The present disclosure relates to a solid-wall screw centrifuge including a discharge for discharging a clarified liquid from a drum of the centrifuge. The drum includes a passage in a drum cover associated with a weir plate. The passage, drum cover, and weir plate form an overflow weir on a radial inner edge. A deflecting device is arranged on an outside on the drum cover. The deflecting device is arranged such that an exiting fluid flow from the centrifuge is one of deflected in the circumferential direction and subjected to a twist in the circumferential direction.
Solid-wall screw centrifuges are known.
DE 102 03 652 B4 discloses a solid-wall screw centrifuge comprising a device for discharging clarified fluid from a drum having a drum cover with a passage. The passage associated with a throttle device, for example, an orifice gauge, the distance of which to the passage is variable. The passage is further associated with nozzles for the discharge of the clarified fluid, which nozzles are aligned obliquely in relation to the radial direction through the drum axis for saving energy.
Nozzles on solid-wall screw centrifuges and their effect of energy saving in a respective alignment obliquely in relation to the drum axis are further known from DE 39 04 151 A1.
The publication of “Patent Abstracts of Japan”, No. 11179236A, discloses that guide plates can be associated with passage openings in the drum cover which are respectively partly sealed by a weir plate forming an overflow weir. The guide plates provide fluid exiting the drum with a twist, wherein the occurring repulsion effect is to be used for energy saving. The guide plates are attached to the outside of the overflow weir on the weir plates, for example. They are arranged as flat plates, for example, which are aligned parallel to the rotational axis of the drum. The plane in which the flat plates are disposed does not intersect the drum axis and encloses an angle of approximately 45° with the radially extending straight line which, respectively, extends through the rotational axis of the drum and the respective passage opening.
The present disclosure thus relates to embodiments that provide a solid-wall screw centrifuge which is optimized with respect to energy saving.
The present disclosure further relates to a solid-wall screw centrifuge that includes a discharge for discharging a clarified liquid from a drum of the centrifuge. The drum includes a passage in a drum cover associated with a weir plate, which passage, drum cover, and weir plate form an overflow weir on a radial inner edge. A deflecting device is arranged on an outside on the drum cover, the deflecting device being arranged such that an exiting fluid flow from the centrifuge is one of deflected in the circumferential direction and subjected to a twist in the circumferential direction. The deflecting device is arranged so as to maintain the position of the overflow weir such that the exiting fluid flow is deflected in the circumferential direction at an overflow edge of the weir flute and directly in an axial extension of a region of a passage opening that is not covered by the weir plate
The deflecting device is, accordingly, arranged in such a way, for example, on the weir plate, that, by maintaining the overflow weir, an exiting fluid flow is subjected to a twist in the circumferential direction at the overflow edge in the axial extension of the passage opening.
This can be achieved, according to an embodiment of the present disclosure, in such a way, for example, that the deflecting wall is disposed partly directly in axial extension of the region of the passage opening not covered by the respective weir plate axially outside before the passage opening, and axially partly or fully covers the opening.
It is also known, for example, from U.S. 2004/0072668 A1 or WO 2008/138345 A1,to arrange a housing instead of an overflow weir on the weir plate of the passage opening, with the overflow weir or a nozzle being then arranged in an oblique side of the housing on the passage opening. These constructions are disadvantageous, however, in that co-rotating fluid chambers are formed on the outside of the drum cover, which fluid chambers form a part of the rotating system, so that the clarification or separation process can still continue in the fluid chambers. This separation process may lead to undesirable deposits in the chambers which lead to cleaning problems.
It is, therefore, advantageous that an embodiment according to the present disclosure leaves the overflow weir directly on the weir plates on the drum cover, and only the fluid which has already left the rotating system via the overflow weir will be deflected in the circumferential direction. After the exit from the drum, no clarification effect can occur any more. Instead, the entire exiting fluid jet will rather be deflected by the deflecting device in the circumferential direction.
Advantageous embodiments of the present disclosure are discussed herein and in the appended claims.
Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.