Description

Laboratory Pressure Sample Filters, Bench Model, mild steel construction, complete with hand wheel, pressure relief valve, quick release air connection, oversized rubber seal gasket, air release valve, pressure gauge, stainless steel backing screen and filter cloth.

Laboratory Sample Pressure Filter, Floor Model, mild steel construction, complete with top swing away lid with hand-wheel, base lowers for removal of cake, pressure relief valve.

Quick release air connection, oversized rubber seal gasket, air release valve, pressure gauge, stainless steel backing screen, rubber lining, filter cloth and structural steel support frame.

Laboratory Pressure Filters Installation Instructions

The Laboratory Pressure Filter is designed for batch filtration of metallurgical products. It is primary use is in dewatering test products in a laboratory but is equally useful for filtering mill samples.

The filter consists of a fabricated base, a cylinder that serves as the pulp container, and a yoke with a hand wheel for securing the lid. The filter cloth and paper are supported on a stainless steel backing screen placed over the drain grooves in the base. A tapped and threaded opening is provided in the base for the removal of filtrate.

The base of the filter permits mounting of the filter on any flat surface. Two holes are drilled in the base for mounting purposes.

A water connection with two (2) to three (3) feet of rubber tubing should be provided at the filter location for washing purposes.

A ½” rubber drain hose connected to the hose barb in the base is required.

A regulated air supply set at 60 psi. connected to the air connection (1/2”) is required for operation.

Operation

• Place the filter cloth over the stainless steel backing screen.
• Wet the filter cloth thoroughly using a small diameter hose connected to your water supply.
• Place a piece of filter paper (customer supply) over the wet filter cloth. The filter cloth should be sufficiently wet to fully wet the superimposed filter paper. If not gently spray additional water on the filter paper until it is thoroughly wet.
• Place the cylinder (pulp container) in the base.
• Pour the pulp to be filtered in to the filter.
• Place the lid in place on top of the cylinder insuring the cylinder sits in the machined groove of the lid.
• Swing the yoke up and tighten the pressure screw on the lid with the handwheel
• Connect the air supply to the “quick as wink air connection”
• After all visible moisture has been removed continue to apply pressure for a few minutes to insure a reasonably dry cake. If the filter cake contains soluble compounds which should be eliminated, water washes can be applied after the initial liquid has been pulled out.
• Disconnect the air supply
• Release the air by opening the drain cock
• Once all the air is released loosen the pressure screw and swing the yoke back
• Remove the lid.
• Carefully remove the cylinder and lift the filter cake off by picking up the filter cloth.
• Discharge the filter cake and filter paper into the drying pan. If a small amount of filter cake adheres to the cylinder it can be removed with a spatula or your finger and then rubbed onto the filter paper to avoid and loss of solids. Place the pan in a drying oven.
• Wash the filter with water and it is ready for reuse.

Helpful Hints

 Pulp such as concentrates and relatively slime-free products can be quickly filtered; however, slimy products will filter at a slow rate. Time can be saved by flocculating the pulp and decanting of the clear solution before filtering, this minimizes the amount of filtrate that must be pulled through and enhances filtration due to the flocculated condition of the solids. It also reduces the volume of material to be filtered within the capacity of the cylinder. Occasionally clear liquid can be siphoned off the filter to save time.

The sample to be filtered should always be thoroughly mixed and then poured into the filter. This procedure minimizes the initial blinding of the filter paper with slimes only.

With certain slimy pulps it is desirable to filter only a limited amount of sample and then remove the cake and repeat this procedure until all the pulp has been filtered. This method permits using a clean filter paper for each batch and avoids the formation of a thick and virtually nonpermeable cake. Considerable time can be saved if the volume of sample in this instance is rather large