Screw Extruder Biomass Briquetting

Size: px

Start display at page:

Download "Screw Extruder Biomass Briquetting"

Stanley Hood
6 years ago
Views:

1 Mridaney S. Poudel et al.: Screw Extruder Biomass Briquetting Screw Extruder Biomass Briquetting Mridaney S. S Poudel, Krishna R. R Shrestha* Shrestha and Ramesh M. M. Singh Abstract The The paper describes an ongoing research activities carried out by the Centre for Energy and Environment Nepal (CEEN) under the project entitled Production of biomass briquetted fuel based on agroagro- forestry wastes as substitute for fuel wood in domestic and industrial sector of Nepal Nepal ID: RENP RENP 172 funded by NORAD and managed by Renewable Nepal Programme of Kathmandu University and SINTEF, SINTEF, Norway. Nepal still relies heavily on traditional fuel resources such as fuel wood, agro-residues agro residues and animal dung, which meet over 88% of the energy demand. To relieve the pressure on these traditional fuels, biomass briquetting was introduced in Nepal Nepal in early 1980 s as a promising to produce briquette fuels. These industries could not survive because of technical as well as marketing problems. During those days, the technologies used by those industries were very costly and complicated. It includes equipment for drying the raw material and transporting system as well. This package requires a big space for installation and operation. Further the screw of the briquetting system wears out very quickly due to the abrasive nature of the raw material material rice husk containing more than 19% ash. A comparative study of the of rice husk briquettes from the Taiwanese machine with that of the simple extruder type of briquetting unit modified by the project is presented.8 Index terms: rice husk, fuel briquettes, screw extruder, briquetting machine I. INTRODUCTION M HEPI Briquette Udhyog Pvt. Ltd. is the only surviving briquette industry in Nepal which was established in 2050 B. S. in Kawasoti, Nawalparasi and has been continuously producing the rice husk briquette. It ran eight briquetting units/ machines briquette lowered. The Industry has been operating only two extruder units/machine at present. The existing plant requires a big plot of land and big shed to house it. In addition to the cost of plant machinery and equipment, this increases the establishment cost of the industry, making briquetting business very expensive. Some Details of the Industry TABLE I MAJOR TECHNICAL COMPONENTS, POWER CONSUMPTION AND FLOW OF MATERIALS Name of Factory Mhepi Briquette Udhyog Pvt Ltd, (Location) Kawasoti, Shiva Mandir-3, Mandir 3, Nawalparasi. Owner Mr Surendra Gorkhali Land area 2.5 ropani Shed area and size >2800 sq ft Production capacity About 4.8 tons per shift average (nominal) Operation hours One shift = 8hrs Origin of plant/ Taiwan made machinery Raw material Rice husk, present cost of rice husk = Rs 6 /kg Briquetting Plant cost ~USD 50, ( ( price) Manpower Skilled labour labour-2, 2, non-skilled-3, non 3, administration-1 administration No of briquette 8 (4 Taiwan made 4 Nepali Made) extruders Heating of die Originally Electric (4x3.4 kw), later briquettes were used Power for briquette 4x 15HP (4x 15 horse power motors) extruder Other power See diagram below Initiatives from Tried briquette with square owner die for better packing and delivery Fig. 2: Production of RH Briquettes to Heat the Die (Electric Heaters Removed) Fig. 1: Layout of the Mhepi Briquette Industries Pvt Ltd, Nawal Nawalparasi * Corresponding author: a shresthakr@hotmail.com Rentech Symposium Compendium, Volume 1, March

2 Fig. 3: Schematic Diagram with Technical Details II. PROBLEMS OF RICE HUSK BRIQUETTEE PRODUCTION TABLE II PROBLEMS OF RICE HUSK BRIQUETTE PRODUCTION Problem Effect Request/Remarks of Ind. partner Moisture problem in rice husk (required moisture content is ~10 %) Wearing of screw (screw gets worn out after 4-5 hrs) 1. Smooth not possible. 2. Production with explosions 3. Deformed briquettes 1. Briquette stops 1. Any possibility of preheating of rice husk to control moisture. 2. Simple equipment to measure moisture 1. Technique or to increase life of screw Temperature adjustment of combustion chamber for die heating (Electric heaters for die removed because of high cost) No stable Market for briquettes High power consumption 1. Non-uniformity in product 2. Pollution from combustion 1. Reduction in 2. No security of market 1. High cost of 1. System to control T o C 2. Mechanism to control pollution 3. Support in Market protection 4. Subsidy & promotion from govt 1. How to reduce power Source: Annual Technical Report, for illustration purposes only Hard facing rods not available freely (Indian rods) High cost of and plant (Taiwanese cost ~US$50,000) Size of plant is big (requires big land & huge amount of space ) 1. Always dependant on contact person 1. Complex requiring big investment 2. Production cost high 3. Difficult to payback bank loan 4. No subsidy or incentives 1. Cost of land & industrial shed increases 2. Manpower requirement increases 1. Alternative materials 1. Cheap and simple 2. Subsidy and tax incentives 3. Market support & protection from govt 1. Simple cheaper affordable 2. Simply operable Fig. 4: Production Stops when Screw is Worn Out Rentech Symposium Compendium, Volume 1, March

3 Other problem related information Mridaney S. Poudel et al.: Screw Extruder Biomass Briquetting The factory has capacity of 4.8 tons per day /shift, but presently it is producing only 1.5 ton/day. A ton of rice husk can produce 650 kgs rice husk briquette. The price of briquette is Rs.16.00/kg. The machine is operated 8hrs/day with six staffs. The life of screw extruder life is very short. The screw wears out within 4-5 hours and needs to be repaired by hard facing welding rods of Indian origin. The brand name and the composition are not known as it is supplied on personal basis. It is believed to be a product of Larsen and Toubro, India. Even new screws needs repairing within 4-5 hours of operation. A screw could be repaired 8 to 9 times only and needs replacement in a month TABLE III SOME COMPARATIVE DATA OF DIFFERENT FACTORIES (VISITED FOR STUDY) Parameters/Name Ayesha Bikolpa Jalani, Tanvir Hasan Briquette Mhepi Briquette Remarks/ conclusions Daulatpur, Khulna factory Udyog, Nepal Established 2003 BS 2050 Rate of 80kg/hr 80-90kg/hr 4 tons/shift Production is higher because briquetting units are more No of workers 3 persons: 1man permanent +1woman daily wages +1 welder- repair of screws) 3 persons (same) man-tks 6000/month Woman-3400/month 6 persons (2 skilled, 3 non-skilled & 1 admin staff, (welder- Rs 10,000/m) Manpower cost is higher for Nepali industry, so cost of will be higher No of briquetting units 2 units 2 units 8 units Most of the time 2 units only operate in Nepali industry Established 2003 BS 2050 Rate of 80kg/hr 80-90kg/hr 4 tons/shift Production is higher because briquetting units are more Cost of one unit Takas 50,000.-/unit Takas 50,000/unit 4 Taiwan units US$ ~50,000/ Technology is very expensive in case of Nepali industry TABLE IV WORKSHOP CAPABILITY IN SCREW DIE FABRICATION IN NEPAL AND BANGLADESH Parameters Rupali Engg works Ayub Ali Engineering works In Nepal (no specific workshops) Cost of screw Tks2500/pc (Screw made from Tks 1500/pc (Screw flight is ~Rs single rod) welded to a rod) Cost of die Tks 700/pc Tks 700/pc ~Rs Time to make screw 6-8 hrs 3 hrs One day Time to make die 1-2 hrs (Die made from readymade 1.5 hrs (Die made from Min 1 week (taper is 6 degrees) forms) readymade forms) Pitch of screw As per order Length of die 10.5 inches 10.5 inches As per order Remarks 1. In Bangladesh there are many industries so there are many workshops serving these industries. Cost and time for making dies and screws is well established. 2. The capability of workshops is well developed and the products are cheap. In Nepal there are no particular workshops to serve briquette industries, so the information varies and the products area expensive. Rentech Symposium Compendium, Volume 1, March

4 Fig. 5: Stock of Unfinished Die/Muff Fig. 6: Making a New Screw from Rod Fig. 7: Sectional Elevation of Screw Type Briquetting Machine Rentech Symposium Compendium, Volume 1, March

5 III. PROTOTYPE BRIQUETTING UNIT BY CEEN Based on the knowledge gained from the visits to various organizations/institutions abroad and in Nepal the project came up with a different design of the briquetting unit for the RENP project. The briquetting unit was fabricated in Nepal using the housing unit provided by NAST and the screw and the die brought from Bangladesh. The technical AutoCAD drawing of the unit as well as the screw and the die is provided in Fig. 7. The details and dimensions of the machine will be provided in the final report after registration of the design with the Department of Industries. Some New Points Taken up in the New Design Usually in most briquetting units (in Japan, Bangladesh, Thailand, Mhepi, etc) the Electric motor has been mounted on the top. Because of the vibrations created by the machine, the whole briquetting unit tends to move/shift sideways during briquetting. Because of this the briquetting units has to be fixed to the ground using some concrete and nuts and bolts. The unit thus becomes fixed. The electric motor in this design is concealed in the bottom case. It is secure from dust, smoke and pollution. Also it is protected from any water vapour which may accidentally fall on the motor. The weight of the motor holds the entire briquetting unit in place as if it fixed with nuts and bolts. This stabilizes the whole briquetting unit from shifting. Normally briquetting units use 2 fan belts to transmit the power. This unit has 3 fan belts, which good transmission of power without slipping. A temperature controller has been incorporated to the die, so that the temperature of the die during briquetting can be set at a definite value for research purposes. Based on the experiences/lessons learnt a 20 HP motor has been used to run the unit. Initially 2 collar heaters of 1kW each has been used to heat the die. Normally spiral heaters of high power were found to be used elsewhere. The briquetting unit has been installed in the NAST biomass workshop for testing. of briquettes will also be conducted in different industrial applications to replace firewood where our industrial partner has been constantly promoting its products. ACKNOWLEDGEMENT The authors wish to thank NORAD and Renewable Nepal Programme of Kathmandu University for providing support to CEEN for conducting this research work. The contributions made by its research partner, Nepal Academy of Science and Technology (NAST) and the industry partner, Mhepi Briquette Udyog (P) Ltd and everyone involved in the project is gratefully acknowledged. REFERENCES [1] Grover, P.D and Mishra, S.K.,(1995). Proceedings of the International Workshop on Biomass Briquetting, FAO/RWEDP, Bangkok, Thailand. [2] Moral, N.A,.(2005).Renewable Energy technologies in Asia, Department of Mechanical Engineering, Khulna University of Engineering and (KUET), Bangladesh [3] WECS (2010), Nepal Energy Sector Synopsis Report, Water and Energy Commission Secretariat, Sigh Durbar, Kathmandu. BIOGRAPHIES Mridaney Sharma Poudel is a Researcher in the Current project and a Life Member of CEEN. Krishna Raj Shrestha is Project Leader of the Current project and Chairman of CEEN. Dr. Shrestha is also a Professor at RECAST, Tribhuvan University. Ramesh Man Singh is a Technical Expert and Senior Advisor to the project and Vice Chairman of CEEN. Dr. Sigh is formerly Chief of Technology Faculty at NAST. IV. CONCLUSION The research output of the project in its first year showed that, rice husk briquetting industries could be run profitably in Nepal, if simple extruder machines are used instead of making huge investment on the import of complicated from abroad. Rice husk the basic raw material for briquetting, is very abrasive in nature with over 19 % ash which causes the wearing of the screw. The project is undertaking research to address the technical problem of wearing of the screw by the introduction of new type of spray welding techniques to enhance the life of screw. Further, the project will identify less abrasive and better raw materials including forest waste as alternative to rice husk. The project will fabricate and test heating and cooking devices to use the briquette fuels for domestic and institutional cooking purposes to replace firewood. Tests Rentech Symposium Compendium, Volume 1, March

PROJECT PROFILE ON COAL BRIQUETTES MANUFACTURING UNIT

PROF. NO.20 PROJECT PROFILE ON COAL BRIQUETTES MANUFACTURING UNIT 1. INTRODUCTION Coal briquettes are made of slack coal powder, washers sink etc. with bentonite, molasses and sodium silicate as bonding