Title of Invention

A BIO-MASS GASIFIER

Abstract

This invention relates to a bio-mass gasifier comprisin~ a easifier chamber (1) having an opening (2) at the top for feeding of bio-mass and air; a side inlet (3) for air; characterised by a rotating vertical grate (4) with parallel rods arranged vertically to the burning chamber of the gasifier chamber (1), through which fuel gas produced in the said gasifier chamber, is sucked out; a strut (5) fIXed to the said gasifier chamber to provide support to grate (4); a reduction gear box (6) connected to grate (4) through shaft (7) which runs through the fuel gas passage and has gear box (6) at one end and grate (4) at the other end; a motor (8) coupled to the gear box for rotating the shaft (7); a stuffing box (9) to seal against the leakage of the fuel gas; fuel gas outlet (10) and a displacement system (11) to remove continuously the ash and other matter resulting from the burning of the bio-mass. '

Full Text

FIELD OF INVENTION This invention relates to a bio-mass gasifier. PRIOR ART Gasification is the conversion of hydrocarbons present in the bio-mass into combustible fuel gas by thermo-chemical reaction of the bio-mass. Gasification of the bio-mass like wood, rice, husk, coconut shells, etc. is done by drawing producer gas through a grate. The grate acts as a barrier for the burning bio-mass and facilitates drawing of the gas through it. Depending upon the air entry and gas exit, fixed bed gasifiers are classified into different types such as updraft gasifier, down draft gasifier and cross-draft gasifier. In updraft gasifier, the air flow is counter current to the fuel flow and is introduced through the bottom grate. In down draft gasifiers, the air is introduced from top of the fuel and gas is drawn through the grate at the bottom. In the case of cross draft, there is no formal grate and air enters from one side and gas exits from the other side. The designs of updraft gasifier, down draft gasifier and cross draft gasifier are shown in fig. 1(a) to 1(c). In both updraft and down draft gasifiers, providing of horizontal grate with or without grate-clearing system is a standard practice. Recently two more designs of bio-mass gasifiers have come into use. They are fluidized bed gasifiers (Fig.2(a))and entrained bed gasifier (Fig.2(b)). In such gasifiers, air and bio- mass are continuously fed. A limitation of these gasifiers is that these gasifiers are suitable only for loose bio-mass like rice husk. The common problem of all the above bio-mass gasifiers is that the grate provided are horizontal in position which hinders the natural flow of bio-mass. During gasification of the bio-mass, there is formation of clinkers, tars, ash etc. which settle down or adhere to the grate and block the downward free flow of bio-mass. OBJECTS OF PRESENT INVENTION An object of the present invention is to provide a bio-mass gasifier with rotating vertical grate which enables unobstructed downward flow of bio-mass. Another object of the present invention is to provide a bio-mass gasifier which enables self-cleaning of the grate and thus prevents clogging of grate with the resultant and there is unhindered flow of bio-mass. Still another object of the present invention is to provide a bio-mass gasifier wherein a displacement system is provided to continuously remove the ash and other matter from the bottom of burning chamber. STATEMENT OF INVENTION According to this invention there is provided a bio-mass gasifier comprising a gasifier chamber having an opening at the top for feeding of bio-mass and air; a side inlet for air; characterised by a rotating vertical grate with parallel rods arranged vertically to the burning chamber of the gasifier chamber, through which fuel gas produced in the said gasifier chamber, is sucked out; a strut fixed to the said gasifier chamber to provide support to grate; a reduction gear box connected to grate through shaft which runs through the fuel gas passage and has gear box at one end and grate at the other end; a motor coupled to the car box for rotating the shaft; a stuffing box to seal against the leakage of the fuel gas; fuel gas outlet and a displacement system to remove continuously the ash and other matter resulting from the burning of the bio-mass. DESCRIPTION OF FIGURES This invention will now be illustrated with the help of accompanying drawings. It is to be understood that these drawings illustrates an embodiment of the present invention. The concepts and features of the present invention can be embodied in variant embodiments. The drawings are not intended to be taken restrictively to imply any limitation on the scope of the present invention. Fig. 1 (a); shows the updraft gasifier known the art; Fig. 1 (b): shows the downdraft gasifier known in the art; Fig. 1 (c) shows the cross draft gasifier known in the art; Fig.2 (a); shows the fluidized bed gasifier known in the art; Fig.2 (b): shows entrained bed gasifier known in the art; Fig.3 : shows the bio-mass gasifier of the present invention; DESCRIPTION OF INVENTION Referring to fig-3, the bio-mass gasifier of the present invention comprises a gasifier chamber (1) which has an opening (2) at the top for feeding of bio-mass and air. Air is also drawn into the chamber from a side inlet (3) As there is no horizontal grate, the bio-mass moves unhindered, under gravity from the top to the bottom and is discharged from the bottom after combustion. The bio-mass once ignited, continues to bum inside the chamber (1) due to the presence of air. By controlling the amount of air and the flow of bio-mass inside the gasifier chamber (1), fuel gas is produced which is sucked through the vertical rotating grate (4) arranged to one side of the gasifier chamber (1). The grate (4) is supported by a strut (5) fixed to the gasifier (1). The grate is connected to a reduction gear box (6) through a shaft (7). The grate (4) and the connecting shaft (7) are rotated by the motor (8) coupled to the gear box (6). A stuffing box (9) is arranged in the gas outlet (10) through which the shaft (7) enters the gas passage. This stuffing box (9) seals the gas against leakage during rotation of the shaft (7). The gas is drawn out form the gasifier through the vertical rotating grate (4). As the gas formation takes place, tarry particles adhere to the grate in course of time. However due to rotation of grate (4), the ash and the unburnt bio-mass smear over the rotating grate (4) due to the pressure of their own weight. This constant smearing removes all the adhered particles form the grate (4) and this allowing the gasifier to operate continuously. In this way, by keeping the grate vertical in the gasifier (1) and providing for its self-cleaning by rotation by a motor, there is unobstructed flow of bio-mass in the gasifier. The ash and other matter are continuously removed from the bottom of the chamber using displacement system (11). WORKING OF THE BIOMASS GASIFIER The grate is arranged vertical to the burning chamber of the gasifier and it consists of parallel rods. It continuously rotates in vertical plane, as the grate rotates, the biomass moves from top to bottom while getting burned. The moving biomass direction 8B the rotation of the grate, are in two different directions, due to this the moving biomass will greate a brushing action on the grate bars and clears any adhered substances on the grate bars. Due to this reason, the gate will never get clogged enabling continuous operation of gasifier, locating the grate vertically enables the free fiow of biomass without any obstruction. The ash and other matter are continuously removed from the bottom of the burning chamber using a positive displacement system. This type of system allows the disposal of ash, clinkers, unburnt biomass etc easily without these setting inside the burning chamber. It is understood that the present invention is susceptible to modifications among adaptations, and changes by those skilled in the art. Such variant embodiments are intended to be within the scope of the present invention, which is further said forth under the following claims. I CLAIM; 1. A bio-mass gasifier comprising a gasifier chamber (i) having an opening (2) at the top for feeding of bio-mass and air; a side inlet (3) for air; characterised by a rotating vertical grate (4) with parallel rods arranged vertically to the burning chamber of the gasifier chamber (1), through which fuel gas produced in the said gasifier chamber, is sucked out; a strut (5) fixed to the said gasifier chamber to provide support to grate (4); a reduction gear box (6) connected to grate (4) through shaft (7) which runs through the fuel gas passage and has gear box (6) at one end and grate (4) at the other end; a motor (8) coupled to the gear box for rotating the shaft (7); a stuffing box (9) to seal against the leakag,. of the fuel gas; fuel gas outlet (10) and a displacement system (11) to remove continuously the ash and other matter resulting from the burning of the bio-mass. 2. A bio-mass gasifier as substantially described and herein illustrated.

Documents:

0487-che-2003 abstract.pdf

0487-che-2003 claims.pdf

0487-che-2003 correspondence-others.pdf

0487-che-2003 correspondence-po.pdf

0487-che-2003 description(complete).pdf

0487-che-2003 drawings.pdf

0487-che-2003 form-1.pdf

0487-che-2003 form-18.pdf

0487-che-2003 form-26.pdf