Claims:INVENTION WE CLAIM
1) The impeller seal arrangement comprises, of: a impeller attached in rotatable
fix manner with; a drive shaft ; a housing enclose the impeller & guide the
drive shaft; an impeller seal fitted inside; an impeller seal holder,
Wherein said housing further comprises of housing body; inner diffuser;
outer diffuse; & diffuser blade,
Wherein Said impeller seal holder further comprises of upper element; and
lower element.
2) The impeller seal arrangement as claimed in claim 1, wherein upper element
& lower element have recess at mating portion to adapt impeller seal.
3) The impeller seal arrangement as claimed in claim 1, wherein said impeller
seal, upper element & lower element are integral part.
4) The impeller seal arrangement as claimed in claim 1, wherein said impeller
seal have clearance fit with impeller seal holder, & free to rotate about its
longitudinal axis.
5) The impeller seal arrangement as claimed in claim 1, wherein said lower
element supported by outer diffuser.
6) The impeller seal arrangement as claimed in claim 1, wherein said upper
element supported by housing body.
7) The impeller seal arrangement as claimed in claim 1, wherein said impeller
seal holder is made from a polymer material selected from a group
consisting of polyethylene, polypropylene, polystyrene, polyvinyl chloride,
Polyamides, polyester, polycarbonate, polybutane, Polytetrafluoroethylene,
Fluoroplastic, polyacetals.
8) The impeller seal arrangement as claimed in claim 1, wherein said impeller
seal is made from a polymer material selected from a group consisting of
polyethylene, polypropylene, polystyrene, polyvinyl chloride, Polyamides,
polyester, polycarbonate, polybutane, Polytetrafluoroethylene, Fluoroplastic,
polyacetals.

9) The impeller seal arrangement as substantially described with reference to
the accompanying drawing. , Description:FIELD OF THE INVENTION
The present invention generally relates to pump & more particularly it relates to
development of impeller seal arrangement, this seal arrangement prevents the
reverse flow of fluid from impeller outlet to impeller inlet & increases the
volumetric efficiency.
BACKGROUND
Impeller seal in the pump play very significant role to improve volumetric
efficiency of the pump. The impeller seal fixed around the impeller eye to protect
the reverse flow of fluid from impeller outlet to inlet, as the pumps has high
pressure at outlet side of the impeller & low pressure at inlet side of the impeller.
This pressure difference in centrifugal pump generate circulation of fluid from high
pressure i.e. outlet side to low pressure i.e. inlet side, this circulation of fluid
reduces the volumetric efficiency of the pump. Hence a seal is required to prevent
the free flow of fluid from outlet side to inlet side.
In vertical multistage pump several attempts have been made in the past to improve
impeller seal arrangement, but this is failed due to inappropriate design, it has been
observed that pump running in down float condition damage the impeller seal, &
vibration in the pumps dislocate the seal from its original location, which leads to
substantial damage of the pump. These conditions demands for the development of
new invention, which is capable to overcome from these problems.
PRIOR ARTS AVAILABLE UNDER PATENT SEARCH
Such an arrangement disclosed in US 6267555 B1. Said invention relates
a sheet metal casing for multistage pump and its manufacturing method, the casing
includes an outer shell and an inner shell. The outer shell is integrally formed and
includes a front end ring, a step positioning ring, an outer shell surface and a
positioning end. The inner shell is fixed to the inner side of the outer shell and
includes an inner end, an inner shell surface and a step positioning rim. The step
positioning rim forms a closed holding space with the outer shell surface for

holding and squeezing a seal ring therein. When a plurality of casings being
serially mounted on a spindle, the positioning end of a front casing may make
contact with the step positioning ring of a rear casing, and the positioning rim of
the front inner shell may make contact with the front end ring of the rear outer
shell for axially positioning the casings on the spindle.
Such an arrangement disclosed in US 6398493 B1. Said invention relates to a
floatable impeller for multistage metal working pump includes an impeller hub
which has an impeller metal working member supporting a rear wall of
the impeller and an impeller plastic member integrally formed with the impeller
working member. The impeller plastic member is engaged with and driven by the
pump shaft. The impeller has a front wall attached with
an impeller thrust ring which has a thrust metal working member integrally formed
with a thrust plastic member located in front of the impeller front wall. The thrust
plastic member serves as a bearing when rotating against a metallic pump shell of
an adjacent pump unit for reducing friction loss. The impeller hub has axial
grooves formed in the inside wall. The thrust plastic member has radial slots
formed in the sidewall. The grooves and slots may collect and discharge grits and
sands carried by fluid and generated by friction for reducing friction, improving
pumping efficiency and enhancing pump durability.
Such an arrangement disclosed in US 6439835 B1. Said invention relates to An
improved pump shell for a multistage metal working pump includes a plurality of
pump shell units housed in series within a hollow cylindrical casing and has the
impellers driven by a shaft. Each pump shell unit has an inner shell which forms a
holding end at one side and a sealing flange at another side. The holding end of one
pump shell may align and engage precisely and easily with the sealing flange of an
adjacent pump shell unit to form a smooth fluid passage from the inlet of
the impeller through the inner shell so that pumping efficiency may be enhanced
with less turbulence. The sealing flange, holding end and the casing also form a
close annular compartment for holding a seal ring inside to provide effective
sealing function. The pump shell may be produced by stamping at low cost.
The Present invention is based on double locking arrangement of the impeller seal
holder at inner diameter & outer diameter in order to provide better grip. Moreover

material is used for neck ring holder allow better wear resistance against the metal
impeller.
OBJECT OF THE INVENTION
It is primary object of the present invention to prevent the disengagement of the
impeller seal from its position due to vibration & float down of the pump shaft.
It is further object of the present invention to improve the durability of the impeller
seal during float down running of the pump shaft.
It is another object of the present invention to reduce the cost of manufacturing
process.
It is still another object of the present invention to reduce the process time.
It is further object of the present invention to simplify manufacturing design.
SUMMARY
The present invention relates to impeller seal arrangement in a pump, which
prevents the free flow of fluid from high pressure side i.e. outlet side to low
pressure side i.e. inlet side in order to improve volumetric efficiency. The impellers
seal arrangement imposes in pump are not capable to remain in its position due to
float down running of the pump shaft & vibrations, which leads to damages in
pump. Moreover float down running of the pump shaft leads to wear out of
impeller seal. This conditions demands for the development of new invention,
which is capable to overcome from these problems.
The present invention comprises, of a impeller (11) attached in rotatable fix
manner with a drive shaft (12), a housing (13) enclose the impeller & guide the
drive shaft (12), a impeller seal (14) fitted inside the impeller seal holder (15),
Said housing (13) further comprises of housing body (16), inner diffuser (17),
outer diffuse (18), & diffuser blade (Not shown in drawing),

Said impeller seal holder (15) further comprises of upper element (20) & lower
element (21).
Typically the upper element (20) & lower element (21) have recess (22) at mating
portion to adapt impeller seal (14).
Typically said lower element (21) supported by outer diffuser (17).
BRIEF DESCRIPTION OF THE DRAWINGS
Under this section of the specification a brief description of all the relevant
drawing shall be made with reference to the invention described in the description
part
FIGURE – 1 Shows Sectional View of ‘Impeller Seal Arrangement for Multistage
Sheet Metal Casing’
FIGURE – 2 Shows Exploded View of Impeller Seal & Impeller Seal Holder
FIGURE – 3 Shows Sectional View of Housing
DETAIL DESCRIPTION OF THE INVENTION
In accordance with the present invention an impeller seal arrangement designed to
sustain in float down running condition of the pump shaft & capable to remain in
its position even after float down impacts & vibrations.
The impeller seal arrangement comprises, of a impeller (11) attached in rotatable
fix manner with a drive shaft (12), a housing (13) enclose the impeller & guide the
drive shaft (12), a impeller seal (14) fitted inside a impeller seal holder (15), said
housing (13) further comprises of housing body (16), inner diffuser (17), outer
diffuser (18), & diffuser blade (Not shown in drawing), said impeller seal holder
(15) further comprises of upper element (20) & lower element (21).
Typically said upper element (20) & lower element (21) have recess (22) at mating
portion to adapt impeller seal (14).

Typically said lower element (21) supported by outer diffuser (18), in a way that it
rigidly fix on collar (23) of the outer diffuser (18), which restrict the axial & radial
movement of the impeller seal holder (15).
Typically said upper element (20) supported by housing body (16), wherein upper
element (20) have interference fit with collar (24) of the housing. Moreover male
plug (25) of the upper element push fitted in socket (26) of the lower element,
wherein collar (27) of the upper element limit the axial insertion in socket (26),
therefore maintaining predefined gap for impeller seal (14).
Typically said impeller seal (14) have clearance fit with impeller seal holder (15),
& free to rotate about its longitudinal axis (28).
Alternatively said impeller seal (14), upper element (20) & lower element (21) are
integral part.
Alternatively said lower element (21) has interference fit with collar (23) of the
outer diffuser & collar (24) of housing body.
Typically upper element (20) & lower element (21) have plug (25) & socket (26)
type interference fit with one another.
Typically said impeller seal holder (15) is made from a polymer material selected
from a group consisting of polyethylene, polypropylene, polystyrene, polyvinyl
chloride, Polyamides, polyester, polycarbonate, polybutane,
Polytetrafluoroethylene, Fluoroplastic, polyacetals.
Typically said impeller seal (14) is made from a polymer material selected from a
group consisting of polyethylene, polypropylene, polystyrene, polyvinyl chloride,
Polyamides, polyester, polycarbonate, polybutane, Polytetrafluoroethylene,
Fluoroplastic, polyacetals.
Typically the ‘Impeller Seal Arrangement for Multistage Sheet Metal Casing’
as substantially described with reference to the accompanying drawing.