DESCRIPTION
Working of the Medium size Drain Filter
a. This is a floating filter assembly to separate trash and plastics floating on water surface in streams and drains. This assembly is secured on both sides to the side walls or to the bank by chains.
b. As the floats are laid out
c. The assembly consists of floats (1) connected to main frame (2) and these floats provide buoyancy and ensures the entire assembly and its weight is supported on water surface.
d. The floats are connected to the main frame with strengthening members (3) to provide strength to the connection between the floats and the main frame.
e. There are two floats (1) on the back (downstream) side of the mesh (5) and one float (7) in front of the mesh (5). These floats together provide the full buoyancy to the assembly. The float on the upstream side (7) ensures the assembly does not tilt or fall to the forward side. These floats ensure the buoyancy is well spread out and the centre of gravity of the assembly and the downward force through this centre of gravity falls between these floats.
f. There is a mesh (5) with mesh opening of pre specified size which stops trash on the upstream side which is larger than this mesh opening. This mesh extends for the full width of the assembly. This mesh is made of steel or aluminium to give it strength against impact by trash.
g. As the assembly is held by chain in its place the flowing waters bring the surface trash to the upstream side of this mesh (5). The trash and plastics larger than the mesh opening size is trapped in front of the mesh while the water is free to flow through the mesh and under the mesh.
h. This also ensures the upstream side is never flooded since water is free to flow below the floating MDF assembly.
i. This mesh (5) is held in place by strength members (6). These strength members are curved at the bottom (8) and this gives a curved shape to the mesh at the bottom.
j. This curved shape (8) is given so that trash which is trapped does not
slip below the mesh and go past the assemble. k. On ends of the main frame, there are curved rubbing members (4). These
curved rubbing members ensure that the system slides up and down
freely within the drain walls and the point of contact with the side walls
is not a sharp point that may snag on the wall.
1. The assembly is held by chain connected to main frame at the eye (9) and the other end of the chain is connected to the walls.
m. When there is no water in the canal or drain, the entire assembly is sitting on the canal bed. When water level rises in the canal, the entire assembly starts lifting and floats on water surface.
n. Thus the system ensures it is floating stably and trash is trapped on the font side of the assembly.
o. Lifting eyes are added to facilitate the installation of MDF (10).

Claim 1:
We claim - the particular arrangement of the floats on the frame, that ensures a stable floating platform, in running waters when trash is collected on upstream side.
Claim 2:
We claim - The flower shaped semi circular pipes on extremities of width which . act as rubbing bands on side walls.
Claim 3:
We claim - The curved shape at bottom of the mesh strengthening members that stop trash from escaping under the mesh.