EMAS不只是水與衛生流動學校的名字,也是整個技術及社會對水和衛生的概念;包含收集雨水、太陽能熱水器、風力發電、液壓頂桿、水處理、小型貯水池與水槽、各式各樣的手泵與腳泵,及鋼筋混凝土貯水池。
===Suitable conditions 適宜條件===
[[Image:Emas0.jpg|thumb|right|200px|Emas well drilling]]
Wells as deep as 90 meters can be drilled within 3-4 days without any machine employment and exclusively through the use of manual labor. Depths up to 100 m have been reached with the EMAS method. Most regions of South America (loam and sandy soils) are geologically suitable for this drilling method (predominantly rinsing or suction drilling). 僅以人力鑽鑿,不需使用機器可在三至四日內挖掘90公尺深的井。使用EMAS方法則可挖至100公尺。南美大部份的地區(砂壤土)在地質上適合此種EMAS鑽井方法(以沖洗式及吸式鑽井為主)。
This technique is suitable for weakly cohesive sands and silts. It adapts best to loamy soils, consolidated materials and light rock. In pure coarse sands, progress may be slow when only washing is used: the space between the drill stem and the well walls is relatively large, in relation to the slender drill stem, which makes for a slow upward flow. Sand may sink faster than it can be lifted out with the drilling fluid. In such conditions, it is easy to change from washing to suction drilling, by changing the handle. An example is shown in [http://blip.tv/file/2445078 this movie]. A universal drill bit was designed which is very good for washing and suction, and which cannot get plugged by stones.此技術適用於凝聚性弱之沙及淤泥;最適用於壤土、綜合材料及輕石。地質為純粗砂的情況下如果只使用沖洗式鑽井,進度會有些緩慢:因為就較狹窄的鑽桿而言,鑽桿及井壁間的空隙相對之下較大而造成水流緩慢向上流,導致鑽井泥漿中的沙下沉速度比上升的快。在此情況下能簡單的以改變把手來將沖洗式改變至吸式鑽井。例子提供於影片內。也有特別設計的萬能鑽頭對吸式及沖洗式皆十分好用,且不會被石頭堵塞。
The borehole stays open by water pressure. To prevent collapsing fluid因為鑽孔會因水壓維持敞開狀態,為防止崩塌,整個鑽井及安裝過程中流體鑽孔需保持滿水狀態。一個20公尺的井,一、二桶水即足夠;或每公尺約10-drilled boreholes must be kept full of water during the entire drilling and well installation process. For a 20 m well, one or two barrels are needed, or about 10-20 liters per meter.20公升水。
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! width="50%" style="background:#efefef;" | Advantages優點! style="background:#f0f8ff;" | Disadvantages缺點
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| valign="top" | - Very quick in fine and medium sand formations.在細微至中等沙質中使用起來極快。<br>- Very simple and cheap equipment. 操作儀器簡單便宜。 <br>- No need for machines. 無需使用機器。 <br>- No need for motor-powered mud pump and tower.無需使用電動泥泵及鑽塔。<br>- Can work below the groundwater table. 可在地下水位下作業。<br>- Uses non-corrosive, easily accessible and processable materials (PE and PVC). 使用防腐、易取得及易處理之材料(聚乙烯與聚氯乙烯)。 <br>- Low maintenance costs 維護成本低 <br>- Low cost (approx. US-$ 6 per meter of depth including hand pump). This is about 10 times more economical than the least expensive commercially available method.低成本(含手泵每公尺約六美元)。此方法比起市面上最低成本的方法要經濟約十倍。<br>- Adaptable to other countries and regions with similar soil conditions.適用於有著類似土質的其他國家及區域。<br>| valign="top" | - Generally limited to sandy soils and soft clay. 一般受限於砂質土壤及軟黏土。 - Enough working water needs to be available on the drilling location. 在鑽井工址需有足夠的水可供使用。 <br>- Leaving the borehole open during the night has a risk of collapsing.鑽孔徹夜敞開有崩塌危險。<br>- Slower than motorized drilling工程比電動鑽井耗時。<br>
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===Construction, operations and maintenance建造工程、營運及維護===Soft Clay is the easiest to drill, is suitable conditions 40 meters can be drilled in this material in one single day. For every meter, between 10 and 20 litre of water is needed, inlcuding washing. For a 20 meter well, one or two barrels of water are enough.軟黏土最易鑽鑿,在適宜條件之下,以此土質一天內可鑽鑿40公尺。包含清洗的水,每鑽鑿一公尺需10至20公升的水。一個20公尺的井只需一、二桶水即足夠。
Drilling is continuous: the drill bit is normally not removed from the borehole until it is finished or work is interrupted. As a portion of the drill stem is entered, another length of ¾” (19 mm) metal pipe with reinforced threads is screwed on. Drilling fluid (mud, a suspension of ordinary clay or bentonite with an adequate density) is pumped down through the drill stem using a hand-operated mud pump. The drilling fluid comes back up around the drill stem, carrying broken-up material. Sand and small stones settle in a settling area dug in the ground, and the mud is recycled through the pump. 鑽井是一項不間斷的作業:在鑽鑿工作完成或被中斷之前,鑽頭通常不能從鑽孔上移除。按照插入鑽桿的比例,固定另一個長3/4吋(19毫米)、有著強化螺紋之金屬管。以手動泥泵將鑽井泥漿(普通黏土的懸浮物或密度適中的皂土所成的泥)經由鑽桿抽空。鑽井泥漿回升時會帶著碎裂的材料。沙及小石頭會沈澱於地上挖的沈澱區域,泥土則會經由泵再循環利用。
Percussion action is performed by lifting the drill with a lever, mounted on the drilling tower, and letting it fall down. Moreover, the drill is rotated half-turns in both directions, enhancing the grinding action of the bit. 衝擊式作業為:以槓桿將鑽頭抬起,安裝在鑽塔上再使其落下。接下來,鑽頭的兩頭各旋轉半圈,加強其研磨作用。
The resulting hole diameter is about two inches, and wells are cased with cheap 1 1鑽鑿而成的洞直徑約為兩呎,便宜的1又1/2” (39 mm) PVC pipe. This can accommodate a 1 12吋(39毫米)聚氯乙烯管則作為井的套管。這能容納1又1/4” PVC piston pump, but if required, the upper portion of the well (down to about 1 m below the lowest expected water table) can be reamed to accommodate larger diameter pumps. 4吋的聚氯乙烯活塞泵。但如有需要,井的上半部(比最低預期水位低一公尺) 可擴大至能容納直徑稍大的泵。
As the entire drill stem is metallic, the weight of the drill increases linearly with depth, so the deeper the well, the heavier the stroke, but stroke length is limited to about 30 cm by the lever. 因為整個鑽桿為金屬製,鑽頭的重量會隨著深度線性增加。因此井越深,行程越重 (行程長度被槓桿限制為30公分)。
No temporary casing is used. Upon reaching the desired depth, drilling fluid is removed from the hole by injecting progressively lower density mud. If unstable layers are present, however, this diluting can make the well collapse before it can be cased. In such cases it may be better to case the well with mud in it and evacuate the mud afterwards by pouring or injecting water into the casing (backwashing). 不需使用臨時套管。越接近理想的深度,以逐漸注射低密度的泥土將鑽井泥漿從洞內移除。但如出現不穩定的分層,此稀釋行為可能造成井在裝套前崩塌。在此情況下,最好在井內先以泥裝套然後澆入或注入水進套管內排空泥土(反洗)。
The complete rig can be built locally in about any arc-welding workshop, using only materials found in ordinary hardware stores.完整的設備可於當地的任何弧焊工廠建造,材料在一般五金行即可購買。