Blow molded drum
View Patent ↗Steel and plastic drums are utilized in many industries for transporting and storing various liquids which may be utilized as fuels, lubricants, ingredients, process fluids, or the like. Often the liquids transported and stored in such drums are highly caustic and/or hazardous and absolute containment during storage, transport, and handling are essential. For example in the semiconductor industry, caustic chemicals such as hydrofluoric acid are commonplace. Some liquids develop significant internal gas pressures when contained during storage. Such pressures must be periodically vented. Even when drums with such hazardous and caustic liquids are on site and ready for use, great care must be taken in accessing the liquids so as not to expose personnel or the environment to such chemicals.
1. A blow molded plastic drum made by a process comprising the step of blow molding said drum in a single blow molding operation as a one-piece, integrally molded body including a cylindrical wall, a top structure, and a bottom structure, the top structure comprising a top wall, an integral recessed portion, an upwardly extending first fitting adapted to receive a drum insert with a closure, and an upwardly extending chime for protecting the drum insert and closure from physical contact, the chime having a top edge, the top edge of the chime extending at least 1¼ inches above the top of the first fitting.
2. The drum of claim 1 , wherein the recessed portion is localized around the first fitting.
3. The drum of claim 1 , wherein the recessed portion extends substantially throughout the top wall.
4. The drum of claim 1 , wherein the closure comprises a vent outlet and a vent valve for relieving pressure within the drum.
5. The drum of claim 1 , wherein the first fitting extends from the recessed portion a distance not more than substantially one half the vertical distance between the recessed portion and the top edge of the upwardly extending chime.
6. A combination blow molded plastic drum, and closure, the plastic molded drum comprising, a cylindrical wall, a top structure, and a bottom structure;
the top structure comprising a top wall, an integral recessed portion, an upwardly extending first fitting extending from the recessed portion, and an upwardly extending chime with a top edge; wherein at least the chime, the top wall, and the cylindrical wall are integrally molded in one piece in a single blow molding operation, so that the chime is not part of a separate body attached to the top wall or the cylindrical wall, so that there are no welded portions connecting the chime with the top wall or the cylindrical wall, and so that there are no welded portions connecting the top wall with the cylindrical wall;
the closure engageable with the first fitting to secure the closure in place on the drum;
the chime extending above the recessed portion 1½ to 2¾ inches; and
the distance between the top of the first fitting and the top edge of the chime being at least 1 and ¼ inches.
7. The combination of claim 6 , wherein the recessed portion is localized around the first fitting.
8. The combination of claim 6 , wherein the closure is attached to a drum insert with the drum insert attached to the first fitting.
9. The combination of claim 6 , wherein the closure comprises a vent outlet and a vent valve for relieving pressure within the drum.
10. The combination of claim 6 , wherein the first fitting extends from the recessed portion a distance not more than substantially one half the vertical distance between the recessed portion and the top edge of the upwardly extending chime.
11. A plastic molded drum having a bung opening, the plastic molded drum comprising a cylindrical wall, a top structure, and a bottom structure, all integrally molded;
the top structure comprising a top wall and a top chime having a top edge extending circumferentially around, upwardly, and radially outward with respect to said top wall, the top wall comprising an integrally molded recessed portion, the top structure further comprising an upwardly extending first fitting integrally molded with the recessed portion and extending therefrom, the first fitting having a first neck portion and adapted to receive components including a closure;
wherein at least the top chime, the top wall, and the cylindrical wall are integrally molded so that there are no welded portions connecting the top chime with the top wall or the cylindrical wall, and so that there are no welded portions connecting the top wall with the cylindrical wall;
wherein the distance from the top of the first fitting to the top edge of the top chime is sufficient such that components extending 1 and ¼ inches above the top of the first fitting are below the top edge of the top chime; and
wherein the drum is made by a process comprising blow molding at least the cylindrical wall, the top wall, and the top chime together in a single blow molding operation.
12. The plastic molded drum of claim 11 wherein the recessed portion is localized around the first fitting.
13. The plastic molded drum of claim 11 , further comprising a bottom chime integrally molded so that there are no welded portions connecting the bottom chime with the bottom wall or the cylindrical wall, and wherein the process for making the drum includes blow molding the bottom chime together with the cylindrical wall, the top wall, and the chime.
14. The plastic molded drum of claim 11 wherein the closure comprises a vent outlet and a vent valve for relieving pressure within the drum.
15. The plastic molded drum of claim 14 further comprising a cover extending over the vent outlet, and vent valve.