Abstract: A respirator harness of polymeric components and elastic straps can be made in a 2-part injection mold in a single step. The elastic straps can have superior resistance to pull-out when secured to each polymeric component by a cage that is intergral with the polymeric component, and the cage has at least one transverse rib that is fused to the elastic strap and around which the strap is stretched.

Abstract: A method for preparing an improved filter material, together with the improved material prepared thereby and an improved method for removing impurities from a liquid. The filter material comprises a mixture of ion exchange resin particles and treated filter aid material. In the preferred embodiment, the ion exchange resin particles comprise a mixture of anion and cation exchange resin particles, and the filter aid material is treated with a chemical compound to produce a positive surface charge thereon. The filter aid material may be further treated with a second compound to produce an enhanced negative surface charge.

Abstract: A method for purification of polyhydric alcohols such as sugar syrup by removing chromophoric components, trace metals, and other impurities comprising preparing a liquid slurry mixture of filter particles, including an anion exchange resin, a cation exchange resin, and a filter aid material, the anion and cation exchange resins being smaller than about 100 mesh (about 150 microns); precoating a porous support means with the slurry mixture; and passing the polyhydric alcohol through the precoat layer and the porous support means to purify the alcohol. A further embodiment includes the step of regenerating the precoat layer by delivering a brine solution having a pH between 7 and 10 through the precoat layer.

Abstract: Impurities are removed from a liquid by passing the liquid through an improved filter bed. The filter bed comprises a mixture of oppositely charged particles of filter aid material, the particles normally having a surface charge in aqueous solution. A portion of these particles are treated with a chemical compound to produce a surface charge that is opposite from the normal surface charge. These oppositely charged particles clump in aqueous suspension, and produce a filter bed which is capable of removing suspended particles with very high efficiency, while maintaining a relatively low pressure drop across the filter bed.

Abstract: A process for scrubbing undissolved impurities from the upper portion of an ion exchange resin filtration bed is disclosed wherein air is introduced in the upper portion of the bed and develops a pressure within the vessel. This pressure subsequently forces rinse water down through the upper portion of the bed and out of the vessel. The gas is introduced into the bed and the water is drained therefrom at a level below the bed's upper surface but above a substantial lower portion of the resin bed. In this manner, lesser quantities of scrubbing fluids are required and the majority of the resin material is left undisturbed to maintain maximum ion exchange capacity.

Abstract: A method for recovering and reusing liquid used to backwash a precoated filter in which the backwash liquid used in a previous backwashing cycle is passed through a filter that is about to be backwashed. The used backwash liquid is treated by the remaining capacity in the filter precoat, and is then used to backwash the filter. This backwash liquid is recovered for later treatment and use in another backwashing cycle.

Abstract: A diffusion device is disclosed made from a stack of pairs of semi-permeable membrane walls and plate members positioned between adjacent membrane wall pairs for support thereof. Flow conduits extend transversely of the stack in communication with flow passages between the membranes or between each membrane and each adjacent plate member. In accordance with this invention, staging means are provided for directing fluid in the flow passages successively along different membrane wall pairs to lengthen the fluid path of flow for improved diffusion. The staging means comprises an occluding member in the transversely extending flow conduits, positioned to redirect flow received from along one membrane wall pair along another membrane wall pair.