Filter press with adaptive automated control arrangement

A method for controlling slurry pressure in a filter press in which a slurry material is supplied under pressure to a plurality of filter plates by a feed pump which is activated by a fluid having a defined pump pressure, comprising the steps of:

• actuating the feed pump for operation at a selected initial said pump pressure to feed the slurry into the filter press;
• thereafter, gradually increasing the pump pressure until the slurry pressure reaches an upper pressure limit;
• thereafter, executing a sequence of steps defined by (1) determining that the slurry pressure has reached the upper pressure limit, (2) recording a trigger point in time at which the slurry pressure reached the upper pressure limit, and (3) determining whether the slurry pressure subsequently falls below a lower pressure limit within a predetermined period of time commencing at said trigger point;
• and
• thereafter, and only if the slurry pressure falls below the lower pressure limit within said predetermined period of time, repeating said sequence of steps until the slurry pressure fails to fall below the lower pressure limit within said predetermined period of time;
• and
• shutting down the feed of slurry into the press only if the slurry pressure fails to fall below the lower pressure limit within said predetermined period of time and said predetermined period of time elapses.

A process for controlling a filter press having multiple diaphragm-type plates, a feed pump for pressurizing and supplying slurry into the filter press, and a control unit for controlling operation of the filter press, comprising the steps of:

• providing said press with a programmable control including a control panel having operating keys associated therewith and a visual display for displaying operational prompts and parameters;
• manually inputting into said control via the keys operational parameters including (1) an upper pressure limit corresponding to a maximum slurry pressure at which a press filling cycle will end, and (2) a time interval which determines a minimum length of time which the pump will continue to operate following sensing of the upper pressure limit;
• supplying pressurized air to the feed pump for actuating the feed pump to supply slurry into the press;
• substantially continuously sensing the slurry pressure discharged from the pump and adjusting the air pressure supply to the pump so that the air pressure to the pump is increased whenever the slurry pressure increases so as to maintain the air pressure above the slurry pressure by a substantially uniform pressure difference;
• periodically and sequentially displaying, in the display on the control panel, throughout the filling cycle the pump air pressure and the slurry pressure;
• recording the elapsed time during the filling cycle in progress;
• recording the length of time required to complete the previous filling cycle;
• periodically displaying the elapsed cycle time and the prior cycle completion time in the display during the press filling cycle in progress;
• computing and recording the number of complete filling cycles of the press during the 24 hour time interval which occurred prior to initiation of the filling cycle currently in process;
• periodically displaying the number of completed cycles during the prior 24 hour interval in the display of the control panel during the press filling cycle in process;
• and
• shutting down the feed pump and terminating the filling cycle when the slurry pressure does not fall below a predetermined lower pressure limit and the predetermined time interval thereafter times out.

A process for controlling a filter press having multiple diaphragm-type plates, a feed pump for pressurizing and supplying slurry into the filter press, and a control unit for controlling operation of the filter press, comprising the steps of:

• providing said press with a programmable control including a control panel having operating keys associated therewith and a visual display for displaying operational prompts and parameters;
• manually inputting into said control via the keys operational parameters including (1) an upper pressure limit corresponding to a maximum slurry pressure at which the press fill cycle will end, and (2) a time interval which determines a minimum length of time which the pump will continue to operate following sensing of the upper pressure limit;
• providing an air pressure source which maintains a relatively uniform line pressure which is typically greater than the air pressure supplied to the pump;
• supplying pressurized air to the feed pump for actuating the feed pump to supply slurry into the press;
• supplying the line pressure to the pump through a pressure controller for reducing the line pressure to a desired pump air pressure;
• continuously monitoring the line pressure;
• periodically displaying said line pressure upstream of the pressure controller in the display on the control panel during the press filling cycle in process;
• comparing the line pressure with said upper pressure limit;
• reducing the value of said upper pressure limit when the upper pressure limit is less than a predetermined pressure difference smaller than said line pressure;
• thereafter repeating the latter two steps;
• substantially continuously sensing the slurry pressure discharged from the pump and adjusting the air pressure supply to the pump so that the air pressure to the pump is increased whenever slurry pressure increases so as to maintain the air pressure above the slurry pressure by a fairly uniform pressure difference;
• periodically and sequentially displaying, in the display on the control panel, throughout a filling cycle the pump air pressure and the slurry pressure;
• and
• shutting down the feed pump and terminating the filling cycle when the slurry pressure equals the upper pressure limit and the predetermined time interval thereafter times out.

A process for controlling a filter press having multiple diaphragm-type plates, a feed pump for pressurizing and supplying slurry into the filter press, and a control unit for controlling operation of the filter press, comprising the steps of:

• providing said press with a programmable control including a control panel having operating keys associated therewith and a visual display for displaying operational prompts and parameters;
• manually inputting into said control via the keys operational parameters including (1) an upper pressure limit corresponding to a maximum slurry pressure at which the press fill cycle will end, and (2) a time interval which determines a minimum length of time which the pump will continue to operate following sensing of the upper pressure limit;
• supplying pressurized air to the feed pump for actuating the feed pump to supply slurry into the press;
• substantially continuously sensing the slurry pressure discharged from the pump and adjusting the air pressure supply to the pump so that the air pressure to the pump is increased whenever slurry pressure increases so as to maintain the air pressure above the slurry pressure by a fairly uniform pressure difference;
• sensing when the slurry pressure decreases;
• maintaining the pump air pressure substantially constant when the slurry pressure decreases;
• resuming increasing the pump air pressure only when the slurry pressure is again within the predetermined pressure difference of said pump air pressure;
• periodically and sequentially displaying, in the display on the control panel, throughout the filling cycle the pump air pressure and the slurry pressure;
• and
• shutting down the feed pump and terminating a filling cycle when the slurry pressure equals the upper pressure limit and the predetermined time interval thereafter times out.