Yemen Silver Filter Factory Update
Posted in Document, Water Filter Research, Yemen by kai on the May 28th, 2008Submitted by Richard Boni
This article is an update of activities since April 2007 that have led to commercial production of CWFs under trade name Silver Filters. Much can happen in a year.
In April/May 2007, Burt Cohen of Potters Without Borders visited Yemen and, among other things, taught us how to make Colloidal Silver Impregnated Ceramic Water Filters, a/k/a Silver Filters. This was a tremendous learning experience that put us solidly on the road to the successful production of Silver Filters. During the months immediately following the training, we practiced producing filters while attempting to market the concept to NGOs and other organizations working in health, water resources and community development. We were at the time receiving support from the Gesellschaft fur Technische Zusammenarbeir-Integrated Water Resources Management Project (gtz_IWRM). This support not only enabled the training by Mr. Cohen but also provided an avenue for a Pilot Project to test the effectiveness of Silver Filters in the field, in a Yemeni context. We initiated 2 pilot projects, one with CARE Yemen and the other with the Social Fund for Development, a local organization supported by the donor community and the Yemeni government. For these pilot projects we produced 290 filters for distribution to six rural communities, four of which depend upon surface water for drinking water. We are currently awaiting the official results of the Pilot Projects but initial anecdotes indicate that the users, especially those using surface water only, like the filters. I interviewed one woman who had the filter of one month. “Have you cleaned the filter yet,” I asked. “Three times,” she replied proudly. I asked her how much she would be willing to pay for a filter. “I would whatever price required.” Perhaps a bit emotional and even irrational but telling nevertheless.
During the past year or so, when we had no orders for Silver Filters, the owner of the factory, potter Ali Saleh Salman, was simultaneously excited and frustrated; where were the filter orders? A Yemeni saying, ‘Patience is beautiful’ was my response. In the meantime, we produced clay ovens for the wholesale market and flower pots and planters that were marketed directly to the expatriate community. Our customers for flower pots in 2007 included the German and American Embassies, the Ambassadorial Residences of the British and Royal Netherlands Embassies as well as other diplomats, oil company employees, aid workers and the well-to-do Yemeni elite. Because local pottery is merely heated clay, there is a definite market for improved Garden Ceramics. Our problem is that due to limited capacity at this time we are unable to produce Silver Filters and Garden Ceramics at the same time. Our plan is to establish the Silver Filter business and then expand the site in order to increase our production capacity to meet the high demand for improved pottery. If all goes well, we will build another kiln.
In pursuit of opportunities to market Silver Filters, at the end of February 2008 we signed a contract with the International Committee of the Red Cross (ICRC) to produce 1000 Silver Filters. This was our first sizeable contract for Silver Filters; until then we had produced roughly 400 filters over an 8 month period so producing 1000 filters in 2 months would test our mettle. Because Silver Filters take up a lot of shelf time and space, the first order of business was to build additional shelving. We had room to dry and store about 340 filters and needed room for at least 500 or more. However, shelving is expensive in Yemen and we had to find an inexpensive way to meet our need. Old wooden palettes served the purpose well and we built shelves to hold about 800 filters!
Our first day of pressing produced 31 filters, a bit below our projected target of 40. We had to move employees around in a way that matched production needs with their capabilities and skills. Over the next 2 weeks we continued adjusting and improving until we reached 60 filters a day. Our production team consists of two employees mixing and weighing clay, three on the press and record-keeping and one doing odd chores to facilitate production. Two others are responsible for firing, flow testing, Colloidal Silver application and preparing filters for distribution. In the end, however, the team works together on whatever is required that day. It should be noted that the site is without electricity and all mixing and screening is done by hand, a process that takes considerable time and effort. From our perspective, therefore, pressing 60 filters a day is impressive. After a week or so we began firing.
The kiln is a gas-fired brick kiln designed in 2006 by Bernd Phannkuche, the publisher of New Ceramics and one time kiln designer. It is designed to use sixteen 20kg gas canisters, eight at a time: If pressure is lost during the firing, the kilnsman can switch to the other bank of eight gas tanks. These large canisters, however, are uncommon and hard to refill in Sana’a. Also, the refills are not always complete, i.e. they are often not filled completely. Gas tanks are not weighed and the customer never knows how much gas is in the tank at the time of purchase. Smaller 10kg canisters are ubiquitous in Sana’a and are usually filled to capacity. Our potter Ali Saleh figured out that he can fire the filters as well with the small tanks as with the larger ones and so uses the smaller tanks.
During the first five or six firings, we mapped the filter placement; this enabled us to observe the kiln placement for each filter and match that with the results of the flow tests. Our target firing temperature began at 900C but because filters at the bottom of the kiln were flowing at only 1l/hr and our flow rate target is between 1.5 and 3 liters per hour, we adjusted the target temperature to 940C. This has resulted in a greater number of filters passing the flow test with an average of 1.9 – 2.3 l/hr. It should be noted also that we adjusted our clay-sawdust mix to 8.540kg. – .460kg, from 8.550kg – .450kg, a minor move that nevertheless seems to have improved average flow rates. I haven’t made recent calculations but it seems that the average flow rate has increased slightly over the last month or so. Because it takes at least a day for the kiln to cool, we fire every other day or so.
During the 1.5 months we produced for ICRC, we ended up with about 2000 filters; not bad for a start-up facility. After the ICRC production run, a few of the employees went to their village for a family visit. Over the next week or so we began planning for the expansion of the site. We are currently building a storage room to store finished filters, receptacles, brushes, taps, etc. and we need to replace part of the roof over production site. We recently received a new order from the ICRC for 800 more filters while CARE Yemen has ordered 360 and we continue to seek additional contracts. In the meantime we have been selling Silver Filters to individual customers. Our long time supporter, gtz-IWRM purchased 90 filters and CARE Yemen bought 10. These sales help spread the word about the filters and win converts, if you will. There is considerable interest in Silver Filters largely because Yemen lacks potable water in all geographic areas and across all levels of society. Drinking water can be purchased in nearly every small town, large village or city but this is expensive, especially for the less fortunate, i.e. most of the population.
In June 2008, gtz-IWRM will host a workshop to publicize the results from the Pilot Projects. We hope to invite all organizations involved with water in Yemen as well as private investors, traders, etc. As with all businesses, we hope to expand production and develop distribution channels. Hopefully, in the not too distant future, Silver Filters will become a household name in Yemen.
