INTEGRATED APPARATUS FOR SEPARATING AND PROCESSING OF
MUNICIPAL SOLID WASTE
FIELD OF THE INVENTION
[0001] The field of the present invention relates an apparatus for
separating wet organic waste and dry fraction of mixed municipal solid waste and
processing of organic waste for producing odor free uniform compostable product. More
specifically, the present invention provides an integrated apparatus for separating and
processing of mixed municipal solid waste.
BACKGROUND OF THE INVENTION
[0002] The population of the world is increasing at a rapid rate and the
number of people migrating to small and big cities has further increased in recent years.
This may be due to higher comfort and earning opportunities.
[0003] It is worth noting that millions of tons of waste are generated every
year from these small and big cities. The disposal of waste is a big problem. For example,
it is estimated that 380 million Indians living in 6000 small or big cities generate about
200,000 tons of waste every day and urban population of India generates about 70 million
tons of waste every year. It is estimated that waste generation by urban India shall grow
more than five times to 370 million tons by 2030.
[0004] It is further observed that significantly less percentage of generated
waste is collected and very small portion of collected waste undergoes processing.
Irrational conventional open dumping continues to be prevalent mode of disposal and
sanitary landfills are yet to be maintained. The cities resort to indiscriminate dumping of
domestic, commercial, industrial and medical wastes in low lying areas. This leads to
contamination of surface and ground water by the leachate and contamination of air
greenhouse gases which get generated by decaying waste. There is requirement of 1240
hectares of additional dumping land every year for such unhygienic waste handling.
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[0005] Open storage and dumping creates unhygienic condition in and
around urban areas. The unsightly condition in and around the cities also poses serious
threat to health and well-being of people residing in the cities.
[0006] Open waste collection centers on road sides attract rats, cows, pigs,
street dogs and number of insects like house fly, cockroaches and mosquitoes. WHO
concluded that these Municipal Solid Waste (MSW) fed rodents spread 22 types of
serious diseases.
[0007] Managing municipal solid waste is one of the most essential
services which often fail due to rapid urbanization along with changes in the waste
quantity and composition. New products wrapped with new packaging materials, new
living standards, change in income and affluent people life style has increased the waste
quantity. Average waste generation by affluent people is ten times more than poor’s.
[0008] Adding to complexity of waste disposal, mixed waste from homes
and streets store up in street bins, dhalaos or open site because door to door collection
and segregation at source is not yet functional at an optimal level. Moreover, rag pickers,
who pick up recyclables from waste in many areas of the country, are considered as blot
on society because rag pickers make storage site uglier by scattering waste, while taking
out valuables. Accordingly, a social stigma is attached to the waste collection process. To
add to that rag pickers, despite their hard work, are unable to thoroughly recover plastic,
paper, metal, glass, e-waste and other materials having commercial value because nondegradable
waste intermingle with degradable waste making recovery impossible.
[0009] To add to the problems, openly scattered waste produce foul smell
and unsightly images because open anaerobic (in absence of oxygen) degradation of
moisture rich organic food waste generate foul smell. It is well known that garbage
affects public health because rodents and bugs attracted toward organic food waste and
spread diseases.
[0010] In the country, municipal authorities often fail in their prime duty
of solid waste management because they are unable to make pace with rapid urbanization
and new living standards results in growing waste quantity.
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[0011] Accordingly, waste from storage sites are transported to far away
dumping sites or centralized waste processing facilities because municipal bodies don't
have appropriate technologies to process un-segregated waste at decentralized
locations(waste storage sites or transport stations).It is estimated that 90% of the
collected waste is dumped in landfills because of inefficient recyclable extraction, nonprocessing
of biodegradable waste and non-utilizations of combustible waste. Most of
landfills in India are working over capacity because it is difficult to have additional
landfill sites due to nimby(not in my back yard) syndrome.
[0012] Indiscriminate land filling of biodegradable waste pollutes our
land, water and air. Recyclables and fuels are resources, dumping valuables in landfills
by no mean an intelligent effort but authorities are unable to maintain sanitary landfills
till waste is processed.
[0013] The waste processing plants are not working well because
Compost plants are not getting segregated biodegradable wastes and incarnation plants
faces public resistances due to pollution issues.
[0014] Considering the above problems, there is a need to design various
apparatuses for sorting and processing of the waste. There is an imperative need of
designing apparatuses for biological decomposition or degradation of the waste.
Especially, there is a need to develop apparatus which is integrated and can easily be
placed in the urban landscape in a decentralized manner. Such apparatus should be
modular, easy to operate, transportable, lower operational cost and easy to install at
limited small area.
SUMMARY OF THE INVENTION
[0015] The general purpose of the present invention is to provide an
integrated apparatus for separating and processing the solid waste to produce recyclables,
Refuse Drive Fuel (hereinafter referred as “RDF”) and an odor free uniform product
(Compost). The apparatus can be placed in decentralized locations in modular manner.
[0016] The apparatus includes a rotary cylindrical drum capable of being
rotated by electro-mechanical energy. Further, the apparatus includes two rotary
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cylindrical screens. The inner rotary cylindrical screen is mounted within the rotary
cylindrical drum and outer rotary cylindrical screen being connected with the rotary
cylindrical drum at a discharge opening of the rotary cylindrical drum. Further, both the
rotary cylindrical screens comprise a plurality of sieves capable of separating the solid
waste based upon the variable sizes. Furthermore, inner rotary screen is capable of
segregating raw mixed municipal waste fed in the apparatus while waste larger then sieve
sizes passes through discharge end and waste smaller than sieve size settled in rotary
cylindrical drum.
[0017] In the integrated apparatus, rotary cylindrical drum work as bio
decomposing section. An aerobic culture of micro-organisms is added for fermentation
and decomposing of settled separated organic solid waste in the decomposing section
that is the rotary cylindrical drum, wherein the fermenting and decomposing of the
separated solid waste produces an odor free product(Compost), thereby providing an
integrated apparatus.
[0018] In an embodiment of the present invention, the fermenting and
decomposing of the organic solid waste in aerobic conditions results in drying of the said
organic solid waste by heat generated during the fermenting and decomposing of the said
waste by the culture of micro-organisms.
[0019] In an embodiment of the present invention, the rotary cylindrical
drum and the inner and outer rotary cylindrical screens rotate simultaneously by a
rotating assembly, wherein the rotation of the rotary cylindrical drum results in faster
microbial activity due to tumbling of the organic solid waste.
[0020] In an embodiment of the present invention, outer rotary cylindrical
screen is provided on discharge of rotary cylindrical drum, this outer rotary cylindrical
screen is capable of segregating processed odor free product coming out of rotary
cylindrical drum.
[0021] In an embodiment of the present invention, the apparatus further
comprises a rugged stand adapted to support the cylindrical drum, the stand having a
plurality of legs for supporting the said rotary cylindrical drum. The legs provide an
inclination to the said supported rotary cylindrical drum at the discharge opening. The
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said inclination allows the waste to slide through the discharge opening by force of
gravity.
[0022] This together with the other aspects of the present invention along
with the various features of novelty that characterized the present invention is pointed out
with particularity in claims annexed hereto and forms a part of the present invention. For
better understanding of the present invention, its operating advantages, and the specified
objective attained by its uses, reference should be made to the accompanying descriptive
matter in which there are illustrated exemplary embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The advantages and features of the present invention will become
better understood with reference to the following detailed description and claims taken
in conjunction with the accompanying drawing, in which:
[0024] Fig. 1 illustrates a perspective view of the integrated apparatus,
according to various embodiments of the present invention;
[0025] Fig. 2 illustrates a side view of the integrated apparatus for
separating and processing municipal solid waste, according to various embodiments of
the present invention;
[0026] Fig. 3 illustrates a discharge end view of the integrated apparatus,
according to various embodiments of the present invention;
[0027] Fig. 4 illustrates a top view of the integrated apparatus, according
to various embodiments of the present invention, and
[0028] Fig. 5 illustrates a cross sectional view of the integrated apparatus
across line AA as shown in Fig. 4, according to various embodiments of the present
invention.
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[0029] Like numerals refer to like elements throughout the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The foregoing descriptions of specific embodiments of the present
invention have been presented for purposes of illustration and description. They are not
intended to be exhaustive or to limit the invention to the precise forms disclosed, and
obviously many modifications and variations are possible in light of the above teaching.
The exemplary embodiment was chosen and described in order to best explain the
principles of the invention and its practical application, to thereby enable others skilled in
the art to best utilize the invention and various embodiments with various modifications
as are suited to the particular use contemplated.
[0031] The terms “a” and “an” herein do not denote a limitation of
quantity, but rather denote the presence of at least one of the referenced item.
[0032] The terms “having”, “comprising”, “including”, and variations
thereof signify the presence of a component.
[0033] The present invention relates to an integrated apparatus for
separating wet organic waste from dry and further processing of wet organic waste to
produce an odor free compostable product. The integrated apparatus is designed and
invented to separate mixed municipal solid wastes of variable types and variable sizes
and process the separated organic solid wastes by microbial activity. The said integrated
apparatus shall now be explained in detail in conjunction with Figs. 1-5.
[0034] Referring to Fig. 1, there is shown a perspective view of the
integrated apparatus 100 for separating and processing of municipal solid waste.
[0035] The term ‘waste’ as used throughout the description refers to
municipal waste, mainly including food waste from kitchen waste (50%) mixed with
plastic, paper, cloth, glass, metals, dust, construction waste etc.
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[0036] The terms “integrated apparatus” and “apparatus” are being used
interchangeably throughout the description of the present invention.
[0037] It will be obvious to a person skilled in the art that the Municipal
solid wastes may belong to any category such as -
1. Biodegradable waste: moisture rich food, kitchen and horticulture waste
(vegetables, flowers, leaves, fruits, food residues).
2. Recyclable material: paper, glass, bottles, cans, metals, certain plastics, etc.
3. Inert waste: construction and demolition waste, dirt, rocks, debris, and the like.
4. Combustible wastes: waste clothing, Tetra Packs, waste plastics, and the like.
5. Domestic hazardous waste: medication, e-waste, paints, chemicals, light bulbs,
fluorescent tubes, spray cans, fertilizer and pesticide containers, batteries, shoe
polish etc.
[0038] However, the present invention should not be construed to be only
limited to municipal waste, and could be used for size separating and processing of
organic content of any solid waste, domestic or industrial.
[0039] In the said view, there is shown a rotary cylindrical drum 110
(hereinafter referred as “drum 110”) placed on a rugged stand 135. The rugged stand 135
comprises a plurality of legs 130 for supporting the integrated apparatus 100. The
function of the rugged stand 135 is to provide a support to the apparatus 100 and
particularly drum 110.
[0040] In one embodiment of the present invention, in the said rugged
stand 135 there are provided a plurality of tyres 125 for rotating the apparatus 100 and
particularly drum 110. This plurality of tyres 125 is mechanically powered (not shown in
the figure) for rotating the apparatus 100. Heights of legs 130 are designed in a manner to
provide an inclination necessary for allowing the waste to slope through the drum 110
during processing of said waste.
[0041] The integrated apparatus 100 is positioned in an inclined position
“I” which is shown in Fig. 2 and will be explained later.
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[0042] An inner rotary cylindrical screen 105 (hereinafter referred as
“inner screen 105”) is mounted within the drum 110. This inner screen 105 is adapted to
receive municipal solid waste from feed end 107 whereas it discharges the larger waste
(which could not be sieved through the sieves of the inner screen 105) from the discharge
opening 115 at the other end 108 (refer Fig. 2).
[0043] In the said apparatus 100, there is also provided an outer
cylindrical screen 145 (hereinafter referred as “outer screen 145”) which further consists
of sieves for separating the odor free product generated after processing from the drum
110.
[0044] In one embodiment, the outer screen 145 is attached with the drum
110 towards the discharge opening 115 as shown in the Fig. 1. In another embodiment,
the screen 145 has an abutting length greater than the drum 110 for providing an
elongated discharge opening.
[0045] In an embodiment, the inner screen 105 is a trommel screen having
a plurality of sieves 140 (refer Fig. 5) for separating the solid waste and collecting the
separated solid waste into the drum 110. Similarly, the outer screen 145 also comprises
sieves for separating the processed odor free product generated in the drum 110 for
further segregation and usage.
[0046] More particularly, the solid waste passing through the sieves 140
of the inner screen 105 are generally organic in nature and are biodegradable waste.
These separated solid waste flow through the trommel screen as it rotates, and percolates
into the drum 110 to collect therein. The collected waste is layered in such a manner that
they don’t overflow through the inner screen 105. This means that there always remains a
gap between the upper layer of the waste collected in the drum 110 and the inner screen
105 so that the separated waste lying in the drum 110 does not return to the inner screen
105.
[0047] In the inner walls of the said drum 110, there is provided internal
blades (not shown) extending from the inner walls of the said drum 110. These internal
blades are responsible for lifting the solid waste when they fall back to the base by
gravity.
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[0048] In an embodiment, the drum 110 and the inner screen 105 are
subjected to constant rotation simultaneously. Such constant rotation, lifting and falling
of waste in the drum 110, results into breaking, mixing and homogenizing organic
wastes. Dense, abrasive items in waste such as glass or metal help in accelerating the
breakdown of softer materials, resulting in considerable size reduction of biodegradable
materials.
[0049] In the inner screen 105, sieves 140 of sizes 100 mm are provided.
At the very beginning, when solid waste enters into the inner screen 105 via a belt
conveyor (not shown), the waste smaller than 100mm size are dropped via the sieves 140
and waste larger than 100 mm get discharged through the discharge opening 115.
[0050] In an embodiment of the present invention, the organic waste
which is bio dried and shredded in rotary cylindrical drum 110, are discharged through
slits 150 provided at the discharge end of rotary cylindrical drum 110. Processed waste
coming out of slits 150 falls on outer screen 145 for further segregation and sorting.
[0051] In an embodiment of the present invention, processed waste falls in
outer rotary screen 145 further size separated through trommel screen 145 with sieves
155 of size 20 mm. Material below 20 mm falls through the sieve and material above
20mm discharged through outlet 118.
[0052] In an embodiment of the present invention, the drum 110 along
with the inner screen 105 and outer screen 145 are adapted to constantly rotate together.
In general, they rotate at 2 to 5 RPM. The diameter of the drum 110 is taken as 2 meters
whereas the diameter of the inner screen 105 is taken as 1 meter and the diameter of outer
screen 145 is taken as 2.5 meter. Size of the sieves in inner screen 105 is taken as 80-
120mm and size of the sieves in outer screen 145 is taken as 8-25mm. The processing
capacity of the apparatus 100 is 5 tons/day of mixed waste.
[0053] The rotation of the inner screen 105 and outer screen 145 are
synchronized with drum 110. Additionally, the rotation of the drum 110 results in faster
microbial activity due to tumbling of the organic solid waste collected in the drum 110.
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[0054] In an embodiment of the present invention, the apparatus 100
includes a plurality of steel rings 120 fitted around the said drum 110. The steel rings 120
are also visible in Figs. 2 & 4. The steel rings 120 are capable of holding the drum 110 on
the support stand 135 and rotate through tyres 125.
[0055] It will be obvious to a person skilled in the art that the product
produced by the mechanical and biological process, may vary in their physical and
chemical properties and further separation is required to distinguish recyclables or
compostable or energy rich refuse drive fuel (RDF) or inert.
[0056] Referring again to Fig. 1, there are nails (not shown) fixed in the
interior surface of inner screen 105 near the feed end 107 to break open any bags in the
waste material.
[0057] Once the solid wastes are dropped via the sieves into the drum 110,
the said dropped and separated solid waste are subjected to conditions for aerobic biodegradation.
[0058] In an embodiment of the present invention, the apparatus 100
includes drum 110 to work as mechanical biological treatment (MBT) for processing the
solid waste being segregated by the inner screen 105 and further outer screen 145 is
provided to segregate material treated through drum 110.
[0059] Accordingly, the apparatus 100 includes an outer screen 145 for
further size separation of waste bio-decomposed in rotary cylindrical drum 110.
[0060] In an embodiment, the bio-decomposition in rotary cylindrical
drum 110 is natural biological activities by naturally occurring microorganisms, such as
bacteria and fungi, for decomposing organic food waste. To accelerate decomposition
aerobic bacterial culture are added into the drum 110. The organisms responsible for
decomposition consume organic materials and oxygen in order to grow and reproduce. In
the process, they produce carbon dioxide, water vapors and heat that are vented through
holes in inner screen 105.
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[0061] The said integrated apparatus 100 has a special drying capability.
In the apparatus 100, the drying of the wastes relies on biological activities of
microorganisms, bacteria and fungi, accelerated by culture to reduce the moisture content
of wet waste.
[0062] The drying effect is achieved because of the microbial activity as
well as aeration due to bio-decomposition in the drum 110 of the said integrated
apparatus 100. As the microorganisms feed on the nutrients, carbon (C), nitrogen (N) and
other elements available in the waste, heat is produced as part of the metabolic activities.
This heat, assisted by air, is used to evaporate the excess moisture. The energy necessary
for evaporation is provided mainly by aerobic biodegradation. Decomposers in aerobic
digestion process require oxygen to work their magic. The oxygen consumed during
decomposition is continually replaced through holes or sieves in the inner screen 105 and
through slits 150.
[0063] In an embodiment, the aerobic decomposition of organic matter by
micro-organisms raises matrix temperatures in the drum 110 to the thermophilic range
(55-68°C). Exothermic biochemical transformation helps in drying of organic material
without applying external source of heat.
[0064] In other words, heat generated by the microorganisms during
composting raises the temperature of the decomposing materials in the section 142 of the
drum 110. Material temperatures in a drum often rise above 50°C and sometimes exceed
70°C. High temperatures have the advantage of killing pathogens (microorganisms that
cause disease) and weed seeds. The micro-organisms require oxygen in aerobic digestion.
The oxygen consumed during decomposition continually replaced through holes in screen
105 and slits 150.
[0065] In addition, continuous turning and tumbling in rotating drum 110
creates path way for aeration through material and helps to loosen the compacted
particles and improves aeration. Therefore, constant turning/rotation of drum 110 helps in
faster decomposition of material, improves porosity and oxygen content in material.
Constant turning in rotating drum 110 also helps in removing moisture and redistribute
cooler and hotter portions of the material. Rotary movement of drum 110 not only breaks
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down biodegradable waste, but they also increase the rate of biodegradation. Decomposer
organisms work on the surface of particles. Rotating drum 110 break down organic
material in smaller particles offer more surface area for decomposition. As decomposition
progresses, particles shrink in size and tend to compact.
[0066] From start to finish, the bio degradable waste in the section 142 of
the drum 110 transforms from a diverse mixture of individual ingredients to a uniform
material. The waste materials remain in the drum for 24 to 48 hrs. After this period,
multiple slits 150 provided at discharge end are opened for falling of waste from drum
110 to outer screen 145 for screening and discharge and for further segregation on the
basis of their chemical properties.
[0067] Moreover, from these slits 150, waste falls on outer screen 145.
The outer screen 145 comprises sieves of size 12-30mm. While passing through outer
screen 145, the said processed waste is further separated in two different size segments.
Further, segregation from these two fractions for recyclables or other recovery can be
done manually or otherwise.
[0068] For example, many solid contaminants can more readily be
separated after passing through the apparatus 100. Breakdown of soft organic matter
facilitates further separation of the said waste. It is much easier for people to separate
materials from dried and crushed organic waste of similar size, as small items are not
buried under large uneven stinky waste. Finally, the waste is segregated into three
fractions, namely:-
1. Recyclables, RDF and inert of size of above 100 mm,
2. Recyclables, RDF and inert of size between 20 mm and 100mm, and
3. Compostable organic waste of size of below 20mm.
[0069] As a final product derivable from the said integrated apparatus
100, the process employed in the section 142 of the drum 110 reduces waste quantity by
70-90%. Further, the integrated apparatus 100 separates non-degradable from biodegradable.
Also, the integrated apparatus 100 helps in Recovery of Recyclables and
RDF in much more easy, efficient and hygienic conditions.
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[0070] After processing with the integrated apparatus 100, the segregated
paper, metals, plastic, glassware, RDF & other valuable materials go to recyclers or
consumers. Further, organic wastes of less than 20mm shall move to consumers or
compost plant. Moreover, after recovery of valuables only 10-30% inert is left for
sanitary land filling.
[0071] Fig. 4 provides a top view of the apparatus 100. In the said figure,
there is shown a cross sectional line AA passing through the center of the apparatus 100.
In Fig. 5, there is shown a cross sectional view across the line AA. The various
components of the apparatus 100 are visible in the said cross section view of the
apparatus. Additionally, a slits 150 are also shown towards the end of the drum 110.
Through these slits 150, the processed odor free product passes through and dropped into
the outer cylindrical screen 145.
[0072] The integrated apparatus 100 as disclosed has various advantages.
The said integrated apparatus reduces the burden of municipal authorities as efficient
recyclable recovery, moisture removal, size reduction and compaction of waste results in
substantial reduction of collection, transportation and disposal cost.
[0073] Municipal bodies can install the apparatus to process waste in
different parts of city as required. Therefore, the apparatus diminishes land requirement
for additional landfill and centralized waste processing plants.
[0074] Moreover, said apparatus when used can convert waste collection
centers into material recovery/processing facilities with installation of the said apparatus
at decentralized locations near the origin of waste generation.
[0075] Accordingly, the said apparatus is a tool to municipal bodies to get
rid of garbage menace. The apparatus requires very much less space and hence can be
installed at waste storage sites in heavily populated areas of cities.
[0076] The apparatus shall be acceptable to public as open waste storage
shall be replaced by closed system. The said apparatus can finish ugly open storage and
foul smell from cities. Moreover, the said apparatus minimizes risks of public health as
rodents can be ignored and waste turns to compost.
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[0077] Air water and land pollution reduces with reduction of waste with
the apparatus. Further, the decentralized waste management process by using the said
apparatus can involve rag pickers and waste collectors in an organized way. By the aid of
apparatus there shall be substantial increase in the income of rag pickers and scavengers
most deprived classes of society.
[0078] The foregoing descriptions of specific embodiments of the present
invention have been presented for purposes of illustration and description. They are not
intended to be exhaustive or to limit the present invention to the precise forms disclosed,
and obviously many modifications and variations are possible in light of the above
teaching. The embodiments were chosen and described in order to best explain the
principles of the present invention and its practical application, and to thereby enable
others skilled in the art to best utilize the present invention and various embodiments with
various modifications as are suited to the particular use contemplated. It is understood
that various omissions and substitutions of equivalents are contemplated as circumstances
may suggest or render expedient, but such omissions and substitutions are intended to
cover the application or implementation without departing from the spirit or scope of the
present invention.

CLAIMS
What is claimed is:
1. An integrated apparatus for separating and processing of Municipal solid
waste, the apparatus comprising:
a rotary cylindrical drum capable of being rotated by electro-mechanical energy;
an inner rotary cylindrical screen mounted within the rotary cylindrical drum;
an outer rotary cylindrical screen being connected with the rotary cylindrical
drum at a discharge end of the rotary cylindrical drum,
wherein both the inner and outer rotary cylindrical screens comprise a plurality of sieves
capable of separating the solid waste based upon the variable sizes of the solid waste, the
said inner screen capable of segregating the separated solid waste in the rotary cylindrical
drum for collection of the said waste in the said rotary cylindrical drum and capable of
passing larger waste through the discharge opening of the said rotary cylindrical screen;
and
a bio-decomposing section provided in the rotary cylindrical drum, the biodecomposing
section comprising a culture of micro-organisms for fermenting and
decomposing of separated organic solid waste in the rotary cylindrical drum,
wherein the fermenting and decomposing of the separated organic solid
waste produce an odor free compostable product which is passed through the
outer rotary cylindrical screen for further segregation, thereby providing an
integrated apparatus.
2. The apparatus as claimed in claim 1, wherein the rotary cylindrical drum
and both the inner and outer rotary cylindrical screens rotate simultaneously by a rotating
assembly.
3. The apparatus as claimed in claim 1, wherein the rotary cylindrical drum
comprises a plurality of slits for discharging the odor free compostable product into the
outer rotary cylindrical screen.
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4. The apparatus as claimed in claim 1, wherein the fermenting and
decomposing of the solid waste results in drying of the said solid waste by heat generated
during the fermenting and decomposing of the said waste by the culture of microorganisms.
5. The apparatus as claimed in claim 1, wherein along with mechanical
biological treatment to organic waste said rotary cylindrical screens size separates waste
in three fractions simultaneously by rotation of the rotary cylindrical screen.
6. The apparatus as claimed in claim 5, wherein the said rotary cylindrical
screen is a trommel screen.
7. The apparatus as claimed in claim 5, wherein the separated organic solid
waste is fermented and decomposed by the culture of micro-organisms in the rotary
cylindrical drum.
8. The apparatus as claimed in claim 7, wherein rotation of the rotary
cylindrical drum results in faster microbial activity due to tumbling of the organic solid
waste in the rotary cylindrical drum.
9. The apparatus as claimed in claim 1 comprising a rugged stand adapted to
support the cylindrical drum, the stand having a plurality of legs for supporting the said
rotary cylindrical drum.
10. The apparatus as claimed in claim 9, wherein the plurality of legs have a
length to provide an incline to the said supported rotary cylindrical drum at the discharge
opening.
11. The apparatus as claimed in claim 10, wherein the said inclination allows
the waste to slide through the discharge opening by force of gravity.
12. The apparatus as claimed in claim 11 comprising a plurality of steel rings
fitted around the said rotary cylindrical drum, the steel rings are capable of holding the
drum on the support stand and rotate the drum.
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13. The apparatus as claimed in claim 1, wherein the inner rotary cylindrical
screen has an abutting length greater than the drum for providing an elongated discharge
opening.
14. The apparatus as claimed in claim 1, wherein both the inner and outer
rotary cylindrical screens comprise a plurality of sieves having varying sizes.