Form-2
THE PATENTS ACT, 1970;
COMPLETE SPECIFICATION: SEC.-10;
AN IMPROVED REFINER FOR PULP AND PAPER MILLS
SHEKHAR DASSERDA, Indian National, at Parasons House, 28 Venkatesh Nagar, Opp. Jalna Road, AURANGABAD-431 001, State of Maharashtra, India.
The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed:


This invention relates to an improved pulp grinding and refining device for paper mills.
In the modern age it is needless to elaborate significance, necessity and importance of paper and paper products. Paper and paper products have characteristics depending nature of their use. Paper for writing or printing requires greater smoothness than the paper used for packing or other applications, and vice versa. Paper has become almost basic need in the human life.
Initially the paper was made by hand process. By evolution of industries, paper making is mechanized, automated, computerized, and so on. With mechanizing of the paper making, there emerged competition in producing papers having different characteristics for diverse applications. For instance, papers manufactured for diverse applications are newsprint, craft paper, board, carbonless, tissue paper, grease proof, electric insulation paper, glass line paper, and the like. Manufacturing all these papers having different characteristics require a combination of paper making equipments, paper machine and the process.
It is well known that paper is manufactured out of fibrous materials of agro-based products, such as, wood bamboo and the like. The agro-based fiber is treated in stock preparation. In the stock preparation the agro-based fiber, the properties to give different characteristics to the paper are imparted. One of the significant step in stock preparation is refining of the agro-based fiber, which gives proper configuration to the fiber and formation of the paper.

The fiber refining has the following effects in paper manufacturing:
Internal fibrillation; External fibrillation; Fines production; Fiber shortening; Delamination; Lumen reduction; Axial compression; Form change; Structure change;
The treatment of fiber for paper manufacturing has various effects, such as, cutting, crushing, fibrillation, fines production and the like. However, there are variables in refining as under:
Raw material:
Wood species;
Pulping;
Degree of pulping;
Bleaching treatment;
Prior processing (e.g. drying, mechanical treatment);
Fiber length distribution;
Fiber coarseness;
Early wood/late wood ratio;
Chemical composition (lignin, cellulose, hemicellulose};

Equipment characteristics of the Refiner: Bar size and shape; Area of bar and grooves; Depth of grooves; Presence or absence of dams; Materials of construction (tackle); Wear patterns; Bar angles; Speed of rotation (peripheral speed).
Process variables: Temperature; PH;
Consistency; Additives; Pretreatments; Production rate; Applied energy.
With a view to impart diverse properties to the fiber, such as, strength, optical properties, the devices, such as beater and disc refiners were got evolved.
The disc refiner is provided with at least two discs having grinding surfaces. Grinding of the pulp takes place between the grinding surfaces. The ratio of the pulp fed into the refiner depends on the gap between the grinding surfaces of the pair discs. Grinding area is guided by the diameter of the discs. At least one disc is rotor and is mounted on a shaft driven by a drive.

In large manufacturing facilities there is continuous requirement of large quantity of the refined pulp. One of the drawbacks in disc refiners is that the diameter of the discs restricts the grinding area. To increase grinding area, the option is to increase the radial diameter of the discs. The obstacle in increasing the diameter of the disc is that it increases the size of the refiner, making the refiner large and bulky, and also consumes larger space for installation. Another option for increasing the grinding area is to increase pairs of grinding discs in the refiners, which is again a cumbersome mechanism. Therefore, the tendency so far has been that to install additional refiners involving additional capital investment. Another drawback in the disc refiners is that since the discs are enclosed in a chamber, the variation in the gap between the grinding surfaces of the discs cannot be inspected periodically.
One of the principal objects of the present invention is to provide a refiners having larger grinding surface that can refine a. large quantity of the pulp using the same energy, labour and other maintenance as that of the conventional disc refiners. Another object of the invention is that the gap between the rotor and stator can be verified periodically by not resorting to open the enclosed chamber. Another object of the invention is that the gap between the stator and rotor is maintained uniform throughout.
With above said objects in mind among others, the present invention provides a refiner for pulp and paper mills, having a larger grinding surface for refining large quantity of pulp, efficient, economical and easy to operate.

According to the present invention, a refiner for pulp and paper mills comprising a stator of conical structure with open ends, and at the inner surface having grinding projections, mounted on a body structure, having an inlet, an outlet and a waste discharge openings; a rotor of conical structure having diameter lesser than the inner diameter of the said stator and matching therewith, at least the end having greater diameter being open, at the outer surface having grinding projections located within the said stator; an inwardly directed projection within the said conical rotor structure adapted to receive there-within and couple therewith a shaft member; and a rotary shaft mounted with the said inwardly directed projection.
According to a preferred embodiment of the present invention, the grinding surfaces on the inner surface of the stator and outer surface of the rotor are configured as intermittent halves, each halve having intermittent integral or otherwise provided projecting ribs.
According to another embodiment of the invention, the end of rotor having lesser diameter is sealed with a plug or the like sealing member.
The invention will now be described in more detail with reference to illustration in the accompanying drawings, in which -
FIG. 1 is a cross-sectional illustration of the refiner for pulp and paper mills according to the present invention.
Referring to the illustration in FIG. 1, the refiner for pulp and paper mills according to the invention has a stator 101 of conical structure with open ends. The inner surface of the stator 101 has

grinding projections 102. The stator 101 is mounted on a body structure 103.
The body structure 103 has an inlet 104, an outlet 105 and a waste discharge opening 106. 107 is a rotor of conical structure
having diameter lesser than the inner diameter of the stator 101. The stator 191and the rotor 107 matches in shape and configuration. At least the end 110 of the rotor 107 that is of greater diameter than the end 111 is facilitating assembly. The outer surface of the rotor 107 has grinding projections 108. The rotor 107 is located within the conical locator of the stator 101. 109 is an inwardly directed projection within the conical rotor structure 107 which is adapted to receive there-within and couple therewith a shaft member. 112 is a rotary shaft mounted with the inwardly directed projection 109.
The grinding surfaces 102 and 108 on the inner surface of the stator and outer surface of the rotor respectively are configured as intermittent halves 113, each halve 113 has intermittent integral or otherwise provided projecting ribs 114, which ribs are placed angularly. The end 111 of the rotor having lesser diameter is sealed with a plug or the like sealing member 115.
The refiner for pulp and paper mills according to the invention has a stator 101 of conical structure with open ends. The inner surface of the stator 101 has grinding projections 102. The stator 101 is mounted on a body structure 103.
The pulp (not shown) is pressure fed into the body structure 103 through inlet 104, which pulp travels into the cavity 116 between the stator 101 and rotor 107. The cavity 116 is maintained optimum for achieving better refining of the pulp, and can be varied and

adjusted by axial movement of the. shaft 112. The grinding surfaces 102 and 108 receive the pulp and grind them into required mesh size. In. view of the conical, shape at the. staior g.nd rotor, and the inlet 104 provided at the lesser diameter end of thereof, the pulp ground is moved upwardly due to. pressure, .feeding and therefore undergo repeated crushing. Crushed pulp has a mixture of hard and light material on, rearhing Hisrhargft end. of the stator-rotor, hy gravity hard materials drop down for discharge through the waste discharge outlet 106 and,the refined-fine, pulp moves, towards the. outlet 105.
The angularly provided intermittent projecting ribs render pressure feeding, effect on. the. pulp .to move upwarjdly on the, slope of the conical stator-rotor structure.
1L7 is. drain cover„ L1A is main body 119 is hub retainer 120 is shaft hub, 121 is cover for rotor, 122 is key for shaft hub, 123 is wear sleeve 124 is. neck ring. 125 is cooling ring. 126. island bracket, 127 is centrifugal ring, 128 is cover for centrifugal ring, 129 is rotor side hearing nnver, 130 housing 131 and 131 are caps l33 is bearing sleeve, 134 is key for bearing sleeve, 135 oil tank, 136 is coupling side. bearing over 137 bearing locking sleeve 138 cover for coupling, 139 is key for coupling, 140 coupling, 141 connector, and 142 is,hydraulic cylinder.

I Claim:
1. A refiner, for pulp, and paper mills comprising, a slator of conical structure with open ends, and at the inner surface having, grinding, projections. mounted on a body structure, having an inlet, an outlet and a waste discharge openings; a rotor of conical, structure, having, diameter, lesser than the inner diameter of the said stator and matching therewith, at least the end having, greater diameter being, open, at the outer surface having grinding projections located within the said stator, an inwardly directed projection, within the said conical rotor structure adapted to receive there-within and couple therewith a shaft member; and a rotary shaft mounted with the said inwardly directed projection.
2. A refiner for- pulp and paper mills as claimed in claim 1, wherein the said grinding surfaces on the inner surface of the staler and outer surface of the rotor, are configured as intermittent halves.
3. A refiner for pulp and, paper mills as claimed in claim 2,
wherein each halve having intermittent integral or otherwise
provided projecting ribs,
4. A refiner for pulp and paper mills as claimed in claims 1-to 3,
wherein the end of rotor having lessor diameter is sealed with
a plug or the like sealing member.

5. A refiner for pulp and paper mills as claimed in claims 1 to 4, and as substantially described, with reference to illustration in the accompanying drawings.

Dated this 21st day of November 2001.