DE2122882A1 - Process for water desalination and for the production of thick-walled pressure vessels - Google Patents

Description

Dieter Bliesener

2 Hamburg 34, Culinstr. 6/617

Process for water desalination and for the production of thick-walled pressure vessels

The invention relates to a method for the desalination of army water and a method for the production of thick-walled Pressure vessel which is used to carry out the desalination process according to the invention with large desalination capacities required are.

The previously known methods for water desalination are because of their high energy requirements for desalination unsuitable for large amounts of water. The invention is therefore based on the object of a To enable water desalination with only little energy expenditure.

Building on the known fact that salt water separates into fresh water and brine in the critical area, this object is achieved according to the invention with the help of a Process for water desalination by separating fresh water and brine in a pressure chamber at a critical temperature and heat transfer from the fresh water and the brine to the water to be desalinated, characterized in that, that the desalination at a supercritical pressure (about 450 ata), at which the specific Elüssigkeitswärme des Salt and fresh water and the brine up to the critical temperature rises only a little, and the compensation takes place the heat loss necessary additional heat is generated in the salt water or with the help of a part of the gained Fresh water directly aai the salt water is transferred and the extraction of the cooled fresh water and the cooled brine from the Druaberaum and the

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"Bringing an equal amount of food to be heated and to Desalinated water is carried out by double pistons, the cylinder chambers of which are controlled by valves and check valves the pressure chamber can be switched on and separated from it, and springs are arranged in their dead centers prevent loss of acceleration when reversing the direction of movement of the double pistons.

The "advantage of this process over the previously .be * * known is that only for the friction losses of the mechanically moving parts and the flowing media and because of the imperfect heat transfer from the fresh water and from the brine to the water to be desalinated Energy is to be expended.

The heat transfer can be achieved all the more completely and the required additional heat is thus lost the lower the (less the specific heat of the liquid of salt and fresh water and brine increases when the temperature rises up to the critical temperature, i.e. each the higher the supercritical pressure for carrying out the desalination is chosen.

As a result of the high temperatures and pressures at which the desalination is to be carried out, the necessary Pressure vessels with large Eatsalzungsleistungen large wall thicknesses, so that they according to conventional Process can no longer be produced. In particular, there is no longer any bending of the container jackets possible. The invention therefore also relates to a method for producing thick-walled pressure vessels.

According to the invention, the production of thick-walled pressure vessels is made possible by a method that thereby is characterized by the fact that several relatively thin

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dige steel jackets arranged concentrically one above the other and through a pourable and hardenable material (e.g. concrete), the thermal expansion of which corresponds to that of steel, are positively connected to each other.

An exemplary implementation possibility of the method according to the invention for water desalination and the method according to the invention for producing thick-walled pressure vessels is explained with reference to drawings.
They represent:

Fig. 1: an apparatus for carrying out the method for water desalination

2: a schematic longitudinal section through a heat exchanger

To put the system shown in FIG. 1 into operation, it is first filled with fresh water, which then from the pump 1 from the line 2 through the superheater 3 », in which it absorbs heat, into the separation space 4 is conveyed in a circle until the critical temperature prevails in it and the desired supercritical temperature Pressure, expediently 450 ata, set can be. Then begins the supply of salt water into the pressure space, the segregation space 4, the Heat exchanger 5 and 6 and the connecting lines, with simultaneous withdrawal of fresh water or after the eel run phase of fresh water and brine from it.

By closing valve 7 and opening the valve In cooperation with the check valves 9 and 10, the cylinder chambers 11 and 12 of the double piston separated from the pressure chamber and by moving the double

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piston 13 in. the right end position is at atmospheric pressure Sucked into the cylinder space 12 salt water and pushed out of the cylinder space 11 fresh water. By opening valve 7 and closing valve 8 Then, in cooperation with the check valves 9 and 10, the cylinder chambers 11 and 12 become the pressure chamber switched on and by pushing the double piston 13 in the left wheel position, the salt water is pushed out of the cylinder space 12 and admitted into the cylinder space 11 fresh water.

* It is done in the same way by closing or opening the valves 14 and 15 cooperate with the lini Check valves 16 and 17 the connection of the cylinder spaces 18 and 19 of the double piston 20. to the pressure chamber or the separation of it and by moving the Double piston 20 via the cylinder space 19 brings salt water into the pressure space and via the cylinder space 18 at the same time a withdrawal of brine from it.

The displacement of the double piston can be done hydraulically or pneumatically. To avoid acceleration. loss of movement when reversing the direction of movement of the Double pistons 13 and 20 can be arranged inside or outside the cylinder in the dead center, which springs absorb the kinetic energy of the double pistons and the water masses during deceleration and during acceleration return.

The salt water conveyed into the pressure chamber via the cylinder chambers 12 and 19 flows through the heat exchangers 6 or 5 and heats up almost to the critical temperature. In the line 21 it receives more heat fed so that it reaches the critical temperature

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and into the specifically heavier i> ole and into the specifically lighter fresh water separates. In the segregation room 4, due to its higher specific weight, the brine collects in the lower part of the tank and flows via the line 22 through the heat exchanger 5 »in the it gives off heat to the salt water flowing in the opposite direction, into the cylinder space 18. That itself in the upper part of the budget mix rauiaes 4 collecting fresh water passes through the line 2 through the heat exchanger 6, in which there is also heat to the opposite The direction of flowing salt water releases into the cylinder space 11.

The supply of additional heat that heats the salt water up to the critical temperature and thus its separation effected in fresh water and brine, takes place with the help of a part of the fresh water produced, which with the pump 1 taken from line 2 and via the superheater 3 »in which it absorbs the additional heat, is conveyed into the line 21, where it then receives its absorbed heat the salt water gives off.

In order to avoid sealing problems, the pump 1 is connected to a coupling 23, which is a poor conductor of heat, by a Drive hermetically sealed motor 24, the rotor 25 of which in cooled fresh water o <äarin an electrically Non-conductive liquid, e.g. oil, runs, with sealing rings 26 preventing the passage of warm fresh water into the Prevent motor 24.

The superheater (3) to be heated with steam, which flows with a temperature of about 374- ⁰ CJ. For reasons of economy, it can also be used to drive a steam engine, which in turn drives a generator. The generated electrical energy can then be used

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Drive the hydraulic pumps for driving the double pistons and to distribute the fresh water obtained for irrigation purposes ".

The required additional heat can also be generated by alternating electrical fields in the salt water. Because some of the salts dissolved in salt water are in ionic form, the salt water can be polarized as soon as it is in an electric silk. By changing the polarity of the electrical field, kinetic energy is applied to the ions transmitted, which has the effect of increasing the temperature of the salt water.

There is also a passage of electricity through the salt water to warm it up. To avoid electrolysis, it is preferable to use alternating current.

The temperature of the salt water can also be increased with the help of electromagnetic waves, their energy is converted into heat by absorption in salt water. Microwaves and sun rays can preferably be used for this purpose can be used.

ψ The system parts exposed to salt water or brine at high temperatures must be made of pure nickel to avoid corrosion.

The 3? 2 shows an example of a schematic longitudinal section through a heat exchanger, corresponding to the heat exchangers (5) and (6) and all other pressure vessels and lines of the desalination plant are to be formed, provided that their jacket is too thick due to the wall thickness cannot be produced in the conventional way by bending

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Let len- The jacket of the heat exchanger shown is formed by several concentrically one above the other arranged sheet steel jackets 1 and by concrete jackets 2, which the sheet steel jackets frictionally with each other Connect - The thickness of the individual sheet steel jackets is to be selected so that they can still be produced by bending "and their number is to be determined in such a way that their overall strength has the required strength of the container jacket results.

The cover of the heat exchanger shown consists of the base cover 3, the stiffening webs 4 and the concrete lining 5 · They are secured by anchor bolts 6 stretched against the cylindrical container jacket.

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Claims (2)

Claims 1. A method for water desalination by separating fresh water and brine in a pressure chamber "at critical temperature and heat transfer from the fresh water and the brine to the water to be desalinated, characterized in that the desalination takes place at a supercritical pressure (about 4-50 ata), in which the specific liquid heat of the salt and fresh water and the brine rises only slightly up to the critical temperature, and the additional heat required to compensate for the heat loss is generated in the salt water or transferred directly to the salt water with the help of part of the fresh water obtained and the extraction of the cooled fresh water and the cooled brine from the pressure chamber and the introduction of an equal amount of water to be heated and desalinated by double pistons, the cylinder chambers of which can be connected to and separated from the pressure chamber by controllable valves and check valves and springs are arranged in their dead centers who have favourited Accel Prevent inconsistent losses when reversing the direction of movement of the twin pistons. 2. A process for the production of thick-walled pressure vessels, characterized in that several relatively thin-walled steel jackets (1) are arranged concentrically one above the other and are positively connected to one another by a cast and curable material (2) whose thermal expansion corresponds to that of the steel. 209848/0291 Blank page