Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

[SAMPATH S]

FILTERS (Contd.)

Type-2 Effective RWH filter fabrication:

Type 2 filter fabrication is very similar to that of Type 1, with a few modifications.

For each of the inner filter buckets, similar 20 liter paint buckets are used. Only difference is that in addition to the filtration mesh at the bottom, mesh is also pasted along the sides. Approximate measurement for cutting along the sides may be about 8 to 10 inches. These measurements are approximate and may vary slightly from case to case.

Inner bucket cut along the sides also:

Type 2 inner bucket slots cut bottom and sides inner view.jpg (74.65 KiB) Viewed 565 times

Type 2 inner bucket slots cut bottom and sides bottom view.jpg (102.9 KiB) Viewed 565 times

[SAMPATH S]

FILTERS (Contd.)

Inner bucket with mesh pasted along the sides, in addition to bottom:

Type 2 Filter with mesh pasted inner view.jpg (169.36 KiB) Viewed 564 times

Type 2 pre-filter mesh pasted inner bucket.jpg (293.83 KiB) Viewed 564 times

[SAMPATH S]

FILTERS (Contd.):

The outer bucket used is of a larger size, say about 25 liters. Due to this, the inner bucket would completely sit inside the outer bucket, which will not allow proper outflow of filtered water. We need to suspend the inner bucket from the outer bucket, allowing a gap of atleast half an inch along the sides and at the bottom about 2 inches. This is done by fixing a pipe of suitable dia along the rim of the inner bucket, so that the desired suspension is achieved. The outer bucket is so chosen that it has a gap of about half inch to maximum one inch around the inner bucket.

In my present model, the gap is close to 1 inch. Hence I used the washing machine outlet pipe to achieve the necessary suspension. This pipe has a dia of more than 1 inch.

IMG_20210427_172054076.jpg (204.95 KiB) Viewed 561 times

Picture of the Type-2 Effective RWH filter wall mounted presently being used by me.

Type2 Filter system wall mounted.jpg (33.32 KiB) Viewed 561 times

This completes fabrication of Type-2 filters.

[SAMPATH S]

FILTERS (Contd.):

Other aspects:

Point to note that the inlet pipe to the filter should be at the center of the filter bucket. If not there may be frequent occurrence of blockage.

Rain water is made to fall through the pipe routed (as described in the piping section) from a height vertically into the pre-filter. The pipe is made to just enter the pre-filter bucket (and no further). The water falling with great force from a height automatically pushes the impurities to the sides of the bottom filter mesh keeping the center portion free for filtration and the filtered water is routed to the fine filter in a similar way. This dynamics of water falling at force from a height helps the filter to avoid blockage at the middle of filter mesh.

After filtration through the 75 micron fine filter, the filtered water goes to the sump tank. To the collar of the fine filter, a piece of 75 mm pipe is attached (without pasting). This pipe connects to the 75 mm elbow (bush/washer type), the washer of which is removed to facilitate easy assembly/disassembly of the fine filter. The pipe further leads to the sump tank through appropriate piping. Pictures of my installation below:

Filter outlet to sump pipe.jpg (186.11 KiB) Viewed 561 times

Filter to sump.jpg (258.6 KiB) Viewed 561 times

Both the pre-filter set and the fine filter set of buckets can be easily pulled out for the purpose of cleaning. Please note to clean the impurities collected in the filter meshes, along with the outer buckets regularly everyday when it rains. If the impurities remain they may start decaying and may contaminate the further rainwater, besides possibly blocking the filter mesh.

To facilitate cleaning of the buckets easily and to reduce the water used for cleaning, one may use a faucet jet, preferably placed near to the filters. By directing the jet water appropriately, the filters can be cleaned fairly quickly.

The filter buckets are made of plastic. Hence it may be necessary to ensure that it is protected from direct sunlight. Further, shading the filter unit area would also help one to monitor the filtration aspects even during heavy rains.

With this, the fabrication part of the Effective RWH Filter is complete.

To get info about the fillter, also refer to my following videos:

https://www.youtube.com/watch?v=2yO3Q2-5SEo

https://www.youtube.com/watch?v=glAbOpJ0c14