INDUSTRY PROFILE #12
PORTABLE METALLIC
COOKSTOVE
Prepared By
Andre Charette
Reviewed By
Timothy Wood
Rafe Ronkin
Published By
VITA
1600 Wilson Boulevard, Suite 500
Arlington, Virginia 22209 USA
Tel: 703/276-1800 . Fax:703/243-1865
Internet: pr-info@vita.org
Portable Metallic Cookstoves
ISBN: 0-86619-299-9
[C]1988, Volunteers in Technical Assistance
INDUSTRY PROFILES
Introduction
This Industry Profile is one of a series briefly describing small or medium-sized industries. The
Profiles provide basic information for starting manufacturing plants in developing nations.
Specifically, they provide general plant descriptions, financial, and technical factors for their
operation, and sources of information and expertise. The series is intended to be useful in
determining whether the industries described warrant further inquiry either to rule out or to
decide upon investment. The underlying assumption of these Profiles is that the individual
making use of them already has some knowledge and experience in industry development.
Dollar values are listed only for machinery and equipment costs, and are primarily based on
equipment in the United States. The price does not include shipping costs or import-export taxes,
which must be considered and will vary greatly from country to country. No other investment
costs are included (such as land value, building rental, labor, etc.) as those prices also vary.
These items are mentioned to provide the investor with a general checklist of considerations for
setting up a business.
IMPORTANT
These profiles should not be substituted for feasibility studies. Before an investment is made in
a plant, a feasibility study should be conducted. This may require skilled economic and
engineering expertise. The following illustrates the range of questions to which answers must
be obtained:
* What is the extent of the present demand for the product, and how is it now being
satisfied?
* Will the estimated price and quality of the product make it competitive?
* What is the marketing and distribution plan and to whom will the product be
sold?
* How will the plant be financed?
* Has a realistic time schedule for construction, equipment, delivery, obtaining
materials and supplies, training of personnel, and the start-up time for the plant
been developed?
* How are needed materials and supplies to be procured and machinery and
equipment to be maintained and repaired?
* Are trained personnel available?
* Do adequate transportation, storage, power, communication, fuel, water, and
other facilities exist?
* What management controls for design, production, quality control, and other
factors have been included?
* Will the industry complement or interfere with development plans for the area?
* What social, cultural, environmental, and technological considerations must be
addressed regarding manufacture and use of this product?
Fully documented information responding to these and many other questions should be
determined before proceeding with implementation of an industry project.
Equipment Suppliers, Engineering Companies
The services of professional engineers are desirable in the design of industrial plants even though
the proposed plant may be small. A correct design is one that provides the greatest economy in
the investment of funds and establishes the basis of operation that will be most profitable in the
beginning and will also be capable of expansion without expensive alteration.
Professional engineers who specialize in industrial design can be found be referring to the
published cards in various engineering magazines. They may also be reached through their
national organizations.
Manufacturers of industrial equipment employ engineers familiar with the design and installation
of their specialized products. These manufacturers are usually willing to give prospective
customers the benefit of technical advice by those engineers in determining the suitability of their
equipment in any proposed project.
VITA
Volunteers in Technical Assistance (VITA) is a private, non-profit, volunteer organization
engaged in international development. Through its varied activities and services, VITA fosters
self-sufficiency by promoting increased economic productivity. Supported by a volunteer roster
of over 5,000 experts in a wide variety of fields, VITA is able to provide high quality technical
information to requesters. This information is increasingly conveyed through low cost advanced
communication technologies, including terrestrial packet radio and low-earth-orbiting satellite.
VITA also implements both long- and short-term projects to promote enterprise development and
transfer technology.
PORTABLE METALLIC COOKSTOVE
Prepared By: Andre Charette
Reviewed By: Timothy Wood
Rafe Ronkin
PRODUCT DESCRIPTION
The Product
The product is a metallic, wood-burning cookstove designed to fit
a pot of specific dimensions. It uses a small amount of wood and
cooks rapidly. It can be made entirely from new or recycled sheet
steel, with joints fastened by metal rivets or spot welding. The
cookstove is designed for preparation of such foods as the rice
and sauce or stew of Africa. Its manufacture is easily adaptable
to other locations.
The basic structure is a short cylinder with internal pot supports,
an opening for inserting fuelwood, two handles, and a
metallic grate with air vents below (Figure 1). Correct dimensions
pmc1x7.gif (353x353)
are extremely important and should follow a few basic
principles:
o The distance from the grate to the bottom of the cooking pot
should be about 40 percent of the stove diameter.
o The gap between the cylindrical wall of the stove and the
cooking pot should be uniform, ranging between 6 mm for small
stoves to 9 mm for the larger sizes. If the gap is smaller than
this, the fire may smoke excessively. If it is wider, fuel
efficiency will be greatly reduced.
o The front opening should be no larger than necessary to accommodate
two or three sticks of wood at a time.
Because of the important gap between pot and stove, every potsize
requires its own stove. In West Africa, the success of this
particular model is due, in part, to the standardized sizes of
the popular cast aluminum pots (Table 1).
The design of pot supports is a critical factor in stove performance.
These supports must be strong and must keep the pot at the
proper height above the fuel bed. They must also center the pot
so that its distance from the stove body is uniform all around.
Finally, many women require the pot to be held firmly so it does
not slide around while they are stirring. A system that meets all
these needs consists of three wedges fashioned from sheet metal
(Figure 2). They are fastened to the inside of the stove either
pmc2x7.gif (317x317)
with rivets or by welding. An additional advantage of these
supports is that they make good use of metal scraps left after
cutting other pieces.
Table 1. Metallic Cookstove Sizes, in Millimeters; Examples from
West Africa.
Pot Size No. 2 No. 4 No. 6
Range of pot diameter 241-247 310-312 343-345
Stove diameter 245 311 344
Stove height 238 295 328
Fuel opening, h x w 88X150 105x160 120x175
Draft vent, h x w 45x45 45x56 45x67
Size of sheet needed 263x842 325x1046 358x1150
The draft vents are equally spaced below the grate around the
base of the stove. Common stove sizes (for Pot Nos. 1-7) have
four vents, larger sizes have six.
The grate is supported by tabs formed when the sides and bottom
of draft vents are cut and then bent upwards. After the stove
blanks are cut from a 1 x 2-meter metallic sheet, the remaining
metal is used to make the grates, handles, and pot supports.
Openings in the grate must be large enough for ash to drop
through naturally without losing small coals. If the grate is
positioned with the rough side up, it will hold a small bed of
insulating ash and reduce heat loss.
Folds at the top and bottom rims of the stove eliminate sharp
edges, provide rigidity, and give an attractive appearance.
Production
Metal stoves are often made with a hammer and chisel in rural
areas where recycled oil drums or other metal items are available.
These can be worked into flat, rectangular sheets according
to stove size (Table 1). Blanks are traced on the metal with the
help of a template. The various openings are then chiseled out.
The two 180 degree folds are made lengthwise at the edges. These
reinforce the top and bottom rims. The stove is then shaped to
specifications, using a Dutch fold to join the ends in a cylinder
(Figure 3).
pmc3x7.gif (285x285)
In some areas, special hand tools can be used to ensure correct
dimensions every time and reduce fabrication time. Such tools
could include:
o A press for forming the pot supports shown in Figure 2.
o A set of forms to make smooth curve for the cylinder and to
ensure a correct diameter. Each consists of a partial cylinder
for each stove model. These are quickly interchangeable on a
common holder. When the cylinder is formed and the seam is
made, the-cylinder is put back on its form and made truly round
with the help of a rubber hammer.
o A hand operated bench shear for cutting the grate into a circular
disc. Even with this tool the operation is tedious.
circular shear is better; it operates on the same principle as
a can opener.
o A piece of steel pipe about 15 cm diameter and 60 cm long to
provide solid support when the Dutch fold is hammered closed.
The hammer and chisel method permits production of five stoves
daily by two workers. The tooling-aids package permits production
of up to 25 units daily by two workers.
The Facility
Stoves can be made in any space that accommodates two workers, a
work table, and storage of materials and products.
GENERAL EVALUATION
The product was designed in response to deforestation of such
areas as the West African Sahel. Its main objective is to reduce
the use of fuelwood. The stove itself has the added advantage of
decreasing the exposure of the cook to smoke, and since the fire
is contained, the user is less susceptable to burns. Cooking time
is also reduced about half.
Outlook
A. Economic
A fabricator can meet a demand of up to 2, 000 stoves per
year. Bigger markets will require more fabricators. Stove
making is a labor intensive process that creates jobs.
B. Technical
The stove is a simple product, easily manufactured by unskilled
workers under supervision.
Manufacturing Equipment Flexibility
Either of two methods are used to achieve the accurate dimensions
that are needed: the basic hammer and chisel, and tooling aids
mounted on a table. The tooling aids include forms specifically
designed for each stove size. Joints may be riveted if spotwelding
equipment is not available.
Knowledge Base
No special knowledge is required. Training requires only a few
days.
Quality Control
The tooling aids enable fabrication of each stove to dimension
tolerances.
Constraints and Limitations
Local cooking pots must be available in standard sizes. Production
is slowest with the hammer and chisel method. Hearing can be
permanently damaged by prolonged exposure to loud noise; workers
should therefore use ear plugs or muffs.
MARKET ASPECTS
Users
Women, housewives. In addition to reducing fuel costs, cooking
times are shortened, and health and safety are improved. This
stove improves women's working conditions.
Suppliers
Any supplier of sheet steel, whether new or recycled.
Sales Channels and Methods
Retail sales may be done directly by fabricator to buyer. Distribution
and pricing of products may involve a wholesaler. Door-to-door
sales, advertising (radio, TV), demonstrations, etc. may be
used. Endorsement and promotion or support from local and
national women's groups and by popular leaders and personalities
would help.
Geographic Extent of Market
Cities and towns where extensive fuelwood consumption takes
place.
Competition
This stove is likely to compete with and offer a ready market
alongside of gas, charcoal, petroleum, traditional, and unimproved
stoves.
Market Capacity
In households normally using two pots to cook a meal, there would
need to be a minimum of two stoves per family of ten persons. In
many places, the stove pays for itself within two months with the
savings made from the purchase of fuelwood. Stove life is over
two years. The potential market is 100,000 stoves per million
population.
PRODUCTION AND PLANT REQUIREMENTS, SMALL PLANT
Requirements Amount
1. Infrastructure, Utilities
Land
Building According to
Power local
Fuel conditions
Water
2. Major Equipment & Machinery
Tools & Machinery
Fabrication table $125
Pot holding tab forming press 47
Set of nine forms with support 156
Pipe mandrel to hammer fold 16
Rubber hammer 9
Support Equipment & Parts
Templates 84
(*) TOTAL ESTIMATED COST
of equipment & machinery only $437
(*) Based on US$ 1987 prices. The estimated costs are provided only
for general guidance. Actual costs will depend on local conditions
and may differ significantly from these estimates.
3. Materials & Supplies
Raw Materials
Sheet metal. One 1x2 m sheet makes:
3 #3 stoves and 3 #4 stoves, or
2 #7 stoves, 3 #2 stoves, and 1 #1 stove, or
2 #10 stoves, or
6 #3 stoves, etc.
4. Labor
Skilled 0
Semi-skilled 0
Unskilled fabricators 2
PRODUCT ILLUSTRATIONS
Figure 1. Metallic cookstove with pot.
pmc1x7.gif (285x285)
Figure 2. Wedge-shaped pot support made from scrap sheet metal.
pmc2x7.gif (285x285)
(Three are needed.)
Figure 3. A Dutch fold.
pmc3x7.gif (317x317)
Figure 4. Universal pattern for stove blanks with a key for
pmc4x8.gif (540x540)
dimensions in each of seven pot sizes
REFERENCES
1. Technical Manuals & Textbooks
Biomass Stoves (1987). Samuel F. Baldwin. Arlington, Virginia:
VITA. 287 pp.
Burning Issues: Implementing Pilot Stove Programs: A Guide for
Eastern Africa (1984). Stephen Joseph and Philip Hassrick.
London: UNICEF/IT Publication. 184 pp.
Improved Cooking Stoves in Developing Countries. Technical Report
No. 2 (1983). Gerald Foley and Patricia Moss. London: Earthscan.
175 pp.
Wood-Stove Dissemination, Proceedings of the Conference held at
Wolfheze, The Netherlands (1985). Edited by Robin Clarke. London:
IT Publications. 202 pp.
2. VITA Resources
VITA has a number of documents on file dealing with industrial
processes. On request, VITA will supply dimension tables and
pattern drawings for metallic cookstoves used in West Africa.
3. VITA Venture Services
VITA Venture Services, a subsidiary of VITA, provides commercial
services for industrial development. This service-for-fee includes
the following: technology and financial information,
technical assistance, marketing, and joint ventures. For fee
schedule, contact VITA.
`INDUSTRY PROFILE SERIES'
VITA is pleased to present this series of industrial profiles.
These Profiles provide basic information for starting manufacturing
plants in developing nations. Specifically, they provide general
plant description, financial, and technical factors for their
operation, and sources of information and expertise. Dollar values
are listed only for machinery and equipment costs, and are
primarily based on equipment in the United States. The price does
not include shipping costs or import-export taxes, which must be
considered and will vary greatly from country to country. No other
investment costs are included (such as land value, building rental,
labor, etc.) as those prices also vary.
The series is intended to be useful in determining whether the
industries described warrant further inquiry either to rule out or
to decide upon investment. The underlying assumption of these
Profiles is that the individual making use of them already has some
knowledge and experience in industrial development.
These profiles should not be substituted for feasibility studies.
Before an investment is made in a plant, a feasibility study should
be conducted. Each profile contains a list of questions to which
answers must be obtained before proceeding with implementation of
an industrial project.
All profiles are available in English only. They are priced at
$9.95 each. You may take advantage of the introductory offer and
order any three profiles for just $25.00 or order the entire set of
nineteen profiles for a bargain price of only $150.00.
BAKED, LEAVENED BREADS
Richard J. Bess
Describes a small bakery operating with a single shift and
producing 100 tons of baked products a year. It also describes a
medium-sized plant operating on the same basis but producing 250
tons of baked goods a year.
(IP # 19) 6pp.
BLUE JEANS
Edward Hochberg
Describes one plant operating with one shift and making 15,000
dozens of blue jeans a year, and another that produces 22,000
dozens a year.
(IP # 6) 8pp.
DIMENSION HARDWOOD
Nicolas Engalichev
Describes a medium-sized mill operating with one shift that
produces 4,500 cubic meters of dimension hardwood per year. Some
information is also provided for a mill twice as large.
(IP # 16) 8pp.
FISH OIL AND FISH MEAL
S. Divakaran
Describes two plants. The first is a 20-ton per day plant operating
with an eight-hour shift and producing 8,000 tons of fish meal and
4, 000 tons of fish oil a year. The second is a 40-ton plant
operating an eight-hour shift and producing 8,000 tons of fish oil
and 16,000 tons of meal per year.
(IP # 8) 8pp.
GLASS CONTAINERS (BATCH PROCESS)
William B. Hillig
Describes small batch production plants with a work force of 10 to.
50 people that produce 500 to 25,000 containers per day.
(IP 118) 8pp.
GLUCOSE FROM CASSAVA STARCH
Peter X. Carrell
Describes a plant that can operate 250 days a year on a three-shift
continuous basis and produce 2,500 tons of glucose syrup.
(IP #17) 8pp.
LIQUID PETROLEUM GAS
Jon I. Voltz
Describes two plants, operating with three shifts for 52 weeks per
year. The smaller has an annual manufacturing capacity of 2,220,000
barrels; the larger plant has an annual capacity of 4,440,000
barrels.
(IP #12) 8pp.
MEN'S DRESS SHIRTS
Edward Hochberg
Describes one small plant operating with one shift and manufacturing
15,000 dozen men's dress shirts a year. It also describes a
larger plant running a single shift and manufacturing 22,000 dozen
shirts a year.
(IP #13) 8pp.
MEN'S WASH AND WEAR PANTS
Edward Hochberg
Describes one plant operating with one shift and producing 15,000
dozens pairs of pants a year, and another that produces 22,000
dozens a year.
(IP # 4) 8pp.
MEN'S WASH AND WEAR SHIRTS
Edward Hochberg
Describes a plant operating with one shift, manufacturing 15,000
dozen men's wash and wear shirts a year, and another that manufactures
22,000 dozen shirts a year.
(IP # 5) 7pp.
MEN'S WORK SHIRTS
Edward Hochberg
Describes one plant operating with one shift and manufacturing
15,000 dozen men's shirts a year. It also describes a larger plant
running a single shift and producing 22,000 dozen shirts a year.
(IP # 2) 8pp.
PAINT MANUFACTURING
Philip Heiberger
Describes a small plant that will serve local needs, mainly in the
trade-sales-sector. Its output may exceed 4, 000 liters per week
(L/wk).
(IP #14) 10pp.
PORTABLE METALLIC STOVE
Andre Charette
Describes a facility that accommodates two workers, a work table,
and storage of materials and products. The hammer and chisel method
permits production of five stoves daily. The tooling-aids permits
production of up to 25 units daily.
(IP # 10) 9pp.
PORTLAND CEMENT
Dave F. Smith & Alfred Bush
Describes a small plant producing 35,000 metric tons of cement a
year.
(IP # 9) 10pp.
ROUGH-SAWN LOGS
Nicolas Engalichev
Describes plants (sawmills) operating with one shift that can
produce 10,000 and 30,000 cubic meters (cu m) of product per year.
(IP # 15) 8pp.
SMALL CERAMICS PLANT
Victor R. Palmeri
Describes a small plant operating with one shift and producing
16,000 pieces a year. It also describes a medium-sized plant
running a single shift producing about 80,000 units a year.
(IP # 11) 8pp.
STARCH, OIL, AND FEED FROM SORGHUM GRAIN
Peter K. Carrell
Describes a small plant operating with three shifts on a seven-day
work schedule and processing about 200 tons of sorghum a day. Two
shifts are down per week for maintenance. This facility may be
considered a heavy industry because of the emission from the boiler
and dryers and the noise from its high speed machinery.
(IP # 1) 8 spp.
UNFERMENTED GRAPE JUICE
George Rubin
Describes a plant operating with one shift and producing 125,000
gallons of grape juice a year, and another that produces 260,000
gallons a year.
(IP # 7) 8pp.
WOMEN'S BROADCLOTH DRESSES
Edward Hochberg
Describes a plant operating with one shift and manufacturing 72, 000
women's dresses a year (1,440/week, 288/day). It also describes a
larger plant running a single-shift and producing
104,000 dresses a year.
(IP # 3) 8pp.
========================================
========================================