Method of and apparatus for shielding inert-zone electron irradiation of moving web materials
AssigneeEnergy Sciences Inc.
InventorSam V. Nablo
Life of this patent
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Abstract
This disclosure is concerned with novel techniques for shielding electron-produced scattered radiation in systems wherein a web or sheet is passed longitudinally through an electron irradiation processing region or zone, through the use of a shielded enclosure comprising longitudinally extending shielded-wall collimator slots operating in conjunction with cavity shield traps and critical angles of web-guiding inlet and outlet feed that insure minimal irradiation escape while providing a minimal volume for oxygen-limiting in the irradiation processing zone.
Claims20
Apparatus for passing a web through an oxygen-limited electron irradiation zone and for shielding against scattered radiation, having, in combination, a longitudinally extending shielding enclosure provided with inlet and outlet regions connected by an intermediate zone at which the electron irradiation is to be concentrated;
- means for generating and directing electron beam radiation through an electron-pervious window disposed along the intermediate zone and serving as a wall of the zone;
- means forming an opposing wall along the intermediate zone comprising a shielded box radiation trap including angulated walls defining a box for stopping the electron beam at the intermediate zone, said box having within it a low atomic number plate upon which the electron beam radiation impinges and provided with cooling means;
- each of said inlet and outlet regions comprising parallel shielded wall surfaces forming longitudinally extending slots that collimate radiation scattered therealong outward from the irradiation intermediate zone;
- shielded cavity trap means disposed at said inlet and outlet regions to receive radiation scattered outward along the collimating slots from said intermediate zone;
- means for feeding a web to the inlet region collimating slot and longitudinally through the same, and thence longitudinally between the said window and shielded box trap through the said intermediate zone and then along the outlet region collimating slot to exit therefrom;
- and means for providing an oxygen-restricted or ozone-confining atmosphere within said zone.
Apparatus for passing a web through an oxygen-limited electron irradiation zone and for shielding against scattered radiation, having, in combination, a longitudinally extending shielding enclosure provided with inlet and outlet regions connected by an intermediate zone at which the electron irradiation is to be concentrated;
- means for generating and directing electron beam radiation through an electron-pervious window disposed along the intermediate zone and serving as a wall of the zone;
- means forming an opposing wall along the intermediate zone comprising a shielded box radiation trap provided with cooling means;
- each of said inlet and outlet regions comprising parallel shielded wall surfaces forming longitudinally extending slots that collimate radiation scattered therealong outward from the irradiation intermediate zone;
- shielded cavity trap means disposed at said inlet and outlet regions to receive radiation scattered outward along the collimating slots from said intermediate zone;
- means for feeding a web to the inlet intermediate zone;
- means for feeding a web to the inlet region collimating slot and longitudinally through the same, and thence longitudinally between the said window and shielded box trap through the said intermediate zone and then along the outlet region collimating slot to exit therefrom, said cavity trap means being disposed within terminal shielded sections containing inclined guides for directing the web at acute angles into and out of said enclosure;
- and means for providing an oxygen-restricted or ozone-confining atmosphere within said zone.
A method of minimizing electron-produced reflection and scatter radiation while providing a minimal volume zone for electron irradiation of a passing web and the like, that comprises, passing the web between an inlet and an outlet and longitudinally past an intermediate processing zone;
- directing a transverse line of electrons upon the web as it longitudinally passes along said region;
- trapping and suppressing electrons emerging on the other side of the web within said processing zone;
- collimating electron-produced scatter longitudinally outward in opposite directions from said zone toward the inlet and outlet;
- cavity-trapping the collimated scattered radiation;
- introducing the web at an angle to the direction of inlet collimation and exiting the same at an angle to the direction of outlet collimation with said angles adjusted to block the escape of such scatter;
- and inerting or providing ozone confining within said zone.
Apparatus for passing a web through an oxygen-limited electron irradiation zone and for shielding against scattered radiation, having, in combination, a longitudinally extending shielding enclosure provided with inlet and outlet regions connected by an intermediate zone at which the electron irradiation is to be concentrated;
- means for generating and directing electron beam radiation through an electron-pervious window disposed along the intermediate zone and serving as a wall of the zone;
- means forming an opposing wall along the intermediate zone comprising a shielded box radiation trap provided with cooling means;
- each of said inlet and outlet regions comprising parallel shielded wall surfaces forming longitudinally extending slots that collimate radiation scattered therealong outward from the irradiation intermediate zone;
- shielded cavity trap means disposed at said inlet and outlet regions to receive radiation scattered outward along the collimating slots from said intermediate zone, the shielding of said traps and wall surfaces comprising lead faced with a low atomic number surface such as aluminum, said cavity trap means being bounded by said shielding and comprising a labyrinth faced with an electron-permeable window to close off the same but into which radiation scattered outward along the collimating slots may enter the cavity labyrinth;
- means for feeding a web to the inlet region collimating slot and longitudinally through the same, and thence longitudinally between the said window and shielded box trap through the said intermediate zone and then along the outlet region collimating slot to exit therefrom, said electron beam extending transversely across said web;
- and means for providing an oxygen-restricted or ozone-confining atmosphere within said zone.
Apparatus for passing a web through an oxygen-limited electron irradiation zone and for shielding against scattered radiation, having, in combination, a longitudinally extending shielding enclosure provided with inlet and outlet regions connected by an intermediate zone at which the electron irradiation is to be concentrated;
- means for generating and directing electron beam radiation through an electron-pervious window disposed along the intermediate zone and serving as a wall of the zone;
- means forming an opposing wall along the intermediate zone comprising a shielded box radiation trap provided with cooling means;
- each of said inlet and outlet regions comprising parallel shielded wall surfaces forming longitudinally extending slots that collimate radiation scattered therealong outward from the irradiation intermediate zone;
- shielded cavity trap means disposed at said inlet and outlet regions to receive radiation scattered outward along the collimating slots from said intermediate zone;
- means for feeding a web to the inlet region collimating slot and longitudinally through the same, and thence longitudinally between the said window and shielded box trap through the said intermediate zone and then along the outlet region collimating slot to exit therefrom, at least one of said cavity trap means being disposed within a terminal shielded section containing a guide for directing the web-substantially horizontally, with the web passing inclinedly through said zone;
- and means for providing an oxygen-restricted or ozone-confining atmosphere within said zone.
Dependencies are inferred from the claim text.