Abstract
Leguminous crops are very sensitive to mechanical abuses. Furthermore, chickpea is more prone for mechanical damage due to its germ tip located at protruding structure and are dicotyledonous. Even minor injury to seed affects seed quality adversely. Hence, a conventional cylinder and concave cannot be used to thresh chickpea seed crop. In general, pulse production and productivity is low world over and more so in developing countries (Jeswani and Baldev, 1990). One of the important reasons for low pulse productivity is non- avialability of quality seed. The aviability of quality seed, of chickpea is least i.e. about 2 per cent, among all the major crops of the country. However, it had been reported that about 20- 30 per cent average increase in productivity could be achieved with the use of quality seed (Chowdhary, 2004). Varying operational parameters such as cylinder speed, cylinder-concave clearance, fan speed helped to limited range in threshing but with induced significant amount of visible damages. In light of above facts, the new thresher was developed to thresh chickpea of high seed quality attributes i.e. maximum germination percentage; vigour and viability and minimal visible as well as invisible injuries. These quality attributes are dependent on operational parameters and design parameters of thresher. The optimum operational parameters of cylinder speed, beater type, feed rate, moisture content and concave clearance was 8.94 m/s, Teflon or nylon beater, 200 kg/h, 10 per cent and 14 mm, respectively. The specially configured threshing cylinder using Teflon beater/ threshing element produced seed of germination capacity (98), vigour (1800) and viability (98) coupled with minimal visible breakage (1.17) and internal injury (0.03) with optimum threshing efficiency (98).
Specification
4 DESCRIPTION
Field of Invention:
This invention relates to safe threshing of Chickpea seed crop consisting of
threshing cylinder, cleaning unit, feeding system and frame. It facilitates to enhance
quality seed recovery for further seed multiplication or grain production.
Brief description of the Invention:
The developed thresher is capable to thresh 200 kg of chickpea crop per hour.
Threshed product exhibited more than required quality attributes (Germination
percentage, vigour and viability) than Indian Minimum Seed Certification Standards.
Least percentage of visible and invisible damage was observed in the threshed seed.
Principle involved in the Invention:
Chickpea seed being dicotyledonous and the germ tip being located at the
protruding structure, makes it prone to mechanical injuries. Mechanical threshing of
chickpea induces significant amount of visible damages. Even minor injury to seed
deteriorates the seed quality very fast during storage period. However, the traditional
method of chickpea threshing is linked with lower recovery, time consuming and
higher seed losses. Taking in account these factors, threshing element and its
arrangement on the threshing cylinder has been designed. The type of beater and its
arrangement reduced the impact on seed.
Originality / Novelty of the Invention:
The machine is based on a concept of optimum impact in threshing to produce
threshed product with minimal damage to seed quality in terms of physical seed coat
damage. The higher capacity of machine enables to complete the operation in time
with lesser labour and energy requirement. In turn, reduces cost of operation with
higher seed quality recovery.
Advantages over other known alternatives
There is no seed crop thresher for chickpea available. Presently, chickpea is
threshed by manual beating of plants with stick or trampling under the hooves of
animals or under tractor wheels. It is not only labour intensive, tedious and time
consuming but also causes damage in form of bruising of seed coat or splitting,
resulting in low recovery of quality seed. The post-harvest loss of grains of pulses is
estimated to be around 1.0 million ton per year, which converts into a monetary loss
of around Rs. 1,000 crores (Khuntia el al, 2001). Physically damaged seed are prone
to fungal infection which affects the seed lot quality considerably during storage
(Christensen and Sauer, 1982, Sharma and Thind, 1998). The machine can be used
efficiently for threshing of chickpea seed crop, yielding of higher quality seed with
adequate machine performance (Table-1). The machine can reduce cost of threshing
of chickpea from Rs. 350/q to Rs. 75/q. Also produce higher quality product and
minimal loss to the tune of only 1 per cent in place of 10 per cent, which occurs in
manual threshing (Table-2).The threshed product exhibited significantly higher seed
quality attributes i.e. germination percentage, vigour, and viability than Indian
Minimum Seed Certification Standards. Hence, this thi'esher is also suitable for seed
crop threshing of chickpea.
Table 1: Performance of chickpea (cv. BG-1088 (Kabuli) & cv. BG-1103 (Desi))
threshing by developed thresher.
(Table Removed)
Table 2: Comparative performance and cost analysis of chickpea threshing.
(Table Removed)
The advantages of this machine are:
1. It is simple in operation and requires unskilled labour.
2. The operational parameters e.g. cylinder speed, cylinder concave
clearance, concave grate can be easily adjusted or changed
according to the particular crop lot requirements.
3. It can deliver the threshed product of 98 per - cent germination
capacity and visible damage up to 1.2 per cent only.
4. The capacity of the machine is 200 - 210 kg/h with threshing
efficiency of 98 per cent and seed loss about 1 per cent.
5. There is no known such machines either indigenous or imported for
chickpea seed crop threshing.
Main Frame: It consists of arrangement to fix the cylinder assembly, sieve
assembly, electric motor, safety guards and ball bearing with casing for main shaft.
The frame has also provided with four wheels for transportation of the thresher.
Feeding Chute: A feeding chute fabricated by 16 gauge (1.78'mm) mild steel
with nuts and bolt arrangement of attaching it to main body. Safety provisions have
taken into consideration in configuration of feeding chute.
Threshing Cylinder: Thresher consists Peg tooth type cylinder using six mild
steel flats. On each flat having seven 18 mm diameter holes 48 mm apart. The
position of holes on different m.s. flats were arranged such that they are staggered.
These threaded hole carry threaded threshing element/beater; made of nylon and
reinforced by embedding 6 mm diameter steel tempered rod to withstand load during
threshing operation. The beaters is of diameter: 18 mm and length: 130 mm and
threaded throughout the length with 2.12 mm pitch. With the help of nuts and spring
washers the beaters are fixed into the cylinder. Cylinder-concave clearance can be
adjusted minutely by positioning of beaters in accordance with the requirement.
Concave: Semicircular concave covering 140 degree angle of the cylinder
circumference has been used which is fabricated with square iron bars 6 mm and mild
steel flat 30 x 6 mm. The concave is removable and it can be slided into a guide of
cylinder concave assembly. The removable feature, facilitate to change the concave as
per crop requirement. To hold the concave at its specified position, it has provision of
locking arrangement of nuts and bolt at the one end.
Blower: There are two centrifugal, straight blade blowers for cleaning
threshed mass. The two blowers are arranged in series in flow path of threshed
material on sieve. First blower removes coarse light impurities-where as second
separates fine/light impurities of threshed mass.
Sieve Assembly: There are two sieves placed on the mainframe of thresher
paced with on to arrangement. Top and bottom screen opening are 11 mm; round and
5 mm; slotted, respectively. The frame of the sieve is fabricated with 25x25x3 mm
size angle iron, provided space of 1000 x 600 mm for placement of sieves. There is
slope of 8 degree towards seed discharge for bottom sieve whereas; top sieve had a
slope of 10 degree. The sieve frame is hanged with help of four adjustable hangers of
nuts and bolt arrangement made of m.s. square to main frame with ball bearing at the
end. There is provision of fine adjustment of slope of sieve. An eccentric crank
mechanism is used to provide oscillation of sieve. The pitch of oscillation can also be
adjusted.
References:
Chowdhary R K (2004) Impact of quality seed and seed technoiogy research in
transformation of agriculture in India. Proc National conference on Seed; a
global prospective, pp 34. NASC, New Delhi.
Christensen C M and Sauer D B (1982) Microflora in storage of cereal grains and their
products. In: Christensen C M (ed) American Association of Cereal Chemists .
pp 102-105. St. Paul Minn, New York.
Jeswani L M and Baldev L (1990) Advances in pulses production technology. ICAR,
New Delhi.
Khuntia S K, Sahu A K and Acharya CR (2001) Report on performance of power
operated pulse thresher in Orissa, Regional Research Laboratory, Council of
Scientific & Industrial Research, November.
Sharma R C and Thind T S (1998) Microbial spoilage of stored grains and its
management. In: T.S. Thind (ed). pp 405-421. Diseases of Field Crops and
Their management.
5. CLAIMS
We claim
I. the design of the chickpea thresher.
II. the threshing element/beater made of Nylon and reinforced with iron &
Teflon. The beater diameter was 18 mm and length 130 mm. Nylon beater was
reinforced by embedding 6 mm diameter steel tempered rod to withstand load
during threshing operation. All the beaters had thread throughout the length
with 2.12 mm pitch. The beaters were arranged cylinder made of m.s flat in
staggered fashion to improve combing action and reduce injury to seed.
III. the threshing operational parameters i.e. concave clearance: 14 mm, moisture
content of grain: 10 per cent, cylinder speed: 8.94 m/s and feed rate: 200kg/h.
IV. the use of the thresher for chickpea seed crop threshing.s
