Shockproof steam heating system for causticizing aluminum oxide

Abstract

The utility model discloses a shockproof steam heating system for aluminum oxide causticization in the field of aluminum oxide production, and the shockproof steam heating system comprises a washing liquid pipe, a liquid discharge pipe, a steam pipe and a Laval pipe mixing heater, the washing liquid pipe is sequentially provided with a washing liquid flowmeter and a first washing liquid thermometer, the liquid discharge pipe is sequentially provided with a second washing liquid thermometer and a washing liquid pressure gauge, and the Laval pipe mixing heater is provided with a second washing liquid thermometer and a second washing liquid pressure gauge. The steam pipe is provided with a steam flow adjusting valve, a steam inlet mixing pressure gauge and a steam pressure adjusting valve, the steam inlet mixing pressure gauge is located at the end, close to the Karval pipe mixing heater, of the steam pipe, and the system is communicated with a controller through electric signals. The device can control the steam inlet amount according to the flow and the speed of the washing liquid, measures the pressure through the washing liquid pressure gauge, controls the pressure value of the steam pipe, balances the pressure difference of the steam pipe before and after heating, can reduce the influence caused by the pressure fluctuation of the steam pipe, and stabilizes the temperature and the flow of the washing liquid.

Description

Technical Field

[0001] The utility model belongs to the field of aluminum oxide production, and particularly relates to a shockproof steam heating system for aluminum oxide causticizing. Background Art

[0002] The causticizing of the side stream of the washing liquid is one of the essential processes in the production of alumina. As the quality of alumina ore continues to decline, a lot of high carbon and other impurities are mixed in the alumina ore. The impurities enter the alumina production system with the production of alumina. The high carbon impurities will react with the sodium aluminate solution to form sodium carbonate. As the sodium carbonate continues to accumulate, the accumulation of sodium carbonate in the sodium aluminate solution will greatly reduce the production efficiency of alumina and reduce the production of alumina.

[0003] In order to remove sodium carbonate from the sodium aluminate solution, the method of causticizing the side stream of the washing liquid will be adopted. In the causticizing system of the washing liquid side stream, the washing liquid is first pre-causticized, and the solid and the washing liquid are causticized for the second time after solid-liquid separation. In order to obtain a higher causticizing efficiency, the temperature of the second causticizing reaction is generally controlled above 105°C. In the traditional heating device, the washing liquid passes through the large-diameter washing liquid pipe, and the steam passes through the small-diameter steam pipe, and the steam pipe and the washing liquid pipe are perpendicular to each other. The heating device is simple to install and occupies a small area, but it can only meet the small-scale heating and temperature rise of the washing liquid. If the heating and temperature rise effect is further improved, the amount of steam needs to be increased. However, in the heating device, after the amount of steam is increased, it cannot be evenly mixed with the washing liquid. When a large amount of steam enters the washing liquid pipe through a small-diameter pipe, the vibration of the heating device will be increased, resulting in unstable operation of the heating device.

[0004] On this basis, a new improved method is provided, in which a Lafarge tube mixing heater is added in the middle of the heating device, such as Figure 1As shown, a Rafael tube mixing heater is arranged in the system, including a Rafael tube and a sleeve, a plurality of through holes inclined toward the outlet are opened at the tail of the Rafael tube, the sleeve is sleeved on the outside of the Rafael tube, the middle of the sleeve is connected to the steam pipe, the inlet of the Rafael tube is connected to the washing liquid pipe, the outlet of the Rafael tube is connected to the drain pipe, the inside of the Rafael tube is a washing liquid channel, and the position between the outside of the Rafael tube and the sleeve is a steam chamber. The Rafael tube mixing heater increases the flow rate when the washing liquid flows through the tail of the Rafael tube, and the steam enters the inside of the Rafael tube through the through hole of the tail to achieve full mixing of steam and washing liquid. However, in the second causticizing stage of the washing liquid side stream causticizing, when the large flow washing liquid needs to be heated, the pressure fluctuation of the steam pipe will directly affect the steam-pressure differential fluctuation of the Rafael tube mixing heater, and the pressure differential fluctuation of the Rafael tube mixing heater will cause the noise of the heating device to increase, and also affect the fluctuation of the washing liquid temperature at the outlet of the Rafael tube mixing heater, and the vibration of the drain pipe. It may even cause the washing liquid to flow back into the steam pipe and the washing liquid to vaporize extremely rapidly, resulting in flash explosions and severe vibrations in the steam pipe, which in turn affects the temperature and flow fluctuations of the washing liquid. Utility Model Content

[0005] The utility model aims to provide a shockproof steam heating system for aluminum oxide causticizing to solve the problems of uneven temperature rise of washing liquid, large vibration and high noise caused by uneven steam flow.

[0006] A shockproof steam heating system for alumina causticizing in the present scheme comprises a washing liquid pipe, a drain pipe, a steam pipe and a Rafale tube mixing heater, wherein the washing liquid pipe is provided with a washing liquid flow meter and a first washing liquid thermometer in sequence, the drain pipe is provided with a second washing liquid thermometer and a washing liquid pressure gauge in sequence, the steam pipe is provided with a steam flow regulating valve, a steam inlet mixing pressure gauge and a steam pressure regulating valve, the steam inlet mixer pressure gauge is located at one end of the steam pipe close to the Rafale tube mixing heater, and the components in the heating system are all connected to a controller via electrical signals.

[0007] How this solution works and its beneficial effects:

[0008] 1. When the system is working, the washing liquid enters the washing liquid pipe. The first washing liquid thermometer and washing liquid flowmeter of the washing liquid pipe can measure the current temperature and flow of the washing liquid, and then feed back the value to the controller. The second washing liquid thermometer sets the required temperature of the washing liquid after heating in advance. Therefore, the controller can control the steam flow regulating valve according to the temperature and flow to control the required amount of steam, so as to avoid the situation that the steam volume does not match the washing liquid flow and temperature, resulting in excessive steam volume, so that the steam and washing liquid are not evenly integrated and cause the steam pipe vibration.

[0009] 2. The washing liquid pressure gauge can measure the pressure of the washing liquid after heating and feed the value back to the controller. The controller can control the steam pressure regulating valve to adjust the pressure of the steam inlet mixer pressure gauge to avoid the situation where the steam pressure is too low to enter the Lafarge tube mixing heater. The step pressure difference of the steam pipe pressure, the pressure of the steam inlet mixer pressure gauge and the washing liquid pressure gauge can be achieved to balance the pressure difference of the steam pipe before and after heating and the pressure of the washing liquid after heating, which can reduce the impact of the steam pipe pressure fluctuation, further reduce the vibration of the steam pipe, and stabilize the temperature and flow fluctuation of the washing liquid.

[0010] Furthermore, the steam pipe is provided with a steam check valve, which can avoid steam backflow, reverse flow of washing liquid, and steam pipe vibration and flash explosion caused by reverse flow and backflow, thereby further improving the safety value of the system.

[0011] Furthermore, the steam pipe is provided with a steam flow meter, which can count the flow velocity and flow volume of the steam, so as to further monitor the pressure value of the steam in the steam pipe.

[0012] Furthermore, the steam pipe is provided with a steam main pressure gauge, which is located at the end of the steam pipe away from the Rafale tube mixing heater. The steam main pressure gauge can monitor the pressure of the steam just entering the steam pipe, and is used to further monitor the pressure value of the steam to avoid the situation where the pressure value is too small and the steam cannot flow into the Rafale tube mixing heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of a Lafarge tube mixing heater in the prior art;

[0014] Figure 2 The utility model is a structural schematic diagram of a shock-proof steam heating system for alumina causticizing. DETAILED DESCRIPTION

[0015] The following is further described in detail through specific implementation methods:

[0016] The figure marks in the drawings of the specification include: washing liquid flow meter 1, first washing liquid thermometer 2, Laval tube mixing heater 3, steam flow meter 4, steam main pipe pressure gauge 5, steam flow regulating valve 6, steam check valve 7, steam inlet mixer pressure gauge 8, steam pressure regulating valve 9, second washing liquid thermometer 10, washing liquid pressure gauge 11, liquid inlet 12, washing liquid pipe 13, drain pipe 14, drain port 15, steam pipe 16, steam inlet 17.

[0017] The embodiment is basically as shown in the attached Figure 2As shown: a shockproof steam heating system for alumina causticizing, comprising a washing liquid pipe 13, a drain pipe 14, a steam pipe 16 and a Rafale tube mixing heater 3, wherein the inlet end of the Rafale tube mixing heater 3 is connected with the washing liquid pipe 13, the outlet end is connected with the drain pipe 14, and the middle part is connected with the steam pipe 16, the end of the washing liquid pipe 13 away from the Rafale tube mixing heater 3 is a liquid inlet 12, the end of the drain pipe 14 away from the Rafale tube mixing heater 3 is a drain port 15, and the end of the steam pipe 16 away from the Rafale tube mixing heater 3 is a steam inlet 17;

[0018] The washing liquid pipe 13 is provided with a washing liquid flow meter 1 and a first washing liquid thermometer 2 in sequence from the liquid inlet 12 to the Lafarge tube mixing heater 3;

[0019] The discharge pipe 14 is provided with a second washing liquid thermometer 10 and a washing liquid pressure gauge 11 in sequence from the Rafale tube mixing heater 3 to the discharge port 15;

[0020] The steam pipe 16 is provided with a steam flow meter 4, a steam main pressure gauge 5, a steam flow regulating valve 6, a steam check valve 7, a steam inlet mixer pressure gauge 8 and a steam pressure regulating valve 9 in sequence from the steam port to the Lafarge tube mixing heater 3;

[0021] All components of the device are connected to an external controller (such as a PLC controller) through electrical signals.

[0022] The specific implementation process is as follows: the washing liquid used for the second causticizing flows into the washing liquid pipe 13 from the liquid inlet 12 and reaches the Rafale tube mixing heater 3, and the steam enters the steam pipe 16 from the steam inlet 17, and then enters the steam chamber of the Rafale tube mixing heater 3, enters the Rafale tube from the through hole of the Rafale tube, reacts with the washing liquid therein, and after the washing liquid is heated to the required temperature, flows into the drain pipe 14, and then flows out from the drain port 15 to participate in the second causticizing reaction;

[0023] When the washing liquid flows into the washing liquid pipe 13, the washing liquid flow meter 1 and the first washing liquid thermometer 2 can measure the current flow rate and temperature of the washing liquid and feed it back to the controller, while the second washing liquid thermometer 10 will set a set value, which is the temperature that the washing liquid needs to reach after heating. The controller will control the steam flow regulating valve 6 according to the washing liquid temperature and speed measured before heating, and control the amount of steam required to heat the washing liquid to avoid the situation where the steam amount is too large and cannot be evenly mixed with the washing liquid, or the steam amount is too small and the washing liquid temperature is low;

[0024] The washing liquid pressure gauge 11 can measure the pressure of the washing liquid after heating and feed it back to the controller. The controller can control the pressure of the steam pressure regulating valve 9 and the steam inlet mixer pressure gauge 8, cooperate with the steam flow meter 4 and the steam main pipe pressure gauge 5, and further control the pressure in the steam pipe 16 to avoid the situation that the steam pressure is too low to enter the Lafarge tube mixing heater 3 or the steam pressure is too high to cause the steam pipe 16 to vibrate, and realize the pressure of the steam pipe 16, the pressure of the steam inlet mixer pressure gauge 8 and the step pressure difference of the washing liquid pressure gauge 11, balance the pressure difference of the steam pipe 16 before and after heating and the pressure of the washing liquid after heating, realize the influence of the pressure fluctuation of the steam pipe 16, further reduce the vibration of the steam pipe 16, and stabilize the temperature and flow of the washing liquid;

[0025] The steam check valve 7 can avoid the backflow of steam and the reverse flow of washing liquid, and prevent the vibration and flash explosion of the steam pipe 16 caused by the backflow and reverse flow, thereby greatly improving the safety factor of the device.

[0026] The above is only an embodiment of the utility model, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the utility model, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A shockproof steam heating system for alumina causticizing, comprising a washing liquid pipe, a drain pipe, a steam pipe and a Rafale tube mixed heater, characterized in that: The washing liquid pipe is provided with a washing liquid flow meter and a first washing liquid thermometer in sequence, the discharge pipe is provided with a second washing liquid thermometer and a washing liquid pressure gauge in sequence, the steam pipe is provided with a steam flow regulating valve, a steam inlet mixing pressure gauge and a steam pressure regulating valve, the steam inlet mixer pressure gauge is located at one end of the steam pipe close to the Kaval tube mixing heater, and the components in the heating system are all connected to the controller through electrical signals.

2. A shockproof steam heating system for alumina causticizing according to claim 1, characterized in that: The steam pipe is provided with a steam check valve.

3. A shockproof steam heating system for alumina causticizing according to claim 2, characterized in that: The steam pipe is provided with a steam flow meter.

4. A shockproof steam heating system for alumina causticizing according to claim 3, characterized in that: The steam pipe is provided with a steam main pressure gauge, and the steam main pressure gauge is located at one end of the steam pipe away from the Rafale tube mixing heater.

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