Mutli-lateral filter underdrain block

In a filter system for distributing a backwash fluid uniformly throughout a bed of granular media, including:

• a distributor positioned beneath and supporting said media, said distributor having a plurality of walls defining a primary horizontal conduit and a secondary horizontal conduit, at least one of said walls containing metering orifices and having a wall thickness, t;
• the improvement comprising:
• an insert for at least one of said metering orifices, said insert having an inside diameter, d and a length, l;
• wherein the length, l of said insert is greater than the thickness, t of said wall, with the length, l of said insert equal to or greater than the inside diameter, d of said insert.

In a filter system for distributing a backwash fluid uniformly throughout a bed of granular media, including:

• a distributor positioned beneath and supporting said media, said distributor having a plurality of walls defining a primary horizontal conduit and a secondary horizontal conduit, at least one of said walls containing metering orifices and having a wall thickness, t;
• and
• a backwash fluid inlet for said primary conduit;
• the improvement comprising:
• at least one baffle positioned within said primary conduit to facilitate uniform flow of backwash fluid from said primary conduit through said metering orifices into said secondary conduit;
• an insert for each of said metering orifices, said insert having an inside diameter, d and a length, l;
• wherein the length, l of said insert is greater than the thickness, t of said wall, with the length, l of said insert equal to or greater than the inside diameter, d of said insert.

In a filter system for distributing a backwash fluid uniformly throughout a bed of granular media, including:

• a distributor positioned beneath and supporting said media, said distributor having a plurality of walls defining a primary horizontal conduit and a secondary horizontal conduit, at least one of said walls containing metering orifices that connect said primary conduit to said secondary conduit;
• and
• a backwash fluid inlet for said primary conduit;
• the improvement comprising:
• at least one baffle positioned within said primary conduit to facilitate uniform flow of backwash fluid from said primary conduit through said metering orifices into said secondary conduit, said baffle comprising at least one flange positioned within said primary conduit normal to a fluid flow direction therein.

In a filter system for distributing a backwash fluid uniformly throughout a bed of granular media, including:

• a distributor positioned beneath and supporting said media, said distributor having a plurality of walls defining a primary horizontal conduit and a secondary horizontal conduit, at least one of said walls containing metering orifices that connect said primary conduit to said secondary conduit;
• and
• a backwash fluid inlet for said primary conduit;
• the improvement comprising:
• at least one baffle positioned within said primary conduit to facilitate uniform flow of backwash fluid from said primary conduit through said metering orifices into said secondary conduit, said baffle comprising two posts adjacent one another centrally located within said primary conduit.

In a filter system for distributing a backwash fluid uniformly throughout a bed of granular media, including:

• a distributor positioned beneath and supporting said media, said distributor having a plurality of walls defining a primary horizontal conduit and a secondary horizontal conduit, at least one of said walls containing metering orifices that connect said primary conduit to said secondary conduit;
• and
• a backwash fluid inlet for said primary conduit;
• the improvement comprising:
• at least one baffle positioned within said primary conduit to facilitate uniform flow of backwash fluid from said primary conduit through said metering orifices into said secondary conduit;
• and
• a tubular insert positioned within each metering orifice to facilitate flow of backwash fluid from said primary conduit to said secondary conduit.

In a filter system for distributing a backwash fluid uniformly throughout a bed of granular media, including:

• a distributor positioned beneath and supporting said media, said distributor having a plurality of walls defining a primary horizontal conduit and a secondary horizontal conduit, at least one of said walls containing metering orifices that connect said primary conduit to said secondary conduit;
• and
• a backwash fluid inlet for said primary conduit;
• the improvement comprising:
• a baffle positioned within said primary conduit to facilitate flow of backwash fluid from said primary conduit through said metering orifices into said secondary conduit, said baffle comprising at least two posts upwardly extending within said primary conduit, said posts adjacent one another centrally located within said primary conduit.

In a filter system for distributing a backwash fluid uniformly throughout a bed of granular media, including:

• a distributor positioned beneath and supporting said media, said distributor having a plurality of walls defining a primary horizontal conduit and a parallel secondary horizontal conduit, at least one of said walls containing metering orifices that connect said primary conduit to said secondary conduit;
• and
• a backwash fluid inlet for said primary conduit;
• the improvement comprising:
• at least one baffle positioned within said primary conduit to facilitate uniform flow of backwash fluid from said primary conduit through said metering orifices into said parallel secondary conduit, said baffle comprising at least one flange positioned within said primary conduit normal to a fluid flow direction therein.

In a filter system for distributing a backwash fluid uniformly throughout a bed of granular media, including:

• a distributor positioned beneath and supporting said media, said distributor having a plurality of walls defining a primary horizontal conduit and a parallel secondary horizontal conduit, at least one of said walls containing metering orifices that connect said primary conduit to said secondary conduit;
• and
• a backwash fluid inlet for said primary conduit;
• the improvement comprising:
• at least one baffle positioned within said primary conduit to facilitate uniform flow of backwash fluid from said primary conduit through said metering orifices into said parallel secondary conduit, said baffle comprising at least one flange positioned within said primary conduit normal to a fluid flow direction therein;
• said flange being contiguous with at least one of the walls which define said primary conduit.

In a filter system for distributing a backwash fluid uniformly throughout a bed of granular media, including:

• a distributor positioned beneath and supporting said media, said distributor having a plurality of walls defining a primary horizontal conduit and a parallel secondary horizontal conduit, at least one of said walls containing metering orifices that connect said primary conduit to said secondary conduit;
• and
• a backwash fluid inlet for said primary conduit;
• the improvement comprising:
• at least one baffle positioned within said primary conduit to facilitate uniform flow of backwash fluid from said primary conduit through said metering orifices into said parallel secondary conduit;
• said baffle comprising at least two posts, upwardly extending and adjacent one another, centrally located within said primary conduit.

In a filter system for distributing a backwash fluid uniformly throughout a bed of granular media, including:

• a distributor positioned beneath and supporting said media, said distributor having a plurality of walls defining a primary horizontal conduit and a parallel secondary horizontal conduit, at least one of said walls containing metering orifices that connect said primary conduit to said secondary conduit;
• and
• a backwash fluid inlet for said primary conduit;
• the improvement comprising:
• at least one baffle positioned within said primary conduit to facilitate uniform flow of backwash fluid from said primary conduit through said metering orifices into said parallel secondary conduit;
• and
• a tubular insert positioned within each metering orifice to facilitate flow of backwash fluids from said primary conduit to said secondary conduit.

In a filter system for distributing a backwash fluid uniformly throughout a bed of granular media, including:

• a distributor positioned beneath and supporting said media, said distributor having a plurality of walls defining a primary horizontal conduit and a parallel secondary horizontal conduit, at least one of said walls containing metering orifices that connect said primary conduit to said secondary conduit;
• and
• a backwash fluid inlet for said primary conduit;
• the improvement comprising:
• a baffle positioned within said primary conduit to facilitate flow of backwash fluid from said primary conduit through said metering orifices into said parallel secondary conduit, said baffle comprising at least two posts, upwardly extending and adjacent one another, centrally located within said primary conduit.