Technical field

Present invention relates to device with variable cross-sectional area for treatment of gases and liquids. More specific, the invention relates to a treatment vessel with two or more internal walls dividing the flow area of the vessel. The term “treatment vessel” in this context, is meant to encompass processing apparatuses such as scrubbers, contactors, and reactors for liquid- gas, gas-gas and liquid-liquid systems.

Background Art

Scrubbers, contactors, and reactors for liquid-gas, gas-gas and liquid-liquid systems with vessel internals consisting of e.g. random or structured packing are in use today for treating gasses and liquids. They are e.g. used for cleaning chemical residue or removing certain components from gasses and liquids, either through e.g. coalescing, washing, chemical reaction, mass transfer, absorption, desorption, or a combination. The cross-sectional area, and hence the diameter of the vessels comprising the scrubber, contactor or reactor is determined by factors such as optimal flow regime, velocity of the phases and gas and/or liquid load at a given flow rate. A certain flow rate is consequently required for any given cross-sectional area to ensure the correct loads, flow regime and velocities over the internal packing of the vessel. This ensures optimum conditions and is essential for successful mass transfer, reaction, or coalescing. Similar phenomena are true for gas phase reactions in catalytic reactors where achieving the correct flow regime through the packing is essential. At a reduced flow rate, for gas-liquid, liquid-liquid, and gas-gas systems, the efficiency of the scrubber/contactor/reactor will be reduced due to sub-optimal flow regime and/or channeling can occur in the packing. In this event the fluid will find its way through channels and cavities in the packing and hence exposure and contact surface area between the media (e.g. stripping gas or cleaning) agent will be reduced. To maintain required velocity/load over the packing at reduced flowrates one can direct the flow to a smaller vessel desianed for the reduced flow. This will however reauire the construction of several vessels which will impact cost and space. The present invention solves the reduced flow problem by placing one or more inner circular walls inside the vessel. In another embodiment of the present invention, one or more straight walls across the vessel cross section can be erected. This will however introduce somewhat angular chambers, which may in turn adversely impact the flow regime. The outer shell will maintain the integrity of the vessel as the inner walls will be vented and hence pressure balanced. The inner walls will see no differential pressure at any point and would be considered vessel internals. The concept with several chambers inside the vessel means only one vessel sized for full flow will need to be constructed. Each inner wall will provide a chamber with a fraction of the vessels total flow area.

CN106552577A describes a bubble reactor with multiple layers of draft tubes which are sleeved by a reactor shell. The diameter of each draft tube is different and the draft tubes are used for internally dividing the reactor shell into a plurality of stages of ring-shaped areas.

CN21 1159291 U describes a multi-bin SCR reaction system for treatment of exhaust gases comprising several reaction chambers. The number of reaction chambers in use are depending on the amount of gas to be treated, and an inlet arrangement controls the number of reaction chambers to be used.

None of these prior art publications describe a treatment device according to the invention comprising a number of vertical internal walls defining a number of chambers, wherein each chamber are connected to a manifold via separate valves for sperate supply of fluid to each chamber.

Summary of the invention The above and further advantages are achieved by a device for treatment of gases and liquids, comprising: a generally upright, cylindrical vessel, said vessel having closed top and bottom, and one or more inlets and outlets, wherein the vessel further comprises a number of vertical internal walls defining a number of chambers which are open in the top section, wherein each chamber is connected to a manifold via separate valves for separate supply of fluid to each chamber.

In one embodiment, the internal walls of the vessel are circular and concentric to the vessel’s outer wall.

In another embodiment, the internal walls are straight walls across the vessel’s cross-section.

Each of the internal walls defines a chamber and each chamber defines an equal percentage of the total flow area of the vessel.

In another embodiment, each of the internal walls defines a chamber and each of the chambers defines a different percentage of the total flow area of the vessel.

In one embodiment, the vessel, in the top section, is provided with a fluid distribution system, said fluid distribution system comprises one or more nozzles for each of the chambers for separate supply of fluid to each chamber. In this embodiment, the fluid distribution system further comprises separate valves for each nozzle and said valves are connected to a manifold.

In one embodiment, each chamber is filled with a packing material, preferably a catalyst or an adsorber.

In another embodiment, each of said chambers are filled with packing elements.

The vessel is preferably provided with one or more inlets and one or more outlets in the top section and/or the bottom section of the vessel.

Brief description of the drawings

Figure 1 shows a cross section drawing of an embodiment of a vessel fitted with three circular inner walls.

Figure 2 shows a side section view of a vessel in Fig. 1 fitted with three circular inner walls.

Figure 3 shows an embodiment for a gas/liquid scrubber application.

Detailed description of the invention The invention will now be described more detailed with reference to the preferred embodiments shown in Figs. 1 and 2.

The figures 1 and 2 show a preferred embodiment of the present invention for a gas scrubber application with a vessel outer shell (1), three circular inner walls (2, 3, 4), comprising 4 circular chambers (5, 6, 7, 8) inside the vessel, each representing 25% of the vessels total area. A manifold (9) directs gas to the respective chambers through an arrangement of valves (10, 11 , 12, 13). In the event of a required reduced flow rate of 25%, valve (10) would be open and valves (11 , 12, 13) would be closed consequently only directing gas flow into chamber (5). The gas at 25% of full flow will ascend through the scrubber packing at the correct velocity due to the reduced vessel diameter granted by inner wall (2). At 50% flow, valve (11) will open. Gas is now flowing into chambers (5, 6). Correct gas velocity at 50% flow rate is granted due to the 50% area of chambers (5, 6) combined in which the gas is directed into. At 75% flow, valve (12) will open and directing gas into chambers (5, 6, 7) for use of 75% of the vessel’s total capacity. At 100 % flow all valves are open and gas flows through the scrubber as it would through a traditional scrubber.

Fig. 3 shows an embodiment of a gas/liquid scrubber. Fig. 3 is similar to Fig. 2, except that the vessel (1 ) is provided with a liquid distribution system (14) on top of each chamber (5, 6, 7, 8). In this embodiment, liquid is supplied separately to each chamber (5, 6, 7, 8) at the top of the vessel via a distribution system (14). The distribution system can for example comprise separate nozzles for supply of liquid to each chamber (5, 6, 7, 8). Each nozzle will then be connected to a valve system (not shown) and a manifold, in order to supply liquid separately to each of the chambers (5, 6, 7, 8).

In physical mass transfer processes, the purpose of the packing will be to increase the surface area for mass transfer between the fluids, and not be a part of the physical process other than providing a large surface area. The packing material will either be random or structured. In vessels where chemical reactions take place, i.e. reactor, packing may in addition serve the purpose og acting as a catalyst for the desired reaction taking place. In adsorption processes, e.g. temperature swing adsorption for gas drying the packing will be a fundamental part of the process, where water adsorbs to the surface of the packing in operational mode, and water is released in regeneration mode.

Present invention also includes embodiments where the number of circular inner walls is different from three, for example one or two circular inner walls or more than three circular inner walls. The number of valves will be correspondingly altered. Such embodiments are also encompassed by present invention. It is also conceivable with configurations with different cross-section areas in the different chambers. For example will a configuration of chambers with 10%,

30% and 60% cross-sectional areas provide a dedicated cross-section corresponding to 10, 30, 40, 60, 70, 90 and 100% flowrate, depending on the combinations of open and closed valves. Such embodiments are also encompassed by present invention.

The manifold and valve arrangement may need individual flow elements and flow control to ensure that the correct flow is introduced to the various chambers. This can be solved using readily available systems and components and are not explained in further detail.