Methods and Apparatus for Foam Control in a Vacuum Filtration System

A vacuum collar for use on a filtrate storage bottle for a liquid filtering system comprising:

• a vacuum port for connection to vacuum;
• a vacuum collar coupling structure for making connection to the storage bottle so that the vacuum is applied to the interior volume of the storage bottle;
• and
• a flow diverter having a surface that catches sample liquid drawn by the vacuum into the storage bottle and directs the sample liquid onto a sidewall of the lower storage bottle.

A liquid filtering system comprising:

• an upper sample reservoir for receiving a volume of sample liquid,
• a sample filter positioned proximate a bottom of the sample reservoir for mechanically filtering the sample liquid;
• a lower storage bottle for receiving filtered sample liquid from the sample reservoir;
• a vacuum in fluid communication with the lower storage bottle to draw sample liquid through the sample filter into the storage bottle;
• and
• a flow diverter tube connected to receive sample liquid drawn through the sample filter and to guide the sample liquid down close to a bottom interior surface of the lower storage bottle.

A vacuum collar for use on a filtrate storage bottle for a liquid filtering system comprising:

• a vacuum port for connection to vacuum;
• a vacuum collar coupling structure for making connection to the storage bottle so that the vacuum is applied to the interior volume of the storage bottle;
• and
• a flow diverter tube connected to receive sample liquid drawn by the vacuum into the storage bottle and having an outlet end close to a bottom of the storage bottle so that sample liquid is guided down through the tube and out into the bottle near the bottom of the storage bottle.

A base for use with a liquid filter assembly comprising:

• a weighted bottom to avoid tipping over;
• a vacuum inlet port;
• a support arm secured to the weighted bottom and having a vacuum outlet port arranged in a cradle for connection to the liquid filter assembly;
• a fluid conduit connected between the vacuum inlet port and the vacuum outlet port;
• and
• wherein the cradle is movable relative to the weighted bottom so as to hold the liquid filter assembly tilted at a non-vertical angle.

A liquid filtering system comprising:

• at least one filter assembly including:
• an upper sample reservoir for receiving a volume of sample liquid,
• a sample filter positioned proximate a bottom of the sample reservoir for mechanically filtering the sample liquid;
• a lower storage bottle for receiving filtered sample liquid from the sample reservoir;
• and
• a vacuum in fluid communication with the lower storage bottle to draw sample liquid through the sample filter into the storage bottle;
• and
• a base for receiving a filter assembly to stably support the assembly in an adjustable orientation relative to vertical so that the filter assembly may be held in a tilted non-vertical orientation.

A base for use with a liquid filter assembly comprising:

• a vacuum inlet port;
• a support arm extending up from a bottom of the base and having a vacuum outlet port arranged in a cradle for connection to the liquid filter assembly;
• a fluid conduit connected between the vacuum inlet port and the vacuum outlet port;
• and
• a vacuum controller for regulating fluid flow through the fluid conduit.

A liquid filtering system comprising:

• at least one filter assembly including:
• an upper sample reservoir for receiving a volume of sample liquid,
• a sample filter positioned proximate a bottom of the sample reservoir for mechanically filtering the sample liquid;
• a lower storage bottle for receiving filtered sample liquid from the sample reservoir;
• and
• a vacuum in fluid communication with the lower storage bottle to draw sample liquid through the sample filter into the storage bottle;
• a base for sitting on a work surface and for receiving a filter assembly to stably support the assembly;
• and
• a vacuum controller accessible atop the work surface for regulating the vacuum.

A method for filtering liquid samples comprising:

• securing a filter assembly above a work surface, the filter assembly including an upper reservoir above a filter and a storage bottle below the filter for receiving filtered liquid drawn through the filter;
• depositing a liquid sample into the upper reservoir;
• applying a vacuum underneath the filter to draw liquid through the filter;
• and
• adjusting a controller to regulate the applied vacuum to reduce foaming of the filtered liquid sample.