Water filter abstract
A water filter has a body provided with an inlet, an outlet and
a drain pipe provided with lock valves and a main filtering element
composed of an ion-exchange material and having input and output
surfaces for filtrated liquid, wherein the ion-exchange material
is embodied in such a way that it is voluminous, has a required
shape, is reinforced with a rigid reinforcement which is fixed to
a perforated support, and forms a continuous porous frame from sphero
colloids having required pore sizes which are defined by required
cleaning parameters, the volume of the filtering mass of the element
material being calculated according to mathematical expressions,
and the input surface of the main filtering element is coated with
an additional filtering and correcting layer of a fine substance
introduced in the form of a powder through a loading valve in the
cavity of the body in a filtered liquid flow deposited on the input
surface of the main filtering element and dynamically retained by
ram pressure of liquid, with the powder granule sizes being higher
than the pores of the pores of the ion-exchange material, and the
volume thereof corresponding to the shape of the main filtering
element and defined according to mathematical expressions.
Water filter claims
18. A filter for water, comprising a housing provided with an inlet
branch pipe, an outlet branch pipe and a drain branch pipe with
shutoff valves; a main filtration element composed of an ion-exchange
material and having inlet and outlet surfaces for a liquid being
filtered, said ion-exchange material of said main filtration element
being volumetric with a predetermined geometric shape, is armored
by a load-bearing reinforcement attached to a perforated support
and forming a continuous porous framework of microglobules with
pores of predetermined size in correspondence with parameters of
cleaning, wherein the filtration mass volume of the material of
said main filtration element is determined according to the follows
expression: 7 V fl Q L 2 k h v For a flat filter 8 V cyl = Q L 2
( L + d ) k h v d for a hollow cylindrical filter; 9 V co n = Q
L 2 ( 2 L + d k + D k ) k h v ( d k + D k ) --for a conical filter;
where Q is a required flow rate of the liquid being purified, kg/s;
L is a filtering layer thickness, mm; d is an internal diameter
of the cylinder filter, mm; d.sub.k and D.sub.k are internal diameters
of an upper and a lower cross-section of the conical filter, mm;
k=0.12-0.14 mm/s, is an experimental coefficient for the material
with a spatial globular structure make; an additional filtration
correction protection layer covering an inlet surface of said main
filtration element and composed of a finely grained substance introduced
in form of powder via a loading valve in a housing cavity into a
flow of filtration liquid deposited on said inlet surface of said
main filtration element and dynamically retained on it by a liquid
velocity head, so that a powder granule size is greater than a size
of ion-exchange material pores, wherein an additional volume introduced
depending upon a shape of the main filtration elements determined
according to a following expression V.sub.add=HB.DELTA., mm.sup.2
for a flat filter; V.sub.add.pi.H.DELTA.(D+.DELTA.), mm.sup.3 for
a cylindrical filter; V.sub.add=H(R.DELTA.+r.DELTA.+.DELTA..sup.2),
mm.sup.3 for a conical filter; where H is a filtration element height;
mm B is a filtration element width; mm D is a filtration element
diameter, mm; R is a radius of a lower conical base, mm; r is a
radius of an upper conical base, mm; .DELTA. is a required thickness
of the protective layer, mm.
19. A filter for water as defined in claim 18 wherein the filter
is formed as a hollow cylinder.
20. A filter for water as defined in claim 18 wherein the filter
has an inlet surface and an outer surface with a ratio of said inlet
surface to said outlet surface equal to 1.6-2.6.
21. A filter for water as defined in claim 18 wherein the filter
is formed as a cone.
22. A filter for water, as defined in claim 18 wherein said filter
is formed flat.
23. A filter for water as defined in claim 1 wherein said volumetric
reinforcement is composed of a fibrous non-woven sheet material.
24. A filter for water as defined in claim 23 wherein said fibrous
non-woven sheet material is a synthetic winterizer.
25. A filter for water as defined in claim 18 wherein said protection
additional layer is composed of a filtration material which is a
chemically active substance.
26. A filter for water as defined in claim 25 wherein said chemically
inert substance is perlite.
27. A filter of water as defined in claim 18 wherein said filtration
material of said protective additional layer is composed of a chemically
28. A filter of water as defined in claim 27 wherein said chemically
active substance is resorein-formaldehyde resin.
29. A filter of water as defined in claim 18 wherein said additional
protective layer has a material which corrects pH value of water
being filtered and is composed of dolomite.
30. A filter of water as defined in claim 18 wherein said additional
protection layer is composed of a material with inclusion of a bacteriostatic
31. A filter of water as defined in claim 30 wherein said bacteriostatic
substance is active silver.
32. A method of manufacturing a filter, comprising the steps of
preparing a reaction mixture of polymer-forming agents; conducting
a reaction with obtaining a filtration element of a predetermined
shape; during the preparing the reaction mixture first dissolving
resorein in water, then warming up a solution up to 40.degree.-50.degree.
C., then introducing a catalyst, steering up and adding formaldehyde
after homogenization of the solution, holding at a room temperature
until the solution gets turbid; pouring the obtained polymer solution
into a mold with a perforated support and a load-bearing reinforcement
being preliminarily installed in the mold; using the mold in form
of a sheet non-woven volumetric material and fixed on a perforated
support; thermostating the mold in two stages: first a polymer is
to be held until a gel is generated at a pouring temperature and
after that at a temperature of 80.degree.-90.degree. C.; after cooling
to a room temperature removing the porous ion-exchange element obtained
from the mold and placing into a filter housing; filling the filter
housing with a suspension of a finely grained hydrophilous powder
containing substances correcting properties of filtered water with
a granule size greater than a size of ion-exchange element pores;
bubbling the suspension; creating an easily breakable protection
corrective filtration layer on an inlet surface of the filtration
element by settling granules of the powder on an inlet surface of
the element; and after its complete covering by a layer of a given
thickness, retaining the layer by a velocity head of a flow; and
after contamination removing the layer by a backflow of the liquid.
33. A method as defined in claim 32; and further comprising carrying
out the bubbling of the suspension of a finely grain powder by a
flow of a liquid being filtered.
34. A method as defined in claim 32; and further comprising carrying
out the bubbling of the suspension by aeration of the liquid.
35. A method as defined in claim 32; and further comprising for
obtaining an element pore size equal to 0.001-0.02 .mu.m, taking
an initial concentration of the polymer forming agents to be 50-40
mass % and a ratio of formaldehyde resorein equal to 2.5-1 moles,
with a ratio of a number of cross-linking ether bonds to a number
of methylene bonds being equal to 1.2 and for generation of the
protection layer taking a powder granule size equal to 0.03-0.3
.mu.m and a thickness of the protection layer of 0.01-0.5 .mu.m.
36. A method as defined in claim 32; and further comprising for
obtaining an element pore size equal to 0.02-0.2 .mu.m, taking an
initial concentration of polymer-forming reagents to be 40-35 mass
% and a ratio of formaldehyde-resorein equal to 2.0-1 moles, with
a ratio of a number of cross-linking ether bonds to a number of
methylene bonds being equal to 1.15; and for generating the protection
layer taking a powder granule size equal to 0.3-4.0 .mu.m and a
thickness of the protection layer to be equal to 0.05-0.2 .mu.m.
37. A method as defined in claim 32; and further comprising for
obtaining an element pore size equal to 0.2-0.3 .mu.m, taking an
initial concentration of polymer-forming reagents to be 35-25 mass
% and a ratio of formaldehyde-resin equal to 1.8-1 moles as a ratio
of a number of crosslinking ether bonds to a number of methalene
bonds being equal to 0.9; and for generation of the protective layer,
taking a powder granule size to be equal to 4.0-10.0 .mu.m and a
thickness of the protection layer to be equal to 0.2-1.0 .mu.m.
38. A method as defined in claim 32; and further comprising, for
obtaining an element pore size equal to 3.08.0 .mu.m, taking an
initial concentration of polymer forming reagents to be 25-20 mass
% and a ratio of formaldehyde-reserin equal to 1.5-1 moles, with
a ratio of a number of cross-linking ether bonds to a number of
methylene bonds being equal to 0.8; and for generating the protection
layer, taking a powder granule size equal to 10.0-25.0 .mu.m and
a thickness of the protection layer equal to to be 1.0 .mu.m and
Water filter description
AREA OF ENGINEERING
 The invention relates to water purification devices, in
particular, for potable water, by means of mechanical and ion-exchange
purification as well as to methods of their manufacture.
PREVIOUS ENGINEERING LEVEL
 It is known that there is a filter for an additional purification
of potable tap water  containing a cylindrical housing, a sorption
filtration element located inside the housing and a lock fastening
the device on a tap; at that the filtration element from resorcin-formaldehyde
resin is made in the form of a cup located coaxially inside the
housing with a gap; in addition, the cup wall thickness is 2/3 of
its diameter, and the detachable outlet pipe and the inlet valve
equipped with a locking nut are located at an angle being not less
than 45.degree. to the filter housing. Here, the ratio of the internal
diameter of the housing to the outer diameter of the filtration
element is made equal to 1:0.75+0.85.
 A drawback of the device is that the cup from ion-exchange
resorcin-formaldehyde resin does not have a sufficient mechanical
strength, the cup pore size is not controlled and the main thing
is that it is not protected against sudden emissions of contaminated
water, which leads to immediate clogging of the pores and poisoning
of the flirtation element. Its regeneration is impeded.
 It is known that there is a method for the production of
a micropore filter by treating a film from polyethylene-terephthalate
by a solution of the water-acetone mixture with the acetone concentration
of 40-50 vol. % . Its drawback is that it has no selectivity
and the sorption ability of the filtration product in respect to
polyvalent cations of magnesium, calcium, aluminium, zinc, cadmium,
manganese and iron as well as that it does not allow to control
the filter material pore size during the fitter manufacture process.
 It is known that there is a method for the, production of
moulded materials based on urea-formaldehyde acid  including
polycondensation of urea and formaldehyde in a water medium and
moulding; at that the polycondensation of urea and formaldehyde
and moulding of the resin being generated are carried out by means
of holding of a water solution of urea, formaldehyde and an acidic
catalyst with their mass ratio being equal to 1:(0.5-1.0):(0.01-0.12)
respectively and the urea concentration of 250-600 g/l in the static
conditions in a leak-tight mould during 10-50 minutes at 15-25.degree.
C. and for the production of a porous moulded material the urea
is used with the solution concentration of 250-400 g/l. In order
to secure mechanical strength, resorcin is added in the amount of
10-15% of the urea mass.
 The material obtained by this method is sufficiently cheap
but its mechanical strength is low for its use as a filter for water.
 The theoretical justification of ion-exchange processes
is set forth in the book of .
 It is known that there are Geyser filters of various modifications
for the purification of potable tap water, for example, Geyser-32
. Their distinctive ability is the availability of an ion-exchange
filtration element (elements) installed in the housing and based
on resorcin-formaldehyde resin, with a possibility of its regeneration
by the method of washing by a back water flow and purging by compressed
air (up to 7 kgf/cm.sup.2).
 Its drawback is that it is also susceptible to clogging
by sudden emissions of contaminated water, which leads to poisoning
of the ion-exchange element.
 Nevertheless, by its design and the materials being used,
it is mostly close to the technical essence of the device being
proposed and can serve as its prototype.
DISCLOSURE OF INVENTION
 The task of this device is to provide a possibility of regulation
of the filtration ability of the filtration element for various
purification degrees; in addition, it has an increased strength
and it is protected from poisoning at the moment of sudden emissions
of strongly contaminated water as well as its correction depending
upon what water is contaminated with and what degree of purification
is required to achieve.
 The problem stated above is solved by selecting a size of
the filtration element pores for the required purification degree
bearing in mind that the size significantly influences on the filter
performance. To this end, there is a filter for water containing
a housing equipped with inlet, outlet and drain branch pipes with
corresponding shutoff valves and the main filtration element made
from an ion-exchange material and having, the inlet and outlet surfaces
for the liquid being filtered. In doing so, the ion-exchange material
of the main filtration element is made to be volumetric, of the
required geometrical shape, it is armoured by a load-bearing reinforcement
attached to a perforated support and it constitutes a continuous
porous framework from microglobules with pores of the required size.
The liquid flow-rate and the rate of filtration through a flat filter
is determined by the following dependencies: 1 Q = kSh v L ; W =
 where k is the empirical coefficient for the filtration
material of the inlet surface, mm.sup.2/s;
 S is the area of the inlet surface of the filter, mm.sup.2;
 h.sub.v is the pressure head being lost from the inlet surface
of S.sub.in to the outlet surface of S.sub.out, kg/mm.sup.2;
 L is the filter layer thickness, mm; 2 J = h r L
 is the head gradient (the value of head drop per a unit
path length), kg/mm.sup.2.
 For a filter in the form of a hollow cylinder, the ratios
remain as before, but in the above-mentioned equation S.sub.out,
the outlet surface area, should be taken as S. The comparison of
objects for the flat and cylindrical filters 3 V V cyl = d L + d
 provided equal thickness (L) of the filtration layer and
other equal conditions, shows that the flat filter has a lesser
volume of the filtration material mass.
 It is evident that from the point of view of the material
consumption, the flat filter is more beneficial than the cylindrical
one and the more so than the conical filter, as it has a lesser
 The drop of the pressure head per a unit path length (J.sub.fl)
is constant with the flat filter, and for the cylindrical filter
the head gradient (J.sub.cyi) sharply grows from the inlet surface
to the outlet surface (taking the outer cylinder surface as the
inlet surface). It is caused by a decrease of the tree cross-sectional
area of the filter with the liquid motion from the periphery to
the centre. But at the same time the velocity of liquid at the cylindrical
filter inlet is far less than that for the flat filter. This velocity
decrease improves the ion exchange and sorption parameters. The
contaminant particles settle in the outer layers of the filter and
on its protection layer, which creates prerequisites for a better
 The authors have proposed the following formulae for the
calculation of required filter volumes: 4 V = Q L k h v
 --for the flat filter; 5 V cyl = Q L 2 ( L + d ) k h v d
 --for the hollow cylindrical filter; 6 V co n = Q L 2 (
2 L + d k + D k ) k h v ( d k + D k )
 --for the conic filter;
 where Q is the required flow-rate of the liquid being purified,
 L is the filtering layer thickness, mm;
 d is the internal diameter of the cylindrical filter, mm;
 d.sub.k and D.sub.k are the internal diameters of the upper
and lower cross-sections of the conical filter, mm;
 k=0.12-0.14 mm/s, is the experimental coefficient for the
material obtained with the spatial globular structure.
 In doing so, the inlet surface of the main filtration element
is covered by an additional filtration corrective protection layer
of a finely grained substance introduced in the form of powder via
a loading valve in the housing cavity into the flow of filtration
liquid deposited on the inlet surface of the main filtration element
and dynamically retained on it by the liquid velocity head, the
powder granule size is greater than the size of ion-exchange material
pores, and the additional volume being introduced into it, depending
upon the main filtration element shape, is determined according
to the following expressions:
V.sub.add=HB.DELTA., mm.sup.2 for the flat filter,
V.sub.add=.pi.H.DELTA.(D+.DELTA., mm.sup.3 for the cylindrical
V.sub.add=.pi.H(R.DELTA.+r.DELTA.+.DELTA..sup.2), mm.sup.3 for
the conical filter,
 H is the filtration element height,
 B is the filtration element width, mm;
 D is the filtration element diameter, mm;
 R is the radius of the lower conical base, mm;
 r is the radius of the upper conical base, mm;
 .DELTA. is the required thickness of the protection layer,
 The filter can easily be made in various geometrical shape,
which depends upon the housing design, for example, in the form
of a hollow cylinder, a hollow cone, a plate or any other geometrical
figure, as it is manufactured by casting into a mould. The optimal
ratio of the of the inlet surface of the filter to its outlet surface
equals to 1.6-2.6.
 The volumetric reinforcement is made from a fibrous non-woven
sheet material, for example, synthetic winteriser. As a filtration
material of the protection additional layer, various substances
are used depending upon the required correction of the composition
of finished product, i.e. water. To this end, non-required and harmful
substances are to be removed from the initial liquid to be filtered
and then necessary and useful substances are to be added; water
pH value shall be changes, if the main filter is not capable to
do this. For example, using a chemically inert substance as the
protection layer material, for example, perlite, we will in no way
affect the composition of purified water. The additional layer performs
the protection function only.
 But if a chemically active substance if used as a filtration
material of the additional layer, for example, resorcin-formaldehyde
resin, then the purification functions of the additional layer will
 Dolomite is used as a material of the additional protection
layer correcting the pH value of water being filtered.
 In order to protect filtered water from harmful microorganisms,
a bacteriostatic substance, for example, active silver, is introduced
into the material of the additional protection layer.
 For the realisation of the filter design being declared,
a filter manufacture method has been proposed, including preparation
of the reaction mixture of polymer-forming reagents and conduction
of the reaction with obtaining of the filtration element of the
given shape, differing by the fact that at the reaction mixture
preparation one shall first dissolve resorcin in water, then warm
up the solution up to 40.degree.-50.degree. C., then introduce the
catalyst, stir up and add formaldehyde after homogenisation of the
solution, hold at the room temperature until the solution gets turbid;
then the polymer solution obtained shall be poured into the mould,
with the perforated support and the load-bearing reinforcement being
preliminarily installed in it, such mould being made in the form
of a sheet non-woven volumetric material laid in one or several
layers and fixed on the perforated support; then the mould shall
be thermostated in two stages: first the polymer is to be held until
a gel is generated at the pouring temperature and after that at
the temperature of 80.degree.-95.degree. C.; after cooling to the
room temperature the porous ion-exchange element obtained shall
be removed from the mould and placed into the filter housing, which
is to be filled by a suspension of a finely grained hydrophilous
powder, which granule size is greater that the size of ion-exchange
element pores; the suspension shall be bubbled; an easily breakable
additional protection corrective filtration layer shall be created
on the inlet surface of the element by settling granules of the
above-mentioned powder on the inlet surface of the element, and
after its complete coverage by a layer of the given thickness, the
layer shall be retained by the velocity head of the flow and after
contamination the layer shall be removed by the back flow of the
 The bubbling of the finely grained powder suspension is
carried out by the flow of the liquid being filtered and/or by aeration
of the liquid being filtered.
 A distinctive peculiarity of the method is a possibility
of regulation of the filter pore size, the ion-exchanging activity
of the filter by changing the concentration of initial components.
The mechanical strength of the main ion-exchange element as well
as the content of formaldehyde in water are determined by the ratio
of the number of cross-linking ether bonds to the number methylene
bonds, It is well-known that the mechanical characteristics of a
resorcin-formaldehyde substance are proportional to the amount of
formaldehyde, which it releases, however an excessive amount of
formaldehyde is not permissible in potable water. The authors have
proposed the optimal ratio of the above-mentioned bonds, which does
not permit any excess of its maximum permissible limits and is within
the range of 0.8-1.2.
 The optimal ratio of ingredients is given in the following
1 Concentration Ratio of the Size of of polymer- Formaldehyde/
numbers of granules of Thickness of forming resorcin ether/ Pore
size the protection the protection reagents, ratio, methylene obtained,
layer powder, layer, mass. % moles bonds .mu.m .mu.m .mu.m 50-40
2.5:1 1.2 0.001-0.02 0.03-0.3 0.01-0.05 40-35 2.0:1 1.15 0.02-0.2
0.3-4.0 0.05-0.2 35-25 1.8:1 0.9 0.2-0.3 4.0-10.0 0.2-1.0 25-20
1.5:1 0.8 3.0-8.0 10.0-25.0 1.0 and over
 As is known, ion-exchangers with the groups of --COOH and
--OH are obtained as a result of the reaction of polycondensation
of phenols with resorcin acid. Te exchanging capacity of ion-exchangers
strongly depends upon the pH value of the solution . The most
effective pH area is within the pH range of 6-14. The typical property
of ion-exchangers is their high selectivity to ions of H.sup.+ and
a relatively high affinity to alkaline-earth metal ions. The selectivity
series for metal ions have the reverse order as compared with strong
 The selectivity series at pH 7 is as follows: Mg.sup.2+<Ca.sup.2+<Ni.sup.2+<Co.sup.2+<Cu.sup.2+;
 The normal series is as follows: H.sup.+>Ca.sup.2+>Mg.sup.2+&-
 The essence of the ion exchange is that active groups are
added into a neutral hydrocarbon polymer medium retaining positively
charged ions (in the given case, sodium ions) due to its negative
charge. When water contaminated, for example, by iron salt, is passing,
the iron ions, due to their higher charge force out th sodium ions
and occupy their place.
BRIEF DESCRIPTION OF DRAWINGS
 FIG. 1 shows the filter for water declared. It consists
of the housing 1 equipped with the inlet 2 outlet 3 and drain 4
branch pipes with corresponding shutoff valves 5 and 6 the main
filtration element 7 made from an ion-exchanging material in the
form of a hollow cylinder, having the inlet 8 and outlet 9 surfaces
for the liquid being filtered. The filtration element 7 has been
armoured by the load-bearing reinforcement 10 attached to the perforated
support 11. In doing so, the inlet surface 8 of the main filtration
element 7 is covered by the additional filtration corrective protection
layer 12 of a finely grained substance. The housing 1 is equipped
with the loading valve 13.
 FIG. 2 shows a filter with the conical filtration element,
and FIG. 3 depicts a filter with the flat filtration element.
 The device operates as follows.
 After studying the nature of water contaminants, water being
purified is supplied into the filter housing 1 though the inlet
branch pipe 2 and depending upon the appearance of the contaminants
the powder composition should be selected for the additional filtration
corrective protection layer. The powder shall be poured into the
cavity of housing 1 with the water being purified through the loading
valve 13. The powder generates a suspension in the flow, which,
while passing through the main filtration element 7 is settling
on its inlet surface 8 with the generation of a protection layer
of the identical thickness. Water, passing through the protection
layer 12 which mechanically retains the main amount of impurities,
is being preliminarily purified from harmful impurities and acquires
necessary additives, then it follows through the main filtration
element 7 where it is subjected to the ion exchange being finally
purified and supplied to the user through the outlet branch pipe
 The design is especially effective at sudden salvo emission
of contaminated water with a huge amount of contaminants. In this
case, the protection layer 12 perceives the whole volume of contaminants,
thus preventing poisoning of the main filtration element 7.
 The filter regeneration is carried out by a back flow of
water. To this end, the shutoff valve 5 on the inlet branch pipe
2 is to be closed and the valve 6 on the drain branch pipe 4 is
to be opened. The contaminants being accumulated along with the
protection layer shall be removed and the filtering properties of
the filter shall be restored by means of filling of a new portion
of the powder.
 The Best Version of the Invention Implementation
 The selection of the best version of the invention implementation
shall be carried out on the basis of specific conditions to be determined
by the composition of water being supplied to purification and by
the required parameters of the finished product, i.e. potable water.
A Filter for Water Being Strongly Contaminated by Iron Salts
 Load 420 ml of water, 130 g of resorcin, 140 ml of 37% formalin
and 3 ml of hydrochloric acid (d=1.18) into the reactor. Stir up
the reaction mixture at the temperature of 40.degree. C. up to turbidity,
pour into the mould, into which the volumetric reinforcement was
preliminarily installed, thermostate the mould at 45.degree. C.
until the gel generation is completed (3 hours) and then at 80.degree.
C. during 24 hours. Upon cooling, remove the ion-exchange filtration
elements with the pore size of 8 .mu.m obtained, place it into the
filter housing, which shall be filled with a suspension of the finely
grained powder of resorcin-formaldehyde resin in water (the powder
granule size of 20-25 pan, the particulate concentration is 5 g/l),
by bubbling wash up a protection layer with the thickness of 1.9
mm on the inlet surface retaining it by the flow of liquid being
A Bacteriostatic Filter for Water Containing Hazardous Microorganisms
 Load 410 ml of water, 120 g of resorcin, 370 ml of 37% formalin
and 3 ml of hydrochloric acid (d=1.18) into the reactor. Add 300
mg of active silver. Stir up the reaction mixture at the temperature
of 40.degree. C. up to turbidity pour into the mould, into which
the volumetric reinforcement was preliminarily installed, thermostats
the mould at 45.degree. C. until the gel generation is completed
(3 hours) and then at 80.degree. C. during 24 hours. Upon cooling,
remove the ion-exchange filtration elements with the pore size of
0.001-0.02 .mu.m obtained, place it into the filter housing, which
shall be filled with a suspension of the finely grained powder of
resorcin-formaldehyde resin in water (the powder granule size of
0.03-0.3 .mu.m), by bubbling wash up a protection layer with the
thickness of 0.01-0.05 mm on the inlet surface retaining it by the
flow of liquid being filtered.
 At the filtration of water contaminated by microorganisms,
the suppression of the multiplication of filtered microorganisms
 An example of calculation of the filtering mass volume.
 Set the required performance of the filter: Q=10 l/min,
the filtration layer thickness L=30 mm, k=0.12 mm/s, the head drop
at the length of L equals to h.sub.v=0.1 g/mm.sup.2. Substituting
the values taken into the above-mentioned formula for the cylindrical
filter volume, calculate V=18.75 dm.sup.3.
 The applicant has manufactured prototypes of the invention
being declared. There are filtration elements of various geometrical
shape: flat, in the form of hollow cylinders and cones. The most
successful, from the point of view of design layout, have become
cylindrical elements. The tests conducted have provide all advantages
declared. In doing so, the following technical specifications have
 Maximal diameter: 75 mm
 Height: 245 mm (for standard housings 10 inches);
 120 mm (for standard housings 5 inches).
 It is possible to connect cartridges with threaded joints
 490 mm (for standard housings 20 inches);
 735 mm and over (for nonstandard housings).
 Capacity: from 3 to 20 l/min (depends upon the porosity).
 Maximal working pressure: 6 atm.
 Maximal working temperature of water: up to 100.degree.
 Total resource: not less than 25 000 l.
 Weight: not more than 0.8 kg.
 The mechanical regeneration consists of the removal of filtered
suspension from the filtration element surface (by a brush under
a water jet in the domestic conditions or by backflow of water or
compressed air in the event of industrial cleaning).
 The chemical regeneration consists of the recovery of the
sorption ability of the filtration element material during its treatment
 Minimal value of a litre of purified water with the required
quality of cleaning due to a possibility of multiple regeneration
of the filtration element.
 Possibility of Hot Water Filtration
 The self-indication of the necessity of regeneration is
determined by the reduction of the purified water flow.
 Possibility of using filters with different properties:
various porosity and performance, for "soft" and "hard"
water, for water with an increased content of dissolved iron, etc.
 Effectiveness of Cleaning
 Suspended particles>1 .mu.m--up to 98%
 Microbes and colibacillus--up to 99.9%
 Heavy metals--up to 99%
 Organic compounds and chlorine--up to 96%
 Hardness salts*--up to 90% *The ion-exchange filter for
hard water is capable to remove from water up to 12 g of calcium
and up to 8 g of dissolved iron, after which chemical regeneration
is required. The regeneration process frequency depends upon the
hardness of water and upon the concentration of dissolved iron in
 The material uniqueness consists of the fact that even after
saturation by hardness salts it changes their structure no removing
them from water so that water having passed through the filter gives
no sediments and scale.
2 Material pore size, .mu.m Technical specifications 0.05-0.1 0.1-0.5
0.5-1.0 1.0-0.5 1.5-2.0 2.0-3.0 3.0-4.0 Performance, l/min 3-5 6-8
9-11 12-15 16-20 20-30 30-40 Effectiveness of cleaning from pathogenic
microbes, % Colibacillus 99.9 99 97 90 75 58 50 Coli-fags 99.9 98.5
90 80 70 50 35 Penetration of viruses through the filter Hepatitis
A No No No Yes Yes Yes Yes Rotoviruses No No No No Yes Yes Yes
 1. Useful model No. 818 1993. Filter for additional purification
of potable tap water.
 2. Author's Certificate No. 715501 1980 A method for the
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