Abstract: The present invention discloses a sand control device for marine hydrate production, which comprises a top motor, a bottom motor, and an inner-layer sand control cylinder, an outer-layer sand control cylinder and an outer-layer sand control screen coaxially arranged from inside to outside, wherein the top motor and bottom motor are configured to control the inner-layer sand control cylinder and the outer-layer sand control cylinder to rotate reversely, and wherein a plurality of sand retaining balls are provided between the inner-layer sand control cylinder and the outer-layer sand control cylinder and between the outer-layer sand control cylinder and the outer-layer sand control screen. According to the present invention, the arrangement of the inner-layer sand control cylinder and the outer-layer sand control cylinder rotating reversely can effectively prevent formation sand from accumulating on the surface of a sand control screen pipe and blocking the sand control screen pipe.

Abstract: The present invention discloses a sand control device for marine hydrate production, which comprises a top motor, a bottom motor, and an inner-layer sand control cylinder, an outer-layer sand control cylinder and an outer-layer sand control screen coaxially arranged from inside to outside, wherein the top motor and bottom motor are configured to control the inner-layer sand control cylinder and the outer-layer sand control cylinder to rotate reversely, and wherein a plurality of sand retaining balls are provided between the inner-layer sand control cylinder and the outer-layer sand control cylinder and between the outer-layer sand control cylinder and the outer-layer sand control screen. According to the present invention, the arrangement of the inner-layer sand control cylinder and the outer-layer sand control cylinder rotating reversely can effectively prevent formation sand from accumulating on the surface of a sand control screen pipe and blocking the sand control screen pipe.

Abstract: The present invention relates to catalytic distillation equipment having a reaction section divided into several beds by separating plates. New catalyst is packed into the beds through a packing inlet. Used catalyst is withdrawn from a packing outlet. The invention has the advantages of permitting greater contact between reactants and catalyst which increases the reaction rate and efficiency of catalyst.