High Pressure Cleaning of ZHF Filter Elements

All filter elements has to be stored in a vertical position as close to each other as possible top and bottom, to avoid any part of the rim resting on the filter surface of the element behind it. If a pallet is available the elements can be stored stacked properly horizontally, however there is a chance of larger elements being dragged over the screen below it. All filter elements have to rest on two parallel 2 x 4 or 4 x 4 boards (to prevent them from moving and to keep them off the floor), the elements themselves should not touch the floor. Basic High pressure sprayers are requirement:

Minimum capacity: 3,500 to 5,000 psi at 15 to 18 gpm. (280 – 340 bar at 3,000 – 4,000 l/h) (Pending on the product heat or solvent might be required in the sprayer)

Filter elements with KPZ 55 or PZ 80 to 120: (Screens 55 to 100 micron with no cellulose)

Set the elements up as vertical as possible, with supports towards the outer edge on both sides (to avoid wobble from the force of the spray).

Element is supported by pipes on both sides to prevent wiggling when the high pressure sprayer is applied. First clean the back of the element (seal area), then clean the screen side.

Horizontal Cleaning

Filter elements with Durafil, or fine screens, (or any elements

with high loads of contaminants, or cellulose) These elements will be cleaned horizontally resting on a pallet, first upside down,

then with the hub up from the ground and free drainage through the hub.

Cleaning the spacer seal grove and the Primus channels on the back of an

element, water should spray out of the vertical internal hub feed channels to indicate they are open on ZHF/Z-Primus elements.

Always clean the back of the elements prior to cleaning the screen.

Spray from rim towards center, driving the contamination out the center hub. Water should leak from the filtrate drain channels into the hub, if not they may have to be manually opened.

Spray the element from the edge towards the center, making sure that material under the membrane or screen is drained out through the hub center.

Concentrate the spray on the periphery of the element (this is normally where the heaviest deposits are), however do not forget the spray the whole element surface on both back and front, making sure the seal areas are clean Clean until there are no dark wet areas showing on the rim of the element, the water will not be retained in a clean element (there should be no deposit felt along the clamp ring).

Raise the element vertical to check the edge drainage.

Cleaning check, dark area still contains dirt.

Durafil element no properly cleaned with DE deposit remaining at edge. This could be the result of spinning the element at higher speed than speed

1 during the internal clean element steps, or placing the element vertical during external cleaning.

Durafil will not allow backwards particle flow, it instantly plugs up.

Dirt is Cellulose and/or DE lodged under a 80 micron or finer screen after 1

year of normal old type cleaning.

Cellulose and DE lodged under the edge of the screen

Clean Element, water drains out on the bottom of the rim.

Clean element edge after extensive cleaning. Tom Thilert Technology Director Pall Corporation