HU210735B - Method for producing of drinking water from sea water - Google Patents

Abstract

The process according to the invention is characterized in that the seawater is introduced into a preheating tank (1) and then transferred to a heat exchanger (7), the heat transfer medium is heated by a solar collector (5) in a heat-holding tank (4) containing deflector plates and then in a heat-transfer medium compression unit (3). ) is adiabatically compressed and then fed to the heat exchanger (7), where its thermal energy is transferred to the seawater to be desalinated, the sea water so heated is introduced into a vaporizing space (2) from which the resulting steam is condensed into the condensing unit (9) and condensed salt-free water into the storage tank (10). ), the heat transfer medium is fed back to the heat collecting container of the solar collector (5) after passing through the buffer tank (8) after passing through the buffer tank (8) in an expanding unit (6), to a portion of the evaporation residue produced in the evaporator unit (2). mixing an aqueous solution of the dissolver (11) and the salt solution thus prepared were mixed quantity necessary for human consumption in the mixing tank (12) of demineralized water. EN 210 735 A Scope of the description: 4 pages (within / on page)

Description

The present invention relates to a process for producing drinking water from seawater.

The supply of adequate, inexpensive, drinking water is still an unsolved problem for a very large part of coastal and tropical and subtropical coastal countries and extensive hot climates.

At the expense of huge financial efforts, the supply of drinking water and industrial water produced by the desalination of seawater in large cities and large industrial facilities is already well established in most of these regions. However, the supply of drinking water and industrial water to smaller coastal communities is still met by either transporting water produced by hydroelectric installations over long distances (by water or land) or by producing a part of the seawater desalination plants for water supply in the nearest large cities or industrial facilities. is used for this purpose. Both of these solutions are quite expensive, as transporting them over long distances is often costly and consumes a lot of money and limits on water consumption.

Seven major processes are currently known for desalination of seawater. These are the following:

- thermal compression,

- ion-exchange and electrolysis processes,

- single flow multi-stage drive,

- multi-stage air recirculation,

- reverse osmosis,

multi - body evaporation and

- mechanical vapor compression.

The thermocompression process can be one or multi-step. The multi-stage process is much more economical than the single-stage process. It is also important from an economic point of view that electricity is 3.6 times more expensive than steam.

The use of ion-exchange and electrolysis is gradually being neglected due to expensive electricity.

Of the known methods, the reverse osmosis (RO) process is the most efficient because it requires 33-50% less energy. In this process, the water must also be pre-treated. It consists of decarbonisation of slaked lime, partial soft writing with sodium carbonate followed by distillation with sodium aluminate and ferric chloride. It is also necessary to flatten the water on the filters and finally filter on the sand.

In evaporative processes, conventional oil, coal or gas fired boilers generate steam and are fed to evaporators with heating pipes, which are single or multi-body. The latter is more economical, and therefore a larger proportion of such equipment is being built recently. The vapor generated in the evaporator is condensed through a drip trap, cooled, and in a multi-body evaporator, the heat energy of the vapor is passed through the heating pipe of the subsequent evaporators and then the condensed vapor is removed.

The equipment and processes listed or briefly described above require some form of conventional energy and energy, so they must be taken into account in their installation. Their disadvantage is that they use a very large amount of fuel in their operation and can only be installed where the power supply is uninterrupted.

A further disadvantage is that they require high operating costs, which can be recouped over a relatively long period of time. In addition, significant environmental pollution during operation is disadvantageous.

A process using the evaporation principle is described in U.S. Patent No. 4,376,679. description, in which seawater is heated and condensed in a storage tank.

A further common disadvantage of the listed processes is that the (purified) water produced by such methods is not suitable for direct human consumption due to lack of salt.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process for desalination of seawater at low cost, economically and to make desalinated water suitable for direct human consumption.

The development of the process of the present invention has led to the discovery that, when the process is carried out in a special way, solar-assisted evaporation becomes more efficient and, on the other hand, the discovery that salts for desalinated water for human consumption can be covered from the residue.

The present invention relates to a process for producing potable water from seawater, characterized in that the seawater is introduced into a preheating vessel and from there to a heat exchanger, the heat transfer medium is heated by means of a solar collector and wherein the heat energy is transferred to the seawater to be desalinated, the heated seawater is then transferred to a vaporization space, then the condensed salt-free water is discharged into the storage tank; a portion of the remainder is mixed with saline water to form an aqueous solution in the dissolution tank, of the brine in the mixing tank and the desalinated water for human consumption. In the process, it is preferable to use more than one series-connected evaporation space.

The parabolic solar collector is preferably made of glass fiber reinforced plastic with a reflective layer on the inside.

The parabolic solar collector is preferably movable. The heat receptacle is preferably conical and has a tungsten coating on the inside.

In order to heat the heating medium faster and to improve the heat transfer, baffles are preferably arranged in a spiral line upwardly inside the heater tank (cavity). The process of the invention will be described in more detail with reference to Figure 1, which illustrates the principle scheme of the process of the invention.

HU 210 735 A

The seawater to be desalinated is designated by the so-called 1. stored in a preheater tank, where due to the formation of the outer surface of the tank the solar radiation will be exposed for approx. It warms up to 40 ° C. The heat transfer medium, which in this case is a gaseous state in the heat sink 4, is provided with baffles of approx. It is heated to 120-130 ° C by the concentrating action of 5 solar collectors. The heat transfer medium is then introduced into the compression unit 3, where it is adiabatically compressed, thereby bringing it to a superheated state. The compressing heat transfer medium then enters the heat exchanger 7 where it transfers heat to the seawater introduced there. The seawater is then introduced into the evaporator space 2 where evaporation takes place, whereupon the vapors enter the condensing unit 9 where it is condensed.

The refrigerant introduced into the condensing unit is preferably recirculated through the preheating tank to recover its waste heat.

The condensed salt-free water and 10 desalinated water are stored in a storage tank.

After passing through the heat exchanger 7, the heat transfer medium is adiabatically expanded in the expansion unit 6 and then introduced into the collector via the buffer tank 8.

Due to the heat transfer medium superheated by adiabatic compression, the heat transfer in the heat exchanger is very intense with good efficiency.

A portion of the excellent mineral salts in the evaporator unit is introduced into the dissolution vessel 11 where an aqueous solution is prepared.

The desalinated water and the brine thus produced are introduced into the mixing vessel 12, whereby the dissolved mineral salts are mixed in the amount required for consumption.

In order to recover the waste heat from the heat transfer medium, it is also advisable to install a turbo generator to cover the on-site electricity needs.

The main advantages of the process according to the invention are as follows:

- low energy demand,

- intensive heat transfer,

- water suitable for direct human consumption may be obtained.

Claims (1)

A process for producing potable water from seawater using evaporation, characterized in that the seawater is introduced into a preheating vessel (1) and from there to a heat exchanger (7), in a compressing unit (3) adiabatically compressed and then fed to a heat exchanger (7), where its heat energy is transferred to the seawater to be desalinated, the heated seawater is supplied to the evaporation space (2), whereupon the water vapor the heat transfer medium, after adiabatic expansion in an expanding unit (6), after being passed through the buffer tank (8), is recycled to the heat receptacle of the solar collector (5), the vapor formed in the evaporator unit (2) A portion of the residue is mixed with saline water to form an aqueous solution in the dissolving vessel (11), and the salt solution thus obtained is mixed with desalinated water for human consumption in the mixing vessel (12).