RU108436U1 - DEVICE FOR PRODUCING HYDROXIDES OR OXIDES OF ALUMINUM AND HYDROGEN - Google Patents

Abstract

 1. A device for producing hydroxides or oxides of aluminum and hydrogen, containing a reactor, a source of a suspension of finely divided powdered aluminum with water with an adjustable means for supplying a suspension with a signal input, an adjustable valve for removing a mixture of water vapor and hydrogen with a signal input, adjustable for a signal input, a valve for removing a mixture water and hydroxides or aluminum oxides in the receiving device, a temperature sensor in the reactor, a pressure sensor with a signal at the output of the gas mixture from the reactor, characterized in that The property contains a controller, means for measuring the liquid level in the reactor with two adjustable outputs-settings, a water source with adjustable means for supplying it to the reactor with a signal input, a signal input to an adjustable valve for removing a mixture of water vapor and hydrogen, is electrically connected to the signal output from the pressure sensor, the signal input to the water supply means is electrically connected to the setpoint outputs of the liquid level measuring means, the signal input of the valve for removing the mixture of water and hydroxides or aluminum oxides is electrically connected to the controller rum. ! 2. The device according to claim 1, characterized in that the signal output from the pressure sensor is electrically connected to the signal input to an adjustable means of supplying a suspension.

Description

The proposed utility model relates to devices for producing hydroxides or aluminum oxides, and in particular, to installations for producing hydroxides or aluminum oxides from aluminum metal by oxidation in an aqueous medium. Aluminum oxides and hydroxides are used in industry as adsorbents, catalysts, and as abrasive powders.

The device also relates to the production of hydrogen, namely to the production of hydrogen in the chemical interaction of aluminum and water.

Thus, the fields of application of the utility model are the chemical industry and energy.

A device for producing hydroxides or oxides of aluminum and hydrogen from metal powdered aluminum [Russian patent for invention No. 2278077, class CO1F 7/42, registered in the State register of inventions of the Russian Federation on 06/20/2006], containing a high-pressure reactor in which finely divided powdered aluminum reacts with water, a source of a suspension of powdered aluminum with water, a high pressure pump for supplying a suspension, a receiver for reaction products, a condenser, means of conducting a working process and adjustment of its parameters. The device provides the active interaction of aluminum with water and the achievement of process characteristics that guarantee the receipt of output products of the specified types and purity. The disadvantage of this device is that more than half of the thermal energy released as a result of aluminum oxidation is excreted together with a mixture of reaction products with water, which significantly reduces the efficiency of further use of this energy.

Closest to the proposed device is a device [patent R.F. 2223221, class CO1F 7/42, CJSC Firma RIKOM SPb]], which includes a high pressure reactor, a receiving device for hydroxides, a condenser, means for continuously removing steam and gas and a mixture of hydroxides or aluminum oxides with water, means for conducting the process and controlling its parameters. The disadvantage of this device is the difficulty of dynamically maintaining the continuous removal of a mixture of water vapor with hydrogen and a mixture of aluminum hydroxides with water and the output of about half of the thermal energy released as a result of aluminum oxidation, together with the mixture of reaction products with water, which significantly reduces the efficiency of further use of this energy.

The technical problem solved by the proposed device is to ensure the withdrawal of most of the thermal energy released as a result of aluminum oxidation with water vapor while maintaining the basic functional qualities, namely, the production of aluminum hydroxides of a given composition and hydrogen. The solution of this problem allows you to use most of the thermal energy released during the oxidation of aluminum in water, for example, to generate electricity by directing high-pressure steam to the turbine.

The solution of the problem in the proposed device is that the device, the operation of which is illustrated by the flowchart shown in Fig. 1, contains a high pressure reactor (1), a source of a suspension of finely divided powdered aluminum with water (17) with an adjustable means for feeding the suspension ( 18) with a signal input (19), a valve for discharging a mixture of water and hydrogen vapor (2), regulated with a signal input (3), a valve for discharging a mixture of water and hydroxides or aluminum oxides (9), adjustable with a signal input (8), to a receiving device ( 10), pace sensor the temperature in the reactor (6), the pressure sensor in the reactor (5) with the output of the signal (4) at the outlet of the gas-vapor mixture from the reactor and has distinctive features, namely, the device contains a controller (7) that sets the necessary sequence of operation of the exhaust valve (9) mixtures of water and hydroxides or aluminum oxides in the receiving device (10), means for measuring the liquid level in the reactor (14) with two adjustable outputs - settings (15), (16), a water source (11) with adjustable means (12) for its supply to the reactor (1) with the input of the signal (13), the input of the signal (3) to the adjustable tap valve mixtures of water and hydrogen vapors are electrically connected to the signal output from the pressure sensor (4), the signal input to the water supply means (13) is electrically connected to the outputs - settings (15), (16) of the liquid level measuring means, and the signal input (8) electrically connected to a controller (7) into an adjustable valve for discharging a mixture of water and hydroxides or aluminum oxides.

To expand the scope of the proposed device while maintaining the declared goal, the output of the signal from the pressure sensor (4) can be electrically connected to the input of the signal (19) into an adjustable means for supplying the suspension (18).

A device for producing hydroxides or oxides of aluminum and hydrogen, the block diagram of which is shown in figure 1, consists of an Executive unit, including:

1. High pressure reactor.

2. Adjustable valve to remove a mixture of water vapor and hydrogen.

3. Signal input to an adjustable valve for removing a mixture of water vapor and hydrogen ..

4. The output signal from the pressure sensor.

5. The pressure sensor in the reactor.

6. Temperature sensor in the reactor.

7. The controller.

8. Signal input to the valve for diverting a mixture of water and aluminum hydroxides.

9. Valve for discharging a mixture of water and aluminum hydroxides.

10. The receiving device.

11. Source of water.

12. Adjustable means for supplying water to the reactor.

13. The signal input to the means of supplying water to the reactor.

14. Means for measuring the liquid level in the reactor.

15, 16 - Outputs-settings of the means for measuring the liquid level in the reactor.

17. The source of the suspension.

18. Adjustable suspension feed means.

19. The signal input to an adjustable means of supplying a suspension.

Known initial data defining the main technical characteristics of the device are the consumption of aluminum, the operating temperature in the reactor and _a residence time τ needed to complete the reaction. Typical values of thermophysical parameters in the reactor: temperature -300-350С, pressure 10.0-17.0 MPa. The exposure time τ _in depending on the goal is set by the researcher and has the order of a minute. The geometric characteristics of the reactor must satisfy the following requirements: the height of the reactor must be at least an order of magnitude greater than its characteristic transverse size, the volume occupied by water should be 60-70% of the total volume of the reactor, if the mass of water is equal to 20-30 masses of aluminum entering to the reactor during the time τ _in .

The operation of the proposed device is as follows:

The source of the suspension is filled with a cold suspension of fine powdered aluminum in water with a mass concentration of aluminum in the range (1: 4.5) - (1: 5.5).

The reactor is filled with water so that 30-40% of its volume remains free of liquid, up to the mark "maxim" on the means for measuring the level of liquid in the reactor.

The basis for achieving the declared goal is to maintain a certain constant pressure in the reactor, which can be achieved either by using an adjustable valve to remove a mixture of water and hydrogen vapors (2), or by using an adjustable means of supplying a suspension (18).

If valve (2) is used to maintain the pressure in the reactor, then this valve is preliminarily adjusted to maintain a constant pressure, which is 0.5-0.7 MPa higher than the saturated water vapor pressure corresponding to the accepted working temperature in the reactor; then the water in the reactor is heated to a predetermined temperature. The pressure in the reactor corresponds to the pressure of saturated water vapor.

Upon reaching a predetermined operating temperature, the suspension begins to flow into the upper part of its volume occupied by water or into the “gas” volume of the reactor. The reaction of aluminum oxidation with water begins with the release of energy at the level of 15-17 kJ per 1 g of aluminum. The reaction should occur at a given operating temperature. Therefore, if the temperature in the reactor differs from the set one, it is necessary to adjust the valve for removing the mixture of water vapor and hydrogen, increasing or decreasing the pressure level in the reactor until the set temperature is established in the reactor. Maintaining a predetermined working temperature in the reactor means that the partial pressure of water vapor corresponds to the pressure of its saturated vapors at a given working temperature and the energy released during the oxidation of aluminum (with the exception of that spent on heating the reaction products, for example, ALOOH, to the temperature of the liquid in the reactor) intensive evaporation of water takes place, and water vapor mixed with hydrogen formed as a result of the reaction is continuously removed through a valve that maintains a constant pressure in the reactor. Calculations show that in this case, the reaction per 1 g of aluminum accounts for ~ 5 g of water vapor; in addition, approximately 1.2 g of water is spent on the formation of reaction products. Thus, if the concentration of the suspension is in the range (1: 4.5) - (1: 5.5), the amount of water in the reactor during its normal operation will decrease.

If an adjustable suspension feed means is used to maintain the pressure in the reactor, then the constant pressure valve must be fully open to minimize hydraulic losses of the mixture of water and hydrogen vapor constantly removed from the reactor, and the required constant pressure in the reactor is maintained by the action of the output signal (4) from the sensor pressure (5) on the adjustable means for supplying the suspension (18) through the signal input (19); with an abnormal increase in pressure in the reactor, the flow of the suspension decreases, and with a decrease in pressure, the flow of the suspension increases.

After a time τ _in , installed in the controller, a mixture of water and hydroxides or aluminum oxides is withdrawn from the bottom of the reactor to a receiving device. The output stops after a certain time then by the signal of the controller. This time is determined on the basis of the condition: the volume of the mixture of water and reaction products withdrawn from the reactor during this time should be within V = 1.5G _AL · τ / ρ _in ÷ 2.5G _AL · τ / ρ _in ,

where τ, s is the time period between the end of one and the beginning of the next withdrawal of the mixture (0 <τ≤τ _c ), G _Al , g / s is the mass flow rate of aluminum, ρ _c is the density of water, g / cm ³ .

For example, if τ _B = 100C, τ = 30C, G _Al = 3 g / s, then the coefficient at 2.0 volume of the mixture is withdrawn V = 2 · 3 · 30/1 · s · g · cm ³ / s · g = 180 cm ³ .

The presented dependence is selected in such a way as to ensure, on the one hand, the residence time of aluminum in the reactor of at least τ _in , and on the other hand, to prevent an excessive increase in the concentration of solid reaction products in the water in the reactor.

After time τ, at the controller's signal, a mixture of water and hydroxides or aluminum oxides is withdrawn from the bottom of the reactor; in the future, alternately following the controller signals through time τ, the aforementioned regulated output of a mixture of water and hydroxides or aluminum oxides from the reactor to the receiver is carried out. Thus, the controller provides a sequence diagram of the valve for removing a mixture of water and hydroxides or aluminum oxides from the reactor, shown in Fig.2.

During operation of the device in the normal mode due to the evaporation of part of the water and removal of steam outside the reactor, as well as the removal of the mixture of solid reaction products with water in the collector, the level of the mixture of water with the solid phase in the reactor will decrease; when the level drops to the minimum permissible marked on the means of measuring the liquid level, the signal from one of its two output settings from the water source is used to supply water to the reactor, which stops when the maximum level is reached by the signal of the second set point of the level measuring means. In order to avoid additional perturbations of temperature and pressure in the reactor, it is recommended to limit the permissible change in the volume occupied by the mixture of liquid and solid phase to ten percent, providing this with the appropriate values of the settings of the means for measuring the liquid level in the reactor.

A four-channel microprocessor digital timer МЦТ-3504 manufactured by Dana-Term can be used as a controller: the four channels of this timer allow programming the operation of the valve for removing the mixture of water and hydroxides or aluminum oxides in accordance with the above sequence diagram. The means for measuring the liquid level in the reactor, by means of which the level of the layer of incompressible components in the reactor is controlled and regulated, can be based on the principle of communicating vessels, one of which is the reactor, and the other is a quartz tube with its sealing nodes at the ends. To seal the joints, rings made of heat-resistant rubber can be used, the sealing units must be cooled. Level changes can be monitored by a photosensor.

Thus, the proposed device allows you to expand the functionality of the prototype: along with the production of hydroxides or aluminum oxides, as well as hydrogen, the device allows you to get a significantly larger part of the thermal energy released during the oxidation of aluminum with steam at a temperature of 300-350C and a pressure of 10-17 MPa, which increases the efficiency of its further use. This is achieved due to the fact that the process of oxidation of aluminum in the reactor takes place at a constant pressure corresponding to the pressure of saturated water vapor at a given operating temperature in the reactor. The operation of the controllers and two outputs-settings of the liquid level measuring means ensures the maintenance of a quasistationary state of the contents of the reactor — reacting aluminum, water, solid reaction products, and allows it to realize a long continuous working process.

By setting the necessary values of the temperature of the working process in the reactor and the exposure time τ _in , you can get the reaction products of a given composition and hydrogen, and maintaining the pressure in the proposed device in the reactor, corresponding to the pressure of saturated water vapor at a given temperature, provides the accumulation of the thermal effect of the reaction of aluminum oxidation in steam water discharged from the reactor together with hydrogen.

The use of a valve to remove a mixture of water and hydrogen vapor to maintain a constant pressure in the reactor allows for a given flow rate of the suspension (i.e., for a given thermal power of the reactor) to parametrically change the operating temperature in the reactor, providing solid reaction products of a given composition, which is important when conducting research , but complicates the direct use of a high-temperature mixture of water vapor and hydrogen, for example, in a turbine. The use of an adjustable suspension feed means instead of a valve to maintain a constant pressure in the reactor is effective during stationary operation of the device in a predetermined mode, characterized by three requirements: obtaining solid reaction products of a given composition, producing hydrogen, and directly using a high-energy mixture of water and hydrogen vapors leaving the reactor to generate energy , for example, in a turbine.

Claims (2)

1. A device for producing hydroxides or oxides of aluminum and hydrogen, containing a reactor, a source of a suspension of finely divided powdered aluminum with water with an adjustable means for supplying a suspension with a signal input, an adjustable valve for removing a mixture of water vapor and hydrogen with a signal input, adjustable for a signal input, a valve for removing a mixture water and hydroxides or aluminum oxides in the receiving device, a temperature sensor in the reactor, a pressure sensor with a signal at the output of the gas mixture from the reactor, characterized in that The property contains a controller, means for measuring the liquid level in the reactor with two adjustable outputs-settings, a water source with adjustable means for supplying it to the reactor with a signal input, a signal input to an adjustable valve for removing a mixture of water vapor and hydrogen, is electrically connected to the signal output from the pressure sensor, the signal input to the water supply means is electrically connected to the setpoint outputs of the liquid level measuring means, the signal input of the valve for removing the mixture of water and hydroxides or aluminum oxides is electrically connected to the controller rum. 2. The device according to claim 1, characterized in that the signal output from the pressure sensor is electrically connected to the signal input to an adjustable means of supplying a suspension.