Alternative Cooking Technologies for Sheephead Traders in NUNU

Prepared for: The City of Cape Town

Prepared by: Ashleigh Hein, Liam Swanson, Anza Khubana, Nhlanhla Makhanye

Key Words: cooking, technology, sheephead traders, waste disposal, Nyanga, Cape Town, Upgrade

03/02/2016

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Synopsis

The City of Cape Town is planning to upgrade the Nyanga trading area. One of the groups of traders in the area are the sheephead traders. Despite them not owning or paying for the land they trade on, the city does not want to forcefully evict them as they have been trading there for over 50 years. The City would rather work with the traders to improve their trading methods and environment. The City has thus approached a team from Engineers Without Boarders South Africa to provide solutions to 1. Reduce the amount of wood used by the traders for cooking and 2. Improving their waste and wood storage procedures 3. Reduce the amount of smoke being released into the surroundings. This can be done by introducing alternative and more efficient cooking stove. Several cooking technologies were researched: Biomass stove, Rocket Stove, Estufa Finca, Braai Stove, Justa Stove and the Double-drum stove. Based on the research the Estufa Finca, Braai and Rocket stoves seemed most suited for the traders. An Estufa Finca stove was built and it was found to be very easy and cheap to make. As expected the traders were very apprehensive about this new technology. They do not want to deviate far from their current cooking method and they do not seem to understand the concept of efficiency. When the Estufa Finca stove was tested some smoke was released and the traders also worry that the stove is too tall and will not be capable of reaching the same boiling capacity. It is thus recommended that further testing be done and the necessary modifications made. The stove should then be taken through a procedure of community organisations (such as the SNACS and Gunye Reference Group) to assist in implementation. After a collaborative involvement with community representatives a cook off with the traders can be held. The stove should then be taken to the traders and a cook-off held so that they can see firsthand how efficient the stove is and they can compare it to their current method of cooking. The wool still needs to be burnt off of the sheepheads and thus a big fire is needed. It is suggested that a braai type design be used for this and in the long-term a chimney could be added. Pests are a problem as the wood just piles up and rots and they keep buying/receiving more and more. It is suggested that there should be one area for wood storage and one area for waste storage. A container or bin could possibly be used for the wood storage and thus when full they cannot accept more wood but this would need to be regulated. It is also suggested that community organizations like SNACS be involved in the negotiation process.

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Table of Contents

Synopsis.....................................................................................................................................................2

Table of Contents.....................................................................................................................................3

List of Figures............................................................................................................................................4

List of Tables.............................................................................................................................................5

Glossary.....................................................................................................................................................5

1. Introduction........................................................................................................................................1

1.1 Subject of Report......................................................................................................................1

1.2 Background to Report...............................................................................................................1

1.3 Objectives of Report.................................................................................................................1

1.4 Scope and Limitations..............................................................................................................1

1.5 Plan of Development................................................................................................................2

2. Literature Review..............................................................................................................................3

2.1 Alternative Cooking Technologies..........................................................................................3

2.1.1 The Justa Stove.................................................................................................................3

2.1.2 The Double-Drum Stove...................................................................................................4

2.1.3 The Rocket Stove..............................................................................................................7

2.1.4 The Biomass Stove...........................................................................................................9

2.1.5 The Estufa Finca Stove..................................................................................................10

3. Experimental....................................................................................................................................12

3.1 Procedure.................................................................................................................................12

3.1.1 Meeting with Wiebke Toussaint (Engineers Without Borders South Africa)...........12

3.1.2 Meeting with David Lello (Khaya Power).....................................................................13

3.1.3 Meeting with Wikus Kruger from the Energy Research Centre (ERC) UCT...........14

3.1.4 Meeting with City of Cape Town (CoCT) Officials......................................................14

3.1.5 Site Visit 14 December 2015.........................................................................................15

3.1.6 Meeting with Jiska de Groot (ERC UCT).....................................................................16

3.1.7 Testing Braai Stove.........................................................................................................16

3.1.8 Site Visit 26 January 2016.............................................................................................16

3.1.9 Building Estufa Finka Stove...........................................................................................16

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3.1.10 Testing Estufa Finca Stove............................................................................................19

4. Risk Assessment.............................................................................................................................20

5. Results and Discussion..................................................................................................................21

5.1 Results of stove tests.............................................................................................................21

5.1.1 Braai Test.........................................................................................................................21

5.1.2 Estufa Finca Test............................................................................................................21

5.2 Results of second site visit....................................................................................................22

6. Conclusions.....................................................................................................................................23

6.1 Unpromising results of Braai test..........................................................................................23

6.2 Promising results of Estufa Finca test..................................................................................23

6.3 Comments on Site Visits........................................................................................................23

7. Recommendations..........................................................................................................................25

7.1 Implement Estufa Finca stove with modifications and further testing:.............................25

7.2 Implement alternative stove designs....................................................................................25

7.2.1 Brick fireplace (Braai).....................................................................................................25

7.2.2 Rocket Stove....................................................................................................................25

7.3 Construct area for wood and waste storage........................................................................26

7.4 Connection to appropriate water pipes................................................................................26

8. References.......................................................................................................................................27

9. Appendices......................................................................................................................................28

9.1 Anglo American Risk Matrix...................................................................................................28

9.2 Health and climate impact of various cooking technologies..............................................29

9.3 Photographs of the braai stove test......................................................................................30

9.4 Photographs of the Estufa Finca stove test.........................................................................31

List of Figures Figure 2.1: Diagram of the Justa Stove.......................................................................................................3

Figure 2.2: Diagram of the Double-Drum Stove (Wartluft, 1975)...............................................................4

Figure 2.3: Diagram of the Double-Drum Stove with measurement (Wartluft, 1975)................................5

Figure 2.4: Photograph of the Double-Drum Stove ashtray (Himalayan institute, 2013)...........................6

Figure 2.5: Photograph of a Rocket Stove (Regenold, 2009)......................................................................8

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Figure 2.6: Photograph of a Biomass Stove (TradeIndia.com, 2016)..........................................................9

Figure 2.7: Photograph of an Estufa Finca Stove (Ternes et al, 2011)..............................................10

Figure 3.1: Photograph of the lid cutout (James, 2010)...........................................................................18

Figure 3.2: Photograph of the final product (James, 2010)......................................................................18

Figure 9.1: Figure showing the climate and health impacts of various cooking stoves (World Bank, 2014)...................................................................................................................................................................29

List of TablesTable 2.1: Showing the advantages and disadvantages of the Justa stove.................................................4

Table 2.2: Showing the advantages and disadvantages of the Double-Drum stove....................................6

Table 2.3: Showing the advantages and disadvantages of the Rocket stove...............................................8

Table 2.4: Showing the advantages and disadvantages of the Biomass stove..........................................10

Table 2.5: Showing the advantages and disadvantages of the Estufa Finca stove....................................11

Table 4.1: Showing the results of the revised risk assessment for this practical.......................................20

Table 5.1: Showing the results of the braai stove test..............................................................................21

Table 5.2: Showing the results of the Estufa Finca test.............................................................................21

Glossary

PPE: Personal Protective Equipment that is to be worn during the practical Pyrolysis: Heating without air, that releases gases SNACKS:

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1. Introduction

1.1 Subject of Report

This report proposes alternative cooking technologies and methods of waste disposal for the sheephead traders in Nyanga.

1.2 Background to Report

The City of Cape Town plans to upgrade the trading areas around the Nyanga Transport Interchange. This will involve allocating trading areas to the various traders. The traders occupy a large area, their woodpiles taking up most of the space. These piles attract rats and cockroaches. They dispose of their waste into the municipal waste water system. The City of Cape Town anticipates that the traders will be reluctant to change their way of doing business and if they continue to trade as they are they will not abide by the new regulations that will be imposed following the upgrade. They have thus approached Engineers Without Boarders South Africa (EWBSA) to assist them with suggesting alternative cooking technologies and means of waste disposal that could help the traders occupy less space and abide by the new regulations.

1.3 Objectives of Report

The objectives of the report are to:

Propose more efficient cooking technologies that the traders can invest in and/or make themselves.

Suggest improved methods of waste storage and disposal Draw conclusions on the best cooking technology and means of waste

disposal and storage. Make recommendations as to which cooking technology and waste

storage and disposal methods should be implemented.

1.4 Scope and Limitations

This report provides suggestions of alternative and more efficient cooking technologies that are inexpensive as it is anticipated that the traders will be reluctant to invest large amounts of money in new stoves when their business is doing well with their open fires.

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More expensive cooking technologies are thus not discussed in this report. Waste storage and disposal methods suggested in this report are limited to what the City of Cape Town can provide. So more expensive means of waste storage and disposal are not highlighted. Also current regulations prohibits the use of crates on the trading sites which needs to be addressed.

1.5 Plan of Development

Firstly, a review of the literature that was studied for the investigation is given. This was done to support the chosen methodology and to explain the necessary theory. The experimental section follows which gives a detailed account of the method and apparatus used in the study. A risk assessment was carried out using the Anglo American Risk Matrix prior to the experiment. This assessment was then revised after the practical was performed. The results of both assessments are given in the Risk analysis section. The results are then analyzed and discussed. Conclusions and recommendations are then made based on these results. Additional information and photographs and the Anglo American Risk Matrix are provided in the Appendices.

2. Literature Review

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2.1 Alternative Cooking Technologies

2.1.1 The Justa Stove

The Justa stove is a rocket stove with ceramic material built around it as an insulator, usually clay, cement, bricks or metal. It is flexible to any shape and size depending on the requirements, with the rocket stove inside being the limiting factor. A chimney can be built at the top of the rocket stove, allowing the smoke to escape in a control flow avoiding exposure by the users. The ceramic allows the stove to be built permanently on the ground. A metal griddle or flat plate is used at the top, supporting the pot. The insulated firebox forces the heat directly underneath this metal griddle improving the cooking efficiency. The insulation reduces fuel consumption by 50% [1]. Under the chimney, a channel is included to catch the soot, which helps when cleaning the stove. Different fuels are applicable, including wood, coal, pellets, etc. Overall, the Justa stove saves up to 70% of fuel consumption, and the chimney helps remove 95% of the toxic gases which are harmful to the users [2].

Figure 2.1 below is a schematic example of a Justa stove. Two cylindrical patterns are used to make the L-shaped rocket elbow and a ceramic material is built around it (insulator). The insulator is made of either wood ash or clay and the body built from bricks or clay. A chimney made of a thin metal sheet is attached to the top griddle or metal plate behind the brick walls. A small section is left at the bottom of the rocket elbow, where wood is loaded. This allows easy removal of the ash which makes it easier to clean.

Advantages DisadvantagesFigure 2.1: Diagram of the Justa Stove

Table 2.1: Showing the advantages and disadvantages of the Justa stove

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Cheap to build Produces ash which is not easy to remove

Low maintenance Limited to indoor use

Insulation increases the efficiency Can be difficult to construct with the metal and ceramic

Harmful gases directed away from the surrounding air

2.1.2 The Double-Drum Stove

The Sheephead traders in Nyanga are currently using the 55-gallon drums as pots for cooking and boiling water. A bigger stove is thus required for stability and increasing the heat surface area on the pot. Using another big drum would solve the size problem to improve stability and heat surface area. To build a double-drum stove requires a 30 and 55-gallon drum, stovepipe for making a chimney, a metal sheet for making an ash tray, steel rods used to make the handles and a ceramic material i.e. ash which fills the space between the two drums. Tools needed for fabrication is a cutting saw, a drill, welding equipment, fasteners, brazing equipment and a hummer. Figure 2.2 below shows a completed double-drum stove.

Figure 2.2: Diagram of the Double-Drum Stove (Wartluft, 1975).

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Figure 2.3 above shows the design with labeled dimensions. Steps to build the double-drum stove are as follows:

Cut a circular hole or two at one side of the 55-gallon drum where the chimney will be inserted (near the top).

Cut a rectangular hole at the bottom of the opposite side. This is where the ash tray will fit. Figure 2.4 bellow show the sliding ash tray.

Bore one hole on the bottom seal of the 30-gallon drum, which will allow the ash to drop through onto the tray

An extra metal (bar or rod or sheet) is inserted inside the bigger drum to support the smaller drum and allows the tray to slide in and out.

Insert the 30-gallon drum into the 55-gallon drum Depending on the type of fuel used, a hole is drilled above the tray sec-

tion. This is where woods are inserted. If pellets are used, it is not neces-sary to cut this hole as pellets can be easily loaded from the top.

The chimney is welded at the back on the cut section and a minimum of three legs (metal bars) are welded at the bottom seal of the 55-gallon drum.

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Advantages DisadvantagesConcentrated heat (elbow) and can accommodate insulation which in-

creases efficiencyLimited size and shape

Lighter material – less heat absorbed by walls

Need to constantly tend to it (adding or pushing the wood)

Mobile Susceptible to rustWood burns at the tips – less wood burnt at the time – complete burn – can control rate – reduces smoke

Not easy to control the fire– fire tends to run away - heat tends to escape from the

sidesChimney (elbow) increases draft – wood burns rapidly and cleanly Uses a lot of wood

An additional chimney can be added Wood does not burn from the tip/headHeat is directed through narrow chan-nels that force hot gases against the pots - increasing heat transfer effi-

ciency

Produces a lot of smoke

Outdoor useEasy to use

Low pollutionLow maintenance

No need to chop woodHeats up quickly

2.1.3 The Rocket Stove

Figure 2.4: Photograph of the Double-Drum Stove ashtray (Himalayan institute, 2013).

Table 2.2: Showing the advantages and disadvantages of the Double-Drum stove

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A rocket stove is an efficient cooking stove. Rocket stoves are designed to increase fuel efficiency without increasing emissions. They require very little fuel and they are cheap and easy to build. They also help slow down climate change and saves the lives of people from the open fires that are polluting indoor air. It was first developed by Doctor Larry Winiarski in the 1980s as a safe, effective, environmentally conscious alternative open fires for people in impoverished communities

Elements of a rocket stoveA basic rocket stove consists of just a few components: • An insulated rocket elbow, formed of a horizontal fuel chamber that fits into a vertical combustion chamber (also referred to as a “chimney”)• A stove body that surrounds the elbow, made of sheet metal or some other inexpensive material, with a small opening• A fuel grate, placed inside the fuel chamber, on which the fuel wood rests• A pot skirt, a sheet metal shield that surrounds the cooking vessel, creating a gap, to ensure that more heat from the flue gases enters the vessel

How does it work?Rocket stoves can use most any dry plant matter, not just wood — leaves, twigs, and brush will work as well. Fresh air enters the fuel chamber from beneath the burning wood resting on the grate, allowing the air to be preheated before it enters the combustion chamber, which in turn leads to cleaner combustion. The small fuel entry not only demands less fuel wood, but also limits the amount of cold air that can get in. The combustion itself is confined to a small, insulated space, so most of the energy in the wood is converted to heat for cooking. The cook pot sits directly on top of the combustion chamber, so the hot gases contact it immediately after combustion, reducing smoke. The pot skirt that surrounds the vessel further improves efficiency by increasing the temperature of the flame that contacts the pot, and by directing the gases to scrape the sides of the pot as well as the bottom, increasing heat transfer.

Figure 2.5: Photograph of a Rocket Stove (Regenold, 2009)

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Advantages Disadvantages

Concentrated heat (elbow) and can accommodate insulation

Due to building materials: limited size and shape-use rocket box stove

Lighter materials are used – less heat lost to walls

Tended more frequently (pushing or adding wood at a time)

Mobile Susceptible to rustingWood burns at tips – less wood burnt at a time – complete burn-control rate-

reduce smokeChimney (elbow) increases draft –

wood burn fiercely and cleanlyAdditional chimney (smoke) can be

added

Heat is directed through narrow chan-nels that force hot gases against the pots - increasing heat transfer effi-

ciencyCan use outdoors

Easy to useLow pollution

Low maintenance No need to chop wood

Heats up quickly

Figure 2.5: Photograph of a Rocket Stove (Regenold, 2009)

Table 2.3: Showing the advantages and disadvantages of the Rocket stove

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2.1.4 The Biomass Stove

Biomass stoves have been around since 1800s and earlier. Biomass is any material that is produced by nature, most popular types off biomass fuel are wood pellets, corn, and manure

How does it work?

Combustion happens in a two-stage process, which makes modern stoves more effi-cient. First, there is  primary combustion where the main fuel burns with oxygen from the air to release heat. In theory, if combustion happens perfectly, it releases heat en-ergy and produces only carbon dioxide and water (steam). In practice, we don't get complete combustion, so smoke (unburned particles of carbon), carbon monoxide, and other gases are produced too, wasting energy, reducing efficiency, and making pollu-tion. That's why, in a well-designed stove, there's also a process of secondary com-bustion, where the unburned carbon in the smoke is itself burned to release further en-ergy and reduce pollution. This is usually achieved by making a stove work in what's called downdraft mode. Instead of simply having a flue open directly above the burning fuel (allowing unburned fuels and gases to escape), there's an extra flue at the bottom and around the back of the stove. With this open, smoke and combustion gases initially move downward, through the combustion zone, before passing out safely through the back flue.

Figure 2.6: Photograph of a Biomass Stove (TradeIndia.com, 2016).

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Advantages DisadvantagesCan use a variety of fuels such as:

crops, food waste or industrial waste, can also use wood pellets, manure,

corn and dried cherry pits

Expensive to install and fuel can be expensive (wood pellets)

Close to being carbon neutral Dry fuel – need storage areaProduces very little waste and smoke Requires regular cleaning

2.1.5 The Estufa Finca Stove

The stove uses the technique of Top Lit Updraft gasification (TLUG). Gasifier stoves, unlike other biomass stoves, separate the various stages of combustion. These stages are: Pyrolysis, combustion of released gases with air, gasification and combustion of remaining charcoal. By separating these stages efficiency is increased and pollution is reduced. A good gasifier stoves completely burns all the gases. The stove can be designed to burn the char or conserve it.

Table 2.4: Showing the advantages and disadvantages of the Biomass stove

Figure 2.7: Photograph of an Estufa Finca Stove (Ternes et al, 2011).

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The stove (Figure 2.7 above) consists of a 20 L drum (combustion chamber) with a metal shell (galvanized roofing) around it and half of a number 10 tin (large coffee tin) as a riser on top of the drum. Concrete blocks can be used as a support to ensure cooking is safe and easy. These are inexpensive and readily available. The air is preheated in the gap between the drum and the shell and is then directed to the top of the combustion chamber to be burnt. The shell ensures the combustion chamber remains hot and the outer surface of the stove cool (Hatfield et al, 2010).

Advantages Disadvantages

Low emissions Not suited to cooking of large volumes at one time

High efficiency Fuel source needs to be cut/chopped so as to fit in the stove

Useful by-product (charcoal)

Scalability unknown

Inexpensive and easy to makeCan use a variety of fuels

MobileOutdoor/indoor useLow Maintenance

Very PowerfulUses less wood than other

technologies covered in this report

Table 2.5: Showing the advantages and disadvantages of the Estufa Finca stove

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3. Experimental

3.1 Procedure

This report concerns issues affecting both the Sheephead traders and the community of Nyanga and in order to best understand the problem and reach a collective solution, it is advisable that all stakeholders are involved. Interviews, meetings and practical experiments were arranged to gather information entailed in this report and to get the perspectives of all parties involved.

3.1.1 Meeting with Wiebke Toussaint (Engineers Without Borders South Africa)

A semi-structured meeting was conducted in private with Wiebke Toussaint, CEO of Engineers Without Borders South Africa (EWB-SA) on 8 December 2015. Present in this meeting was Wiebke Toussaint, Liam Swanson, Anza Khubela, Nhlanhla Makhanye and Ashleigh Hein. Various Stakeholders were introduced by Wiebke and their contacts were provided. We were each given respective activities and responsibilities and the opportunity to address questions to Wiebke. Positions were decided not to be too rigid. Each would contribute to research and work on a task relevant at the time. Liam was chosen to be the point of contact with Wiebke, stakeholders and those to be met with.

Wiebke agreed to introduce us to those contacts outside UCT, Nicky Sassman (CoCT), Jan Kluiver (EWB-NL), Matt Docherty (EWB-SA) and Illana Steenkamp (VPUU). We were then introduced to Jiska de Groot from UCT who has high energy and interest in the project. And then agreed that all the other UCT researchers and knowledgeable people are to be contacted directly (Harro Von Blottnitz, Wikus Kruger and Holle Wlokas). A meeting with Wikus was set. And Wiebke agreed to add the group to a google drive containing all information gathered by EWB thus far and send Matt Docherty’s paper on high-efficiency stoves.

The day was spent on general group familiarization with the problem to be solved, reading relevant literature and having the open discussion on various points of view of the problem. It was then planned to start grappling with the complexity of the environment.

Based on Wiebke’s reports on previous visits, our first priority was to: Develop our understanding of the current business model and

environment Develop our understanding of stove specifications

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Start finding relevant and applicable stove designs and investigate the feasibility of each.

3.1.2 Meeting with David Lello (Khaya Power)

A meeting with David Lello from Khaya Power was conducted at his private residence, Stelekaya, in Stellenbosch on 9 December 2015 with the intention of learning about his own products and finding out information behind general cooking stove technologies. The meeting was attended by all four students. And the following points were discussed:

How the Gasification stove is made and used How to burn the fuels efficiently and techniques to ensure a complete

combustion Benefits of the Gasifier stove over Rocket Stoves Using wood Pellets as a fuel (Cost, availability etc.) Scalability

Gasification methods cause a complete burn i.e. fewer particulates released into the air and less harmful gases released into the air. One can remove gases by charring the wood previously (make charcoal) but then lots of the energy in the wood has been removed. To promote combustion, the stove can have free air flow (inlet at bottom and outlet like a chimney at the top) or forced air flow. Forced air flow is obviously more consistent and controllable but needs a fan and an electric source: the more the air the faster the fuel burn. Khaya stoves have air gaps and insulation in order to keep the outer temperature down. It was suggested that the stove is made from a 55 Gallon drums. And that there must be some sort of separation to prevent burns.

Khaya stoves cannot be much bigger (as yet) than a 25-litre paint bucket. A 5-litre sized stove will boil 2 litres of water in an hour. 3Kg of pellets used in 5-litre stove. Changing the diameter doesn’t affect the rate of burn (currently around 1mm/min) but will add more energy. Water Boiling Test is used to determine the efficiency of the stove. The amount of ash is dependent on the type of fuel used: pellets make very little ash. One of the problems identified was that fuel cannot be loaded from above while burning, it must be finished and started again. Hence, there can be another pod ready to be swapped out. Pellets price is about R5/kg. This is slightly more expensive than electricity and slightly cheaper than gas.

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It was established that rocket stoves should have an open door to see that fire is still going and feed wood from the side. David emphasized that we look at the Global Alliance CC (GACC) and World Bank research. He agreed to look at hiring out the electric part at a cost per day, however, this adds, even more, admin and cost. David agreed to provide a document with a lot of relevant information, which he sent short after our meeting.

We will consider the cost of the Khaya stove in this project to see feasibility but currently, it does not seem like it will work. Seeing that all these individual costs might not incentivize the traders, the team suggested that these costs be incorporated into the rent of the land (regulated by the City of Cape Town).

3.1.3 Meeting with Wikus Kruger from the Energy Research Centre (ERC) UCT

A meeting was conducted at Wikus Kruger’s office at the ERC department to see his perspective of the social impact of our project and ways in which to approach the solution.

3.1.4 Meeting with City of Cape Town (CoCT) Officials

A meeting was conducted in private at the CoCT offices in Langa on the 14 December 2015. Present were Nicky Sasman (CoCt SPUD), Dumisani Ncapayi (CoCT MURP), Phumlani Ntsele (CoCT ECON DEV), Hilman Maqaza (BAM), Xolisa Nkayi and Thando Myamya (City Health), Anza Khubana, Ashleigh Hein, Nhlanhla Makhanye and Liam Swanson (EWB UCT).

Nicky gave a background on how this supports the larger NUNU (Nyanga Urban Node Upgrade) project, the first phase of which is the implementation of a trading plan where traders will need to conform to the standard trading contracts of the City. This is a short and medium term solution: in the long term, the idea is for them to join a meat-market and food-court at the PTI. Hillman is available to be part of the meetings, to prepare the traders for the implementation of the trading plan. Phumlani said City would want to support the traders in whatever way, but he and Nicky were clear that the City cannot purchase any equipment for the traders themselves.

Xolisa gave a background on the history of the trading business, and his efforts at encouraging the traders to improve their conditions. He has built up trust with them, but it will still be difficult to get financial information from them. Thando stated that his priority was around reducing and managing the woodpile: this was a harbour for rats and cockroaches. Secondly, reducing the smoke pollution, and

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improving the general cleanliness of their trading area. Dumisani offered to support the project by including the wider community representatives, the Safe node Area Committee (SNAC), and the ward councillor.

We raised and discussed many technical questions. We (students) then made connections with Etafeni, who are keen on the ash for fertiliser. They are investigating the use of other waste products. This was aimed to reuse the waste products which will, in turn, help with waste management. It was agreed that we could recommend more than 1 option which will be implemented for the short, medium and long term and also make recommendations for when the trading plan can be implemented.

We met the ward councillor while visiting the slaughter slab on Sithandatu Ave, and alerted him to the students coming back to site in the second half of January. He seemed happy to see any progress. Xolisa agreed to be the primary contact person, and Dumisani and Hillman agreed to support him. Xolisa suggested that he may need to draw in George Brown / Peter Jaggers (Solid Waste).

3.1.5 Site Visit 14 December 2015

We headed to the site in Nyanga with all the Stakeholders present. Xolisa introduced us to the traders and we were able to ask them a few questions about their trading business. Upon arrival, we found that the traders were not cooking or selling meat on that day but were able to look around. Phumlani suggested that we go to a nearby trading area where they braai meat. This area seemed to be more organised and cleaner compared to the sheephead trading site. They slaughter sheep on site, on a concrete floor and wash all the waste away with water. This helps to ease the cleaning process. It was also discovered that they are using hand-made stoves to braai the meat. There were more traders stationed in a row around the corner at the intersection. We got the opportunity to ask them questions about their business, cooking techniques, fueling and storage. The braaiers pay R50/trolley of firewood.

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3.1.6 Meeting with Jiska de Groot (ERC UCT)

A meeting was held in private with Jiska de Groot on 15 December 2015. Jiska made clear the complexity of the social environment that the sheepshead traders operate in. It was realised that not many inspirations in terms of operation could be taken from the Braaiers as they operate under different management with different business priorities. It was interesting to note the female dominated Braaing business compared to a mostly male sheepshead trading business. Jiska noted that we had a lot of relevant questions which needed answering and could be asked to the sheepshead traders at our next visit. The team was given advice on how to approach the traders. It was advised to talk and dress humbly so as not to appear to be coming as a superior party.

3.1.7 Testing Braai Stove

The test was conducted on 13 January 2016. A brick fireplace in Newlands forest was used for this test. The test was performed outside and it was windy. Wood from the area was used. Firelighters and a lighter were used to start the fire. Water in a 5L paint tin (no lid) was placed on a grid above the fire, once the fire got going, and the time taken for this water to boil was recorded. The amount of smoke was measured visually and was rated on a scale of 1 to 5, 1 being extremely small and 5 extremely large smoke.

3.1.8 Site Visit 26 January 2016

A second site visit was organized to get the traders input on the Estufa Finca design. Questions such as: How much a truck of wood costs, whether there are owners and employees or only the owners working, how the cooking process works and how long it takes were asked.

3.1.9 Building Estufa Finka Stove

To build the stove a step-by-step photo guide was followed (James, 2010).

Materials used are listed below:

20l paint tin 0.35m x 1m Corrugated iron Binding wire ±15cm long cylindrical wood 3x M4 Nut and Bolt

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16x 3mm pop rivets 4x self-tapping screws 150mm diameter Tin Can (Large Coffee Tin, number 10 tin) 4x right angled elbow supports

The tools used are listed below:

Angle Grinder Rivet Tin Snips Drill Screwdriver Hammer 5mm Punch G-clamp

Method for making the:

Lid:

1. Bend all of the clamps around the lid till flat2. Remove the gasket3. Using tin snips cut out the pattern showing in figure 1. Diameter of the circle is

140mm and dimensions of the supports are 20mmx35mm4. Bend all supports to 90ᴼ upwards5. Place a half of the tin within the boundary of the supports6. Drill a 3mm hole through each support and the tin at the same time to ensure

alignment7. Rivet the supports to the tin8. Take a length of binding wire and bend each end through two separate holes in

the tin clamps so as to form a handle. Repeat on the opposite side of the lid.

Chamber:

1. Remove handle from the tin2. Drill 16 25mm holes 70mm below rim of the tin. Space the 16 holes evenly

around the tin.3. Punch between 25 and 30 4mm holes in the base of the tin4. Wrap corrugate iron around the tin ensuring at least one overlapping valley and

secure the ends together via g-clamp5. Rivet ends together using 2-4 3mm rivets6. Slide this sleeve over the tin until the bottom edge is 50mm about the base of the

tin and the top edge lies 20mm above the rim of the tin. 7. Clamp the sleeve to the tin

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8. Drill 3x 4mm holes in the middle of the tin through the sleeve and tin. Ensure that they are spaced evenly around the circumference of the tin.

9. Fasten the sleeve to the tin using the nuts and bolts.

Handles:

1. Screw an elbow support to each end of the wooden cylinder. Repeat for the other handle

2. Mark where the holes for the handle will go on the sleeve and drill 3mm holes where marked

3. Rivet handles to sleeve.

Figure 3.1: Photograph of the lid cutout (James, 2010).

Figure 3.2: Photograph of the final product (James, 2010).

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3.1.10 Testing Estufa Finca Stove

The stove was tested on the 20th of January 2016. The weather was clear with little wind. Wood was collected, cut and chopped into the required size. Wood was then stacked in the stove up to the side holes. Small twigs and firelighters were used to start the fire. A timer was used to measure the time it takes for the wood to burn completely. After the fire had built up, a 5-litre tin filled with clean water (uncovered) was placed on a grid. The time it took to boil was recorded and the 5-litre tin removed. The fire was left burning until the wood burnt completely, leaving charcoal. The amount of smoke was measured visually and was rated on a scale of 1 to 5, 1 being extremely small and 5 extremely large smoke.

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4. Risk Assessment

When the stoves were tested and the Estufa Finca stove was built the correct PPE was worn (long pants, hair tied up and closed shoes, gloves). Care was taken when chopping the wood and only the handles (insulated) of the cans with the boiling water were handled to avoid burns. When the Estufa Finca stove was built it was built by people who had experience with using the required tools.

Table 4.1: Showing the results of the revised risk assessment for this practical

Hazard Classification Likelihood Hazard Effect Risk

Burns S/H Unlikely Minor 3 (L)

Chopping injury S/H Unlikely Insignificant 2 (L)

Slipping due to water leakage/spilling of tracer

S/H Unlikely Insignificant 2(L)

Building the Estufa Finca stove – using tools

S/H Unlikely Minor 5 (L)

Based on the revised risk assessment the tests are safe as all risks fall into the green section of the Anglo American Risk Matrix (see Appendix 9.1).

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5. Results and Discussion

5.1 Results of stove tests

5.1.1 Braai Test

The above table gives the time it took for the water in the paint can to boil. Photos of this test are included in the appendices and it was found that a large amount of smoke was released and the heat was not very well contained or concentrated. Ash was produced which can be used as fertilizer. See Appendix 9.3 for photographs of the test.

5.1.2 Estufa Finca Test

Additional Notes Open fire, windy, took can off fire to add more wood for about 1 min

Details22 min 39sSee photo

5 (a lot)Ash

PropertyTime taken for water to boil

Amount of wood usedAmount of smoke produced

What by-product is produced

Table 5.1: Showing the results of the braai stove test

Property DetailsTime taken for water to boil 13 min 48s

Amount of wood used Half a paint tin load

Additional Notes Breeze but not enough to affect flame. Hot day.

Time Fire Lasted 48 min 12s

Amount of smoke produced 3What by-product is produced Charcoal

Table 5.2: Showing the results of the Estufa Finca test

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The above table gives the time it took for the water in the paint can to boil and how long the fire lasted for. Charcoal was produced which can be used/sold as a fuel source. Interestingly a lot of smoke was released but less than the open fire. This is not supposed to happen. It could possibly be due to paint on the stove burning off or an error in construction. This would need to be addressed during design refinement. See Appendix 9.3 for photographs of the test.

5.2 Results of second site visit

After showing the sheephead traders the Estufa Finca stove they were apprehensive about it. This is because it is a lot smaller than the stove they are currently using. Even though it would be more efficient and should thus cook the sheepheads faster they are reluctant to change their cooking strategies. They also feared that the stove was too tall and it was discovered that an open fire is still needed to burn the wool off the heads.

It was found that the traders consider an expensive load of wood to be R200 and that there are a lot of employees working for the sheephead traders. We were able to follow the cooking process from start to finish and got a clear understanding of it. They estimate that the whole process takes about 1 hour and cooking the heads 20 to 30 minutes.

Since the last visit even more ash and wood had accumulated onsite and another truck was there to deliver even more wood.

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6. Conclusions

Based on the above results, the following conclusions were made:

6.1 Unpromising results of Braai test

Based on the results from the braai test it is clear that this method of cooking would not solve many of the problems at hand. It does however look neater and provides a single area for ash buildup and contains the hot coals. The ash can then be scooped from the stove into bags and disposed of as necessary. A braai-type stove could be used to burn the wool off the sheepheads and possibly in the long-term a chimney could be built to direct smoke away from immediate environment. The braai stove took too long to boil as the heat is lost to the surroundings. The sheephead traders take 20 to 30 minutes to cook a head so they would not want to have to wait that long just to get the water boiling. Will also have to buy bricks and cement to make the braai stand and it is a permanent structure.

6.2 Promising results of Estufa Finca test

The Estufa Finca stove boiled the water quickly, 13 minutes 48s. Some smoke was released which is not supposed to occur. This could be due to there being paint on the tin or an error in the design. More testing is needed, especially of larger drums and the necessary modifications should then be made based on the results. This stove is a promising option as it is cheap and easy to make and relatively easy to use.

6.3 Comments on Site Visits

As was expected the traders are unwilling to change to alternative cooking technologies which is understandable as they are successful now and more than likely fear that change will be bad for their businesses. They do not seem to understand the concept of efficiency i.e. the Estufa Finca stove at the size we built would not be able to cook the same amount of heads at one time as they currently do. However, being more efficient it should cook the heads quicker and overall result in faster production. They worry that their customers may have to wait for heads but like any restaurant of food place there is

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usually a waiting period, they have the monopoly in the area and that would be serving their customers in a healthier environment. Extra waiting time would not impact on sales due to the traders’ monopoly in the area with the added benefit of serving their customers in a healthier environment.

The waste and wood storage is an issue. Too much wood is being delivered to the site and ash is not being disposed of often enough. Wood and ash are dumped haphazardly instead of in designated areas for ash and wood.

Dirty water from boiling and preparation is disposed of into the storm water drain which contributes to poor environmental practices. The open fire releases too much smoke which causes air pollution and affects the health of surrounding residents.

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7. Recommendations

Based on the foregoing conclusions the following recommendations were made:

7.1 Implement Estufa Finca stove with modifications and further testing:

Perform further tests using a 55 gallon drum and based on those results make the necessary modifications

Conduct further research to find a place to produce the stoves for the traders. Possibly metal workers in the area could make them and sell them to the traders.

Hold a cook-off with the improved stove and their open fires so that they can see firsthand how the Estufa Finca stove is more efficient and it will bring people to their stalls which could mean more sales for them.

This option is an appropriate cooking solution , with modifications, for the short and long term

Engage with community forums like SNACS to make communicating with the traders easier.

7.2 Implement alternative stove designs

7.2.1 Brick fireplace (Braai)

More likely to be accepted by the traders as it is very similar to the cooking methods they currently use

This option is an appropriate cooking solution for the long term Build a chimney on the fireplace

7.2.2 Rocket Stove

Traders suggested a similar design Not as efficient as the Estufa Finca stove but does solve some of the problems at

hand This option is an appropriate cooking solution , with modifications, for the short

and long term

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7.3 Construct area for wood and waste storage

Provide one area for waste storage Provide one area for wood storage. Perhaps a bin or container. The waste and wood storage must be regulated to ensure they do not accept

more wood than they can use (do not want wood to rot) and that the ash is placed in the waste bags and collected to avoid an ash buildup as is occurring currently on site.

Ash could be sent to the Etafeni Center (Sihume Road, Nyanga) to be used as fertilizer. The ash needs to be transported to their site in Nyanga. Can contact ‘Stephanie Kilroe' stephanie@intermail.co.za to arrange this.

7.4 Connection to appropriate water pipes

In the long-term, setup a connection to the wastewater pipes so as to avoid the dirty water from the cooking poisoning the environment.

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8. References

Bank, W., 2014. Clean and Improved Cooking in Sub-Saharan Africa, Washington: s.n.

Himalayan Institute, 2013. Carpentry School Expansion: Help us grow.. [Online] Available at: https://www.himalayaninstitute.org/2013/05/10/carpentry-school-expansion-help-us-grow/[Accessed 2 February 2016].

James, L., 2010. Building SeaChar.org's Estufa Finca 5 Gallon BioChar Farm Stove, s.l.: s.n.

Regenold, S., 2009. Wood-Burning Camp Stove. [Online] Available at: https://gearjunkie.com/wood-burning-camp-stove[Accessed 2 February 2016].

Ternes, T. B. ,. S. D. A., 2011. Estufa Finca- Santos Piolt Project, s.l.: s.n.

TradeIndia.com, 2016. Biomass Stove For Cooking. [Online] Available at: http://www.tradeindia.com/fp1178865/Biomass-Stove-For-Cooking.html[Accessed 2 February 2016].

Wartluft, J. L., 1975. DOUBLE-DRUM SAWDUST STOVE , s.l.: United States Department of Agriculture .

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9. Appendices

9.1 Anglo American Risk Matrix

9.2 Health and climate impact of various cooking technologies

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Figure 9.1: Figure showing the climate and health impacts of various cooking stoves (World Bank, 2014).

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9.3 Photographs of the braai stove test

9.4 Photographs of the Estufa Finca stove test