NZ202699A - Purifying liquid by evaporation - Google Patents

Description

202699 Priority D«i\a(s): 7r ;F,^?\ Complete Specification Filed: t Class: f.A?'.f.3/4 Publication Data: .... 15 J. tlAY J9Q51. | P.O. Journal, F'Jo: t?*.-?.4?.. .. f ;N.Z. No ;NEW ZEALAND ;Patents Act 1953 ;COMPLETE SPECIFICATION ;"METHOD OF TREATING A SUBSTANCE BY EVAPORATION, DEVICE AND INSTALLATION FOR CARRYING OUT THE METHOD" ;I, MARC SCHUMANN, 35 rue du 700ieme Anniversaire, 6760 Virton, Belgium, a o^jeA ;do hereby declare the invention, for which I pray that a Patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: - ;- 1 - ;/■'o' . ;N, ' ;- 2 - ;202699 ;METHOD OF TREATING A SUBSTANCE BY SUBLIMATION—QR-EVAPORATION, DEVICE AND INSTALLATION FOR CARRYING OUT THE METHOD ;~»limati< ;FIELD OF THE INVENTION ;This invention relates to a treatment by sublimation of a substance or material, but more particularly the evaporation of a liquid such as water, seawater, fresh water or waste water, in which the objective is to remove therefrom or indeed to recover at least a portion of the solid matter which it may contain. In a preferred manner, the heat source envisaged for bringing the material to a sublimation og evaporation temperature is 6olar radiation. ;In ®e possible mode of embodiment for the carrying out of the process J1 a device is envisaged which will capable of use for treatment of seawater for the purpose, principally, of desalting it or of recovering or obtaining salt and, of course, for these two purposes in combination. ;The objectives of the present invention are therefore very varied and the method can lead to different devices and, finally, to a complete installation and, for example in the case of a remarkable solution, an installation for the regeneration of a soil or earth comprising a high percentage of salt which renders it unsuitable for cultivation or indeed of very low value. ;SUMMARY OF THE INVENTION t ;The method according to this invention is charac.t^ri^&^fei^ u ;* -sM"» 202699 that the material to be treated is caused to pass by capillary attraction through a granular, permeable zone, that is to say « permitting percolation of the material, this zone being bounded by a heat capture plane which forms at least the inclined lower part of a heating chamber or zone, with the plane facing towards a heat source, the part of the material sublimated or evaporated or indeed in vapour form being condensed in at least one condensation chamber or zone, which is situated outside the direct influence of the heat source, the condensation chamber or zone being maintained at a temperature lower than that of the heating chamber or zone, and any surplus of non-evaporated material being caused to flow from the oublimQtion or evaporation plane or planes towards a lower channel, which may be-reached directly by the heat source so as to continue or complete at least partially the sublimation or evaporation of the material and to recover therefrom the solid constituents.

More especially, however, the invention relates to the evaporation of liquids and the device for carrying it out will be described below, which device or assembly of devices, when appropriately equipped, will enable a complete treatment installation to be constructed for the purpose of obtaining fresh water partly or almost completely free from 6alts or other bacteria, which fresh water will enable adjoining land areas to be desalted and thus, in successive cycles, will make possible complete regeneration of a soil. 2026 On the other hand, the installation could be designed with the objective of obtaining or recovering, for example, salt in the case of seawater treatment, or indeed or in addition for the purpose of recovering residual solid constituents.

To assist in a better understanding of the invention, it is now described in relation to a drawing which shows, by way of examples; BRIEF DESCRIPTION OF THE DRAWINGS In figure 1, a general schematic view in section of a device for carrying out the method according to this invention; In figure 2, a schematic plan of an installation for desaltinat ing seawater; In figure 3, a schematic plan of an installation for regenerat ing a soil; i In figure 4, a sectional view along the line IV-IV of figure 3 In figure 1 there are shown : Reference 1, a glass roof as heating surface, through which solar rays can pass; Reference 2, cellular concrete, of type "Ytong", which provides good facilities for capillary attraction, although any porous permeable material may be used, for example simply sand forming a capillary mass; Reference 3, evaporators composed generally of a heat absorbing plate1 3a, for example a perforated black plate, or any 2 026 99 other permeable and absorbent material which will collect salt on its outer face, behind which plate 3a a filter will be placed in the case where the porous permeable material is sand, to prevent this material entering the apparatus, since cellular concrete in any case fulfils this function; Reference 4, the heating chamber, which is bounded above by the glass roof 1 and at the sides by the inclined evaporators 3; Reference 5, the two condensation chambers which are beyond the zone of action of the solar rays, these condensation chambers being bounded at the bottom by a component 5a in the form of a trough which serves for collecting the treated water; Reference 6, a central portion in the form of a trough or channel in which a filter 7 is generally situated, this channel serving for collecting the unevaporated water which might flow from the evaporators 3, for example due to the inflow of an excessive quantity of liquid, and also the solid material which could accumulate on the evaporation plate 3a and fall down by gravity.

As can be clearly seen, it is preferably arranged for the evaporators 3 to be extended downwards by a portion 3b, which tends to form a kind of funnel above the channel! 6. Since the channel 6 is situated directly underneath the action of the solar rays, if the central channel 6 collects water trickling down from the evaporators 3, this water could also evaporate due to overheating and the filter 7 will enable an additional quantity of solid 202699 material to be collected.

In order to achieve the condensation effect, the chambers 5 should be kept at a temperature substantially lower than that of the heating chamber 4 with which they are in communication; to achieve this cooling, provision is made for at least a portion of the walls of the chambers 5 to be in contact, for instance with the incoming water 8, that is to say the water which has yet to be treated, or at least with a portion of the soil 9 which is still thoroughly wetted with water, which at this level will not yet have reached a high temperature.

More especially if the device is used for treating seawater (as shown) as a function of the tides, the water in the soil 9 will reach a height A at high tide, to fall to a substantially lower level B at low tide; in order to limit the entry of water attracted by capillary attraction through the mass of cellular concrete 2, a slot 11 is provided on the external casing 10 of the device, in which slot 11a strip 12 can be slid upwards to form a wall, which can be lowered progressively as a function of the level of the water in the soil 9. These strips 12 are also intended more generally for regulating the device as a function, for example, of a greater or lesser heating effect. These strips 12 are even capable of completely stopping any entry of water, for example at night, when it is desired to remove the filter 7 (if provided), to clean certain components, to recover the solid material etc. These strips 12 are situated outside the capillary mass 2. Preferably, as shown, 2026 - 7 -- the glass roof is arranged (as shown) inclined in such a way as to facilitate the automatic or otherwise cleaning of the external face by a jet of water from pipe 13, which will be necessary, for example, for a device situated in the sand of a seashore to obtain desalinated water; this may be the case also for a device placed on a land area.

In a preferred form of embodiment, a slot (not shown) with a funnel is provided at the two ends of the apparatuses or of the rows of apparatuses, and also a drum at each end, so as to provide a continuous filter 7; one of these drums will unreel the new filter (or cleaned filter) 7, while the other drum wind up the dirty filter 7 (to be cleaned), so that it is not necessary to open the apparatus or apparatuses of a row.

Although it is not shown here, it will readily be understood that the device comprises an outlet at one of its ends for the condensation troughs 5a collecting the treated water, and that preferably an outlet is also provided for the residual water collected by the channel 6, which might not be evaporated. It is expressly provided that an air inflow shall be maintained into the device in order to keep a circulation of air, to prevent overheating but also "'ith the objective of promoting heat exchange and creating the conditions necessary for obtaining condensation after evaporation.

The device shown in figure 1, which has just been described, is especially intended, on the one hand for the treatment of seawater and as a function of solar rays as heating means; however, it will 2026 be understood that the process can be used for other objectives and with other radiation means than the rays of the sun and therefore otherwise than with solar heat and/or with cooling means other than the water which is yet to be treated, which will involve certain modifications to the device. Similarly, it may be arranged for a sub-atmospheric pressure to be created inside the device, to favour evaporation.

Referring to figure 2, an installation is shown intended for the desalination of seawater, and which is composed of a certain number of rows of devices 14 which are like those shown in figure 1, which have been connected together by a certain number of piping systems 15 connected to the outlets for treated water, these pipes 15 conducting the treated water by natural flow to a balancing tank 16, which in turn is connected with a storage tank 17. To enable the treated water to be fed into this storage tank 17, a pump 18, for example of the solar pump type or heliothermic chamber, is interposed between the storage tank 17 and the balancing tank. It is also envisaged to provide (not shown) between the two tanks 16 and 17 a non-return system in such a way that, when the device is slowed down or stopped, the solar pump or heliothermic chamber is not emtied.

In practice, only the glass roofs and the storage tank will be visible, all the other components being buried in the ground. The installation can, of course, be located not at the edge of the sea but set back therefrom; it will be necessary ,-only to provide I 2026 covered trenches (or indeed piping) for supplying the seawater.

It is especially clear that various arrangements can be adopted; depending upon the situation encountered, the plant might be situated in a rocky, not a sandy environment.

Referring to figures 3 and 4, use is made of rows of devices 19 of the type shown in figure 1 and described above for regenerating a soil containing an excessive percentage of salt; in this case, the following cycle will of course need to be achieved; the soil to be treateld is sprinkled with water, which becomes charged with salt and becomes the water to be treated by the devices 19; then, after the salt has been extracted from it, the fresh water is returned to the soil and a new cycle can be created or, if the soil has been sufficiently regenerated, seawater or other water is then simply introduced into the device and, after treatment, the treated water is used for sprinkling the regenerated soil.

In figures 3 and 4 reference 2 0 has been used for indicating the pipes for recovering the treated water, which is conducted to a storage tank 21 through the intermediary of heliothermic chambers 22, while the stored, treated water can then be fed back to the soil to be regenerated through pipes 23, since finally only simple watering of the soil may be needed once the soil has been completely regenerated, a pipe 24 being provided for bringing the water from the first cycle to the device 19, or for directly supplying, for example, salt water or water to be treated to this same device 19.

Referring to these figures 3 and 4, it can J?e seen that it 202699 is envisaged to place the rows of devices 19 at a certain distance from each other (from one another), for example at a distance of 10 metres, to prevent almost immediate evaporation of the water for treatment of the soil (or sprinkled water); preferably, the soil to be treated will be covered over at a certain height by screens, simple metal plates 25 resting on a frame 26 partially fixed in the ground.

In the case (not shown) in which a device or series of devices are provided for treating waste waters (for example industrial waste water), the partial or total desalination for recovering or otherwise certain solid materials, it is not necessary to bury the device in the soil but simply to immerse it partly in a basin containing the waste waters (or other liquids) to be treated.

The invention is therefore not limited to the method, device and installation described, which may indeed require various adaptations depending upon the objective and the substance treated.

The functioning of the device (see figure l) is especially simple, the water (or any other liquid) situated in the soil, the sand of the beach or indeed in a large receptacle (for example for the treatment of waste water), will ascend by capillary attraction in the permeable, granular element in which it is situated, for example the soil, or again in the complementary element which has been created, for example the mass of capillary concrete ) (in the direction of arrow 27, figure 1); the liquid percolated through this mass, passes through the heated evaporators, and 11 202699 therefore evaporates instantaneously. This vapour, as a result of the air movement, will reach the lower parts and the condensation chambers (figure 1, arrow 28).

In its form itself, the device as shown in figure I, is especially suitable for variation, for example it may be of square or rectangular form, of a greater height in proportion or otherwise; it can be conceived as simply having a single lateral, inclined evaporator and also being equipped with a single condensation chamber, but all these features do not in any way modify the principle defined by the invention and remain within the framework of the claims given below.

As an accessory to an installation in accordance with this invention, it may be envisaged that a balancing tank may be provided for the water to be treated, so as to maintain a constant head at the ihlet for water to be treated.

If the treated water is intended for human or animal consumption, then to make it more easily assimilated, a waterfall can be created within the storage tank so as to oxygenize the fresh water obtained.

Furthermore, for example in order to increase the intensity of radiation, provision may well be made for concentrating the solar rays for the purpose of obtaining an increase in the heating facilities.

Claims (17)

202699 - 12 - WHAT I CLAIM IS:

1. A method of treating a liquid substance by evaporation of a liquid to remove therefrom or recover at least a portion of the solid particles which it contains, characterized in that the substance to be treated is caused to pass by capillary attraction through a granular, permeable zone, that is to say a zone permitting percolation of the substance, this zone being terminated by a heat capture plane which forms at least the inclined, lower part of a heating chamber or zone, this plane facing towards a heat source, a portion of the vapour being condensed in at least one condensation chamber or zone, which is situated outside the direct influence of the heat source, this condensation chamber or zone being maintained at a temperature lower than that of the heating chamber or zone, any non-evaporated substance being conducted by flowing from the evaporation plane or planes to a lower channel, which can optionally be reached directly by the heat source, in order to continue or at least partially complete the evaporation of the substance and to recover therefrom the dissolved solids.

2. A method according to claim 1, characterized in that, in the condensation chamber or chambers or zone or zones, a temperature lower than that in the heating chamber or zone is maintained by placing them in contact, that is to say by partly surrounding them with, a cooling liquid which may be the substance yet to be treated, so as to create a thermal exchange.

3. A method according to any one of claims 1 and 2, for the regeneration of soil, characterized in that the substance to be treated at th.e start is obtained by injecting a liquid from an external source into the soil for the purpose of forming in the soil, the liquid substance to be treated and that, thereafter, the treated substance is re-injected into soil - 13 - 202699 to continue the regeneration of soil or simply to irrigate it.

4. A method according to any one of claims 1 to 3, characterized in that the heating means are solar rays, concentrated or not concentrated.

5. A device for carrying out the method according to any one of claims 1 to 4, characterized in that it comprises at least one heating zone or chamber constituted in respect of its upper part either of a glass plate which is a glass roof, forming a surface for the passage of the radiation, or a heating surface, this slightly inclined or not inclined horizontal upper part being completed at the sides over at least a portion of its height by a granular, permeable mass, of which at least the surface facing the heating chamber or zone is of a heat absorbent material and forms at least the essential part of the evaporation surface, the surface or surfaces being situated inclined downwardly to a greater or lesser extent from the outside towards the inside and through which the liquid may enter, which device is consituted at its lower part of one or more condensation chambers or zones situated external to the surface for the passage of the radiation or at least being disposed beyond the reach of the rays passing through the surface for the passage of the radiation or the heating surface, and the condensation chambers or zones comprising, at one end, at least one outlet for the treated liquid and, in addition, in the downward extension of the evaporation surface or surfaces, one or more channels or zones for the flow of the surplus, non-evaporated liquid and the optional recovery of the dissolved solids, these channels or zones forming a complementary evaporation surface capable of being reached directly by the rays passing through the surface for the passage of the radiation or heating surface.

6. A device according to claim 5, characterized in that the evaporation zone comprises a means for regulating the flow rate of the inflow of liquid by capillary attraction. 202699 14

7. A device according to claim 6, characterized in that this means for regulating the inflow rate of the liquid is a strip forming a wall, which can be raised to a greater or lesser height and is situated behind the capillary mass.

8. A device according to any one of claims 5 to 7, characterized in that the evaporation channel or zone comprises a filter.

9. A device according to any one of claims 5 to 8, characterized in that a filter is situated between the capillary mass and the evaporator.

10. A device according to any one of claims 5 to 9 characterized in that the condensation chamber or chambers are at least partially surrounded by the substance to be treated, the device being situated in the substance to be treated or in a supply channel for the substance to be treated.

11. A device according to any one of claims 5 to 9, characterized in that at least the evaporation surfaces are situated on a capillary material forming a mass through which the liquid to be treated can pass.

12. A device according to any one of claims 5 to 11, characterized in that the various filters are removable.

13. A device according to any one of claims 5 to 12, characterized in that the filter of the evaporation channel is continuous and enters at one end of a device or of a row of devices, to leave at the opposite end of the device or of the row of devices.

14. An installation for the treatment of a substance, comprising one or more of the devices according to any one of claims 5 to 13, characterized in that the device or devices are situated in trenches excavated in soil, the heating surfaces projecting above the ground, and that a connection is created between these - 15 - 202699 trenches and the source of substance to be treated which is constituted of secondary pipes or channels complemented or not complemented by a balancing tank and that the treated substance recovered in the condensation chambers is conducted by natural thermosiphon flow to a storage area.

15. An installation for the regeneration of soil, characterized in that it comprises at least two rows of devices according to any one of claims 5 to 13, spaced apart from one another, a storage tank to which the treated water is conducted by heliothermic chambers, it being possible for this water to be conducted through pipes or channels to soil to be regenerated, ♦ to continue its regeneration or, more simply, its irrigation, and a pipe or channel for supplying the water to the various devices.

16. The method according to claim 1 substantially as herein described.

17. A device for carrying out the method according to any one of claims 1 to 4 substantially as herein described with reference to the accompanying drawings. MARC SCHUMANN By His Attorneys HENRY HUGHES LIMITED //