Title of Invention

FLOATING IMPELLER TECHNOLOGY IN SUBMERSIBLE PUMPS

Abstract

The invention relates to methods of improving the suction head and discharge capacity of deep-well submersible water pumps. More particularly, specific bore well submersible pumps that have an impeller and diffuser configuration and design, which bring about an increase in efficiency. The invention provides for new system, means and design values for the impeller-diffusers parameters to achieve better results. The resultant impeller and diffuser designs increase the suction lifting capacity and discharge capacity. As a result of the improvement in design, the suction capacity of the pump is increased by manifold times.

Full Text

PATENT APPLICATION NO.291/CHE/2004 FLOATING IMPELLER TECHNOLOGY IN SUBMERSIBLE PUMPS BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The invention relates to methods of improving the suction Head and discharge capacity of deep-well submersible water pumps. More particularly, specific bore well submersible pumps that have an impeller and dififuser configuration and design, which bring about an increase in efficiency. DESCRIPTION OF THE PRIOR ART Pumps are of various types based on the design and are fiuther classified according to their functionality. The invention relates to pumps, which by design are called "Centrifugal Pimips" and by functionality as deep well pumps and Bore well Submersible Pumps". Centrifugal pumps have been used for pumping well water (open well/bore well) for many years and there is an ever-increasing need to increase the efficiency of these pumps to pump water from greater depths. Deep-well pumps are basically centrifugal pumps and for that reason all rotodynamic pumps have got a problem of limited suction i.e. the depth from which water can be lifted. This puts a restriction on usage of these types of pumps for lifting (sucking) water from depths greater than 6 to 8 meters. The theoretical suction lift of rotodynamic pumps at sea level and 30o Celsius temperature is 10.33 m but due to fiiction losses, vapour-pressure etc. the highest permissible suction lift is 8.40 meters with an optimum value of 6,6 m. If water is to be lifted either from open well or tube-wells (also called bore wells) of depth more than 6.6 m, the pumps should be installed very close to the water level at PATENT APPLICATION N0.291/CHE/2004 depths or the design of pump has to be modified. The particular type of Deep-well pump with which the present invention relates to is called "Submersible pumps". Submersible pumps can lift water from a depth of about 450 meters. In this type, both the pump and its driving motor are installed totally submerged in the deep waters. As such they must be of special design and should be adoptable for installation inside the pipe casing of tube-wells in that the motor has to be 'Water and weather' proof. The history of submersible pumps dates back to 1908, the year in which it was invented. This pump initially foxmd most versatile use in naval applications for salvaging purpose and then gained popularity for deep-well applications. Since 1950, they found tremendous application in the field of irrigation engineering as well as in mine dewatering. With improved materials and construction, submersible pumps continue to find various new applications as circulating water pumps, fuel handling pumps, pumps in fishing trawlers and in oceanography. Nowadays they occupy pioneering position in deep-well pumping and are becoming extremely popular in public water supply, irrigation, domestic water supply and ornamental fountains. Submersible pumping set, both pump and motor, are installed deep inside the tube-well so that a positive suction head is created which makes it possible to lift water from depths as low as 450 meters. These pumps are essentially single or multistage centrifugal turbine pumps designed to form a compact unit in conjunction with a coupled wet type squirrel cage induction motor, both of which operate totally submerged below the surface of water. PATENT APPLICATION N0.291/CHE/2004 The complete unit consisting of pump and motor (motor in the lowest position) is suspended in the bore (casing pipe) vertically from the discharge rising pipe. This pipe is firmly secured to the servicing edge of the well by means of supporting clamps. The pump can be installed in vertical or inclined formation also. Submersible pumps with radial impellers are made for low discharge with high total heads, whereas pumps with mixed flow type impellers are made for medium discharge range with medium heads. The pump bearings are water lubricated and protected against the ingress of sand by suitable structural elements. The casings of radial impeller pumps are clamped together by flat steel tie bars or by outer shell made of Stainless Steel. The non-retum valve located at the top of the pump in discharge outlet connection is fully streamlined for smooth flow and is normally supplied with screwed connections. The pump suction casing / suction interconnector between the pump and motor is guarded by perforated strainer to prevent entry of any suspended material in the water In an effort to increase the efficiency of these Submersible pumps and in order to make it capable of lifting / sucking water from higher depths with lesser number of stages many attempts have been made to modify conventional centrifugal pump components by bringing about changes in the design values of the parameters relating to Impeller and Diffuser that determine the suction / delivery capacity of the submersible pumps. However even these changes to the typical impeller and diffuser configurations have not improved their capacity much. PATENT APPLICATION N0.291/CHE/2004 There, are still problems in achieving higher suction head (lifting capacity) and discharge efficiency. At present, generally the lifting capacity is only upto 16 to 18 feet per stage. Due to the continuous depletion of ground water table, there exists a need for a submersible pump which can pump out water from lower levels in the ground than what was previously possible. SUMMARY OF THE INVENTION Thus according to the basic aspect of the present invention there is provided a system for a floating type impeller and diffuser used in deep-well submersible pump comprising said impeller and diffuser having relative co-operative parameters of (a) Number of vanes of impeller / dififuser; (b) Shape and profile of vanes of impeller / diffuser; (c)Inlet diameter; (d) Outlet diameter; (e) Suction area; (f) Discharge gap; (g) Thickness of vanes of impeller / diffuser, selectively based on the duty point discharge, impeller inlet angle and discharge vane angle determined based on velocity triangles and diameter requirements of borewell pump and wherein for (i) a 23 feet discharge said co-operative parameters comprises: said Impeller having a) Inlet diameter= 023.0 mm min. and 0 26.0 mm max. having tolerance of ±0.50 mm; (b) Outlet diameter= 0 70.10 mm with a tolerance of+1.0/-0.50 mm; (c) Discharge gap=3.70 nun with a tolerance of ±0.30 nun; said diffuser having (a) Inlet diameter= 0 28.0 mm having tolerance of ±0.50 mm; (b) Outlet diameter= 0 74.50 mm with a tolerance of +1.0/-0.50 mm; Discharge gap=3.0 mm with a tolerance of ±0.30 mm; and PATENT APPLICATION NO, 291/CHE/2004 (ii) a 29 feet discharge said co-operative parameters comprises: said impeller having (a) Inlet diameter= 026.5 mm min. and 0 30.4 mm max having tolerance of ±0.50 mm; (b) Outlet diameter= 0 79.20 mm with a tolerance of+1.0/-0.50 mm; (c) Discharge gap=4.60 mm with a tolerance of ±0.30 mm; and said difiuser having : (a) Inlet diameter= 033.40 mm having tolerance of ±0.50 mm; (b) Outlet diameter= 0 80.50 mm with a tolerance of+1.0/-0.50 mm; (c) Discharge gap=4.0 mm with a tolerance of ±0.30 mm, whereby the suction capacity is increased alongwith transferring thrust loads such that the efficiency of the pump increases. The Submersible Pump for which the present invention is made is suitable for bore wells of a diameter of 4" (inches) or more. The most critical parts of a Submersible Pump are i. IMPELLER and ii. DIFFUSER (or Stage Casing or Bowl) An Impeller is a rotating part which sucks the water and transfers it to the Dififuser/Stage Casing. The Difiuser/Stage Casing guides the water delivered by the Impeller and feeds it into the next stage impeller inlet. The above two components form a single functional unit and act in combination and are collectively known as a "Stage". A submersible pump consists of one or more stages. Importantly, thus the effective functioning of an Impeller-Difiuser unit is determined by the following parameters. For better function resulting in better delivery head and discharge of water, the following parameters must be effective, a. Number of Vanes of Impeller/Diffuser PATENT APPLICATION N0.291/CHE/2004 b. Shape and profile of Vanes of Impeller/diffuser c. Inlet Diameter d. Outlet Diameter e. Suction Area f Discharge Gap g. Thickness of Vanes of Impeller/Diffuser The invention provides for new system, means and design values for the above parameters to achieve better results. The resultant impeller and diffiiser designs increase the suction lifting capacity and discharge capacity. As a result of the improvement in design, the suction capacity of the pump is increased by manifold times. The existing designs are capable of sucking water from a depth of 16 feet only whereas the design developed by the inventor is capable of sucking water from a depth of 23 or 29 feet. The Shut off Head of each stage is 23' or 29' according to the proposed designs at rated voltage and frequency. The invention also utilises the existing floating type design capacitating the submersible pump to work in coarser environment wherein the impeller will not get stuck due to sand entry. The invention also incorporates a method of transferring thrust load resulting in an increase in the life of the pump motor. In the known prior art, thrust load will be there in the pump portion according to the total head of working and 100% of this thrust load will be transferred to the Motor thrust bearing. Whereas in the present invention, around 50% of the thrust load developed in the pump portion will be transferred to the stage casing PATENT APPLICATION N0.291/CHE/2004 and in turn to the outer shell and suction inlet of the pump portion. So the life of motor will be increased due to lesser thrust load. BRIEF DESCRIPTION OF THE DRAWINGS So that the manner in which the features, advantages and objects of the invention, as well as others which will become apparent, may be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiment thereof which is illustrated in the appended drawings, which form a part of this specification. It is to be noted, however, that the drawings illustrate only a preferred embodiment of the invention and is therefore not to be considered limiting of the invention's scope as it may admit to other equally effective embodiments. FIG 1 illustrates the cross sectional view of pump assembly. FIG 2 is a cross-sectional view of an impeller which provides for a suction lifting head at shut off condition 23 feet per stage with a discharge rate of 1.5 cubic meter/hour. FIG 3 is a cross-sectional view of a diffuser which provides for a suction lifting head at shut off condition 23 feet per stage with a discharge rate of 1.5 cubic meter/hour. FIG 4 is a cross-sectional view of an impeller which provides for a suction lifting head at shut off condition 29 feet per stage with a discharge rate of 2 cubic meter/hour. FIG 5 is a cross-sectional view of a diffuser which provides for a suction lifting head at shut off condition 29 feet per stage with a discharge rate of 2 cubic meter/hour. PATENT APPLICATION NO.291/CHE/2004 PREFERRED EMBODIMENTS Figure 1 illustrates a typical cross sectional view of the pump portion of a submersible pump assembly. Normally a submersible pump consists of two distinct parts, the pump part and motor part wherein the motor is the prime mover. These two parts are coupled together by means of coupling arrangements. The pump part is also called as Pump End which is the pumping apparatus. A pumping apparatus as is shown in figure 1 consists of two important components, namely, an Impeller (5) and a Diffuser (3) along with a shaft to drive. These two are arranged one above the other and enclosed in a casing. This unit is called a 'stage'. One set of impeller (5) and stationary diffuser (bowl) (3) is known as Stage Assembly / (Bowl Assembly). A typical pump end consists of multiple stages, ranging from 1 to even 90. A typical pump consists of a vertical arrangement of stages comprising of Diffusers (3) and Impellers (5). The discharge from Stage assembly is coaxial with the shaft and contained by a vertical column-pipe (or discharge pipe) which also supports the stationary imits of the pump. The casing which encloses the impeller (5) and diffuser (3) is also referred to as a stage casing or diffuser chamber or a bowl. The water is sucked by the pump from the bore well through the suction inlet and let out through a valve called Non-Retum valve (or) Discharge Casing. The impeller (5), diffuser (3), bowl, shaft and Discharge Casing are the most important components of a pump end. The object of an impeller (5) which rotates fast axially on a shaft attached to the motor is to suck the water from the bore well and feed it from one stage to the other. The object of PATENT APPLICATION NO.291/CHE/2004 a diffuser (3) is to collect the water sucked by the action of the impeller (5) and absorb the pressure and guide the water to the next stage. The impeller (5) and diffuser (3) are of radial flow design wherein the water enters axially and comes out radially. If this water is to enter another stage of the pump i.e. another impeller vertically above the first impeller, its direction should be made axially upward. This is done with the help of a stationary guide known as diffuser (3) which has got guide vanes for this purpose. Such guide diffusers are provided after each rotating impeller stage. The efficiency of a pump depends upon dimension and profile (design value) of certain parameters associated with these components. The design value of these parameters (dimensions and profile) is the most critical aspect. The invented components are unique in the sense that the design values of their critical parameters are unique. Because of the controlling of the design value, the components help to achieve a high head of upto 29 feet per stage (and 23 feet per stage in another model) at rated voltage and frequency, with improved efficiency. The floating type impeller helps in reducing the thrust load on the thrust base of the motor and thereby enhances the life of the motor; it also helps pumping sandy water. In the floating type design, rotating impeller (5) floats between two fixed difftisers (3). When the pump runs, S.S. thrust plate (2) of the lower diffuser (3) supports the impeller boss (1) and the hub of the knpeller (4) presses against the S.S. thrust plate (2) of the top diffuser (3). Thus in the floating type design, while the pump is in operation (i.e. running) PATENT APPLICATION N0.291/CHE/2004 the hydraulic thrust load is partially transferred from the impeller to the diffuser 'Stage Thrust Plates'. This in tum is passed on through the diffuser to the outer shell (6) and suction inter connector (8) and finally transferred to the piping installation resulting in lesser thrust load to the thrust bearing and in tum to the motor. This partial thrust load is approximately a maximum of 50% of the total thrust load. In the design the numbers of vanes are fixed according to the design. These numbers of vanes in tum represent the discharge value for a specific head per stage. Number of vanes cannot be changed for the same performance. The following table shows the number of vanes for impellers and diflusers for various models: S.No. Model No. of Vanes in Impeller No. of Vanes in Diffuser 1. S4H-1E 6 5 2. S4H-2 6 5 Impeller (5) is made up of Engineering Plastics specially selected to suit extreme working conditions suitable for potable water with high wear and tear resistance and lesser water absorption. FIG 2 illustrates the typical cross-sectional view of an impeller as prescribed by the invention and which provides for a suction head at shut off condition 23 feet per stage with a discharge rate of 1.5cubic meter/hour. The key way of the impeller is 2.80mm wide placed at a distance of 9.50mm. In other words the "Key way depth" (1) is 9.50 mm and the "Key way width" (2) is 2.80 mm. The impeller "Bottom plate outer diameter (3)" is 70.50 mm with a tolerance limit of+1.0 to -0.50. The "Suction boss outer diameter (4)" is 30.40 mm with a maximum "Inner diameter (5) of 26.00 mm and minimum "Inner PATENT APPLICATION N0.291/CHE/2004 diameter (6)" of 23.00 mm. The overall tolerance limit for the suction boss is +/- 0.50, The "Impeller hub diameter (7)" is 17.70 mm with the "Impeller hub top diameter (9)" as 18.90 mm. The "Impeller shaft bore diameter (8)" is 12.00 mm. The Impeller outer diameter (10) is 70.10 mm with a tolerance limit of+1.0 to -0.50. The "Discharge gap (11)" that is to be provided is 3.70 mm with a tolerance limit of+/- 0.3. The "Impeller plate thickness (13)" is 1.50 mm with the "Impeller bottom plate thickness (12)" of 1.65mm. The "'Distance that is to be maintained between the impeller hub face (suction sides) and the impeller bottom plate suction boss face' (14)" is 4.25 mm. The Distance that is to be maintained between the impeller hub top face and the impeller plate face' (15)" is 3.00 mm. The "'Distance to be maintained between the impeller hub face (suction side) and the impeller bottom plate face' (16)" is 7.65 mm. The "Total impeller height (17) is 17.50 mm with the "Hub bottom radius (18) as 3.00 mm. The number of vanes present in this type of impeller is 6 with a tolerance limit for profile thickness as +/-0.20 and the profile depth is 3.70mm with a tolerance limit of +/-0.3. The vane directions are anti clock wise viewed from suction side. FIG 3 illustrates the typical cross-sectional view of a difiuser which provides for a suction lifting head at shut off condition 23 feet per stage with a discharge rate of 1,5 cubic meter/hour. The "Diffuser top plate outer diameter (1)" is 85.00 mm with the "Diffuser top plate seating diameter (2) as 80.50 mm. The "Suction boss inner diameter (3)" is provided at 28.00 mm with a tolerance limit of+/- 0.50. The "'Shaft bore inner diameter (a)' (4)" is 13.00 mm and '"Inner diameter (b)' (5)" is 20.00 mm. The "Diffuser inner diameter (6)" is 74.50 mm (with a tolerance limit of +1.0 to - 0.50) and "Outer diameter (8) is 85.00 mm. The "Diffuser seating diameter (7)" is 80.50 mm. The PATENT APPLICATION N0.291/CHE/2004 (6 (6 "Discharge gap (9)" is provided as 3.00 mm. The "Diffuser depth (11) is 12.50 mm and 'Diffuser depth (a)' (12)" is 1.00 mm with a "Seating depth (10)" of 1.50 mm. The Diffuser depth up to profile (13)" is 17.80 mm with "Outer side step depth (14) as 16.00 mm. The "Diffuser height (15)" is 20.50 nun with a tolerance lunit of+/- 0.30. There are a total number of 5 vanes with a "Bottom side vane taper surface height (16) of 5.30 mm and the "Height of top side vane taper surface (17) of 2.30nim. The profile depth is 3.00 mm with tolerance of+/-0.30 and the tolerance for profile thickness is +/-0.20. The vane directions are anti clockwise viewed from top side. FIG 4 illustrates the typical cross-sectional view of an impeller as prescribed by the invention and which provides for a suction head at shut off condition 29 feet per stage with a discharge rate of 2cubic meter/hour. The key way of the impeller is 2.80 mm wide placed at a distance of 11.40mm. In other words the "Key way depth (1)" is 11.40 mm and the "Key way width (2)" is 2.80 mm. The "Impeller bottom plate outer diameter (3)" is 79.80 mm with a tolerance limit of+1.0 to -0.50. The "Suction boss outer diameter (4)" is 35.80 mm with a "Maximum inner diameter (5)" of 30.40 mm and "Minimum inner diameter (6)" of 26.50 mm. The overall tolerance limit for the suction boss is -i-/-0.50. The "Impeller hub diameter (7) is 18.80 mm with the "Impeller hub top diameter (9)" as 18.90mm. The "Impeller shaft bore diameter (8)" is 14.05 mm. The "Impeller outer diameter (10)" is 79.20 mm with a tolerance limit of+1,0 to -0.50. The "Discharge gap (11)" that is to be provided is 4.20 mm with a tolerance limit of -i-/- 0.3. The "Impeller plate thickness (13)" is 1.50mm with the "Impeller bottom plate thickness (12)" of 1.70 mm. The "'Distance that is to be maintained between the impeller hub face (suction sides) and the impeller bottom plate suction boss face' (14)" is 2.40 mm. The PATENT APPLICATION N0.291/CHE/2004 "'Distance that is to be maintained between the impeller hub top face and the impeller plate face (15)" is 2.70mm. The "'Distance to be maintained between the impeller hub face (suction side) and the impeller bottom plate face' (16)" is 5.80 mm. The "Total impeller height (17)" is 18.70mm with the "Hub bottom radius (18) as 3.00 mm. The number of vanes present in this type of impeller is 6 with a tolerance limit for profile thickness as +/-0.20 and profile depth of 4.60mm with a tolerance limit of +/-0.3. The vane directions are anti clock wise viewed from suction side. FIG 5 illustrates the typical cross-sectional view of a diffuser which provides for a suction lifting head at shut off condition 29 feet per stage with a discharge rate of 2cubic meter/hour. The "Diffuser top plate seating (1) diameter is 80.50 mm with "Diffuser seating depth (16) as 1.50mm. The "Suction boss inner diameter (2)" is provided at 33.40 mm with a tolerance limit of+/- 0.50. The "'Shaft bore inner diameter (a)' (3)" is 16.00 mm, "'Inner diameter (b)' (4)" is 15.00 mm and "'Inner diameter (c)' (5)" is 19.50 mm. The "Diffuser inner diameter (6)" is 80.50 mm (with a tolerance limit of+1.0 to - 0.50) and "Outer diameter (7)" is 85.00 mm. The "Discharge gap (8)" is provided as 4.00 mm. The "'Diffuser depth (a)' (11)" is 14.00 mm and '"Diffuser depth (b)' (12)" is 12.30 mm. The "Diffuser top plate height (10)" is 4.50 mm with the '"Distance between the top plate face and suction bore' (9)" face as 2.75 mm. The "Diffuser top plate seating depth (13)", "Top plate seating face thickness (14)" and "Diffuser seating depth (16)" is provided as 1.50 mm. The "Diffuser height (15)" is 21.90 mm with tolerance limit of+/- 0.30. There are a total number of 5 vanes with a "Bottom side vane taper surface height (17)" of 3.30 mm and the "Height of top side vane taper surface (18)" is 2.80mm. The profile depth is PATENT APPLICATION NO.291/CHE/2004 4.00 mm with tolerance of+7-0.30 and the tolerance limit for profile thickness is +/-0.20. The vane directions are anti clockwise viewed from top side. The invention has been explained in relation to specific embodiment. It is inferred that the foregoing description is only illustrative of the present invention and it is not intended that the invention be limited or restrictive thereto. Many other specific embodiments of the present invention will be apparent to one skilled in the art from the foregoing disclosure. All substitution, alterations and modification of the present invention which come within the scope of the following claims are to which the present invention is readily susceptible without departing fi-om the spirit of the invention. The scope of the invention should therefore be determined not with reference to the above description but should be determined with reference to appended claims along with full scope of equivalents to which such claims are entitled. PATENT APPLICATION NO,291/CHE/2004 We Claim: 1. A system for a floating type impeller and diffuser used in deep-well submersible pump comprising said impeller and diffuser having relative co-operative parameters of (a) Number of vanes of impeller / diffuser; (b) Shape and profile of vanes of impeller / diffuser; (c)Inlet diameter; (d) Outlet diameter; (e) Suction area; (f) Discharge gap; (g) Thickness of vanes of impeller / diffuser, selectively based on the duty point discharge, impeller inlet angle and discharge vane angle determined based on velocity triangles and diameter requirements of bore well pump and wherein for (i) a 23 feet discharge said co-operative parameters comprises: said Impeller having a) Inlet diameter= 023.0 mm min. and 0 26.0 mm max having tolerance of ±0.50 mm; (b) Outlet diameter= 0 70.10 mm with a tolerance of+1.0/-0.50 mm; (c) Discharge gap=3.70 mm with a tolerance of ±0.30 mm; said diffuser having (a) Inlet diameter^ 0 28.0 mm having tolerance of ±0.50 mm; (b) Outlet diameter= 0 74.50 mm with a tolerance of+1.0/-0.50 mm; Discharge gap=3.0 mm with a tolerance of ±0.30 mm; and (ii) a 29 feet discharge said co-operative parameters comprises: said impeller having (a) Inlet diameter= 026.5 mm min. and 0 30.4 mm max having tolerance of ±0.50 mm; (b) Outlet diameter= 0 79.20 mm with a tolerance of+l,0/-0.50 mm; (c) Discharge gap=4.60 mm with a tolerance of ±0.30 mm; and said diffuser having ; (a) Inlet diameter= 033.40 mm having tolerance of ±0.50 mm; (b) Outlet diameter= 0 PATENT APPLICATION N0.291/CHE/2004 80.50mm with a tolerance of-I-1.0/-0.50 mm; (c) Discharge gap=4.0 mm with a tolerance of ±0.30 mm. Whereby the suction capacity is increased along with transferring thrust loads such that the efficiency of the pump increases. 2. A system for a floating type impeller and diffuser used in deep-well submersible pump as claimed in claim 1 wherein for a 23 feet discharge said co-operative parameters comprises: said Impeller having a) Number of vanes=6;(b) Shape and profile of vanes as in figure 2 with tolerance of ±0.20 mm; (c) Inlet diameter= 023.0 mm min. and 0 26.0 mm max having tolerance of ±0.50 mm; (d) Outlet diameter= 0 70.10 mm with a tolerance of +1.0/-0.50 mm;(e) suction as in figure 2;(f) Discharge gap=3.70 mm with a tolerance of ±0.30 mm; (g) Thickness of vanes as in figure 2 having tolerance of ±0.20 mm; and said diffuser having:(a)Number of vanes=5;(b)Shape and profile of vanes as in figure 3 with tolerance of ±0.20 mm; (c) Inlet diameter= 0 28.0 mm having tolerance of ±0.50 mm; (d) Outlet diameter= 0 74.50 mm with a tolerance of ±1.07-0.50 mm;(e) suction area as detailed in figure 3;(f) Discharge gap=3.0 mm with a tolerance of ±0.30 mm; (g) Thickness of vanes as in figure 3 having tolerance of ±0.20 mm. 3. A system for a floating type impeller and difftiser used in deep-well submersible pump as claimed in claim 1 wherein for a 29 feet discharge said co-operative parameters comprises: said impeller having (a)Number of vanes=6;(b)Shape and profile of vanes as in figure 4 with tolerance of ±0.20 mm; (c) Inlet diameter= 026.5 mm min. and 0 30.4 mm max PATENT APPLICATION N0.291/CHE/2004 having tolerance of ±0.50 mm; (d) Outlet diameter= 0 79.20 mm with a tolerance of +1.0/-0.50 mm;(e) suction area as in figure 4;(f) Discharge gap=4.60 nrni with a tolerance of ±0.30 mm; (g) Thickness of vanes as in figure 4 having tolerance of ±0.20 mm; and said diffuser having :(a)Number of vanes=5; (b) Shape and profile of vanes as in figure 5 with tolerance of ±0.20 nmi; (c) Inlet diameter= 033.40 mm having tolerance of ±0.50 mm; (d) Outlet diameter= 0 80.50 mm with a tolerance of+1.0/-0.50 mm;(e) suction area as in figure 5;(f) Discharge gap=4.0 mm with a tolerance of ±0.30 mm; (g) Thickness of vanes is as in figure 5 having tolerance of ±0.20 mm. 4. A system for a floating type impeller and diffuser used in deep-well submersible pump as in anyone of claims 1 to 3 wherein the shut off head of each stage is incrementally differential with respect to design of the pump at rated voltage and fi-equency. 5. A system for a floating type impeller and diffuser used in deep-well submersible pump as claimed in anyone of claims 1 to 4 wherein said cooperative parameters of said impeller and diffuser favour the thrust load to partially transfer fi-om the impeller to the diffuser stage thrust plates which in turn is passed on through the diffuser to the outer shell and suction inter-connector and finally transferred to the piping installation.

Documents:

291-che-2004-abstract.pdf

291-che-2004-claims.pdf

291-che-2004-correspondnece-others.pdf

291-che-2004-correspondnece-po.pdf

291-che-2004-description(complete).pdf

291-che-2004-description(provisional).pdf

291-che-2004-drawings.pdf

291-che-2004-form 1.pdf

291-che-2004-form 18.pdf

291-che-2004-form 26.pdf