Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Design and Development of Onion and Garlic Detopper (2019-20)

M A Hoque
Farm Machinery & Postharvest Process Engineering Division, BARI, Joydebpur, Gazipur, Bangladesh

M A Hossain
Farm Machinery & Postharvest Process Engineering Division, BARI, Joydebpur, Gazipur, Bangladesh

M A Mottalib
Farm Machinery & Postharvest Process Engineering Division, BARI, Joydebpur, Gazipur, Bangladesh

S Brahma
Farm Machinery & Postharvest Process Engineering Division, BARI, Joydebpur, Gazipur, Bangladesh

Abstract/ Executive Summary:

Onion and garlic are important spice crops in Bangladesh. After harvesting onion or garlic, the edible bulb portion is separated from the inedible stem by cutting or detopping (leaving only 20–40 mm stem with the bulb). This cutting is usually done manually, one by one, mostly using a sharp kitchen knife (boty) which is laborious, time consuming and costly. Two models (Model 1 and Model 2) of power operated detopper was designed and fabricated at the Farm Machinery and Postharvest Process Engineering Division of Bangladesh Agricultural Research Institute during 2019–20. The detoppers were made with locally available materials and operated with a 0.37 kW electric motor. Important parts of the machine were feeding table, conveyor, cutter and outlet. The detopper was developed and tested in the laboratory during 2019-20. The capacity of the detopper of model 1 and model 2 were 29.35 and 65.10 kgh-1, respectively. The capacity of Model 1 and Model 2 were found as 53% and 77% higher than the manual detopping, respectively. However, for increasing the capacity of those machines, the feeding system along with other technical mechanism will be changed or improved in year.

Keywords: Detopper, Onion, Garlic

Location: Lab. of FMPE Division, and Regional Spices Research Station, BARI, Gazipur

Start Date: 00-00-2019

End Date: 00-00-2020

Program Area: Farm Mechanization

Commodity: Harvester, Onion, Garlic

Objectives:

a. Design and fabrication of the detopper, and

b. Performance testing of the developed machines

Methodology:

Two models of onion and garlic detopper were designed and fabricated at the workshop of the Farm Machinery and Postharvest Process Engineering Division of Bangladesh Agricultural Research Institute, Joydebpur, Gazipur during the period of 2019-20. One machine (Model -1) was design for single bulb feed of onion that need single operator and one helper and another (Model-2) was designed for lot feeds with two operator and 2–3 helpers. The disc and blades with shearing action were used for Model 1and Model 2, respectively. Description of the Model 1: The materials used for the fabrication of different parts of the machine were MS angle bar, MS flat bar, MS rod, MS sheet, MS shaft, rubber sheet, ball-bearing, and miscellaneous small spares. The functional parts of the machine are (1) Power source; (2) Power transmission system; (3) Feeding table; (4) Conveyor; (5) Cutter; and (6) Outlet chutes. The functions of these parts are described briefly as: 1. Power source: A 0.37 kW, 1400 rpm single phase electric motor was used as the source of power; 2. Power transmission: The power transmission system is shown in Fig. 2. In the first step, rpm of motor was stepped down from 1400 to 105 in the main shaft of the reducer gear box. The rpm of the secondary was 105 rpm. The conveyer and rotating disk speed was 105rpm; 3. Feeding table: A feeding tray was made by MS sheet with the dimension of 600×560×550 mm; 4. Conveyor: A 610 mm long conveyer was made with chains to convey the onion (with stem) to the cutting disk. Conveyer was made of four chain. Each chain was 35 mm long; 5. Cutter: Kepner et al., (1982) reported a common way of applying cutting force is by means of two opposed shearing elements which meet and pass each other with little or no clearance between them. Following that principle, a double disk cutter was designed and fabricated from High carbon SS sheet plate. Double disk cutter cuts the stems in shear mode. Diameters of both the disks were 190 mm and thickness was 3 mm. The disks were vertically placed; and 6. Outlet Chutes: Two outlet chutes were fabricated with MS sheet. One chute was designed for collecting the onion whose dimensions were 230 x 160 x 95 mm. The other chute was to collect stem and dimensions were 420 x 225 x 80 mm. Description of the Model 2: The materials used for the fabrication of different parts of the machine were MS angle bar, MS flat bar, MS rod, MS sheet, MS shaft, rubber sheet, ball-bearing, and miscellaneous small spares. The functional parts of the machine are (1) Power source; (2) Power transmission; (3) Feeding fingers; (4) Cutter bar; (6) Outlet chutes. The functions of these parts are described briefly as: 1. Power source: A 0.37 kW single phase electric motor was used as the source of power; 2. Power transmission: The power transmission system is shown in Fig. 4. In the first step, rpm of motor was stepped down from 1400 to 756 in the main shaft of the reducer gear box. A reducer gear box was used to reduce the rpm from 756 to 175 on the cutting blade bar; 3. Feeding finger: The feeding finger were made of MS rod maintaining a uniform spacing of 15mm. The feeding fingers were located in both side maintaining a 500 mm space in middle of the machine. In each side the width of the feeding finger was 360 mm; 4. Cutter bar: The main part of the detopper is cutting system. The cutter was taken with principle of share cutting as same as used in rice reaper. The width of the cutter bar was 1200 mm but the effective width of the cutter bar was (360 + 360) 720 mm. Number of v-shaped cutter were 15 which were placed upon same numbers of base of the cutter. Clearance between the upper and lower shearing element was 0.5 mm; and 5. Outlet Chutes: Two outlet chutes were fabricated with MS sheet to collect onion or garlic after detoppig. The dimensions were 570 x 440 mm. The machine performance could not be evaluated during rabi season of 2019-20 due to COVID 19. Performance evaluation was done during summer season of 2019-20 at the Regional Spices Research Station, Gazipur using summer onion (Fig 5).

Source of Information: Annual Research Report 2019-2020, BARI, Gazipur, Bangladesh

Article Link (Online Journal):

Funding Source:

Budget:

Total Budget (Tk.) :

Achievement/Findings:

Two model of detopper for onion and garlic were designed and fabricated. The capacity of the detopper of model 1and model 2 were 29.35 and 65.10 kg h^-1, respectively. The capacity of Model 1 and Model 2 were 53% and 77% higher than the manual detopping. However, for increasing the capacity of those machines, the feeding system along with other technical mechanism will be changed or improved in the next year.

Knowledge Management: Report/Proceedings