|Title of Invention||
AN IMPROVISED STRAINER, STRAINER-ARRANGEMENT AND A SUITABLE DIFFUSER-IMPELLER COMBINATION IN A SUBMERSIBLE PUMP
|Abstract||The present invention deals with an improvised strainer ina submersible pump set wherin the cuts in the strainer narrow,in the form of helical slits in a sewed manner al around the periphery,the skewed slits also extending to the horizontal circular bottom portions of the strainer and the extended hub portion of the strainer carrying plurality number of grooves which forms water rings and discourages the flow of contaminated water towards the bearings.|
This Invention relates to the improvisations made in a submersible pump with respect to the strainer, the strainer arrangement within the submersible pump and a suitable diffuser-impeller combination in a submersible pump,which has been arrived at, after a lot of research work
With depleting water resources day by day, the ground water table has been going deeper, thus making the pumping operation mere and more complex, at the same time leaving a lot of scope for development in that direction in order to arrive at a trouble-free pumping system.
The tubewells are the most economical means for striking the under ground water and the most energy efficient process known today for pumping out water is by submersible pumpsets and with the advent of reliable submersible pumpsets, the highly ineffcient compressor pumps and jet pumps are being phased out However, the need is felt for improving the relaiabUity of the submersible pumpsets in spite of the fact that these submersible pumpsets are comparatively energy effcient than the compressor and the Jet pumps. However, in the matter of reliability there are two important factors which determine the functioning of a submersible pump. One being the electrical reliability of the windings to sustain widely varying voltages and varying head conditions depending upon the season and most importantly the other factor is the medianical reliability of the submersible pumpsets to ensure trouble 6ee operation for a long period
This Invention 'AN IMPROVISED STRAINER, STRAINER-
ARRANGEMENT & A SUITABLE DIFFUSER-IMPELLER COMBINATION IN A SUBMERSIBLE PUMPSET is aimed at providing total electrical reliability. Further, a lot of research work has been done to ensure the mechanical reliability also. It has been observed that an excessive wear and tear in the pump portion takes place due to the silt and fine sands present in the bore holes, which the pumpset encounters during the pumping operation. The submersible pumpsets presently available are not adequately safe-guarded against this problem. The strainers generally provided in the inlet area of the submersible pumpsets are manufactured using stainless steel/brass sheets, with opening of around 1.5 to 3.0 mm diameter or widths. Often, these are even punched out with rectangular configuration of about 3 mm width and much greater lengths. The silt and sand partides enter in large volumes through these apertures and because of the abrasion of the silt and the sand, the impellers, diffusers, bearing and the sleeves in the submersible pump wear out excessively, resulting in the pre-mature breakdown of the pumps within a short period.
Above being the problems enumerated, this invention AN IMPROVISED STRAINER, STRAINER-ARRANGEMENT & A SUITABLE DIFFUSER-IMPELLER COMBINATION IN A SUBMERSIBLE PUMPSET overcomes all these drawbacks, which has been arrived at after doing an extensive research work by running the pumpsets for several thousands of hours in actual field conditions.
A Cast gunmetal machined strainer cut with narrow, helical slits in a skewed manner all around the periphery, the skewed slits also extending to the horizontal circular bottom portions of the strainer, as shown in fig (A)
on drawing sheet No:l of the accompanying drawings and the strainer arrangement within the submersible pump is by spigoting the strainer to the middle bracket, thus the formation being the extension of the pump middle bracket and positioned in such maimer that the borewell water pumped has no direct access to the drive-end bearing, as enumerated in Fig (C) on dra wing sheet No:2 of the accompanying drawing.
As the pump starts rotating, the kinetic energy imparted to the water in the bore hole dra ws the water along with tire sand and sUt present in the bore hole, thus approaching the stminer all around to gain entry into the pump impellers and diffusers. With the conventional strainer arrangent, all these sUt and sand would enter the pump unchecked, which would cause excessive wear and tear to the pump parts due to the abrasion of the sand and the silt on the rotating and stationary components of the pump. The improvised profile of the strainer in this Invention as claimed in Sg (A) on drawing sheet No:l effectively prevents the entry of sand and slit because the apertures are not only narrow but also these are helical and skewed. The bore well water along with the silt and sand are made to undergo changes in the direction of Sow and since the flow velocity past the strainer gets considerably lowered, the water entering the slit has no energy to hold on the sand and the silt, whose densities are greater than that of the water and these foreign partides tend to dissoaate with the water stream entering into the pump impellers.
As regards the petition of the strains in this newly invented 'AN IMPROVISED STRAINER, STRAINER-ARRANGEMENT & A SUITABLE DIFFUSER'IMPELLER COMBINATION IN A SUBMERSIBLE PUMPSET
is concerned, the strainer is spigoted to the middle bracket, with no openings other than the narrow, helical, skewed slits on the strainer that are available for the water to enter into the pump, unlike the conventional sheet metal strainer, where there are possibiUties of water entry into the pump along with the sand the silt, which can happen not only through the larger strainer apertures, but also through the several other openings available by virtue of the constructional deficiencies.
Another important feature of this newly invented "AN IMPROVISED STRAINER, STRAINER ARRANGEMENT & A SUITABLE DIFFUSER-IMPELLER COMBINATION IN A SUBMERSIBLE PUMPSET" is the protection given to the bearing sleeves both at the driving end and the tar end of the pump. This is to ensure that whatever fine sand and silt that has still escaped into the pump may not damage the bush and the shaft at the bearing portions. However, this arrangement has been incorporated in the strainer itself for protection of the drive-end bearings. A cross-sectional view of the strainer, as shown in fig (B) on the drawing sheet No: 1, reflects the inner profile of die strainer, specially designed for this purpose. The protection of the drive-end bearing is achieved by the stminer arrangement, as the bottom portion of the strainer carries a hub, which diverts the water entering through the stminer apertures straight to the impeller eye and thus the flow of water through the bottom bearing of the pump is discouraged, unlike in the conventional submersible pumpsets available presently. Also the extended hub portion of the strainer stated above carries one or more internal grooves, as shown in fig (B) of drawing sheet No:l of the accompanying drawing, which get filled with water and the water ring also discourages flow of silt and sand entering
through the bottom bearing. Thus the dual arrangetnent of prevention of water 6rom entering through the bottom bearing is a major contribution of this invention towards 'AN IMPROVISED STRAINER, STRAINER-ARRANGEMENT & A SUITABLE DIFFUSER-IMPELLER COMBINA TION IN A SUBMERSIBLE PUMPSET.
As regards protection for the far end bearing is concerned, the slit and sandy water flowing through the pump has no chance of Bowing through the far-end bearing because the top of the bearing bousing is capped by a dome-like arrangement as shown in Fig (D) on the acrompanying drawing sheet No:2, not only to avoid the Bow past the bearing, but also to create a fairly guided Bow of water through the delivery oudet. Besides, the dome shape capping arrangement protection avoids the Bow of water through the far-end bearing in the reverse direction in the event of switching-off of the pump or due to sudden break-down of power supply, particularly when the non-return valves are avoided by the user.
In the conventional submersible pumpsets, the sand, silt and water flow through the noiyl impellers and impings on the noryl diffuser walls, the components are oBen found to get damaged, not only because of the normal Bow of water, but also by the abrasive action of the sand and silt Bowing past the impeller and impinging on the diffuser walh, whether directly or otherwise. However, a number of experiments have been conducted by this applicants, to arrive at a suitable combination of the diffuser-impeller assembly, which is not only reliable, but also durable. Accordingly in this
invention "AN IMPROVISED STRAINER, STRAINER-ARRANGEMENT & A SUITABLE DIFFUSER-IMPELLER COMBINATION IN A SUBMERSIBLE PUMPSET", it has been established that gunmetal has better bearing properties in conjunction with the noryl components rather than any other material commonly employed. In conventional submersible pumpsets, after a a}nsiderable length of time of working, due to wear on the thrust bearing, the impellers are found to rub with diffusers and when both the diffuser and the impeller are of the same noryl material, they tend to fuse with each other and stall the pumpset, thus causing bum out of the motor vnndings. With the introduction of the gunmetal diffuserin conjunction with noryl impeller, it has been validated to the extent that the said arrangement of gunmetal diffuser in conjunction with noryl impeller to have excellent anti-friction properties and the life of the pumpset is substantially elongated. In addition, the gunmetal diffusers have the flexibility for accommodating different heads and discharge requirement of the end users. In the event of repairs and replacement, it has been established that the cost of repair in gunmetal diffuser-notyl impeller pumps, the cost is consideiably less as compared with the conventional noryl diffuser-noryl impeller pumps, which needs the replacement of both, the diffusers and the impellers.
1. "AN IMPROVISED STRAINER, STRAINER-ARRANGEMENT & A SUITABLE DIFFUSER-IMPELLER COMBINATION IN A SUBMERSIBLE PUMPSET"; wherein the cuts in the strainer are narrow, in the form of helical slits in a skewed manner all around the periphery, the skewed slits also extending to the horizontal circular bottom portions of the strainer, as enumerated in Fig. (A) and the extended hub portion of the strainer carrying plurality number of grooves as shown in Fig.(B), which forms water rings and discourages the flow of contaminated water towards the bearings.
2. "AN IMPROVISED STRAINER, STRAINER-ARRANGEMENT & A SUITABLE DIFFUSER-IMPELLER COMBINATION IN A SUBMERSIBLE PUMPSET", as claimed in the Claim. 1, wherein the strainer is spigoted to the middle bracket as shown in Fig.(C}, just forming an extension of the pump middle bracket and positioned in such a manner that the bore well water pumped, which is contaminated with sand and silt has no direct access to the drive-end bearing, thereby protecting it, as the contaminated water is made to undergo changes in the direction of How, consequent to which the Sow velocity past the strainer gets lowered considerably, the water entering the
slits lack the force and the energy to hold sand and slit as the densities are greater than that of water and these foreign particles tend to dissociate with the water stream entering into the pump impellers.
3. "AN IMPROVISED STRAINER, STRAINER-
ARRANGEMENT & A SUITABLE DIFFUSER-
IMPELLER COMBINATION IN A SUBMERSIBLE
PUMPSET" as claimed in Claims 1 St 2, wherein the bottom
portion of the strainer carries an hub as shown in Fig.(D),
which diverts the water entering through the strainer apertures
straight to the impeller eye and thus the flow of water through
the bottom bearing of the pump is discouraged and the dome
like arrangement hindering the Slow of water to the far end
bearing, thereby ensuring that even the residual fine sand and
slit that has entered into the pump may not damage the bush
and the shaft at the bearing positions, as the said arrangement
presects the bearing sleeves both at the driving end and the far
end of the pump.
4. "AN IMPROVISED STRAINER, STRAINER-
ARRANGEMENT & A SUITABLE DIFFUSER-
IMPELLER COMBINATION IN A SUBMERSIBLE
FUMPSET", as claimed in the above said claims, wherein
contrary to the noryl diffuser - noryl impeller combination, a
gun metal diffuser-noryl impeller combination is used, as the
gun metal diffusers have the flexibility for accommodating
different beads and dicharge requirements and further, when a gun metal diffuser is used in conjunction with a noryl impeller, the wear and the tear of the pumpset considerably decreases and also does not leave any scope for fusion, when identical material aw used , both on the diffuser and the impeller.
5. "AN IMPROVISED STRAINER, STRAINER-
ARRANGEMENT & A SUITABLE DIFFUSER-IMPELLER COMBINATION IN A SUBMERSIBLE PUMPSET", as claimed in the above said claims and as substantially explained herein, with reference to the accompanying drawings.
|Indian Patent Application Number||25/MAS/2002|
|PG Journal Number||50/2007|
|Date of Filing||09-Jan-2002|
|Name of Patentee||DHANDAPANI KALIDASS|
|Applicant Address||JAGHAS ENGG., EQUIPMENTS,NO:167,AMMANKULAM ROAD,P.N.PALAYAM COIMBOTORE - 641 037,|
|PCT International Classification Number||B 30 B 9/26|
|PCT International Application Number||N/A|
|PCT International Filing date|