convey titanium tetrachloride under a negative pressure according to the metered amount, and is safe and reliable.

Description

A device and process for continuously preparing titanium oxychloride solution

technical field

The invention belongs to the field of chemical industry, and in particular relates to a device and a process for continuously preparing titanium oxychloride solution.

Background technique

Titanium tetrachloride is an important raw material for sponge titanium and titanium-containing compounds. Most of the titanium tetrachloride is used in the production of titanium dioxide and pigments. At room temperature, titanium tetrachloride is a colorless liquid. When exposed to air, it will react with water in the air, producing a large amount of white smoke, and forming a mixture of hydrated titanium dioxide and hydrochloric acid droplets. Titanium tetrachloride is hydrolyzed at a certain temperature and water amount to generate titanium oxychloride. The chemical reaction equation is as follows:

TiCl ₄ +H ₂ O=TiOCl ₂ +2HCl

Titanium tetrachloride undergoes an irreversible hydrolysis reaction at a higher temperature and an excess of water to generate hydrated titanium dioxide. Usually, the side reaction of excessive hydrolysis to generate titanium dioxide is not desirable when preparing a titanium oxychloride solution. The chemical reaction equation for overhydrolysis is as follows:

TiCl ₄ +3H ₂ O=TiO ₂ ·H ₂ O+4HCl

In electronic materials, nano-scale titanium dioxide, pearlescent effect materials and other industries, titanium tetrachloride is often formulated into a certain concentration of titanium oxychloride solution for use in the next process. The existing titanium oxychloride solution preparation equipment is mostly composed of reaction kettle, cooling water, absorption tower and the like. The existing preparation method is generally to first add the metered process water to the reaction kettle, slowly add the metered titanium tetrachloride under stirring, and simultaneously feed cooling water into the reactor jacket, and the tail gas of the reaction kettle is absorbed by the reactor. tower absorption. Since the titanium oxychloride solution is not just a simple physical mixing and dilution of titanium tetrachloride and water, it involves a complex hydrolysis chemical reaction. Therefore, the difference in solution concentration and temperature control during the preparation process will cause different degrees of hydrolysis of titanium tetrachloride. . The preparation process of titanium tetrachloride releases a large amount of chemical reaction heat, and a large amount of hydrochloric acid mist is generated and escaped. The existing preparation method is mostly intermittent operation, and the concentration gradient changes greatly, which causes the temperature in the preparation process to rise, and then easily forms local bumping; moreover, the existing preparation equipment cannot handle the escaping gas in time, which is easy to cause gas leakage, and then Contaminates the environment and interferes with the formulation process.

For example, Chinese patent document CN2923668Y discloses a complete set of titanium tetrachloride dilution equipment. The device consists of a titanium tetrachloride metering tank, a vacuum unit, a mixing nozzle, a titanium tetrachloride preparation tank, and a falling film absorption system. The device uses a vacuum unit to intermittently pump titanium liquid into a metering tank, and then mix it with the pre-quantified process water. The unit operates intermittently and cannot achieve continuous operation. A small amount of concentrated titanium tetrachloride liquid reacts with a large amount of water each time the preparation is started. The initial concentration of the prepared solution is low, which is prone to irreversible excessive hydrolysis reaction, resulting in titanium dioxide, which affects the quality and causes waste. The concentration gradient of the solution in the preparation process of the device varies greatly, which is not conducive to quality control.

Another example: Chinese patent document CN206676368U discloses a production device for titanium oxychloride solution, the device is composed of a liquid storage tank, a reaction kettle, a buffer tank and a vacuum pump. The device utilizes a vacuum pump to suck the titanium tetrachloride into the reaction kettle, and the titanium tetrachloride liquid reacts with the pre-added water in the reaction kettle. The device operates intermittently and cannot be produced continuously. A small amount of pure titanium tetrachloride solution reacts with a large amount of water each time the preparation is started, and the initial concentration of the prepared solution is low, which is prone to irreversible hydrolysis reaction, and a large amount of titanium dioxide is generated, which affects the quality and causes waste. The concentration gradient of the solution in the preparation process of the device varies greatly, which is not conducive to quality control. Improper control of the device will cause hydrochloric acid to enter the vacuum pump and easily damage the equipment.

Another example: Chinese patent document CN102764601A discloses a titanium tetrachloride aqueous solution preparation device and process. The device consists of jet vacuum pump, graphite heat exchanger, titanium tetrachloride mixing tank, acid mist absorption tower, etc. The device and process are operated intermittently and cannot realize continuous production. There is no gas escape channel in the connection between the jet vacuum pump of the device and the heat exchanger, and the hydrogen chloride gas escaped during the preparation process is brought into the heat exchanger, which affects the heat exchange effect.

To sum up, the existing preparation devices and methods of titanium oxychloride solution have the following problems, one is that continuous production cannot be achieved; the other is the risk of excessive hydrolysis side reactions, uneven concentration and local bumping; It is difficult to measure and transfer titanium liquid; fourth, there is the risk of gas leakage and pollution to the environment.

SUMMARY OF THE INVENTION

The first technical problem to be solved by the present invention is the problem that the titanium oxychloride solution cannot be continuously produced and prepared.

The second technical problem to be solved by the present invention is to reduce the excessive hydrolysis side reaction, the uneven concentration of the titanium oxychloride solution, and the problem of bumping caused by the inability to remove a large amount of exothermic heat in the preparation process.

The third technical problem to be solved by the present invention is the difficulty of measuring and transferring titanium tetrachloride liquid.

The fourth technical problem to be solved by the present invention is the problem of environmental pollution caused by gas leakage during the preparation of titanium oxychloride solution.

The object of the present invention is to provide a device and process for continuously preparing a titanium oxychloride solution, which can not only continuously generate a titanium oxychloride solution with stable concentration and temperature, but also can continuously carry out a mixing reaction and remove the reaction It can also continuously recover the hydrochloric acid escaped from the reaction, and can also continuously extract titanium tetrachloride according to the metered negative pressure.

The present invention is achieved through the following technical solutions:

In the first aspect, the present invention provides a device for continuously preparing titanium oxychloride solution, including: titanium tetrachloride flowmeter, venturi mixer, pure water flowmeter, falling film absorber, hydrochloric acid absorption tower, heat exchanger , dosing circulating pump, dosing circulating tank, absorption circulating pump;

Wherein, the titanium tetrachloride flowmeter is connected with the first suction port of the venturi mixer; the circulating liquid inlet of the venturi mixer is connected with the outlet pipe of the dosing circulating pump, and the mixing of the venturi mixer The liquid outlet is connected with the upper pipe side inlet of the heat exchanger; the pure water flow meter is connected with the second suction port of the Venturi mixer; the upper liquid inlet of the falling film absorber is connected with the outlet of the absorption circulation pump through a pipeline , the lower tube side outlet of the falling film absorber is connected with the inlet of the liquid distribution circulation tank, and the upper tube side outlet of the falling film absorber is connected with the lower air inlet pipe of the hydrochloric acid absorption tower; the lower part of the hydrochloric acid absorption tower gas The inlet is connected with the gas outlet of the falling film absorber through a pipeline; the upper gas outlet of the heat exchanger is connected with the lower pipe side inlet of the falling film absorber, and the lower pipe side outlet of the heat exchanger is connected with the liquid distribution circulation tank. The inlet is connected; the inlet pipe of the liquid dispensing circulation pump is connected with the outlet of the liquid dispensing circulation tank; the inlet pipe of the absorption circulation pump is connected with the outlet of the liquid dispensing circulation tank. Using a venturi mixer to continuously extract titanium tetrachloride and pure water at the same time can realize continuous production; using a venturi mixer to realize the mixing of a large amount of circulating mother liquor with a small amount of titanium tetrachloride and a small amount of pure water, reducing the reaction temperature rise, Reduced concentration gradients.

The titanium tetrachloride flowmeter is preferably a mass flowmeter, and the pure water flowmeter is preferably a vortex flowmeter.

According to the concentration of the titanium oxychloride solution to be prepared, the flow rates of titanium tetrachloride and pure water extracted by the Venturi mixer are respectively set. Suction pipe flow is regulated by valve opening and monitored by a flow meter.

The falling film absorber absorbs the hydrogen chloride produced by the reaction and returns it to the circulating mother liquor in the form of hydrochloric acid. Hydrochloric acid can maintain the acidity of the prepared titanium oxychloride solution and inhibit the further occurrence of excessive hydrolysis side reactions. The heat absorbed by the hydrochloric acid in the falling film absorber is taken away by the refrigerant, and the heat exchange function of the falling film absorber can also reduce the temperature of the circulating liquid.

The dosing circulating pump is used to pump the circulating mother liquor into the Venturi mixer and provide power for the vacuum generated by the two suction ports of the Venturi mixer.

The dosing circulation tank is used to buffer and store the prepared titanium oxychloride solution, and provide the volume space for the solution circulation and mixing.

The absorption circulating pump is used to pump the circulating mother liquor sent to the falling film absorber; it is also used to transport the prepared titanium oxychloride solution to the required process.

Preferably, in the above device, the Venturi mixer includes a circulating liquid inlet, a nozzle, a constriction section, a diffusion section, a mixing chamber, a first suction port, a second suction port and a mixed liquid outlet; the first suction port is from The tangential direction of the outer circle of the mixing chamber enters the mixing chamber; the second suction port enters the mixing chamber from the tangential direction of the outer circle of the mixing chamber; the centerlines of the first suction port and the second suction port are parallel to each other in space , the first suction port and the second suction port are located at any position in the axial direction of the outer peripheral surface of the mixing chamber, preferably, the first suction port and the second suction port are located in the same cross section of the mixing chamber; so The centerline of the first suction port and the centerline of the circulating liquid inlet are vertically disjoint in space; the centerline of the second suction port and the centerline of the circulating liquid inlet are vertically disjoint in space.

When the circulating mother liquid is ejected through the nozzle (smaller than the inlet pipe diameter of the circulating liquid), the flow rate increases and the pressure decreases, so that a certain vacuum is formed in the mixing chamber. Titanium tetrachloride and pure water enter through the two suction pipes respectively by means of vacuum. Venturi mixer. The two suction port pipes arranged tangentially can reduce the mutual influence when the pressure of the two suction port pipes is unbalanced, and it is more conducive to mixing evenly.

Preferably, in the above device, a gas-liquid separation space is provided on the upper part of the tube side of the heat exchanger. The gas-liquid separation space can prevent the gas from entering the tube side of the heat exchanger and affect the heat exchange.

Preferably, in the above device, the device further comprises a U-shaped pipe; the U-shaped pipe is arranged between the outlet of the lower pipe side of the heat exchanger and the inlet of the liquid dosing circulation tank; preferably, the U-shaped pipe The bottom of the pipe is provided with a drain pipe and a valve. The bottom of the U-shaped pipe is provided with a drain pipe and a valve to facilitate draining during maintenance.

Preferably, in the above device, the refrigerant is in the shell side of the heat exchanger, and the reaction heat is taken away by the refrigerant. By adjusting the flow and temperature of the refrigerant, the temperature of the titanium oxychloride solution can be adjusted.

Preferably, in the above device, the height of the U-shaped tube is 50% to 90% of the height of the tube side of the heat exchanger, preferably 80%. The U-shaped tube within the above height range can ensure that the liquid in the tube side of the heat exchanger fills the tube.

Preferably, in the above device, the device further comprises: a tail gas fan, a hydrochloric acid circulation tank, and a hydrochloric acid circulation pump; wherein, the upper gas outlet of the hydrochloric acid absorption tower is connected with the inlet of the tail gas fan through a pipeline, and the gas outlet of the hydrochloric acid absorption tower is The upper liquid inlet is connected with the outlet pipe of the hydrochloric acid circulating pump through the pipeline, and the lower liquid outlet of the hydrochloric acid absorption tower is connected with the inlet of the hydrochloric acid circulating tank through the pipeline; the outlet of the exhaust fan is connected with the exhaust gas treatment system; the hydrochloric acid circulating tank The outlet of the hydrochloric acid circulation pump is connected with the inlet of the hydrochloric acid circulation pump; the hydrochloric acid circulation tank is provided with a pure water inlet.

The hydrochloric acid absorption tower is used to absorb the hydrogen chloride gas that is not completely absorbed by the falling film absorber, and produce hydrochloric acid as a by-product to improve economic benefits.

A small amount of exhaust gas enters the exhaust gas treatment system through the exhaust fan and is discharged after qualified treatment. The exhaust fan is arranged at the end of the gas phase pipeline of the whole device, so that the whole device can maintain a slight negative pressure and reduce the risk of environmental pollution caused by the leakage of hydrogen chloride gas at each sealing point in the device.

The hydrochloric acid circulation tank is used to buffer and store the by-product hydrochloric acid, and provide the volume space for the hydrochloric acid circulation and mixing. The hydrochloric acid circulation tank is provided with a pure water inlet. Adding pure water can adjust the concentration of hydrochloric acid and maintain the ability of the hydrochloric acid circulating liquid to absorb hydrogen chloride.

The hydrochloric acid circulating pump is used to pump the hydrochloric acid circulating liquid; it is also used to transport the by-product hydrochloric acid to the required process.

In a second aspect, the present invention provides a process for continuously preparing a titanium oxychloride solution, comprising the following steps: a titanium tetrachloride flowmeter is drawn into a Venturi mixer from a first suction port, and at the same time pure water flows through the pure water flow The meter is drawn into the Venturi mixer from the second suction port, and the circulating mother liquor is transported into the Venturi mixer by the dosing circulating pump, and the extracted titanium tetrachloride and pure water are fully mixed with a large amount of circulating mother liquor. The produced titanium oxychloride solution is transported by the liquid dispensing circulating pump into the liquid dispensing circulating tank, the heat generated by the mixing reaction is taken away by the refrigerant in the heat exchanger, and the hydrogen chloride gas generated by the reaction is first transported by the absorption circulating pump into the lowering tank. The membrane absorber absorbs, and then returns to the circulating mother liquor in the liquid dispensing circulation tank in the form of hydrochloric acid, and the rest of the hydrogen chloride gas is washed and absorbed by the hydrochloric acid absorption tower to obtain the by-product hydrochloric acid.

The hydrogen chloride absorbed by the falling film absorber is returned to the circulating mother liquor in the form of hydrochloric acid, which can inhibit the excessive hydrolysis of the titanium oxychloride solution.

Preferably, in the above process, titanium tetrachloride is drawn into the venturi mixer from the first suction port through the titanium tetrachloride flowmeter from the tangential direction of the mixing chamber, while pure water is sucked from the second through the pure water flowmeter. The mouth is drawn into the venturi mixer from the tangential direction of the outer circle of the mixing chamber, the flow direction of the titanium tetrachloride and the flow direction of the circulating mother liquid form a spiral mixing, and the flow direction of the pure water and the flow direction of the circulating mother liquid form a spiral mixing. Spiral mix. The tangential direction of entry is to reduce the mutual interference when the pressure of the two suction ports is unbalanced, and the spiral mixing is more uniform.

The flow rate of the circulating liquid inlet pipe of the Venturi mixer is several times to dozens of times the flow rate of the extracted titanium tetrachloride and pure water. A large amount of circulating mother liquor can reduce the concentration gradient change of the prepared titanium oxychloride solution, and a large amount of circulating mother liquor can be used as a heat carrier to reduce the temperature rise of the reaction system, thereby bringing heat into the heat exchanger.

Preferably, in the above-mentioned process, the hydrogen chloride gas generated by the reaction is separated from the liquid through the gas-liquid separation space in the upper part of the tube side of the heat exchanger. After separation, the hydrogen chloride gas enters the falling film absorber through the gas phase pipeline, and the liquid enters the tube side of the heat exchanger. .

Preferably, in the above process, the refrigerant is one or more of circulating cooling water, frozen brine, and ethylene glycol mixed aqueous solution.

When the concentration of the prepared titanium oxychloride solution is greater than or equal to 4 mol/L, the refrigerant is preferably circulating cooling water; when the concentration of the prepared titanium oxychloride solution is lower than 4 mol/L, the refrigerant is preferably -10 ℃～-30℃ low temperature ethylene glycol mixed aqueous solution.

Preferably, when the concentration of the prepared titanium oxychloride solution is greater than or equal to 4 mol/L, the temperature of the prepared titanium oxychloride solution is controlled to be lower than 50°C; preferably, when the prepared concentration of the prepared titanium oxychloride solution is equal to 2 mol /L, the temperature of the prepared titanium oxychloride solution is controlled to be lower than 18°C.

Preferably, in the above process, the by-product hydrochloric acid is transported into the hydrochloric acid circulation tank by the hydrochloric acid circulating pump, and a small amount of tail gas enters the tail gas treatment system through the tail gas fan for treatment.

The technical scheme of the present invention has the following advantages:

The device and process for preparing the titanium oxychloride solution of the present invention can continuously produce and prepare the titanium oxychloride solution with adjustable concentration and temperature, and can remove the reaction heat generated by the continuous mixing reaction and avoid a large amount of exothermic heat. The bumping caused by the excessive hydrolysis inhibits the occurrence of side reactions. Due to the micro-negative pressure operation of the whole system, there is no hidden safety hazard of gas leakage. The device and process of the present invention can continuously suction and transport titanium tetrachloride by metered negative pressure, which is safe and reliable.

Description of drawings

In order to make the content of the present invention easier to be understood clearly, the present invention will be described in further detail below according to specific embodiments of the present invention and in conjunction with the accompanying drawings, wherein:

Fig. 1 is the structural representation of the device for continuously preparing titanium oxychloride solution in the embodiment of the present invention 1; wherein, 1-titanium tetrachloride flowmeter, 2-venturi mixer, 3-pure water flowmeter, 4-down Membrane absorber, 5—hydrochloric acid absorption tower, 6—exhaust fan, 7—heat exchanger, 8—U-shaped pipe, 9—liquid distribution circulation pump, 10—liquid distribution circulation tank, 11—absorption circulation pump, 12—hydrochloric acid Circulating tank, 13—hydrochloric acid circulating pump;

Fig. 2 is the structural schematic diagram of the Chinese Chuli mixer in Example 1 of the present invention; wherein, 14-circulating liquid inlet, 15-mixing chamber, 16-nozzle, 17-contraction section, 18-diffusion section, 19-mixed liquid outlet, 20—the first suction port, 21—the second suction port.

detailed description

Example 1

As shown in Figure 1, the device for continuously preparing titanium oxychloride solution in this embodiment includes: titanium tetrachloride flowmeter 1, Venturi mixer 2, pure water flowmeter 3, falling film absorber 4, hydrochloric acid absorption tower 5. The exhaust fan 6, the heat exchanger 7, the U-shaped pipe 8, the liquid distribution circulation pump 9, the liquid distribution circulation tank 10, the absorption circulation pump 11, the hydrochloric acid circulation tank 12, and the hydrochloric acid circulation pump 13.

Wherein, the titanium tetrachloride flowmeter 1 is connected with the first suction port 20 of the venturi mixer 2; the circulating liquid inlet 14 of the venturi mixer 2 is connected with the outlet pipe of the liquid distribution circulating pump 9, and the venturi mixer 2 The mixed liquid outlet 19 is connected with the upper pipe side inlet of the heat exchanger 7; the pure water flow meter 3 is connected with the second suction port 21 of the Venturi mixer 2; the upper liquid inlet of the falling film absorber 4 is connected with the absorption circulation pump through the pipeline The outlet of 11 is connected, the lower pipe-side outlet of the falling film absorber 4 is connected with the inlet of the liquid distribution circulation tank 10, and the upper pipe-side outlet of the falling film absorber 4 is connected with the lower air inlet pipe of the hydrochloric acid absorption tower 5; the hydrochloric acid absorption tower 5 The lower gas inlet of the hydrochloric acid absorption tower 5 is connected with the gas outlet of the falling film absorber 4 through the pipeline, the upper gas outlet of the hydrochloric acid absorption tower 5 is connected with the inlet of the exhaust fan 6 through the pipeline, and the upper liquid inlet of the hydrochloric acid absorption tower 5 is connected with the hydrochloric acid circulating pump 13 through the pipeline. The outlet pipe is connected, and the lower liquid outlet of the hydrochloric acid absorption tower 5 is connected with the inlet of the hydrochloric acid circulation tank 12 through the pipeline; the outlet of the tail gas fan 6 is connected with the tail gas treatment system; the upper gas outlet of the heat exchanger 7 is connected with the falling film absorber 4. The lower tube side inlet is connected, the lower tube side outlet of the heat exchanger 7 is connected with the inlet of the liquid distribution circulation tank 10, and the upper part of the tube side of the heat exchanger 7 is provided with a gas-liquid separation space; the heat exchanger 7 is a YKch-30 type circular The block-hole graphite dilution cooler has a heat exchange area of 30 square meters; the U-shaped tube 8 is arranged between the lower tube side outlet of the heat exchanger 7 and the inlet of the liquid distribution circulation tank 10, and the height of the U-shaped tube 8 is equal to 80% of the tube height of the heater 7, the diameter of the U-shaped tube 8 is 200mm; the inlet pipe of the liquid distribution circulation pump 9 is connected with the outlet of the liquid distribution circulation tank 10; the inlet pipe of the absorption circulation pump 11 is connected with the liquid distribution circulation tank 10 is connected to the outlet; the outlet of the hydrochloric acid circulation tank 12 is connected to the inlet of the hydrochloric acid circulation pump 13, and the hydrochloric acid circulation tank 12 is provided with a pure water inlet.

As shown in FIG. 2 , the Chinese Churi mixer 2 of this embodiment includes a circulating liquid inlet 14 , a mixing chamber 15 , a nozzle 16 , a constricting section 17 , a diffusing section 18 , a mixed liquid outlet 19 , a first suction port 20 and a second suction port mouth 21. The first suction port 20 enters the mixing chamber 15 from the tangential direction of the outer circle of the mixing chamber 15; the second suction port 21 enters the mixing chamber 15 from the tangential direction of the outer circle of the mixing chamber 15; the first suction port 20 is connected to the mixing chamber 15. The center lines of the second suction port 21 are parallel to each other in space, the first suction port 20 and the second suction port 21 are located at any position in the axial direction of the outer circumferential surface of the mixing chamber, and the first suction port 20 and the The second suction port 21 is located in the same cross-section of the mixing chamber 15; the centerline of the first suction port 20 and the centerline of the circulating liquid inlet 14 are vertically disjoint in space; the second suction port 21 The centerline of , and the centerline of the circulating liquid inlet 14 are vertically disjoint in space. The relationship between the structural parameters is as follows: the relationship between the diameter d1 of the circulating liquid inlet 14 and the diameter d2 of the nozzle 16 is d1≈2×d2; the relationship between the diameter d2 of the nozzle 16 and the diameter d3 of the constricted section 17 is d2≈d3; The relationship between the length h and the diameter d3 of the constricted section 17 h≈d3; the distance between the end of the nozzle 16 and the constricted section 17 h1≈d2; the relationship between the diameter d5 of the first suction port 20 and the diameter d2 of the nozzle 16 is d5=(0.2～ 0.3)×d2; the relationship between the diameter d4 of the mixed liquid outlet 19 and the diameter d1 of the circulating liquid inlet 14 is d4≈1.5×d1; the included angle of the diffusion section 18 is about 7°; the included angle of the constriction section is about 25°. The specific structural parameters are: d1=65mm, d2=30mm, d3=30mm, d4=100mm, d5=15mm, d5=15mm, h=30mm, h1=30mm, the included angle of the diffusion section 18 is 7°, and the contraction section The included angle is 25°. Wherein, the material of the venturi mixer 2 is titanium alloy TA2 or polytetrafluoroethylene.

The device start-up sequence for continuously preparing titanium oxychloride solution in the present embodiment is as follows:

1) Close the valve of the first suction port 20.

2) Close the valve of the second suction port 21 .

3) Close the valve of the hydrochloric acid outlet pipe on the outlet branch pipe of the hydrochloric acid circulating pump 13.

4) Close the valve of the titanium oxychloride outlet pipe on the outlet branch pipe of the absorption circulation pump 11.

5) Open the valve of the refrigerant inlet of the falling film absorber 4. The refrigerant enters the shell side of the falling film absorber.

6) Open the valve of the refrigerant outlet of the falling film absorber 4. The refrigerant takes away the heat of reaction from the shell side.

7) Open the refrigerant inlet valve of heat exchanger 7. The refrigerant enters the shell side of the falling film absorber.

8) Open the refrigerant outlet valve of heat exchanger 7. The refrigerant takes away the heat of reaction from the shell side.

9) Add the titanium oxychloride solution of the concentration to be prepared in the liquid preparation circulating tank 10 as the circulating mother liquor. The circulating mother liquor can reduce the concentration gradient in the preparation process, and can also be used as a heat carrier to reduce the temperature rise in the preparation process and bring heat into the heat exchanger.

10) Pure water is added to the hydrochloric acid circulation tank 12. Pure water acts as an absorbent to absorb hydrogen chloride gas.

11) The exhaust gas treatment system is ready for exhaust gas treatment.

12) Start the exhaust fan 6 to provide a slight negative pressure for the whole system and provide the power for the gas phase flow.

13) Start the hydrochloric acid circulating pump 13 to pump the hydrochloric acid circulating liquid.

14) Start the absorption circulating pump 11 to pump the circulating absorption liquid.

15) Start the liquid dispensing circulating pump 9 to pump the dispensing circulating liquid. The circulating fluid powers the negative pressure at the suction port of the Venturi mixer.

16) Open the valve of the pure water inlet of the second suction port 21, observe the pure water flow meter 3, and adjust the valve opening to the set flow rate.

17) Open the valve of the titanium tetrachloride inlet of the first suction port 20, observe the titanium tetrachloride flowmeter 1, and adjust the valve opening to the set flow rate.

18) Depending on the temperature of the titanium oxychloride solution prepared, adjust the opening of the refrigerant inlet valve of the heat exchanger 7, or adjust the temperature of the refrigerant. Adjust the opening of the refrigerant inlet valve of the falling film absorber 4.

19) Sampling to detect the concentration of the titanium oxychloride solution, and fine-tuning the flow rate of titanium tetrachloride or pure water entering the Venturi mixer 2 according to the change of the concentration.

20) Sampling and detecting the concentration of by-product hydrochloric acid, and adjusting the pure water flow into the hydrochloric acid circulation tank 12 depending on the concentration change.

21) After the system is stabilized, the valve on the outlet branch pipe of the absorption circulation pump 11 can be opened, and the qualified titanium oxychloride solution can be continuously produced according to the required amount.

22) After the system is stabilized, the valve on the outlet branch pipe of the hydrochloric acid circulating pump 13 can be opened, and the by-product hydrochloric acid can be continuously produced according to the required amount.

23) Drive complete.

The parking sequence is as follows:

1) Close the valve of the hydrochloric acid outlet pipe on the outlet branch pipe of the hydrochloric acid circulating pump 13.

2) Close the valve of the titanium oxychloride outlet pipe on the outlet branch pipe of the absorption circulation pump 11.

3) Close the valve of the first suction port 20 and stop the supply of titanium tetrachloride.

4) Close the valve of the second suction port 21 to stop the supply of pure water.

5) Close the pure water inlet valve on the hydrochloric acid circulation tank 12.

6) After the cycle runs for a period of time.

7) Close the valve of the refrigerant inlet of the falling film absorber 4.

8) Close the valve of the refrigerant outlet of the falling film absorber 4.

9) Close the refrigerant inlet valve of heat exchanger 7.

10) Close the refrigerant outlet valve of heat exchanger 7.

11) Stop the dosing circulating pump 9.

12) Stop the absorption circulating pump 11.

13) Stop the hydrochloric acid circulating pump 13.

14) Stop the exhaust fan 6 .

15) Parking is complete.

In this embodiment, the process of continuously preparing a titanium oxychloride solution with a concentration of 4 mol/L includes the following steps: titanium tetrachloride passes through the titanium tetrachloride flowmeter 1 from the first suction port 20 from the outer circle tangent of the mixing chamber 15 At the same time, pure water is drawn into the Venturi mixer 2 from the tangential direction of the outer circle of the mixing chamber 15 from the second suction port 21 through the pure water flow meter 3, and the titanium tetrachloride is The flow direction and the flow direction of the circulating mother liquor form a spiral mixing, the flow direction of the pure water and the flowing direction of the circulating mother liquor form a spiral mixing, and the circulating mother liquor is transported into the Venturi mixer 2 by the liquid dispensing circulating pump 9, and the extracted tetrachloride Titanium and pure water are fully mixed with a large amount of circulating mother liquor, and the heat generated by the mixing reaction is taken away by the refrigerant circulating cooling water in the heat exchanger 7. The inlet temperature of the refrigerant circulating cooling water is 32 ° C, and the outlet temperature is 37 ° C. The reaction generates The hydrogen chloride gas is first transported by the absorption circulating pump 11 into the falling film absorber 4 for absorption, and then returned to the circulating mother liquor of the liquid dispensing circulation tank 10 in the form of hydrochloric acid, and the remaining hydrogen chloride gas is washed and absorbed by the hydrochloric acid absorption tower 5 to obtain by-products. hydrochloric acid.

Wherein, the hydrogen chloride gas generated by the reaction is separated from the liquid through the gas-liquid separation space in the upper part of the tube side of the heat exchanger 7, and after separation, the hydrogen chloride gas enters the falling film absorber 4 through the gas phase pipeline, and the liquid enters the tube side of the heat exchanger 7. The by-product hydrochloric acid is transported by the hydrochloric acid circulating pump 13 into the hydrochloric acid circulating tank 12, and a small amount of tail gas enters the tail gas treatment system through the tail gas fan 6 for processing.

The flow rate of titanium tetrachloride introduced into the first suction port 20 of the venturi mixer 2 is 750 L/h, and the flow rate of pure water introduced into the second suction port 21 is 1000 L/h. Flow in liquid circulating pump 9 Q = 50m ³ / h, head H = 30m; absorbent circulating pump flow rate 11 Q = 50m ³ / h, head H = 30m; flow circulation hydrochloric acid pump 13 Q = 50m ³ / h, Head H=30m.

The device and process for continuously preparing titanium oxychloride solution in this embodiment can realize the production of titanium oxychloride solution with a concentration of 4 mol/L and a temperature ≤ 50°C with a continuous production capacity of 1250 L/h.

Comparative Example 1

The titanium tetrachloride dilution complete set as disclosed in CN2923668Y is used for operation, which consists of a titanium tetrachloride metering tank, a glass sight tube, a mixed nozzle, a vacuum unit, a titanium tetrachloride preparation tank, a first-stage falling film absorption tower, It is composed of absorption circulation tank, secondary falling film absorption tower, voltage stabilizer tube and No. 2 circulating pump.

Since the device uses a vacuum unit to pump titanium tetrachloride to the metering tank, this method of transferring titanium tetrachloride will cause hydrochloric acid mist to enter the vacuum unit, which is likely to cause corrosion and damage to the vacuum unit.

The device adopts the intermittent operation mode, and the intermittent operation cannot avoid that the ratio of water to titanium tetrachloride at the initial stage of preparation is far greater than the chemical balance of titanium oxychloride, causing the side reaction of excessive hydrolysis.

Comparative Example 2

Adopt the titanium tetrachloride aqueous solution preparation device as announced in CN102764601 to operate, it is made up of jet vacuum pump, anticorrosion centrifugal pump, graphite heat exchanger, titanium tetrachloride mixing tank, absorption tower, centrifugal fan etc.

The device uses a jet vacuum pump to suck titanium tetrachloride mixed with the circulating liquid, which has the problem of unbalanced suction. In addition, the device adopts intermittent operation, and the concentration of the system solution will decrease when pure water is added. The system solution concentration will increase. The whole process operation process is the process of system solution concentration fluctuation.

Obviously, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation manner. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. And the obvious changes or changes derived from this are still within the protection scope of the present invention.

Claims

A device for continuously preparing titanium oxychloride solution, characterized in that it comprises: a titanium tetrachloride flowmeter (1), a Venturi mixer (2), a pure water flowmeter (3), a falling film absorber (4) ), a hydrochloric acid absorption tower (5), a heat exchanger (7), a liquid dispensing circulation pump (9), a liquid dispensing circulation tank (10), and an absorption circulation pump (11);

Wherein, the titanium tetrachloride flowmeter (1) is connected with the first suction port (20) of the venturi mixer (2); the circulating liquid inlet (14) of the venturi mixer (2) is connected with the liquid dispensing port The outlet pipe of the circulating pump (9) is connected, and the mixed liquid outlet (19) of the venturi mixer (2) is connected with the upper pipe side inlet of the heat exchanger (7); the pure water flowmeter (3) is connected to the The second suction port (21) of the venturi mixer (2) is connected; the upper liquid inlet of the falling film absorber (4) is connected with the outlet of the absorption circulation pump (11) through a pipeline, and the falling film absorber ( 4) the lower pipe side outlet of the lower part is connected with the inlet of the liquid distribution circulation tank (10), and the upper pipe side outlet of the falling film absorber (4) is connected with the lower air inlet pipe of the hydrochloric acid absorption tower (5); the hydrochloric acid absorption The lower gas inlet of the tower (5) is connected with the gas outlet of the falling film absorber (4) through a pipeline; the upper gas outlet of the heat exchanger (7) is connected with the lower pipe side inlet of the falling film absorber (4), The outlet of the lower pipe side of the heat exchanger (7) is connected with the inlet of the liquid distribution circulation tank (10); the inlet pipe of the liquid distribution circulation pump (9) is connected with the outlet of the liquid distribution circulation tank (10); The inlet pipe of the absorption circulation pump (11) is connected with the outlet of the liquid distribution circulation tank (10).
The device according to claim 1, characterized in that, the Venturi mixer (2) comprises a circulating liquid inlet (14), a constriction section (17), a nozzle (16), a diffusion section (18), a mixing chamber ( 15), the first suction port (20), the second suction port (21) and the mixed liquid outlet (19); the first suction port (20) enters the mixing chamber (15) from the tangential direction of the outer circle of the mixing chamber (15). 15); the second suction port (21) enters the mixing chamber (15) from the tangential direction of the outer circle of the mixing chamber (15); the difference between the first suction port (20) and the second suction port (21) is The center lines are parallel to each other in space, the first suction port (20) and the second suction port (21) are located at any position in the axial direction of the outer circumferential surface of the mixing chamber, preferably, the first suction port (20) The same cross-section as the second suction port (21) is located in the mixing chamber (15); the centerline of the first suction port (20) and the centerline of the circulating liquid inlet (14) are vertically different in space. Intersect; the center line of the second suction port (21) and the center line of the circulating liquid inlet (14) are vertically disjoint in space.
The device according to claim 1 or 2, characterized in that, a gas-liquid separation space is provided on the upper part of the tube side of the heat exchanger (7).
The device according to any one of claims 1-3, characterized in that, the device further comprises a U-shaped pipe (8), and the U-shaped pipe (8) is arranged on the side of the heat exchanger (7). Between the outlet of the lower pipe side and the inlet of the liquid distribution circulation tank (10); preferably, a drain pipe and a valve are arranged at the bottom of the U-shaped pipe (8).
The device according to claim 4, characterized in that, the height of the U-shaped pipe (8) is 50% to 90% of the height of the tube side of the heat exchanger (7), preferably 80%.
The device according to any one of claims 1-5, characterized in that, the device further comprises: a tail gas fan (6), a hydrochloric acid circulating tank (12), and a hydrochloric acid circulating pump (13); wherein, the hydrochloric acid The upper gas outlet of the absorption tower (5) is connected with the inlet of the tail gas fan (6) through a pipeline, and the upper liquid inlet of the hydrochloric acid absorption tower (5) is connected with the outlet pipe of the hydrochloric acid circulating pump (13) through a pipeline, and the hydrochloric acid The bottom liquid outlet of the absorption tower (5) is connected with the inlet of the hydrochloric acid circulation tank (12) by pipeline; the outlet of the tail gas fan (6) is connected with the tail gas treatment system; the outlet of the hydrochloric acid circulation tank (12) is connected with the hydrochloric acid circulation The inlet of the pump (13) is connected; the hydrochloric acid circulation tank (12) is provided with a pure water inlet.
A process for continuously preparing a titanium oxychloride solution, characterized in that it comprises the following steps: a titanium tetrachloride flowmeter (1) is drawn into a Venturi mixer (2) from a first suction port (20), and simultaneously Pure water is pumped into the Venturi mixer (2) from the second suction port (21) through the pure water flow meter (3), while the circulating mother liquor is transported into the Venturi mixer (2) by the dosing circulating pump (9). ), the extracted titanium tetrachloride and pure water are fully mixed with a large amount of circulating mother liquor, and the titanium oxychloride solution of production is transported into the dispensing circulation tank (10) by the dispensing circulating pump (9), and the mixed reaction produces The heat is taken away by the refrigerant in the heat exchanger (7), and the hydrogen chloride gas generated by the reaction is first transported by the absorption circulating pump (11) into the falling film absorber (4) for absorption, and then returned to the liquid preparation in the form of hydrochloric acid In the circulating mother liquor of the circulating tank (10), the remaining hydrogen chloride gas is washed and absorbed by the hydrochloric acid absorption tower (5) to obtain the by-product hydrochloric acid.
The process according to claim 7, characterized in that the titanium tetrachloride is extracted to the venturi from the tangential direction of the outer circle of the mixing chamber (15) through the titanium tetrachloride flowmeter (1) from the first suction port (20) In the inner mixer (2), at the same time pure water is drawn into the Venturi mixer (2) from the tangential direction of the outer circle of the mixing chamber (15) through the second suction port (21) through the pure water flow meter (3), The flow direction of the titanium tetrachloride and the flow direction of the circulating mother liquor form a spiral mixing, and the flow direction of the pure water and the circulating mother liquor form a spiral mixing.
The process according to claim 7 or 8, wherein the hydrogen chloride gas generated by the reaction is separated from the liquid by the gas-liquid separation space in the upper part of the tube side of the heat exchanger (7), and the hydrogen chloride gas enters the falling film through the gas phase pipeline after the separation The absorber (4), the liquid enters the tube side of the heat exchanger (7).
The process according to any one of claims 7-9, wherein the refrigerant is one or more of circulating cooling water, frozen brine, and ethylene glycol mixed aqueous solution; and/or

The by-product hydrochloric acid is transported by the hydrochloric acid circulation pump (13) into the hydrochloric acid circulation tank (12), and a small amount of tail gas enters the tail gas treatment system through the tail gas fan (6) for treatment.