with two helices with opposite pitch on the same shaft; with two helices on the same axis, driven in opposite directions or at different speeds

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Mixers with rotary stirring devices in fixed receptacles (magnetic mixers B01F33/45); Kneaders > with stirrers rotating about a horizontal or inclined axis > with helices or sections of helices > with two helices with opposite pitch on the same shaft; with two helices on the same axis, driven in opposite directions or at different speeds