WO1997029995A1 - Plant for production of drinking water from unfiltered water - Google Patents

Plant for production of drinking water from unfiltered water Download PDF

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Publication number
WO1997029995A1
WO1997029995A1 PCT/DK1997/000060 DK9700060W WO9729995A1 WO 1997029995 A1 WO1997029995 A1 WO 1997029995A1 DK 9700060 W DK9700060 W DK 9700060W WO 9729995 A1 WO9729995 A1 WO 9729995A1
Authority
WO
WIPO (PCT)
Prior art keywords
water
plant
pump
membrane
combustion engine
Prior art date
Application number
PCT/DK1997/000060
Other languages
French (fr)
Inventor
Povl Kaas
Original Assignee
Aqua System A/S
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Aqua System A/S filed Critical Aqua System A/S
Priority to AU17187/97A priority Critical patent/AU1718797A/en
Priority to PCT/DK1997/000060 priority patent/WO1997029995A1/en
Publication of WO1997029995A1 publication Critical patent/WO1997029995A1/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F9/00—Multistage treatment of water, waste water or sewage
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/04—Filters with filtering elements which move during the filtering operation with filtering bands or the like supported on cylinders which are impervious for filtering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/44—Regenerating the filter material in the filter
    • B01D33/46—Regenerating the filter material in the filter by scrapers, brushes nozzles or the like acting on the cake-side of the filtering element
    • B01D33/461—Regenerating the filter material in the filter by scrapers, brushes nozzles or the like acting on the cake-side of the filtering element brushes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/44—Regenerating the filter material in the filter
    • B01D33/46—Regenerating the filter material in the filter by scrapers, brushes nozzles or the like acting on the cake-side of the filtering element
    • B01D33/463—Regenerating the filter material in the filter by scrapers, brushes nozzles or the like acting on the cake-side of the filtering element nozzles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/44—Regenerating the filter material in the filter
    • B01D33/48—Regenerating the filter material in the filter by flushing, e.g. counter-current air-bumps
    • B01D33/50—Regenerating the filter material in the filter by flushing, e.g. counter-current air-bumps with backwash arms, shoes or nozzles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/58—Handling the filter cake in the filter for purposes other than for regenerating the filter cake remaining on the filtering element
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/70—Filters with filtering elements which move during the filtering operation having feed or discharge devices
    • B01D33/74—Filters with filtering elements which move during the filtering operation having feed or discharge devices for discharging filtrate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/80—Accessories
    • B01D33/804—Accessories integrally combined with devices for controlling the filtration
    • B01D33/807—Accessories integrally combined with devices for controlling the filtration by level measuring
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
    • B01D61/025—Reverse osmosis; Hyperfiltration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
    • B01D61/04—Feed pretreatment
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/30—Treatment of water, waste water, or sewage by irradiation
    • C02F1/32—Treatment of water, waste water, or sewage by irradiation with ultraviolet light
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/441—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by reverse osmosis
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/72—Treatment of water, waste water, or sewage by oxidation
    • C02F1/78—Treatment of water, waste water, or sewage by oxidation with ozone
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2201/00—Details relating to filtering apparatus
    • B01D2201/38—Preventing rewetting of the filter cake on the filter media
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2311/00—Details relating to membrane separation process operations and control
    • B01D2311/04—Specific process operations in the feed stream; Feed pretreatment
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/001—Processes for the treatment of water whereby the filtration technique is of importance
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/42—Treatment of water, waste water, or sewage by ion-exchange
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
    • C02F1/56—Macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/16—Nitrogen compounds, e.g. ammonia
    • C02F2101/163—Nitrates

Definitions

  • the invention concerns a plant for production of drinking wa ⁇ ter from unfiltered water, from for example a conatural reser- voir and of the type, which comprises at least one membrane for through reversed osmosis removing salts and ⁇ radio-active substances, if any, and a process conduit with at least one pressure pump for driving the unfiltered water through the membrane.
  • the wa- ter that leaves the membranes, does frequently not have a completely satisfactory quality, and to this can be added that the known plants take up rather a lot of space and are conse ⁇ quently unsuitable as mobile plants to be brought into action in, for example, a war situation, where there suddenly arises a need for provision of clean drinking water.
  • the object of the invention is to provide a plant of the type mentioned in the opening paragraph, which has a compact con ⁇ struction, which without the use of chemicals can produce drinking water of an excellent quality from even heavily con- taminated and salt-containing unfiltered water in a process, which secures that the membranes used will have a -longer life ⁇ time than known up till now.
  • the plant comprises one ozone purification section, inserted in the process pipe before the membrane, which section will, by injection of ozone in the unfiltered water, reduce, flocculate and remove suspended micro-particles and solutions of especially organic substances and strip ra- dioactive gases, and also a succeeding UV-section for espe ⁇ cially decomposing ozone, chlorine and hydrogen peroxide.
  • the membranes are protected safely by means of an ef ⁇ ficient preliminary treatment of the unfiltered water without using chemicals.
  • organic substances are removed, such as mineral oils, in this process, which takes place in the ozone purification section.
  • the preliminary treatment will moreover remove all present chemicals, toxins, endotoxins, microbes and vira, and also an radioactivity, if any, and thereby ensure that clean and healthy drinking water can be produced.
  • the whole plant is run by a combustion engine with a dynamo belonging to the plant, and the plant is therefore able, even under conditions where there is no exterior source of power available, to function, such as often the case in warfare or by catastrophes.
  • the only thing the plant according to the invention requires in order to be able to produce drinking water, is fuel and access to a source with unfiltered water, e.g. the sea.
  • the pressure pump in the process pipe can advantageously be a current pump with several pump steps, which are placed on a joint axle, which runs parallel to the outlet axle of the com ⁇ bustion engine and is directly run by this by means of a me- chanical transmission. Thereby the plant obtains a compact construction.
  • a plant for production of drinking water will often have to operate under conditions, where it is difficult to provide spare parts.
  • the pump steps of the pressure pump can therefore be divided into similar sections, which have been placed in equally similar tubular pump casings with couplings for a series-connection of the pump housings. Thereby just a few spare parts will be adequate for covering the need for re- placement if some of the components of the pump section should break down.
  • the components are similar the pump section, by break-down of some of the components, still be able to function by rebuilding the remaining components.
  • a compact construction of the plant is also obtained by using helical membranes for the reversed osmosis.
  • the helical membranes can be divided into sections, which are placed in membrane hous ⁇ ings, which correspond the pump housings of the pump sections.
  • the same spare parts can therefore expediently be used for replacement of pump housings as membrane housings.
  • The: contents of C0 2 in the exhaust gases can also be utilized to prevent that silicic acid, which in some places in the un ⁇ filtered water is available, will preticipate out on the membranes.
  • the clean water can accord ⁇ ing to the invention be supplied with metal ions from metallic silver and/or copper in a section, which has been inserted in the process pipe.
  • the plant comprises, therefore, according to the in ⁇ vention, a bypass, which is connected to the process pipe be ⁇ fore the heat exchanger and after the membranes, seen in the direction of the process.
  • a pump has been inserted to send the water into circulation through the bypass and the process pipe in the opposite direction of the process.
  • coverings on the active surfaces of the components are removed.
  • the circulating water can be brought to such a high temperature, that the whole process line is disinfected.
  • Fig. 1 diagrammatically shows the whole process according to the invention
  • Fig. 2 shows, seen in perspective, a plant according to the invention
  • Fig. 3 shows, in perspective, a spring picture of the same with some of the parts taken out
  • Fig. 4 shows a combustion engine belonging to the plant, hav- ing a pressure pump coupled on
  • Fig. 5 shows a mechanical transmission between the combustion engine and the pressure pump, seen from the side
  • Fig. 6 shows a section after the line VI- VI in fig. 5
  • Fig. 7 shows in fraction an axial section through two of the sections of the pressure pump.
  • the plant shown in fig. 1 diagrammatically serves the purpose of producing drinking water from available unfiltered water, which during the passage by a process pipe 1 runs through a number of processes to liberate the unfiltered water from im ⁇ purities.
  • the unfiltered water is fetched from a unfiltered water reservoir 2, which can be the sea or a stream, e.g. a flood or a lake. From the reservoir the unfiltered water is with a filter pump 3 via a food pipe 4 and a filter 5 pumped to a process pump 6, which is driven by a combustion engine 7 via a mechanical transmission 8.
  • the only thing, which is nec- es ary, by means of the plant according to the invention, to transform the unfiltered water to drinking water is the fuel, which is added to the combustion engine, as hinted with the arro .
  • the combustion engine drives a dynamo 9, which delivers cur- rent to the different processes of the plant.
  • the cooling wa ⁇ ter of the combustion engine is led to a heat exchanger 10, which is inserted in the process pipe after the process pump 6.
  • the processes in the following process steps are increased, when the water in this way has been heatened up in the heat exchanger 10.
  • the preheated unfiltered water flows then along through the process pipe 1 to an ozone purification section 12, to which is added ozone from a ozone generator 13.
  • ozone purifi- cation section especially organic substances are removed, e.g. mineral oils, which might have contaminated the unfiltered water.
  • Micro-organisms and suspended and dissolved organic substances flocculate and are removed in the shape of floes .
  • Radio-active gases, if any, are stripped by being blown through the ozone section with ozone.
  • the water continues to a first UV-section 14 with a number of UV-lamps 15 for a photo ⁇ chemical treatment of the water.
  • the UV-light will especially could decompose ozone, chlorine and hydrogen peroxide, but will also be able to reduce bacteria, vira, amoeba ⁇ and micro-fungi .
  • UV-section prevents the membranes from being dissolved and destructed by ozone, chlorine and hydrogen peroxide.
  • L 5 be remov € ⁇ d to such an extend, that the water now is suitable for treatment by reversed osmosis in the membranes.
  • the fil ⁇ ters can be a type which in itself is a known self-cleaning type.
  • the purificated and particle-free water from the last fine- filter 18 is now by a main pump 21 put up to the rather high pressure, which is necessary in order to perform the reversed osmosis in the membrane section 22.
  • the main pump 21 is driven by the diesel engine by means of the mechanical transmission 5 8.
  • the pump pressure must be approximately 70 bar.
  • normal salt water it must be approximately 20 bar, and by water from a fresh water sea it must be approximately 8 bar.
  • the process in the membrane section requires, however, that the membranes are supplied with much more water, than leaves the plant as drinking water.
  • the large amount of additional water has, due to the high pressure of the water before the membranes, a substantial amount of energy, which advanta ⁇ geously can be utilized as a contribution to driving the main pump 21, since the water via a turbine 23 drives a water en ⁇ gine 24, which is coupled to the pressure pump 21.
  • the salts are removed in a familiar way. Since the water first has been pre-treated in the above described way, so that all the particular and dissolved sub ⁇ stances, apart from salts, have been removed, the membranes can obtain a life time, which typically will be up to 5 - 10 times as long as it normally is the case by conventional plants. Thereby a substantial economic profit is obtained, since a membrane replacement in the described plant typically can cost between 20.000 - 30.000 US $.
  • lime will therefore be supplied in a up-hardening filter 25 with for example marble breakings, to supply the water with the desired hardness and decompose additional C0 2 .
  • the now very clean water can be kept fresh for a longer period of time by letting it pass a ion section 28 with metallic copper 29 and metallic silver 30 to give off metal ions to the flowing water.
  • the unfiltered water can have a high content of silicic acid, which will be inclined to preticipated as salts, which would be able to block the membrane.
  • the silicic acid is kept in a solution of that C0 2 , which exists in the exhaust gas of the combustion engine, which gas for that purpose is led to a mixer 31 to mix the exhaust gas or separated C0 2 with the flowing water in the process pipe 1.
  • the plant comprises a bypass 32, shown with a dotted line, and having a pump 33.
  • the bypass 32 ' s one end is connected to the process pipe 1 at a spot before the heat exchanger 10 and the other end at a spot after the UV-section 27.
  • Fig. 4 shows one of the central units of the plant, which unit as a whole is designated with the reference number 39.
  • the combustion engine 7 and the dynamo 9 Furthermore can be seen the process pump 6 and the main pump 21, which as shown consists of more sections connected in se ⁇ ries, and also the turbine 23 for utilizing the energy in the additional water from the reversed osmosis process.
  • the reference number 40 is designated a water hydraulic pump for driving the hydraulic engines and the hydraulically run valves of the plant.
  • the exhaust system 41 of the engine is led through a filter 42 to separate the content of C0 2 in the ex ⁇ haust gases, for use, as said before, in the purification processes .
  • the various pumps are all driven directly by means of a me ⁇ chanical transmission 43, which in fig. 4 only is seen from the outside.
  • Fig 5 and 6 show the construction of this mechanical transmis ⁇ sion in details.
  • the outlet axle 44 of the combustion engine 7 is mounted on a driving gear wheel 45 which drives a number of planet-gear wheels 46, each of which is mounted on an axle 47, which is suspended in bearings 48. Furthermore is there on each axle mounted a V-belt disc 49, which by means of a V-belt 50 pulls a second V-belt disc 51, which is mounted on the ax ⁇ les 52 of one the pumps.
  • the pumps which thus receive their motive power, directly by means of a mechanical transmission, takes up between 60% and 70%- of the energy, which is given off by the combustion en ⁇ gine.
  • the pumps can also be driven by electric engines, which are provided with energy from the dynamo of the combustion engine, whereby the weight and volume of the plant due to this fact will be much larger and much more bulky than is the case when the above described direct mechanical transmission is used.
  • the direct mechanical transmis- sion will furthermore ensure, that the plant obtains a compact structure with a modes need for space.
  • the diver's pumps are in principle a number of centrifugal pumps, which in series are placed on a joint axle. The pres- sure will thus rise step by step in the pump. Since there is worked with very high pressures, the main pump 21 can for space-wise reasons be divided into several series connected sections, as shown in fig. 4.
  • the speed of rotation of the pumps can be regulated, and that is precisely the case, when a combustion engine is used, which drives the pumps in question via a direct mechanical transmission.
  • the figure of rotation of a combustion engine can, as well-known, be regulated within wide limits only by regulating the amount of fuel that is supplied.
  • the pumps are divided into similar sections 53 with similar tubular pump housings 54, which can be assem ⁇ bled in series by means of couplings 55 at the ends of the pump housings.
  • This construction results in the fact, that the plan flexibly can be adjusted to the requirements, which might be demanded to the productiveness of the plant in the present situation, and it reduces to a substantial extend the need for spare parts .
  • the membranes used are helical so that they with a large ca ⁇ pacity take up as less space as possible, and they are placed in membrane housings 56, which are similar to the pump hous ⁇ ings of the pump sections. Thereby the need for spare parts is additionally reduced.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Water Supply & Treatment (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Organic Chemistry (AREA)
  • Nanotechnology (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)

Abstract

A plant serving the purpose of producing drinking water from unfiltered water from, for example, a natural reservoir. The plant comprises a membrane (22) which by reversed osmosis can remove salts and radioactive substances, if any, and a process pipe (1) with a pressure pump (10; 22) to drive the unfiltered water through the membrane. The plant comprises furthermore an ozone purification section (12) which by injection of ozone in the unfiltered water reduces, flocculates and removes suspended micro-particles and solutions of especially organic substances and strips radioactive gases, if any, and a UV-section (14) for especially to decompose ozone, chlorines and hydrogen peroxide. The whole plant is driven by a combustion engine (7) with a dynamo (9). The plant has a compact construction and can without using chemicals produce drinking water of a very high quality from even heavily contaminated and salt-containing unfiltered water in a process, which ensures the membranes used a longer lifetime than known up till now. The process takes only fuel for the combustion engine.

Description

Plant for production of drinking water from unfiltered water.
The invention concerns a plant for production of drinking wa¬ ter from unfiltered water, from for example a conatural reser- voir and of the type, which comprises at least one membrane for through reversed osmosis removing salts and ^radio-active substances, if any, and a process conduit with at least one pressure pump for driving the unfiltered water through the membrane.
On many spots on earth there is a lack of drinking water. Ground water, lakes and streams are often contaminated to such a degree that the water cannot be drunk. In many cases there will, furthermore, only be sea water available.
The use of, reversed osmosis, by means of membranes, to de¬ salt the sea water has for a long time been a known process. As well sea water as other kinds of unfiltered water contain, however, a number of substances, which must not be allowed to reach the membranes, which otherwise quickly would be set out of function. In order to remove these substances, chemicals are added to the unfiltered water before the membranes, which chemicals must be tried to be removed to protect the membranes and ensure, that the water afterwards can be drunk without any risks to the health. The expenses for chemicals and for the succeeding separation are substantial, and in practice it has shown that the expensive membranes quickly are damaged during the process and therefore often have to be replaced. The known conventional plants are, therefore, expensive to run. The wa- ter, that leaves the membranes, does frequently not have a completely satisfactory quality, and to this can be added that the known plants take up rather a lot of space and are conse¬ quently unsuitable as mobile plants to be brought into action in, for example, a war situation, where there suddenly arises a need for provision of clean drinking water. The object of the invention is to provide a plant of the type mentioned in the opening paragraph, which has a compact con¬ struction, which without the use of chemicals can produce drinking water of an excellent quality from even heavily con- taminated and salt-containing unfiltered water in a process, which secures that the membranes used will have a -longer life¬ time than known up till now.
The new and unique whereby this is obtained is according to the invention, that the plant comprises one ozone purification section, inserted in the process pipe before the membrane, which section will, by injection of ozone in the unfiltered water, reduce, flocculate and remove suspended micro-particles and solutions of especially organic substances and strip ra- dioactive gases, and also a succeeding UV-section for espe¬ cially decomposing ozone, chlorine and hydrogen peroxide.
Thereby the membranes are protected safely by means of an ef¬ ficient preliminary treatment of the unfiltered water without using chemicals. Thus organic substances are removed, such as mineral oils, in this process, which takes place in the ozone purification section. The preliminary treatment will moreover remove all present chemicals, toxins, endotoxins, microbes and vira, and also an radioactivity, if any, and thereby ensure that clean and healthy drinking water can be produced.
With a particular expedient embodiment the whole plant is run by a combustion engine with a dynamo belonging to the plant, and the plant is therefore able, even under conditions where there is no exterior source of power available, to function, such as often the case in warfare or by catastrophes. The only thing the plant according to the invention requires in order to be able to produce drinking water, is fuel and access to a source with unfiltered water, e.g. the sea. The pressure pump in the process pipe can advantageously be a current pump with several pump steps, which are placed on a joint axle, which runs parallel to the outlet axle of the com¬ bustion engine and is directly run by this by means of a me- chanical transmission. Thereby the plant obtains a compact construction.
A plant for production of drinking water will often have to operate under conditions, where it is difficult to provide spare parts. The pump steps of the pressure pump can therefore be divided into similar sections, which have been placed in equally similar tubular pump casings with couplings for a series-connection of the pump housings. Thereby just a few spare parts will be adequate for covering the need for re- placement if some of the components of the pump section should break down. When the components are similar the pump section, by break-down of some of the components, still be able to function by rebuilding the remaining components.
A compact construction of the plant is also obtained by using helical membranes for the reversed osmosis. In order to reduce the need for spare parts even more, the helical membranes can be divided into sections, which are placed in membrane hous¬ ings, which correspond the pump housings of the pump sections. The same spare parts can therefore expediently be used for replacement of pump housings as membrane housings.
When an combustion engine is used as power source for running the plant, that is cooled by cooling water, it can be an ad- vantage to let said cooling water pass a heat exchanger, which has been inserted in the process pipe. By heating up the un¬ filtered water in the process pipe in this way, the process can be carried through with a reduced use of energy, and/or the capacity of the plant can be increased. The combustion processes in the combustion engine are develop- incf combustion gases with a considerable amount of C02, which according to the invention can be utilized to reduce the pH value of the unfiltered water by letting the exhaust gases or separated C02 pass a mixer, which the unfiltered water passes.
The: contents of C02 in the exhaust gases can also be utilized to prevent that silicic acid, which in some places in the un¬ filtered water is available, will preticipate out on the membranes.
When the unfiltered water has gone through the described puri¬ fication processes and has passed the membrane, it will be in an exceedingly clean condition. In order to keep this condi¬ tion over a longer period of time, the clean water can accord¬ ing to the invention be supplied with metal ions from metallic silver and/or copper in a section, which has been inserted in the process pipe.
When in operation, various sections of the plant, e.g. the membranes, will be turned on so that their efficiency will be reduced. The plant comprises, therefore, according to the in¬ vention, a bypass, which is connected to the process pipe be¬ fore the heat exchanger and after the membranes, seen in the direction of the process. In the process pipe a pump has been inserted to send the water into circulation through the bypass and the process pipe in the opposite direction of the process. Thereby coverings on the active surfaces of the components are removed. Furthermore, by placing an electric heating element after the heat exchanger driven by cooling water, which ex¬ changer is driven by the dynamo of the combustion engine, the circulating water can be brought to such a high temperature, that the whole process line is disinfected. The invention will be explained more fully by the following description of embodiment which just serves as an example, with reference to the drawing, where
Fig. 1 diagrammatically shows the whole process according to the invention,
Fig. 2 shows, seen in perspective, a plant according to the invention,
Fig. 3 shows, in perspective, a spring picture of the same with some of the parts taken out,
Fig. 4 shows a combustion engine belonging to the plant, hav- ing a pressure pump coupled on,
Fig. 5 shows a mechanical transmission between the combustion engine and the pressure pump, seen from the side,
Fig. 6 shows a section after the line VI- VI in fig. 5,
Fig. 7 shows in fraction an axial section through two of the sections of the pressure pump.
The plant shown in fig. 1 diagrammatically serves the purpose of producing drinking water from available unfiltered water, which during the passage by a process pipe 1 runs through a number of processes to liberate the unfiltered water from im¬ purities. The unfiltered water is fetched from a unfiltered water reservoir 2, which can be the sea or a stream, e.g. a flood or a lake. From the reservoir the unfiltered water is with a filter pump 3 via a food pipe 4 and a filter 5 pumped to a process pump 6, which is driven by a combustion engine 7 via a mechanical transmission 8. The only thing, which is nec- es ary, by means of the plant according to the invention, to transform the unfiltered water to drinking water is the fuel, which is added to the combustion engine, as hinted with the arro .
The combustion engine drives a dynamo 9, which delivers cur- rent to the different processes of the plant. The cooling wa¬ ter of the combustion engine is led to a heat exchanger 10, which is inserted in the process pipe after the process pump 6. The processes in the following process steps are increased, when the water in this way has been heatened up in the heat exchanger 10.
The preheated unfiltered water flows then along through the process pipe 1 to an ozone purification section 12, to which is added ozone from a ozone generator 13. In the ozone purifi- cation section especially organic substances are removed, e.g. mineral oils, which might have contaminated the unfiltered water. Micro-organisms and suspended and dissolved organic substances flocculate and are removed in the shape of floes . Radio-active gases, if any, are stripped by being blown through the ozone section with ozone.
The more specific construction of the ozone purification sec¬ tion is described in the applicant's Danish Patent Application No. 0145/96 to which is referred as a reference.
From the ozone purification section the water continues to a first UV-section 14 with a number of UV-lamps 15 for a photo¬ chemical treatment of the water. The UV-light will especially could decompose ozone, chlorine and hydrogen peroxide, but will also be able to reduce bacteria, vira, amoebaε and micro-fungi .
The more specific construction of the Uv-section is describe in the applicant's Danish Patent Application No. 0145/96 to which is referred as a reference. The filtration alone will not be able to remove dissolved sub¬ stances, and it is therefore precisely important, that the plant contains a ozone purification section to remove these dissolved substances, which otherwise could deposit on the 5 membranes and put them out of function.
The function of the UV-section prevents the membranes from being dissolved and destructed by ozone, chlorine and hydrogen peroxide. 0
In the plant shown in fig. 1 there has, after the UV-section, been inserted altogether three fine-filters 16,17,18 with de¬ creasing mesh sizes from e.g. 200 - 5μ . After the passage of the last fin-filter even the finest suspended particles will
•L5 be remov€ϊd to such an extend, that the water now is suitable for treatment by reversed osmosis in the membranes. The fil¬ ters can be a type which in itself is a known self-cleaning type.
0 Between the filter 17 and 18 there has been inserted a com¬ bined ultra-sound- and UV-section 19 to react with micro¬ organisms and decompose amoebas and organisms, which might be hosts for e.g. legionella, which otherwise would be able to poison the water.
25
After the ultra-sound section 19 there has been inserted an active carbon filter 20 for elimination of oxidizable sub¬ stances, if any, through absorption.
30 The purificated and particle-free water from the last fine- filter 18 is now by a main pump 21 put up to the rather high pressure, which is necessary in order to perform the reversed osmosis in the membrane section 22. The main pump 21 is driven by the diesel engine by means of the mechanical transmission 5 8. By very saline water from for example the Red Sea, the pump pressure must be approximately 70 bar. By normal salt water it must be approximately 20 bar, and by water from a fresh water sea it must be approximately 8 bar.
The process in the membrane section requires, however, that the membranes are supplied with much more water, than leaves the plant as drinking water. The large amount of additional water has, due to the high pressure of the water before the membranes, a substantial amount of energy, which advanta¬ geously can be utilized as a contribution to driving the main pump 21, since the water via a turbine 23 drives a water en¬ gine 24, which is coupled to the pressure pump 21.
In the membrane section 22 the salts are removed in a familiar way. Since the water first has been pre-treated in the above described way, so that all the particular and dissolved sub¬ stances, apart from salts, have been removed, the membranes can obtain a life time, which typically will be up to 5 - 10 times as long as it normally is the case by conventional plants. Thereby a substantial economic profit is obtained, since a membrane replacement in the described plant typically can cost between 20.000 - 30.000 US $.
After the pre-treatment and the reversed osmosis the water will be very soft. In the plant shown lime will therefore be supplied in a up-hardening filter 25 with for example marble breakings, to supply the water with the desired hardness and decompose additional C02.
After the up-hardening filter there is a second UV-section 26 with UV-lamps 27, which send out UV-light with wavelengths in the energy-filled area of 185 - 255 nm, whereby a very effi¬ cient final disinfection of the water takes place.
The now very clean water can be kept fresh for a longer period of time by letting it pass a ion section 28 with metallic copper 29 and metallic silver 30 to give off metal ions to the flowing water.
In some cases the unfiltered water can have a high content of silicic acid, which will be inclined to preticipated as salts, which would be able to block the membrane. In order to prevent this, the silicic acid is kept in a solution of that C02, which exists in the exhaust gas of the combustion engine, which gas for that purpose is led to a mixer 31 to mix the exhaust gas or separated C02 with the flowing water in the process pipe 1.
From time to time active sheets in the process steps will be set up with coverings and thereby loose their efficiency. The plant comprises a bypass 32, shown with a dotted line, and having a pump 33. The bypass 32 ' s one end is connected to the process pipe 1 at a spot before the heat exchanger 10 and the other end at a spot after the UV-section 27.
When the plant is to be regenerated, the closing valves 34 and 35 at the ends of the process pipe 1 are shut, and the pump 33 in the bypass 32 is started and now sends water into circula¬ tion through the bypass and the blocked process pipe into the opposite direction of the process, whereby the said coverings are removed. After the heat exchanger there is a heat element 11 for heating up the unfiltered water to a rather high tem¬ perature, e.g. 95°C. The heat element 11 is provided with electricity from the dynamo 9. When the heat element 11 is turned on, and the water is recirculated as described above, the whole process line will be disinfected by the very hot water.
The water leaving the plant has, till now, an unseen high quality. In dependence of the quality of the unfiltered water and the demands raised to the quality of the drinking water one or more of the described process steps can be left out, whereby the expenses to produce and drive the plant are re¬ duced accordingly.
The physical construction of the plant can be seen in fig. 2 in assembled condition and in fig. 3 in a spring picture, where only some of the components are shown. The proper plant is built compactly up in a frame 36. Furthermore can be seen a basin 37 for unfiltered water and a basin 38 for the drinking water. The different components of the plant are described above with reference to the fig. 1 are in fig. 2 and 3 shown as they typically are seen from the outside.
Fig. 4 shows one of the central units of the plant, which unit as a whole is designated with the reference number 39. In the figure can be seen the combustion engine 7 and the dynamo 9. Furthermore can be seen the process pump 6 and the main pump 21, which as shown consists of more sections connected in se¬ ries, and also the turbine 23 for utilizing the energy in the additional water from the reversed osmosis process. With the reference number 40 is designated a water hydraulic pump for driving the hydraulic engines and the hydraulically run valves of the plant. The exhaust system 41 of the engine is led through a filter 42 to separate the content of C02 in the ex¬ haust gases, for use, as said before, in the purification processes .
The various pumps are all driven directly by means of a me¬ chanical transmission 43, which in fig. 4 only is seen from the outside.
Fig 5 and 6 show the construction of this mechanical transmis¬ sion in details. The outlet axle 44 of the combustion engine 7 is mounted on a driving gear wheel 45 which drives a number of planet-gear wheels 46, each of which is mounted on an axle 47, which is suspended in bearings 48. Furthermore is there on each axle mounted a V-belt disc 49, which by means of a V-belt 50 pulls a second V-belt disc 51, which is mounted on the ax¬ les 52 of one the pumps.
The pumps, which thus receive their motive power, directly by means of a mechanical transmission, takes up between 60% and 70%- of the energy, which is given off by the combustion en¬ gine. The pumps can also be driven by electric engines, which are provided with energy from the dynamo of the combustion engine, whereby the weight and volume of the plant due to this fact will be much larger and much more bulky than is the case when the above described direct mechanical transmission is used. As pumps are used diver's pumps, which normally are run by an electric engine in the water flow, but with the plant according to the invention the pumps are expediently driven by the direct mechanical transmission, since the electric engines will not be able to stand the high temperatures of water dur¬ ing the regeneration process. The direct mechanical transmis- sion will furthermore ensure, that the plant obtains a compact structure with a modes need for space.
The diver's pumps are in principle a number of centrifugal pumps, which in series are placed on a joint axle. The pres- sure will thus rise step by step in the pump. Since there is worked with very high pressures, the main pump 21 can for space-wise reasons be divided into several series connected sections, as shown in fig. 4.
By reversed osmosis the necessary pressure to drive the water through the membranes will rise with increasing content of salt in the unfiltered water, while the output in the shape of drinking water oppositely will decrease. By a high content of salt water, which is known from the Red Sea, the output can thus only be 25% of the supplied unfiltered water, while it can rise to 75% with small salt concentrations. If the salt concentration of the unfiltered water decreases, the pressure of difference above the membranes will fall, whereby the pumps, which are centrifugal pumps will try to increase the amount of unfiltered water, which is supplied to the membranes. If the maximum capacity of the membranes in this process is exceeded, they will be destroyed.
It is therefore necessary that the speed of rotation of the pumps can be regulated, and that is precisely the case, when a combustion engine is used, which drives the pumps in question via a direct mechanical transmission. The figure of rotation of a combustion engine can, as well-known, be regulated within wide limits only by regulating the amount of fuel that is supplied.
As shown in fig. 7 the pumps are divided into similar sections 53 with similar tubular pump housings 54, which can be assem¬ bled in series by means of couplings 55 at the ends of the pump housings. This construction results in the fact, that the plan flexibly can be adjusted to the requirements, which might be demanded to the productiveness of the plant in the present situation, and it reduces to a substantial extend the need for spare parts .
The membranes used are helical so that they with a large ca¬ pacity take up as less space as possible, and they are placed in membrane housings 56, which are similar to the pump hous¬ ings of the pump sections. Thereby the need for spare parts is additionally reduced.

Claims

Claims
1. A plant for the production of drinking water from unfil¬ tered water, from for example a natural reservoir and of the type, which comprises at least one membrane for through re¬ versed osmosis removing salts and radio-active substances, if any, and a process pipe with at least one pressure pump for driving the unfiltered water through the membrane, c h a r a c t e r i z e d in that the plant also comprises a ozone section inserted in the process pipe before the membrane for, by in¬ jection of ozone in the unfiltered water, reducing, flocculat¬ ing and removing the suspended micro-particles and solutions of especially organic substances and stripping radio-active gases, if any, and also a succeeding UV-section for especially decomposing of ozone, chlorine and hydrogen peroxide.
2. A plant according to claim 1, c h a r a c t e r i z e d in that it comprises a combustion engine with a dynamo for driv¬ ing the whole plant .
3. A plant according to claim 2, c h a r a c t e r i z e d in that at least the one pressure pump in the process pipe is a current pump with several pump steps, which are placed in a joint axle, which is running parallel to the outlet axle of the combustion engine and is pulled directly by this by means of a mechanical transmission.
4. A plant according to claim 2 or 3, c h a r a c t e r i z e d in that a least the pump steps of the one pump is divided into sections, which are placed in equally tubular pump hous¬ ings with couplings to a series connections of the piαmp housings.
5. A plant according to claim 2, 3 or 4, c h a r a c t e r i z e d in that the membrane for reversed osmosis is helical and divided into a number of sections, each of which is placed in a membrane housing, which is similar to the pump housings of the pump sections.
6. A plant according to each of the claims 2 - 5, c a r a c t e r i z e d in that, there in the process pipe is inserted a heat exchanger with a secondary side, which in operation is passed by the cooling water from the combustion engine.
7. A plant according to each of the claims 2 - 6, c h a r a c t e r i z e d in that it comprises an electrical heating ele- ment for heating up the unfiltered water in the process pipe and that the heating element is provided with electricity from the dynamo of the combustion engine.
8. A plant according to each of the claims 2 - 8, c h a r a c t e r i z e d in that it comprises a mixer, which is inserted in the process pipe and which in operation is passed by the exhaust gases from the combustion engine.
9. A plant according to each of the claims 1 - 8, c h a r a c t e r i z e d in that it contains a section with metallic sil¬ ver and/or copper inserted in the first pipeline after the membrane.
10. A plant according to each of the claims 1 - 9, c h a r a c t e r i z e d in that the plant comprises a bypass, which is connected to the process pipe before the heat exchanger and after the UV-section, and that there in the bypass is inserted at least one by-pass pump with opposite pump direction of the pressure pump in the process pipe.
PCT/DK1997/000060 1996-02-12 1997-02-11 Plant for production of drinking water from unfiltered water WO1997029995A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU17187/97A AU1718797A (en) 1996-02-12 1997-02-11 Plant for production of drinking water from unfiltered water
PCT/DK1997/000060 WO1997029995A1 (en) 1996-02-12 1997-02-11 Plant for production of drinking water from unfiltered water

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DK0145/96 1996-02-12
DK14596 1996-02-12
PCT/DK1997/000060 WO1997029995A1 (en) 1996-02-12 1997-02-11 Plant for production of drinking water from unfiltered water

Publications (1)

Publication Number Publication Date
WO1997029995A1 true WO1997029995A1 (en) 1997-08-21

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999033752A1 (en) * 1997-12-29 1999-07-08 Povl Kaas A method and a system for purifying water
WO2002102723A1 (en) * 2001-06-15 2002-12-27 Vrm Enterprises Pty Ltd Method and apparatus for the treatment of water
CN110255755A (en) * 2019-05-28 2019-09-20 天津城建大学 For mitigating the integral water treating method of fouling membrane

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4855058A (en) * 1986-06-24 1989-08-08 Hydranautics High recovery spiral wound membrane element
US5244579A (en) * 1992-10-09 1993-09-14 Zenon Environmental Inc. Transportable reverse osmosis water purification unit
US5259972A (en) * 1990-08-01 1993-11-09 Nippon Rensui Company Apparatus and method for purifying water
WO1994029228A1 (en) * 1993-06-03 1994-12-22 Purotech International Inc. Water purification system and removal of halides
DE4338851A1 (en) * 1993-11-13 1995-05-18 Dornier Gmbh Treatment of water contaminated with radioactive nuclides, bacteria and chemicals

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4855058A (en) * 1986-06-24 1989-08-08 Hydranautics High recovery spiral wound membrane element
US5259972A (en) * 1990-08-01 1993-11-09 Nippon Rensui Company Apparatus and method for purifying water
US5244579A (en) * 1992-10-09 1993-09-14 Zenon Environmental Inc. Transportable reverse osmosis water purification unit
WO1994029228A1 (en) * 1993-06-03 1994-12-22 Purotech International Inc. Water purification system and removal of halides
DE4338851A1 (en) * 1993-11-13 1995-05-18 Dornier Gmbh Treatment of water contaminated with radioactive nuclides, bacteria and chemicals

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999033752A1 (en) * 1997-12-29 1999-07-08 Povl Kaas A method and a system for purifying water
US6451209B1 (en) 1997-12-29 2002-09-17 Povl Kaas Method and a system for the treatment of water
WO2002102723A1 (en) * 2001-06-15 2002-12-27 Vrm Enterprises Pty Ltd Method and apparatus for the treatment of water
CN110255755A (en) * 2019-05-28 2019-09-20 天津城建大学 For mitigating the integral water treating method of fouling membrane

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