FORM 2
THE PATENTS ACT, 1970
(39 of 1970) As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
MODIFIED UNIVERSAL MIXER FOR BLENDING GRADED PARTICULATE MATTER
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR
Keshawatkar, Baburao of Crompton Greaves Ltd, Conition Monitoring & Diagnostic
Centre, Global R&D Centre, Kanjur (E), Mumbai 400042, Maharashtra, India; an
Indian National.
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

TECHNICAL FIELD OF THE INVENTION :
The present invention relates to Modified universal mixer for blending graded particulate matter.
The present invention relates to blending of various particulate matters in liquid or powder form. The invention is more particularly related resinous particulate matter for the viscosities ranging from 100 centipoises to 55000 centipoises.
BACKGROUND OF THE INVENTION :
In the field of casting the molding of resinous material, it is required to blend the resinous material with hardener or filler or both. It is an essential requirement that the blending operation should be carried out uniformly so as to produce a defect free casted material. The typical steps involved in such type blending consist of a) weighment of filler system; b) Drying of filler system; c) Cooling of filler system and keeping ready for blending; d) Weighment of Resin system; e) Blending of resin system; f) preparation of slurry; g) Blending of slurry with hardener; and h) Casting under vibro vacuum process.
Typically the blending process is carried out in a closed chamber provided with an inlet and outlet arrangement .A means for to provide stirring action is utilized. The stirrer may be in form of blade shaped part or any. The chamber is filled with resinous material and harder or filler to be blended with resinous material. The stirring action is actuated by a driving means such as electrical motor. The required vacuum is created during the blending process. The blending process is followed by molding in which the blended slurry is poured into the mould to get the desired shape and size of the product.
The quality and productivity of out put product i.e. casted product depend primarily upon the homogeneity of slurry produced in blending process and time required for blending. To other extent, the economy of the process depends upon the wastage produced during blending operation.

The problems involved with the existing blending machines are of speed of blending, non uniformity of blending and wastage of slurry material remained unmixed or remained at bottom portion of chamber which makes the blending process less productive, non specified quality and unecomical.
The existing blending machines take a long duration for blending operation and also do not blend the material in homogeneous and uniform manner as desired for the molding process. Also, some material settled at the bottom of the blending chambers which is not blended properly needs to be discarded and makes the blending process uneconomical. Also, problems faced with the existing types of machine are related to breakdown and maintenance. The existing machines are prone to breakdown due to jamming of stirrer arrangement and also the maintenance is time consuming and laborious job.
To mitigate the above disadvantages of existing blending machine, the applicant has invented a blending machine which blends the resinous material with filler or hardener in less durations, does the blending uniformly and reduces the wastages of material, less prone to break down and having ease of maintenance. As an aspect of invention, the machine can be used for blending the liquid material, powder material as well as slurries.
OBJECTS OF THE INVENTION:
An object of the invention is to provide modified universal mixer for blending graded particulate matter.
Another object of the invention is to provide modified universal mixer for blending graded particulate matter, where resinous particulate matter for the viscosities ranging from 100 centipoises to 55000 centipoises are blended homogeneously thereby eliminating waste material and thus it is cost-effective and efficient.
Yet another objective of the invention is to provide modified universal mixer for blending graded particulate matter where maintenance of the blender is easy and reducing the breakdown time of machine

Yet another object of the invention is to provide a process of blending of resinous particulate matter for the viscosities ranging from 100 centipoises to 55000 centipoises by using the modified universal blender of the invention.
Yet another object of the invention is to provide a process of blending of resinous particulate matter by using the modified universal blender of the invention where the blending process gives uniform / homogeneous mixture and thus improving the quality of end product.
Yet another object of the invention is to provide a process of blending of resinous particulate matter by using the modified universal blender of the invention where the blending is carried out at faster rate so as to improve productivity.
Yet another object of the invention is to provide a process of blending of resinous particulate matter by using the modified universal blender of the invention where the blending process gives uniform / homogeneous mixture thereby eliminating the waste material (ie non-uniform mixture).
Yet another object of the invention is to provide a process of blending of resinous particulate matter by using the modified universal blender of the invention where the blending process gives uniform / homogeneous mixture without crosslinked product thereby making the maintenance easy and reducing the breakdown time of machine.
To that extent, the objectives are achieved by not using costly mechanism but with the help of simple but innovative mechanical arrangements.
STATEMENT OF INVENTION
According the invention, a modified universal mixer for blending graded particulate matter comprising a blending chamber provided with an inlet passage valve and outlet passage valve; a vacuum creating arrangement; the said blending chamber comprises a stirring arrangement and a means for material moving wherein the said means is capable moving the blending material towards stirrer arrangement; the said stirrer

arrangement and material moving means are provided rotary motion through a common or separate power drive.
Preferably the material moving means and stirring arrangement are mounted on same shaft and driven by a single power drive.
Preferably the stirring means is of double helical blade shaped with a predefined helix angle degree.
Preferably the material moving means is hollow screw with a predefined pitch.
Preferably the screw direction is right hand side direction.
Preferably the material for stirring means and material moving means is steel.
In the another aspect of the invention a process of blending of resinous particulate matter by using the modified universal blender of the invention is capable of blending the liquid or solid resinous material with filler or hardener at higher speed comprises a blending chamber provided with an inlet and outlet passages; a vacuum creating arrangement; the said blending chamber comprises a stirring arrangement and a means for material moving wherein the said means is capable moving the blending material towards stirrer arrangement; the said stirrer arrangement and material moving means are provided rotary motion through a common or separate power drive.
DETAILED DESCRIPTION OF THE INVENTION
The invention may be more fully understood from the following description of a preferred embodiment made with reference to the following accompanying figures in which:
Figure 1 illustrates an existing blender according to one of the prior art.
Figure 2 illustrates modified universal blender according to the invention according to
one of the embodiment.

According to figure 1, the existing blender (1) comprises a blending chamber (2) provided with inlet passage valve (3) which is opening for material charging; an outlet passage valve (4) which is opening for discharging homogeneous mixture; a vacuum creating arrangement (7); a stirring arrangement (5) provided with vertical spokes (6) and baffles (10); the said stirring arrangement is provided rotary motion through a common and separate motor (8).
The material is charged from inlet passage valve (3) and required vacuum in the blending chamber (2) is created. The stirring arrangement (5) provided with vertical spokes (6) and baffles (10), is rotated through motor (8). It was found that the some quantity of material settling down at the bottom portion of blending chamber near to the outlet passage valve (4) and does not participates in blending operation. This leads to inhomogeneous mixture at the end of the bottom portion of blending chamber near to the outlet passage valve (4) in complete blending process of resinous material with hardener or filler. This inhomogeneous mixture accumulated at the bottom portion of the blending chamber needs to be discarded and this results in loss of material. If the inhomogeneous mixture accumulated at the bottom portion is not discarded and used the entire resinous material for molding application then it affects a quality of the final product which may get rejected.
Also, the time required for blending the mixture in the existing blender is very high which hampers the productivity of the process and still results in inhomogeneous mixture at the bottom which needs to be discarded. Also, the power required to drive the stirrer arrangement is more. Moreover, the maintenance required for this type of machine is complicated and consumes much amount of time. There is possibility of stirring arrangement getting jam which leads to production loss.
According to figure 2, modified universal blender (11) of the invention comprises a blending chamber (12) provided with an inlet passage valve (13) which is opening for material charging; an outlet passage valve (14) which is opening for discharging homogeneous mixture; a vacuum creating arrangement; a stirring arrangement (15) provided with helical blades (16) and a means (19) for material moving; the said stirring

arrangement (15) and means (19) for material moving are provided rotary motion through a common or separate power drive motor (18).
Means (19) for material moving in form of hollow screw is fixed at the lower portion of stirring arrangement (15) with the helical blades (16) and said hollow screw (19) are mounted on the same shaft and driven by a motor drive (18). Alternatively, the stirrer and hollow screw may be mounted on different shafts and power can be supplied through separate motors.
Preferably the helical blade is double helical blades. The helix angle of double helical blade is 30 degree. The distance between the inner walls of the blending chamber to the outer surface of double helical blade is in the range of 10 to 15 mm.
It can be observed from the figure that when the blending operation is initiated, the stirring arrangement with doubie helical blades creates an efficient blending action and at the same time the hollow srew throws the material from the bottom in the upward direction towards the stirring arrangement. This avoids settling of unblended material at the bottom of the blending chamber. As the material is from bottom is thrown upwardly, the blending material which tries to flow down due to gravity is again mixed with the mass of material due to the action of hollow screw. This action not only provides the uniform blending but reduces the process time for blending.
Also, the shape of the blending chamber (12) is of conical shape and is so designed so as to avoid retention of any material at the wall of the blending chamber. As the side walls are tapered, the material received on these walls is dragged down to main mass due to gravity.
The effect of double helical and conical shape produces such a effect that space between stirring arrangement and side walls is very less that means almost all the mass or quantity of material to be blended remains in contact with stirrer and gets blended at faster rate.
Appropriate helix angle to the stirrer may, shape and geometry of chamber, size and pitch of the hollow screw can be decided depending upon the application.

Also, it can be observed that no material will settle down at the bottom of chamber as it is being continuously thrown in upward direction by the hollow screw.
Additionally, there are vary less chances of the stirrer getting jammed and leading to production /productivity loss. During cleaning, one can easily decouple the helical blade containing shaft from the coupler attached to the central portion of the lid, clean it, couple it back on the main shaft coupler at the central portion of the ]id and perform the blending operations without loosing much time. This operation is fast, simpler, cleaner without any loss of material. As the stirring arrangement is easily detachable, the maintenance is easy.
The motor speed is selected in the range of 30 rpm to 160 rpm. The construction material used for blending chamber, hollow screw and stirring arrangement is of stainless steel of suitable grade.
A process of blending of resinous particulate matter with filler or hardener by using the modified universal blender of the claim 1 at higher speed comprising a blending chamber (12) provided with an inlet passage valve (13) which is opening for material charging; an outlet passage valve (14) which is opening for discharging homogeneous mixture; a vacuum creating arrangement; a stirring arrangement (15) provided with helical blades (16) and a means (19) for material moving; the said stirring arrangement (15) and means (19) for material moving are provided rotary motion through a common or separate power drive motor (18); said material moving means is hollow screw capable of throwing the material from the bottom in the upward direction towards the stirring arrangement (15).
The applicant has tried out the blending operation in which smallest quantities of hardener (0.06 kgs) is blended with the large quantity (30 Kgs) of highly filled resinous particulate matter like polycrete in a shortest duration time of 2-3 minutes to obtain homogeneous polycrete mixture without chocking. However, the existing blender took 12-15 minutes for the same operation but 5-8 kg of material settled at the bottom was thrown as a waste material. The homogeneous polycrete mixture obtained from the modified universal blender of the invention and existing blender was subjected to casting

into cubes, bars and cylinders. These cubes, bars and cylinders are subjected to curing at temperature of 25 to 45°C for 4 to 5 hours followed by post-curing at 60 to 80° C. The cured cubes, bars and cylinders are evaluated for Mechanical Properties like Compressive Strength, Flexural Strength & Splitting Tensile Strength. The comparative results of mechanical properties for the cubes, bars and cylinders prepared from the homogenous mixture obtained by using modified universal blender of the invention and existing blender are illustrates in table 1.

Table 1 : Comparative results of mechanical properties for the cubes and cylinders prepared from the homogenous mixture obtained bj using modified universal blender of the invention and existing blender
Mechanical properties for the cubes and cylinders prepared I Mechanical properties for the cubes and cylinders prepared from from the homogenous mixture obtained by using modified the homogenous mixture obtained by using existing blender universal blender of the invention.

Cube
No. Cross Section Area, Cm2 Machin e Load,
KN Compressiv e Strength,
Kg/ cm 2