Pumping certain materials can be challenging. For instance, in sub sea conditions, such as for the mining and transport to the surface of materials e.g. nodules and other deposits found on deep sea ocean floors, the material to be transported comprises solids present in a liquid, that is water.
The present invention relates to a method of transporting a material, to a system of transporting a material, to a computer program to control the system accordingly, to a tube section and to a composition of such tube sections, in particular for use in the system and for applying the method respectively.
The material to be transported may be a more or less viscous substance in a horizontal or vertical system, but the method may also be applied in sub sea conditions, such as for the mining and transport to the surface of materials e.g. nodules and other deposits found on deep sea ocean floors. In that case the material to be transported comprises solids present in a liquid, that is water.
The present invention provides a method and accompanying system for effective transport of materials in general, with an emphasis on mining and lifting of nodules comprising useful compositions and metals.
Thereto a method has the features whereby a material is transported by at least one series of interconnected tube sections that can be opened or closed. At least one downstream tube section whereof holds the material to be transported. A liquid jet is generated which accelerates the held material upstream out of at least the first downstream tube section into at least one opening upstream tube section which then holds a material part waiting for a next liquid jet to propagate that part to the next upstream tube section.
Similarly the system for transporting material comprises:
The inventor had the notion that the pumping of a material comprising solids in a liquid can only be performed by accelerating the solids therein. Since the extent of acceleration is limited in practise a stop and go cycle is suggested wherein the solids in the material are sequentially being held, accelerated by means of a liquid jet and then again held, but now at least partly upstream in a next tube section. During the acceleration phase the solids which are normally heavier than the liquid they are in, do not get the time to sink. So the repeated cycle of holding, acceleration and holding of in particular the solids safeguards their successive movement upstream from one tube section to the next upstream tube section.
An embodiment of the method according to the invention has the features that by opening and closing the individually controlled tube sections, successive parts of the material confined between closed tube sections are stepwise transported through the series of interconnected tube sections.
By individually controlling the tube sections a stepwise sequential transport of at least one batch of material takes place. This advantageously leads to the possibility of successive batches being propelled during cycles in the series arrangement of successive tube sections. An even further advantage provides a parallel arrangement of such series if a higher yield of solids is required, such as may be the case in the mining of manganese nodules where the method is applied in a vertically aligned system in the deep sea. Such a parallel arrangement will turn out to have even further advantages in terms of pump efficiency because then pump actions in one series of tube sections and its neighbouring series may mutually operate in opposite phase.
A further embodiment of the method according to the invention which provides improved operational control of such repeated cycles has features that the interconnected tube sections which have a flexible inner tube fixed therein are controlled such that by pressurising or depressurizing a pressure space between the tube section and the flexible inner tube a resulting inward or outward flexing of the flexible inner tube closes or opens the respective tube sections.
Furthermore it is an advantage of the present invention that this embodiment of the control method and layout of the tube section may, either function as a controllable valve, or as a forcing pump, suction pump, that is a double acting pump for liquids with solids.
A still further embodiment of the method according to the invention has features that a liquid jet directed at the material to be transported is generated:
It is an advantage of this method that the pump which will be a controllable pump may be embodied by a common controllable liquid pump.
Another embodiment of the method according to the invention has features that the pumps if attached to designated mainly vertically aligned tube sections act on the basis of a pressure difference relative to the local water pressure.
Under deep sea conditions to the water, having a depth dependent pressure, only a wanted pressure difference will have to be added by the pump, to propel the confined material over one or more tube sections, in which case a common centrifugal or gearwheel pump will suffice.
An embodiment of the system according to the invention has features that a flexible inner tube which is fixed in the tube section is a flexible inner tube which is flared radially outwardly in upstream direction.
This flaring promotes an unambiguous upstream directed flow of liquid and solids held by the downstream tube section into the upstream tube section, when the pressure space is pressurised.
A further embodiment of the system according to the invention has features that the system comprises a programmable processor capable of communicating a data address signal at least to the liquid jet generating means and the tube sections which are each uniquely addressable in order to generate successive jets with matching opening and closing actions of the tube sections, and which processor is programmed such that said material parts are urged upstream like a running wave from the ones to the next tube section.
The programmable control by the processor safeguards a smooth course of the necessary control actions in the system. Furthermore appropriate actions can be taken by means of operational software running in the processor, usually based on locally present sensors which provide actual control and timing parameter values.
At present the features according to the inventions will be elucidated further together with their additional advantages while reference is being made to the appended drawings, wherein similar components are being referred to by means of the same reference numerals. In the drawings:
To at least promote some extra propagation of the material, liquid jet generating means 3 in the form of a pump driven nozzle 4 are positioned under the material M to be accelerated and are arranged in the tube section 2 as shown in
Basic stepwise propagation in the direction of the arrows in
In order to effect the pressure action the tube section 2 comprises a flexible inner tube 5 fixed in the downstream tube section 2. Between the tube section inner wall and the flexible inner tube 5 there is a pressure space 6 which may be pressurised or depressurized by means of a fluid liquid pump 7. The pump 7 which may also drive the nozzle 4 and may be a water pump which outputs possibly salt water having a pressure which is derived from the local water pressure at a depth where the tube sections 2 concerned are situated. In that case a limited amount of pump power is necessary since only the confined material needs to be lifted in each step which only requires a common centrifugal pump or a gearwheel pump. A pressurising of the space 6 results in an inward flexing of the flexible inner tube 5 forcing the material including water and solids within the flexible tube 5 out to the upstream tube section 2, as the tube section 2 directly downstream of that upstream section is closed. While a depressurizing results in an outward flexing ultimately against the inner wall of the section 2 which may suck in material but more importantly makes space for said forced out material part to enter the flexible inner tube 4 of the upstream inner tube section.
In order to propel and accelerate the material out of the tube section the flexible inner tube may be flared radially outwardly in upstream direction. Then pressurising the space 5 provides an extra force to drive the material into the next section.
Timing of the opening and closing of the various tube sections to get to a kind of stepwise running upstream wave of the material is effected by a programmable processor μ. The processor is capable of generally bidirectional communicating a data address signal via a bus structure like in a computer bus, at least to the liquid jet generating means 3, 4, the controllable tube sections 2 and valves, as well as to sensors S which measure critical parameter quantities. These addresses are unique in order to allow the processor μ to control each and every of the controllable components of the system 1 by means of a computer program and with the help of the sensor parameters. In particular opening and closing actions required for executing the method of transporting the material are properly programmed. Possibly these actions in particular their individual durations dependent on the operating depth of or the pressure in the tube sections 2, and the kind and size of material, as well as the viscosity and/or the solid to liquid ratio of the material and/or velocities and/or degree of filing of a section 2 may be input though the bus to the software concerned.
The tube section 2 as shown in
Returning to the chart of
The present application is a national stage of International patent application Serial No. PCT/EP2019/070022, filed Jul. 25, 2019, and published in English as WO 2021/013350.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2019/070022 | 7/25/2019 | WO |