1. A filter element for separating particulate matter from a gas stream comprising a filter medium comprising a porous substrate having two major surfaces wherein the substrate is adhesively bonded over one of the major surfaces to a first nanoweb having a basis weight less than about 2 gsm by a layer of adhesive and wherein the filter medium is made by a process comprising the steps of
(a) forming a nanoweb directly onto a carrier layer;
(b) providing a porous substrate having two major surfaces;
(c) applying a layer of adhesive to at least a portion of one surface of the porous substrate while it is not in contact with the nanoweb;
(d) contacting the adhesive layer with the nanoweb and bonding the nanoweb to the porous substrate wherein the adhesive layer securely attaches the nanoweb to the substrate;
and
(e) optionally removing the carrier layer, thus forming the filter medium; and wherein the substrate and the first nanoweb remain bonded after the filter element has been subjected to a complete test according to VDI 3926.
2. A filter element for separating particular matter from a gas stream comprising a filter medium comprising exactly one porous substrate having two major surfaces wherein the substrate is adhesively bonded over one of the major surfaces in a face-to-face relationship to a first nanoweb having a basis weight less than about 2 gsm by a layer of adhesive and wherein the filter medium is made by a process comprising the steps of
(a) forming a nanoweb directly onto a carrier layer;
(b) providing a porous substrate having two major surfaces;
(c) applying a layer of solvent based or melt adhesive to at least a portion of one surface of the substrate while it is not in contact with the nanoweb;
(d) contacting the adhesive layer with the nanoweb and bonding the nanoweb to the substrate wherein the adhesive layer securely attaches the nanoweb to the substrate; and
(e) optionally removing the carrier layer, thus forming the filter medium; and wherein the substrate and the first nanoweb remain bonded after the filter element has been subjected to a complete test according to VDI 3926.
3. The filter element of claim 1 or 2 wherein the substrate is selected from the group consisting of spunbond nonwovens, spunlaced nonwovens, airlaid nonwovens, carded nonwovens, felts, spunbond-meltblown-spunbond composite nonwovens, and woven fabrics.
4. The filter element of claim 2 wherein the first nanoweb and the substrate are bonded by means of a solvent-based adhesive, a melt adhesive or a high temperature binding agent.
5. The filter element of claim 1 or 2 wherein the first nanoweb has a basis weight of between about 0.7 gsm and about 2 gsm.
6. A process for removing particulate matter from a gas stream, comprising passing the particle-laden gas stream through the filter medium of the filter element of claim 1 or 2 such that the gas stream enters the filter medium on the surface of the filter medium having the first nanoweb bonded thereto in a face to face relationship and the filtered gas stream exits the filter medium from the surface of the filter medium opposite the first nanoweb.
7. The filter element of claim 1 wherein the first nanoweb and substrate are bonded by a layer of adhesive applied to at least a portion of the substrate.
8. The filter element of claim 2 wherein the first nanoweb and substrate are bonded by a layer of adhesive applied to at least a portion of the substrate.
9. The filter element of claim 1 or 2 wherein the nanoweb is formed by electrospinning or electroblowing.
10. The filter element of claim 1 or 2 wherein the nanoweb is formed by electroblowing and the substrate is selected from the group consisting of spunlaced nonwovens and felts.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A liquid filter comprising:
a filter housing and a filter insert exchangeably situated therein,
the filter housing having a raw liquid inlet, a central clean liquid outlet, and an eccentric liquid discharge channel,
a central standpipe being situated above the clean liquid outlet,
the filter insert being plugged onto the standpipe,
the filter insert having an eccentric closing pin on its side facing the liquid discharge channel, and positioning means being arranged such that, when the filter insert is plugged onto the standpipe, the positioning means guide the closing pin into engagement with the eccentric liquid discharge channel,
the central standpipe being a separate component that connects to the clean liquid outlet by a plug connection,
first positioning means arranged on the central clean liquid outlet and on a lower end region of the standpipe that, when the standpipe is plugged into the clean liquid outlet, guide the standpipe into a particular position in the circumferential direction relative to the filter housing,
second positioning means arranged on the outer circumference of the standpipe and on the inner circumference of the filter insert that, when the filter insert is plugged onto the standpipe, guide the filter insert into a particular position in the circumferential direction relative to the standpipe, and
the first and second positioning means being matched to one another in such a way that the closing pin on the filter insert enters into engagement with the eccentric liquid discharge channel in the filter housing.
2. The liquid filter as recited in claim 1, wherein the standpipe, the filter insert, and a filter housing screw cover can be preassembled to form a unit that can be connected as a whole to the filter housing, with automatic positioning of the closure pin and liquid discharge channel, to form the liquid filter.
3. The liquid filter as recited in claim 2, wherein on the standpipe and on the filter insert, and on the filter insert and on the filter housing screw cover, in each case a locking means system is provided that can be brought into and out of engagement, of which the locking means system between the filter insert and the filter housing screw cover is a locking means system that transmits torques limited to a specifiable magnitude and that permits a rotation relative to one another.
4. The liquid filter as recited in claim 1, wherein the first positioning means are formed at the filter housing side by a tube base having an upper side that runs at least one of obliquely and in stepped fashion and that goes over into an axial slot, and are formed at the standpipe side by a dog that protrudes radially outward.
5. The liquid filter as recited in claim 1, wherein the second positioning means are formed at the standpipe side by a pair of guide webs that run symmetrically to one another obliquely downward toward one another, and that go over into an axial slot, and are formed at the filter insert side by a dog that protrudes radially inward.
6. The liquid filter as recited in claim 5, wherein the filter insert has a hollow cylindrical filter material body in whose hollow interior there is situated a grid-type supporting body with which the radially inward-protruding dog is one of connected and made in one piece.
7. The liquid filter as recited in claim 6, wherein the filter insert has two end plates that enclose the hollow cylindrical filter material body at its ends, and wherein the closing pin is one of, made in one piece with and connected to, one of the end plates.
8. The liquid filter as recited in claim 1, wherein the standpipe is perforated at least in the upper half of its height, and wherein a filter bypass valve is situated in an upper end region of the standpipe.
9. The liquid filter as recited in claim 8, wherein a valve seat that works together with a valve body of the filter bypass valve is fashioned on an end plate of the filter insert that is an upper end plate in an installed position.
10. The liquid filter as recited in claim 1, wherein a no-load blocking valve is situated in or on a lower region of the standpipe.
11. The liquid filter as recited in claim 10, wherein a valve body of the no-load blocking valve works together with the lower end, fashioned as valve seat, of the standpipe.
12. The liquid filter as recited in claim 1, wherein the standpipe, when it is plugged together with the clean liquid outlet, can be locked or clamped to the filter housing in such a way that when the filter insert is withdrawn from the standpipe, the standpipe remains in the clean liquid outlet.