NL2013103B1 - Circular separator device, treatment plant provided therewith, and method for separating a three-phase fluid. - Google Patents

Abstract

The invention relates to a separator device, treatment plant provided with such separator device and method for separating a three-phase fluid containing liquid, gas and solid particles. The separator device according to the invention comprises: - a basin provided with an inlet configured for receiving the fluid; - a separator having a circular shape and connected to the inlet, the separator comprising: - a number of blades having a surface with a length in a first direction in use substantially corresponding to a main flow direction of the liquid through the separator and a width in a perpendicular second direction, wherein the blades are placed at a first angle in the second direction such that the blades are arranged to achieve an increasing distance between two adjacent blades as seen from a center region of the circular separator device towards an outer perimeter of the circular separator device; and - an outlet for the liquid and pre-separated solid particles with the outlet being connected to a solids collection chamber.

Description

Circular separator device, treatment plant provided therewith, and method for separating a three-phase fluid

The present invention relates to a separator device for separating a three-phase fluid containing liquid, gas and solid particles. Such separator device is also referred to as a purifier and is used for aerobic or anaerobic purification of waste water, for example. Such waste waters comprise a fluid that contains water, gas and dissolved and/or non-dissolved solid particles involving organic and/or inorganic material. The gas may contain air, oxygen and gases that are produced in waste water treatments such as methane and carbon dioxide.

Conventional three-phase separators comprise a first separator separating the gas from the fluid. After the first separator there is provided a settler comprising, or alternatively connected to, a second separator for separating the remaining solid particles from this two-phase mixture. Therefore, these conventional separators involve a first separator for separation of gases from the three-phase fluid, while solid particles are separated from the remaining two-phase mixture through discharging from the settler and separation in the second separator. This leads to a relatively inefficient separation process, requiring significant efforts to achieve the desired separation.

The present invention has for its object to provide a separator device obviating or at least reducing the aforementioned problems.

This objective is achieved with a circular separator device according to the invention for a three-phase fluid containing liquid, gas and solid particles, the separator device comprising: a basin provided with an inlet configured for receiving the fluid; a separator having a circular shape and connected to the inlet, the separator comprising: a number of blades having a surface with a length in a first direction in use substantially corresponding to a main flow direction of the liquid through the separator and a width in a perpendicular second direction, wherein the blades are placed at a first angle in the second direction such that the blades are arranged to achieve an increasing distance between two adjacent blades as seen from a center region of the circular separator device towards an outer perimeter of the circular separator device; and an outlet for the liquid and pre-separated solid particles with the outlet being connected to a solids collection chamber.

The basin or housing of the device is provided with an inlet, enabling a three-base fluid comprising solid particles, liquid and gas, to enter the circular separator device. By providing the circular separator device with a separator, the gas is separated from the liquid and solid particles. By providing the separator with a circular shape and a number of plates having a length in a first direction and a width in a perpendicular second direction, the plates are arranged such that an increased distance is achieved between two adjacent plates, as seen from a center region of the circular separator device towards an outer parameter of the separator device. This separator achieves a pre-separation of solid particles. This improves the overall solid separation significantly and thereby enables performing an efficient and effective separation process.

According to the invention, a circular separation device is provided that comprises a separator having a circular shape. It is noted, that a circular shape also includes circle, round, ellipse, oval, etc. types of shapes. When in use, providing such circular shape achieves an additional vortex. Preferably, the solids collection chamber, which in a presently preferred embodiment is positioned below the separator, stimulates this vortex effect and attributes to the efficient separation of solid particles.

In a presently preferred embodiment, the blades are placed with a length at a second angle relative to the vertical, such that the flow between two adjacent blades is caused to flow obliquely between the blades, thereby accumulating gas at or near an upper blade, such that degasification is achieved, and accumulating solid parts at or near a lower blade, such that in use a pre-separation of the solid particles is achieved.

By placing each blade at an angle relative to the vertical, the flow between two adjacent blades is caused to flow obliquely between the blades. In such configuration, gas accumulates at or near the upper blade of adjacent blades. This achieves a degasification of the three-phase fluid. The gases that are separated from the incoming three-phase fluid will be removed from the device through a gas outlet. In a presently preferred embodiment this gas outlet is formed by the fluid inlet of the separator device. Alternatively, a separate gas outlet can be provided. By accumulating gas at or near the upper blade a sort of gas channel inside the tube is achieved. This enables an effective removal of the separated gas from the remaining fluid flow.

In addition to the gas accumulation at or near the upper blade, providing blades at an angle relative to the vertical achieves that in use a pre-separation of the solid parts or particles at or near the lower blade takes place. By performing a pre-separation of the solid parts in the separator device according to the present invention the overall solid separation is significantly improved. Such solid separation is one of the decisive factors in performing an efficient and effective separation.

Preferably, the second angle relative to the vertical is in the range of 0-80°, preferably in the range of 10-70°, more preferably in the range of 25-60° and, most preferably, the angle is about 35°. The inclination of the blades in the separator device according to the present invention decreases the effective settling distance for the solid particles and, in addition, decreases the effective rising distance for gas as compared to a non-inclined settler. Therefore, the inclination according to the present invention improves the separation efficiency.

Surprisingly, providing the blade configuration with an increasing distance between two adjacent blades as seen from a center region of the circular separator device towards an outer parameter of the circular separator device, in combination with providing a second angle, further improves the vortex effect that further improves the overall separation. As a further effect, the use of a circular separator device prevents “dead corners” that relate to ineffective locations in the devices Providing a circular shaped device achieves a significantly improved flow throughout the entirety of the separator device, such that the separating process can be performed more effectively as compared to conventional separators..

In an embodiment according to the invention, the blades are provided with a guiding profile on or at the upper and/or lower side of the surface. Providing a guiding profile, such as grooves, ribs, channels, etc., turns out to be beneficial as it improves accumulating the gas at a specific region at or near the upper blade and/or solid particles at the lower blade. Although a (slightly) curved guiding profile is preferred, alternatively, or in addition thereto, also rectangular or other shapes can be used.

Accumulating gas at or near the upper blade achieves a higher upwards oriented force in the gas, thereby increasing the rising capacity of the gas. In addition, a counter-flow will be generated at or near the top of the upper blade thereby affecting the total flow velocity profile between two adjacent blades. In fact, in a preferred embodiment of the separator device according to the present invention between the blades the highest velocity will be below the centerline of the flow channel defined between two adjacent blades, thereby providing a sort of sweeping effect. This surprising effect brings about the joint separation of small solid particles and gas in the upward direction. With conventional separators gas that is attached to small solid particles often prevents the small solid particles from settling thereby preventing or at least hindering degasification of the three-phase fluid such that these particles with the attached gas will flow through the settler and flush out. Surprisingly, due to the sweeping effect between the blades, that is provided in the separator device according to the present invention, the small solid particles with attached gas will be fed back to the top or upper part of the separator, such that the degassing can restart for these particles.

As a further effect of this counter-flow the solid particles are separated more efficiently, as the downward velocity between the blades is increased. In fact, the solid particles gain settling capacity such that the solid particles are accumulated more effectively at or near the lower blade. This further improves the pre-separation of the solid particles in the separator device according to the present invention with the circular separator. In fact, in this pre-separation a substantial part of the solid particles will be removed. In use, the remaining two-phase flow after the separator, which is degassed and wherein most solid particles have been pre-separated, may enter a solids collection chamber and/or a second separator for further removal of the remaining solid particles in the two-phase fluid.

In a presently preferred embodiment according to the present invention, the circular separator device further comprises a solids collection chamber and a second separator for separating a two-phased mixture of liquid and remaining solid particles.

By providing a solids collection chamber, the solid particles can be separated and removed separately. The second separator separates a two-phased mixture of liquid and remaining solid particles.

In a presently preferred embodiment, a second separator is located at the center region of the device. In such embodiment, the separator is provided with a number of plates that receive the three-phase fluid and are being provided at the outer parameter or outer circle of the circular separator device, while a second separator is provided in the middle or center region. This provides an effective configuration that is capable of efficiently separating the three-phased fluid.

Due to the pre-separation of solid particles in the tubular separator the solid particles are separated effectively. Due to the increased settling capacity of the solid particles a substantial amount of, in fact almost all, solid particles will be removed in the first separator. Preferably, the solid particles are being collected in a cone-shaped collection chamber and forced through the solid outlet due to the different specific mass of the solid particles. The remaining two-phase fluid preferably enters the second separator from below such that the flow direction through the second separator would be upwards. In case one applies a plate-shaped laminar separator the remaining solid particles can be separated from the liquid.

As an additional advantage, due to the pre-separation of solid particles from the three-phase flow in the tubular separator of the separator device according to the present invention, the configuration of the second separator can be brought into conformity with the new separator device. This enables a significant cost-reduction for the second separator. Ultimately, due to the pre-separation of the solid particles, possibly depending on the target set for the solid particle content of the purified liquid, the second separator need not to be provided at all. Obviously, the actual configuration of the second separator strongly depends on the specific application and/or specific dimensions of the entire process.

In a presently preferred embodiment according to the present invention the number of blades in a separator is in a range of 5-200, preferably in the range of 10-100, and most preferably in the range of 10-80.

It has been found that providing the separator with a number of blades especially in the range of 10-80 has proven to provide a cost-effective and relatively very efficient separation enabling a degasification and a pre-separation of solid particles from a three-phase fluid. It will be understood that the exact number of blades may also depend on the treatment plant wherein the separator device according to the present invention would be implemented.

The invention further relates to a treatment plant comprising a separator device as described above.

Such treatment plant provides the same effects and advantages as those stated with reference to the separator device. The treatment plant may comprise one or more separator devices. The treatment plant may involve waste water treatment involving aerobic and/or anaerobic purification of such waste water.

The invention further also relates to a method for separating a three-phase fluid containing liquid, gas and solid particles, the method comprising the steps of: providing a circular separator device as described above; supplying the flow by the inlet to the separator; accumulating gas at or near the upper blade thereby performing a separation of a substantial part of the gas from the fluid; accumulating solid particles at or near the lower blade thereby performing a preseparation of a substantial part of the solid particles from the fluid; and providing the flow to an outlet.

Such method provides the same effects and advantages as those stated with reference to the separator device and/or treatment plant.

Preferably, in the method according to the present invention the flow is directed in a substantially downward direction and/or achieves a substantially laminar flow in the blade configuration. Preferably, a counter-flow is provided at or near the upper blade. As mentioned earlier for the separator device according to the present invention, this significantly improves the separation process and more specifically enhances the pre-separation of the solid particles from the fluid. More particularly, the counter-flow produces the highest average flow velocity between the centerline of the flow channel between two adjacent blades and the lower blade. By providing the highest average flow velocity not along the center axis of the channels, and instead more towards the bottom thereof, and effectively closer to the bottom blade when seen in a vertical cross-section thereof, the settling capacity of the solid particles is improved.

Furthermore, in a presently preferred embodiment the method according to the invention comprises the additional step of separating the solid particles from the flow at the solids collection chamber before separating the remaining solid particles from the flow in a second separator. This improves the overall efficiency of the separation process for the three-phase fluid.

Further advantages, features and details of the invention are elucidated on the basis of preferred embodiments thereof, wherein reference is made to the accompanying drawings, in which: figure 1 shows an overview of a circular separator comprising a circular separator device according to the present invention; figures 2-3 show further views of the separator of figure 1; figure 4 shows a top view of the separator of figure 1; figures 5 and 6 show sectional views of the separation of figure 1; figure 7 shows the flow channels between blades of a separator device according to the invention; and figure 8 shows the method steps according to the invention.

Circular separator 2 (figures 1-6) comprises outer separator device 4, solids collection chamber 6, lower separator part 7 (only shown in figures 1 and 5), and second inner separator 8. Lower separator part 7 is connected to chamber 6 with flange 7a (figure 1). Restriction 7b prevents liquid to enter part 7 from below and enables solids to exit part 7. Separator device 4 comprises a number of blades 10 that are provided at an angle a with the vertical. In the illustrated embodiment a circle configuration of blades 10 has been provided around second separator 8. In the illustrated embodiment separator 2 comprises inlet section 12 with inlets 14 to flow channels 16 between individual blades 10.

Flow channel 16 is defined by two adjacent blades 18, 20 with an upper blade 18 and a lower blade 20. Flow channel 16 has a center line 22. Optionally, grooves, ribs, channels or other guiding profile 30 are provided at the downwards facing side of upper blade 18. In addition or alternatively, grooves, ribs, channels or other guiding profile 32 can be provided at the upwards facing side of blade 20. In the illustrated embodiment about thirty-six blades 10 are provided for separator device 4.

The fluid enters collection chamber 6 with a downward flow in direction A. Chamber 6 is provided with solid outlet 24 and in the illustrated embodiment with an additional connection 26. From collection chamber 6 the remaining flow flows upwards between plates 28 of second separator 8 and the liquid leaves separator 2 through outlet 34.

In the illustrated embodiment, the second separator 8 comprises a circular housing 36 with a number of reinforcement blades 38 capable of holding the inner blades 28. Second separator 8 further comprises a fluid outlet 40.

Flow 130 (figure 7) entering channel 16 at inlet 14 flows in a substantially downward direction A. In the illustrated embodiment blade 10 is put at an angle a with the vertical 132 of about 35°. The three-phase flow 130 comprises a liquid 134, gas 136 and solid particles 138. Gas 136 accumulates at the or near the top 140 of a vertical cross-section 142 while solid particles 138 accumulate at or near bottom 144 of vertical cross-section 142 such that solid particles move in downward settling direction 146. The accumulated gas 136 leaves channel 16 at gas outlet 148. In the illustrated embodiment gas outlet 148 corresponds with the inlet 14. It will be understood that other configurations with a separate gas outlet 148 would also be possible. Due to the specific configuration of blades 10 of tubular separator 4, in use, a counter-flow 150 will be produced in channel 16 thereby improving removal of gas 136 and increasing settler capacity of solid particles 138. Gas 136 is separated from the three-phase flow 130 and exits at outlet 148. The substantially two-phase mixture of liquid 134 and pre-separated solid particles 138 leaves channel 16. The preseparated solid particles 138 can be separated relatively easy from the two-phase flow from outlet 152.

Purification method (figure 8) starts with supply step 156 providing a three-phase flow 130 to separator device 4. In flow step 158 from tube 14 the flow 130 is fed into channel 16 where in accumulation step 160 gas 136 is accumulated and solid particles 138 are accumulated. In gas removal step 162 gas is removed to gas outlet 148. In two-phase removal step 164 the mixture is provided to collection chamber 6 from which the solid particles 138 are removed in solid removal step 166, while the remaining flow of liquid 134 with the remaining solid particles 138 are provided in step 168 to second separator 8. In step 170, purifying liquid is removed from separator 2, with any remaining solid particles being removed from second separator 8 in step 172.

It will be understood that different configurations and/or different dimensions of separator 2 would be possible depending on the specific conditions wherein separator 2 is being applied. For example, in case the pre-separation of solid particles 138 would suffice, the second separator 8 can be omitted from separator 2.

The present invention is by no means limited to the above described preferred embodiments thereof. The rights sought are defined by the following claims within the scope of which many modifications can be envisaged.

Clauses 1. Circular separator device for a three-phase fluid containing liquid, gas and solid particles, the device comprising; a basin provided with an inlet configured for receiving the fluid; a separator having a circular shape and connected to the inlet, the separator comprising: a number of blades having a surface with a length in a first direction in use substantially corresponding to a main flow direction of the liquid through the separator and a width in a perpendicular second direction, wherein the blades are placed at a first angle in the second direction such that the blades are arranged to achieve an increasing distance between two adjacent blades as seen from a center region of the circular separator device towards an outer perimeter of the circular separator device; and an outlet for the liquid and pre-separated solid particles with the outlet being connected to a solids collection chamber. 2. Circular separator device according to clause 1, wherein the blades are placed with their length at a second angle relative to the vertical such that the flow between the two adjacent blades is caused to flow obliquely between the blades thereby accumulating gas at or near an upper blade such that a degasification is achieved and accumulating solid parts at or near a lower blade such that in use a pre-separation of the solid particles is achieved. 3. Circular separator device according to clause 2, wherein the angle relative to the vertical is in the range of 0° - 80°, preferably in the range of 10°-70°, more preferably in the range of 25° - 60°, and most preferably about 35°. 4. Circular separator device according to clause 1, 2 or 3, wherein the blades are provided with a guiding profile on or at an upwards and/or downwards facing side of the surface of the blade. 5. Circular separator device according to one or more of the foregoing clauses, further comprising a solids collection chamber and a second separator for separating a two-phase mixture of liquid and remaining solid particles. 6. Circular separator device according to clause 5, wherein the second separator is located at a center region of the device. 7. Circular separator device according to one or more of the foregoing claims, wherein the number of blades is in the range of 5-200, preferably in the range of 10-100, and most preferably in the range of 10-80. 8. Treatment plant comprising a circular separator device according to one or more of the foregoing clauses. 9. Method for separating a three-phase fluid containing liquid, gas and solid particles, comprising the steps of: providing a circular separator device according to one or more of the foregoing clauses 1-7; supplying the flow by the inlet to the separator; accumulating gas at or near the upper blade thereby performing a separation of a substantial part of the gas from the fluid; accumulating solid particles at or near the lower blade thereby performing a preseparation of a substantial part of the solid particles from the fluid; and providing the flow to an outlet. 10. Method according to clause 9, wherein the flow is directed in a substantially downward direction. 11. Method according to clause 9 or 10, wherein the blades are configured to achieve a substantially laminar flow. 12. Method according to clause 9, 10 or 11, further comprising the step of providing a counterflow at or near the upper blade. 13. Method according to clause 12, wherein the counter-flow produces the highest average flow velocity at or near the lower blade. 14. Method according to one or more of the clauses 9-13, further comprising the steps of separating the solid particles from the flow at a solids collection chamber and separating the remaining solid particles from the flow in a second separator.

Claims (14)

A circular separation device for a three-phase fluid containing liquid, gas and solid particles, the device comprising: an inlet configured to receive the fluid; a separator with a circular shape connected to the inlet, the separator comprising: - a plurality of plates having a surface provided with a length in a first direction in use substantially corresponding to the main flow direction of the liquid through the separator and a width in a second direction perpendicular to the first direction, in which the plates are placed at a first angle in the second direction, such that the plates are arranged to provide an increasing distance between two adjacent blades viewed from the center region of the circular separator in separator in the direction of the outer edge of the circular separator; - an outlet for the liquid and pre-separated solid particles wherein the outlet is connected to a solid collecting chamber. Circular separation device according to claim 1, wherein the plates are placed at an angle in length with respect to the vertical such that the flow between two adjacent plates runs at an angle between the plates, thereby accumulating gas in or near the upper plate, such that a degassing is effected, and solid particles accumulate in or near the bottom plate, such that in use a pre-separation of the solid particles is effected. 3. Separating device as claimed in claim 1 or 2, wherein the angle with respect to the vertical is in the range of 0-80 °, preferably in the range of 10-70 °, more preferably in the range of 25-60 ° , and most preferably about 35 °. Circular separation device according to claim 1, 2 or 3, wherein the plates are provided with a guide profile on or on an upward and / or downward facing side of the plate. The circular separation device according to one or more of the preceding claims, further comprising a solid collecting chamber and a second separator for separating the two-phase mixture of liquid and remaining solid particles. The circular separation device of claim 5, wherein the second screen is provided in the center region of the device. Circular separation device according to one or more of the preceding claims, wherein the number of plates is in the range of 5-200, preferably in the range of 10-100, and most preferably in the range of 10-80. 8. Treatment installation comprising a circular separation device according to one or more of the preceding claims. A method for separating a three-phase fluid-containing liquid, gas, and solid particles, comprising the steps of: providing a circular separation device according to one or more of the preceding claims 1-7; providing the fluid through the inlet to the tubes; accumulating gas in or at the top of the vertical cross section of the tubes thereby performing a separation of a substantial portion of the gas from the fluid; accumulating solid particles in or at the bottom of the vertical cross-section of the tubes thereby performing a pre-separation of a substantial portion of the solid particles from the fluid; and providing the power to an outlet. The method of claim 9, wherein the stream is directed in a substantially downward direction. The method of claim 9 or 10, wherein the plates are configured to effect a substantially laminar flow. The method of claim 9, 10 or 11, further comprising the step of providing a counter current in or at the top plate. The method of claim 12, wherein the countercurrent produces the highest average flow rate at or at the bottom plate. The method of any one of claims 9-13, further comprising the steps of separating the solid particles from the stream in a solid collecting chamber and separating the remaining solid particles from the stream in a second separator.