MEANS FOR THE HANDLING OF CONTAMINATED FLUIDS

Abstract: A means for the handling of fluids contaminated by solid objects and/or being partly solidified comprises a displacement pump (10) of the screw type, as well as a cutter device (18) driven by the pump shaft. The cutter device comprises a cylindrical drum (19) with a number of axially directed edge steel (20), spaced apart a suitable distance to ensure a maceration of solid objects to a size suited for passing through the pump. The drum (19) is located adjacent to an opening (21) in the side wall of the pump housing (22). The pump is preferably reversible, and the material in the cutter device is selected so as to ensure a non-sparking structure.

Description: MEANS FOR THE HANDLING OF CONTAMINATED FLUIDS. During the decontamination of oil or chemical spillage, the cleaning of tanks, the transportation of waste water and on many other occasions of fluid matter handling prob¬ lems are encountered in that the fluid to be pumped contains floating, solid objects of varying size, lumps of asphalt-like consistency, or that the fluid itself has been partly solidified due to the action of chemicals, and so fort . The lack of suitable equipment for the handling of such fluids has proven to be a definite bottleneck during many decontamination operations. It is desirable to have at hand a compact, high-capacity pumping unit, which is not affec¬ ted by contaminants or agglomerations in the fluid, i.e. the pump should itself have a capacity to fragmentate the floating matter to a size suitable for passing through the pump. A means according to the invention therefore includes a displacement pump enclosed in a housing and driven by a motor, and is characterized in a cutter device connected to the drive shaft of the motor, and arranged, when rotating concentrically therewith, to cooperate with at least one cutting edge located at the inlet to the pump housing. The cutter device preferably includes a cylindrical drum structure, having a number of axially directed edge steels, the relationship between the rotational speed of the pump during cavitation-free flow and the peripheral distance between the edge steels at least corresponding to the size of the biggest, solid contaminant having a possibility to pass through the pump. The pump is advantageously a screw pump, enclosed by a stator and connected to the pump shaft by way of an eccen¬ trically movable link having two universal joints. The pump ought to be of a reversible type, the edge steels having double-sided edges, and the opening having oppositely directed counter-edges. The edge steels and the holders therefor are formed so as to provide a certain pumping activity within the cutter device. The invention will below be described with reference to the accompanying drawings, in which Figure 1 shows a longitudinal section through a pumping means according to the invention, and Figure 2 shows a ' section along line II-II in Figure 1. The pumping means shown in the drawings comprises a displacement pump 10 of the screw type, for instance a so called "MONO"-pump, having a rotor 11 enclosed- by a stator 12 of elastically deformable material. A pump of this type can handle fluids containing contaminants of a certain size. The pump is driven by a motor 13, axially aligned with the pump rotor. Due to the oscillating movements of the pump rotor, the torque transfer path contains an eccentri¬ cally movable link 14 with two universal joints 15 and 16. A shaft portion 17, connected to the motor drives a cutter device 18, formed as a cylindrical drum 19 in which four axially directed edge steels 20 are mounted in holders 24, extending between a disc-shaped part 25 of the shaft, and a juxtaposed ring 26. The holder will, in use, rotate concen¬ trically with respect to the motor axis. The relationship between the rotational speed of the pump, during cavitation—free operation and the spacing between the holders 24 will at least correspond to the size of the biggest solid particles able to pass through the pump 10. No solid contaminant will thus, after the passage through the cutter device, cause any trouble in the pump. The inlet 21 to the pump is arranged in the wall of a cylindrical extension 22 of the pump housing 27. Foreign objects in the fluid, which are bigger than what the pump can handle, will temporarily be caught in the inlet 21 to the pump, and will be macerated by the edge steels 20 in cooperation with counter-edge steels 23 along one side edge of the opening. Solidified fluids, or OMPI agglomerations therein will be ground or mashed by the cutter device, as the fluid passes into the housing 22. One or more counter-steels may be fitted in the opening, and in a simple arrangement a border portion defi¬ ning the opening may be sharpened to an edge. . The pumping means should be able to withstand chemical attacks, and due to the nature of many of the fluids, which are actual for handling, the material selected for the edge steels 20 and the counter steels should be of a non- sparking quality. The pump should be submersible and self- feeding, and should provide a satisfactory working pressure, even when handling low-viscous fluids. The pump and the motor are preferably reversible, so it will be possible, on occasions, to wash away matter clog¬ ging the suction line. The edge steels can then be provided with double-sided edges, and a double set of counter steels should be provided. The motor can be selected so the number of revolutions can be varied, but as the cutter device will operate at the same speed, the maceration will automati¬ cally be adjusted to changes in the pumping capacity. Alternatively it. is possible to provide a step-up gearing, so the cutter device will rotate faster than the pump. The edge steels 20 and their holders are preferably designed so a certain pumping action is obtained, i.e. the cutter device will act as a pumping step, preceding the displace¬ ment pump.

Claims: AMENDED CLAIMS [received by the International Bureau on 04 February 1985 (04.02.85); original claims 1—5 replaced by amended claims 1 — 4 (1 page follows)] 1. Pumping means for the handling of fluids contami¬ nated by solid objects and/or being partly solidified in which a pump rotor (11) is enclosed in a housing having at least one radial inlet (21) and is driven by a motor (13), c h a r a c t e r i z e d in that the pump rotor (11) is of the rotating displacement type, connected to a cutter device including a hollow cylindrical drum structure (19), having a number of openings in its side wall defined by substantially axially directed edge steels (20) and holders (24), connected to a drive shaft (17) of the motor (13), and arranged, as rotating centrically in the housing (22), to cooperate with at least one countercutting edge (23) located at the inlet(s) (21) of the pump housing, the relationship between the rotational speed of the drive shaft (17) during cavitation-free flow, and the peripheral distance between the edge steels at least corresponding to the size of the biggest, solid contaminant having a possi¬ bility to pass through the pump (10). 2. Means according to claim 1, c h a r a c t e ¬ r i z e d in that the cutter drum (19) projects from an end wall adjacent to the motor (13), while its opposite end is open, permitting radial entrances to the drum interior and an axial outlet directed towards the pump rotor (11). 3. Means according to either of claims 1 or 2, c h a r a c t e r i z e d in that the pump (10) is of a reversible type, the edge steels (20) having double-sided edges, and the opening (21) having oppositely directed counter-edges. 4. Means according to either of the preceding claims, c h a r a c t e r i z e d in that the edge steels (20) and the holders (24) therefor are formed so as to provide a certain booster pumping activity within the cutter device. OMPI

Inventors: BAECKSTROEM HANS, BAECKSTROEM, HANS
Applicants: BAECKSTROEM HANS, BAECKSTROEM, HANS
Application year: 1984
Main classification: F04C2
IPC codes: F04C2, F04C13