- Abyssinian well device
- Hydrogeological requirements
- Choosing a place for a well
- Bottom filter
- Well installation
Sometimes the simplest autonomous source of water with a small flow rate is enough for the water supply of the dacha, the main thing is to arrange it simply and with minimal costs. An example is the Abyssinian well, the construction of which does not require special equipment or exhausting digging..
Abyssinian well device
Technically, an Abyssinian well is a pipe with a lumen of 25–40 mm, with which the soil is punctured to the depth of the first aquifer, therefore it is also called a needle well. In the lower part there is a needle filter, the so-called spear. It prevents the pipe from silting up and makes it easier to clog during installation..
1 – sand aquifer; 2 – clay; 3 – filter; 4 – squeegee clutch; 5 – pipe; 6 – self-priming pump
The water in the Abyssinian well comes from deposits of sand and fine gravel, which are located directly under the loam. A self-priming pump is used to extract water from a well..
The piezometric level should not exceed 8-10 meters. At higher values, a high power pump, airlift or deepening into the ground will be required, followed by the arrangement of the caisson.
The borehole pipe sometimes sinks much below the static level, depending on the conditions of occurrence of the water-resistant layer. Aquifer on the ground should include mainly rocks of high hygroscopicity. An increased content of clay and silt is extremely undesirable: this can greatly reduce the flow rate of the well, which, even under optimal conditions, rarely exceeds 0.8–1 m3/ h.
It is not necessary to conduct hydrogeological surveys, but it is advisable to interview neighbors who have encountered the construction of wells or drilling wells. If at a depth there are large boulders or the soil is too dense, the construction of a well is impossible..
Choosing a place for a well
One of the main advantages of the Abyssinian well is that it can be mounted almost anywhere on the site and even indoors. At the same time, the landscape is not disturbed, and the pipe emerging from the ground is easy to decorate. The pump does not have to be located above the well, but if there is a caisson, it is better to place it in it. In this case, consider the issue of power supply in advance..
The main requirement for the area is the absence of nearby sewers, drainage collectors and other sources of pollution.
The bottom filter is the elongated part of the “spear” without a tip. It is made from a piece of stainless pipe at least 1 meter long. The pipe has 4 or 6 rows of holes 8–10 mm in diameter with a pitch of 5–7 cm, the holes in adjacent rows are staggered. A 20 mm plumbing thread is cut at both ends of the pipe..
The pipe must be tightly wrapped in a spiral with stainless steel wire with a pitch of about 1 cm between turns. The pipe is then wrapped in one or two layers of filter mesh or stainless steel metal cloth. It is advisable to take the cell size no more than 0.2 mm.
The mesh and wire are attached to the pipe by soldering, which requires a balloon-type propane burner with piezo ignition. The thickness and length of the flame core should not exceed 5 and 35 mm, respectively. For home soldering, the Kemper 1060pz is well suited, but you can find cheaper analogs..
The stainless steel is brazed with pure tin without impurities, or with silver-containing solders. A paste of borax and boric acid in equal proportions on a solution of zinc chloride acts as a flux. First, the surface of the pipe must be sanded with 500 grit sandpaper and the ends of the spiral must be soldered. Along the pipe, the mesh is laid out in such a way that after tacking it you can wrap the pipe and the sieve closes all the holes. The mesh is tied in dots to the spiral with a step of 4-5 cm.
First, the wire is heated until the surface becomes cloudy and covered with a gray coating. Then a pencil of solder is introduced into the flame of the burner and slightly heated, dipped in flux to collect it a little on the tip. The flux must be put on a heated metal and wait until it spreads and partially dries, then you can melt a little solder and tin the surface. The mesh is also etched with flux and soldered with wire.
After tacking, the mesh is wrapped around the pipe and the edge is cut off on the line of dots with a slight overlap of 2-3 mm. Next, you need to solder the one-piece longitudinal seam, and solder the side edges of the mesh filter directly to the pipe. Pull the mesh as tight as possible to make soldering easier..
To facilitate the immersion of the pipe in the ground, a tapered tip is attached to its lower end. Its diameter in the wider part is 3-5 cm larger than the diameter of the main pipe, the length usually does not exceed 120 mm.
You can make the tip yourself from a 50 mm pipe segment 110 mm long. This is for a 25mm pipe filter, for larger diameters the tip should be wider.
First you need to find a pipe seam or draw a straight longitudinal line, from which the marking will be carried out. From one end of the pipe, you need to retreat 40 mm and draw a circle over the entire surface. This circle is divided into 4 equal segments, marks are applied. In the same way, mark the free edge of the pipe, but with an offset of 1/8 of the circumference. Thus, on the surface of the pipe, you need to mark and cut out 4 identical triangular teeth with a height of 70 mm.
They are simply folded inward until they converge and form a cone. The seams are welded from the inside, then from the outside after cutting the gap. The surface is ground with angle grinder to a conical shape. The open end of the tip must be plugged and welded to the plug, strictly in the center, with the grommet for the thread on the filter pipe. Now it is enough just to screw the cone onto the filter and tighten it well, this connection does not need to be sealed.
In addition to the bottom filter, a stainless pipe is also needed, which is cut into sections of 1.5 meters. It is not necessary to take too long, it will be inconvenient to hammer. At the ends of the segments, a plumbing thread is cut with a length of about 20 mm and the required number of shrink sleeves is purchased.
To facilitate the work, it is recommended to drill a hole about one and a half meters deep with a garden drill. A “spear” is inserted into it, twisted with a pipe by a surge clutch. The connection is sealed with tow and silicone.
A “grandma” is put on the free thread of the pipe – a 30-centimeter section of a pipe of a larger diameter, into the end of which a surge sleeve is welded, and 4 holes are drilled along the length with welded M10 nuts. The “headstock” is screwed onto the pipe thread, the bolts in the nuts are tightened and loaded with an additional weight of about 30 kilograms. With clear, but not too strong blows of the sledgehammer, the pipe is immersed in the ground, then the “grandma” is removed, the next pipe is wound and again hammered. It is necessary to constantly monitor the recoil from the pipe, it must be soft, elastic. If there is a strong recoil, the pipe rings and does not sink upon impact, then a stone or other impassable obstacle has appeared on the way. In this case, the pipe is removed from the well and installed in another place..
Starting from the fourth extended pipe, water is poured into it. If, upon impact, the water abruptly left, then the aquifer has been reached. The pipe is driven into another 70–100 cm, after which the installation of the well can be considered completed. After blocking the pipe, a check valve is screwed onto it and connected to the pump by means of a PND pipe.