Description:FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

1. TITLE OF THE INVENTION: “A LAMINAR FLOW EXTRACTOR FAN ASSEMBLY”
2. APPLICANT:

(a) NAME : Tirth Agro Technology Pvt. Ltd.
(b) NATIONALITY : Indian
(c) ADDRESS : Shaktiman, Survey No. 108/1, Plot No. B
NH-27, Nr. Bharudi Toll Plaza
Bhunava, Taluka: Gondal
Dist.: Rajkot 360 311
Gujarat INDIA

3. PREAMBLE TO THE DESCRIPTION
PROVISIONAL

The following specification describes the invention. þ COMPLETE

The following specification particularly describes the invention and the manner in which it is to be performed.

Field of the invention
The present invention relates to an extractor fan assembly. More particularly, the present invention relates to a lami flow extractor fan assembly to generate laminar airflow to efficiently remove lighter waste materials or trash from a harvester machine such as sugarcane harvester.

Background of the invention
A sugarcane harvester is configured to sever a mat of sugarcane material and feed that mat to a chopping section where it is chopped, including stalk which is cut into segments called "billets." The sugarcane harvester advances the billets along with crop residue (e.g., leafy material) to a primary extractor that separates at least a portion of the crop residue from the billets and removes the separated crop residue from the sugarcane harvester. However, some crop residue may remain with the billets as the billets travel up an elevator for discharge into a wagon to be hauled away. The sugarcane harvester may have a secondary extractor that separates crop residue from the billets discharged by the elevator and removes the separated crop residue from the sugarcane harvester.
Presently known trash removal apparatus uses a fan to draw air through harvested cane and entrain trash therewith. Problems which arise in such machines inc1udes reduction of fan efficiency during use due to the trapping or jamming of trash in various parts of machine and lack of control over the direction of discharge of trash from the machine.

A problem which arises in cane harvesters of the kind stated is that the material passing through the outlet with the air flow is not projected with a well defined trajectory with respect to the harvester. Further, in conventional extractor fans often suffer from inefficiencies in trash separation when airflow becomes turbulent. Turbulent flow causes suspended particles or lightweight trash to fall back due to eddy currents, reducing the system's separation efficiency. Additionally, parts such as the bottom cover in such assemblies are subject to frequent wear, leading to high maintenance and replacement costs.
Hence, there is a need to develop extractor fan assembly that can effectively remove trash and dust during harvesting process.

Object of the invention
The main object of the present invention is to a laminar flow extractor fan assembly.
Another object of the present invention is to provide a laminar flow extractor fan with low noise, high air volume and high air pressure.
Further object of the present invention is to reduce wear of bottom cover and reduce replacement cost.
The other object of the present invention is to create air draft in extractor hood which removes trash from sugarcane harvester.
One more object of the present invention is to provide fan assembly includes strategically angled blades and a replaceable bottom cover guard to ensure durability, efficiency, and cost-effectiveness.
One more object of the present invention is to eliminate turbulence and improved efficiency in removing trash from machine.
One more object of the present invention is to provide the laminar airflow systems which can be cost-effective in the long run, as they require minimal maintenance and repair compared to other types of trash removing systems.
One more object of the present invention is improving the cleanliness level, vibration and greatly reduce construction costs.
One more object of the present invention is provide modular design allows for easy replacement of worn components and maintains structural integrity under continuous operation.

Summary of the Invention
A present invention relates to a laminar flow extractor fan assembly. The present invention provides an extractor fan assembly to generate laminar airflow (Lami Flow), enhancing removal efficiency of lightweight waste/trash material in sugarcane harvester machine. It comprises a fan hub having central mounting structure for the blades, covers, and spindle interface. Said blades are arranged on outer peripheral surface of the fan hub and inclined at an angle of 52° to 55° to induce laminar airflow and create vacuum effect for trash extraction. Bottom cover is mounted on underside of hub to guide flow path. A bottom cover guard is a wear-resistant part fixed using brackets and studs to protect the bottom cover from erosion. Top cover is mounted on top of hub to enclose upper part of fan assembly and the entire fan assembly is mounted on spindle, which in turn is mounted on extractor hood structure.

Brief Description of the Drawings
Fig. 1 illustrates exploded view of a laminar flow extractor fan assembly showing all main components according to the present invention.
Fig. 2 and 2a depicts blade inclination angle to illustrate generation of laminar flow.

Detailed description of the Invention
Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application. The nature of invention and the manner in which it is performed is clearly described in the specification. The invention has various components and they are clearly described in the following pages of the complete specification. It is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.

Fig. 1 illustrates exploded view of a laminar flow extractor fan assembly showing all main components. The present invention provides an extractor fan assembly to generate laminar airflow (Lami Flow), thereby enhancing removal efficiency of lightweight waste or trash material in sugarcane harvester machine. The present invention comprises a fan hub (1) having central mounting structure for blades (3), covers (2, 4, 5), and spindle interface (8). Said blades (3) are arranged on outer peripheral surface of the fan hub (1) that inclined at an angle (a) of 52° to 55° with respect to vertical axis y to induce the laminar airflow and create a vacuum effect for trash extraction in the machine. A bottom cover (2) is mounted on underside of the said fan hub (1) to contain and guide flow path. A bottom cover guard (4) is a wear-resistant part that is fixed by using brackets (6) and studs (7) to protect the said bottom cover (2) from erosion, thus extending component lifespan and reducing replacement costs.

In continuation and as per fig. 1 of the present invention, top cover (5) is mounted on top of the fan hub (1) to enclose upper part of the fan assembly. Further, the entire fan assembly is mounted on the spindle (8), which supports the entire fan assembly and said spindle (8) is connected to extractor hood of the sugarcane harvester machine. Said fan assembly driven by hydraulic motor.

Now, Fig. 2 and Fig. 2a depicts blade (3) inclination angle to illustrate laminar flow. In operation according to the present invention, the fan assembly rotates at a specified speed of 900-1600 RPM and the blades (3) are positioned at the angle (a) of 52° to generate a draft (vacuum) as shown in fig. 2 and fig. 2a. Said draft creates the laminar flow effect that efficiently removes lighter trash materials from airflow stream and propels them outward through the extractor of the sugarcane harvester machine. Due to the specific angle of the blades (3) and laminar flow effect, it minimizes turbulent zones within the airflow and ensuring that trash does not recirculate or settle back in to the extractor hood.

Furthermore, the bottom cover guard (4) strategically placed to protect the main bottom cover (2) from material abrasion, thus enhancing system longevity and reducing maintenance costs. The present invention laminar flow extractor fan assembly allows for easy replacement of worn components and maintains structural integrity under continuous operation.

While various elements of the present invention have been described in detail, it is apparent that modification and adaptation of those elements will occur to those skilled in the art. It is expressly understood, however, that such modifications and adaptations are within the spirit and scope of the present invention as set forth in the following claims.

List of Reference Numerals:
1 Fan Hub
2 Bottom cover
3 Blades
4 Bottom Cover Guard
5 Top Cover
6 Bracket
7 Stud
8 Spindle
Y vertical axis
a angle
, Claims:We Claim:
1. A laminar flow extractor fan assembly comprising:
a fan hub (1);
blades (3) arranged on outer pheripheral surface of the fan hub(1);
a bottom cover (2) mounted on underside to the fan hub (1);
a bottom cover guard (4) fixed below the bottom cover (2) via a bracket (6) and a stud (7) mechanism;
a top cover (5) enclosing an upper portion of the fan assembly;
a spindle (8) for mounting the fan assembly to an extractor hood;
wherein
the blades (3) are extended from the fan hub(1) at an angle (a) of 52° to 55° with respect to a vertical axis y.

2. The laminar flow extractor fan assembly as claimed in claim 1, wherein the angle (a) of the blade preferably is, 52°.

3. The laminar flow extractor fan assembly as claimed in claim 1, wherein the bottom cover guard (4) is configured as a replaceable wear part to reduce maintenance costs.

4. The laminar flow extractor fan assembly as claimed in claim 1, wherein the fan assembly rotates at a speicified speed of 900-1600 RPM.

Dated this on 23rd day of May 2025