JP6856672B2 - Centrifuge with ventilation system - Google Patents

Description

The present invention relates to the field of centrifuges, and more particularly to centrifuges having a system for ventilating the space around the centrifuge rotor.

Centrifuges are commonly used for the separation of liquids and / or solids from liquid or gas mixtures. During operation, the fluid mixture that is about to be separated is introduced into the rotating bowl, and centrifugal force causes dense liquids such as heavy particles or water to accumulate around the rotating bowl, while low density liquids rotate. Accumulates closer to the central axis of. This allows the recovery of the separated fractions by using the outlets located in the periphery and the outlets located near the axis of rotation separately.

There is a risk of creating an explosive atmosphere when processing flammable fluids above the flash point in a centrifuge. This can occur when flammable gas and oxygen are present in a particular concentration at the ignition source. Various laws require action to be taken to reduce or minimize the risk of an explosion. For example, the European Union has an ATEX Directive that regulates what equipment and working environments are acceptable in environments with explosive atmospheres.

A common method today to prevent explosions when treating flammable fluids is to purge the separation system with an inert gas such as nitrogen or carbon dioxide, thereby reducing or eliminating oxygen content. To do. Such a system is described, for example, in Patent Document 1, in which the centrifuge is positioned in a container that can be sealed by a lid. To supply an inert gas to purge all oxygen and other flammable gases / vapors etc. from the vessel and centrifuge prior to the start of the centrifuge process to reduce the risk of explosion. Means are provided.

However, such purge systems based on inert gas are invested and operated, for example, because inert gas systems usually require means to maintain the overpressure of the inert gas around the centrifuge. It increases both the cost and the complexity of the centrifuge system. Therefore, there is a technical demand in the art for less complex systems to reduce the risk of explosion when processing flammable fluids in a centrifuge.

UK Patent Application Publication No. 2011808

ISO 8217, Petroleum products --Fuels (class F) --Specification of marine fuels. Editions 2005 and 2012

A main object of the present invention is to provide a centrifuge having a convenient ventilation system.

A further object is to provide a centrifuge with a reduced risk of explosion during the treatment of flammable fluids.

A first aspect of the invention is a centrifuge for separating at least two components of a fluid mixture of different densities.
With a fixed frame
A drive member configured to rotate a rotating component with respect to a fixed frame, the rotating component comprising a mandrel and a centrifugal rotor surrounding a separation space, the centrifugal rotor being the axis of rotation (X). Mounted on the mandrel to rotate with the mandrel around, the rotating parts are supported by a fixed frame by at least one bearing device, with a drive member,
With
The fixed frame surrounds the centrifugal rotor, thereby forming a rotor space between the fixed frame and the centrifugal rotor, and the fixed frame is placed to provide fluid communication into the rotor space at least one. With one first air inlet and at least one first air outlet arranged to provide fluid communication out of the rotor space,
At least one first air inlet and at least one first air outlet exit from at least one first air inlet through the first air outlet toward at least one first air outlet. Placed in a fixed frame to provide air flow,
At least one first air inlet is arranged to be connected to a source of pressurized air and at least one first air outlet is arranged to allow air outflow from the rotor space. A centrifuge is provided.

Centrifuges are for the separation of fluid mixtures such as gas and liquid mixtures. The fixed frame of the centrifuge is a non-rotating component, and the rotating component, such as a mandrel, is supported by the frame by at least one bearing device, such as at least one ball bearing.

The drive member is arranged to rotate the mandrel, and the centrifugal rotor is mounted on the mandrel. Such a drive member for rotating a rotating component may include an electric motor having a rotor and a stator. The rotor may be provided on the mandrel or fixed to the mandrel so as to transmit driving torque to the mandrel during operation and thus to the centrifugal rotor.

Alternatively, the drive member may be provided beside the mandrel, rotating the rotating component by a suitable transmission device, such as a belt or gear transmission device.

The centrifugal rotor is adjacent to the first end of the mandrel and is therefore mounted to rotate with the mandrel. Therefore, during operation, the mandrel forms a rotating shaft. The first end of the mandrel can be the upper end of the mandrel. Therefore, the mandrel is rotatable around the axis of rotation (X).

Rotating parts can be configured to rotate at speeds above 3000 rpm, such as above 3600 rpm.

The centrifugal rotor further surrounds the separation space where the separation of the fluid mixture occurs. Therefore, the centrifugal rotor forms a rotor housing for the separation space. The separation space may include an overlap of separation disks arranged about the axis of rotation. Such a separation disk forms an insert that expands the surface in the separation space. The separation discs can have the form of a truncated cone, that is, the overlap can be a stack of truncated cone-shaped separation discs. The discs may be axial discs arranged around the axis of rotation.

The centrifuge may further include at least one inlet for the fluid mixture to be separated, i.e. the feed. Such an inlet can be a fixed tube arranged to supply the supply into the separation space. The inlet may be provided inside a rotating shaft such as a mandrel. Thus, the mandrel may be hollow and may further have a diameter of at least 10 mm, such as at least 20 mm. For example, the outer diameter of the mandrel can be between 10 and 300 mm, such as between 20 and 200 mm.

The centrifuge may further include at least one liquid outlet for the separated fluid. At least one liquid outlet for the separated fluid may have a first outlet and a second outlet located at a greater radius than the axis of rotation as compared to the first liquid outlet. Therefore, liquids of different densities can be separated and discharged through the first liquid outlet and the second liquid outlet, respectively. During operation, sludge phase, a mixture of solid and liquid particles forming a heavy aspect, may be recovered at the outer peripheral portion of the separation space. Therefore, the centrifuge may further include an outlet for discharging such a sludge phase from the periphery of the separation space. The outlet can be in the form of multiple peripheral ports extending from the separation space through the centrifugal rotor into the rotor space between the centrifugal rotor and the fixed frame. Peripheral ports may be configured to be opened intermittently over a short period of time, on the order of milliseconds, to allow the discharge of sludge phase from the separation space into the rotor space. Peripheral ports may be in the form of nozzles that open periodically during operation to allow for the periodic discharge of sludge.

The fixed frame may be a single wall, for example a double wall or a triple wall, which surrounds the centrifugal rotor at a distance from the rotor, thereby providing a rotor space between the rotor and the frame wall. To form. The fixed frame comprises at least one first air inlet and at least one first air outlet. Thus, the frame may have a single air inlet and / or a single air outlet, or, as an alternative, may have two or more air inlets and / or two or more air outlets. At least one first air inlet and at least one first air outlet are arranged to provide fluid communication between the outside of the frame and the rotor space. Thus, at least one air inlet and at least one air outlet can be through holes in the fixed frame.

At least one first air inlet and at least one first air outlet are arranged in a frame to provide air flow from at least one first air inlet to at least one first air outlet. , At least one first air inlet is further arranged to be connected to a source of pressurized air.

Pressurized air can come from common air sources found in almost any industrial environment. Thus, at least one air inlet may be arranged to provide a connection with such a pressurized air source, for example using screws or other suitable connecting means.

Pressurized air can have a composition that is substantially the same as the atmosphere. For example, pressurized air may contain oxygen and nitrogen.

In an embodiment of the first aspect of the invention, at least one first air inlet is connected to a source of pressurized air. This connection can be, for example, via a tube for supplying pressurized air to at least one first air inlet, or any other suitable means.

In addition, at least one first air outlet is arranged to allow the outflow of air from the rotor space. "Air outflow" refers to an air outlet that is arranged to allow the flow of air out of the rotor space.

Therefore, at least one first air outlet may not have a device that exerts opposing pressure on the air in the rotor space. As a result, at least one first air outlet can be arranged to allow the free outflow of air from the rotor space. Therefore, at least one first air outlet may not have, for example, a liquid seal.

At least one first inlet and / or at least one first air outlet, such as 1.0 cm ^2, greater than such 1.5 cm ^2, greater than such 2.0 cm ^2, greater than such 2.5 cm ^2, greater than 0.5 cm ² Can have a super cross-sectional area.

At least one first air inlet and / or at least one first air outlet may have a substantially circular through hole in the frame with a diameter greater than 5 mm, such as greater than 15 mm, such as greater than 10 mm. Good.

At least one first inlet and / or at least one first air outlet has a cross-sectional area of less than ^{100 cm 2} , such as less ^{than 50 cm 2,} less than 20 cm ^2, less than 10 cm ^2, less than 5 cm ^2. Can have.

Furthermore, at least one first air inlet and at least one air outlet, exits through its outlet toward the inlet to the outlet, such as 6 Nm ³ / hour greater, such as 8 Nm ³ / hour, greater than 4 Nm ³ Can be arranged to provide a flow of pressurized air over / hour.

A first aspect of the invention is based on the insight that a centrifugal rotor can be ventilated using a stream of pressurized air. This is therefore advantageous in that the centrifuge does not require any complex inert gas system to reduce the risk of explosion. Therefore, ventilation can be performed regularly with pressurized air. In addition, because the air inlet is arranged so that it is connected to the source of pressurized air, the centrifugal rotor can be ventilated during the break of the separator, and ventilation using pressurized air is performed on a regular basis. Can be done or can be done frequently according to a time schedule.

In an embodiment of the first aspect of the invention, at least one first air inlet is arranged in the frame so as to communicate with the left portion of the rotor space, and at least one first air outlet is the rotor. They are placed in the frame so that they communicate with the right part of the space, or they are reversed.

The "left" and "right" parts can be when viewed in an axial plane penetrating the center of the centrifuge. Therefore, the "left" portion can be to the left of the axis of rotation X, while the "right" portion can be to the right of the axis of rotation X. Therefore, the left part and the right part can be different parts of the rotor space.

The air inlet, air outlet, and axis of rotation may all be located in the same axis plane.

Therefore, the air inlet may be provided in the frame to communicate with the first half of the rotor space, and the first outlet communicates with the second half other than the first half of the rotor space. It may be provided on the frame for this purpose. This can facilitate a large amount of rotor space to be ventilated as air flows from the air inlet to the air outlet.

In an embodiment of the first aspect of the invention, at least one first air inlet is arranged in the frame so as to communicate with the upper portion of the rotor space, and at least one first air outlet is the rotor. They are placed in the frame so that they communicate with the lower part of the space, or they are reversed.

This is also advantageous in that it facilitates ventilation of a large amount of rotor space as air flows from the air inlet to the air outlet.

The "upper" and "lower" parts can be when viewed in an axial plane penetrating the center of the centrifuge. Therefore, the "upper" portion can be axially above the center of the centrifugal rotor, while the "lower" portion can be axially below the center of the centrifugal rotor. Therefore, the upper part and the lower part can be separate parts of the rotor space.

As an example, at least one first air inlet may be arranged in the frame to communicate with the upper left portion of the rotor space, and at least one first air outlet may be located in the lower right portion of the rotor space. They may be arranged in a frame to communicate with, or they may be reversed. This can facilitate a large amount of rotor space to be ventilated as air flows from the air inlet to the air outlet.

In an embodiment of the first aspect of the invention, the centrifuge further comprises at least one sensor configured to detect a parameter relating to the concentration of flammable gas in the air in the rotor space.

The flammable gas can be a flammable gas such as a hydrocarbon derived from a flammable fluid such as oil or fuel. Thus, the sensor can be, for example, a sensor that includes infrared or catalytic bead detection techniques for detecting flammable gases. At least one sensor may be placed in rotor space, such as on the inner surface of a fixed frame.

Using a sensor to detect parameters with respect to the concentration of flammable gas can be advantageous in that it allows the air flow, i.e. ventilation, to be regulated based on the output from the sensor. Further information may be provided that the concentration of flammable gas is below a certain harmless level.

As an example, the parameter can be the ratio of hydrocarbons to oxygen in the air in the rotor space. The parameter may be the actual concentration of hydrocarbons. Therefore, the centrifuge may be equipped with a sensor configured to detect the concentration of oxygen in the rotor space, or the ability to detect both the concentration of oxygen and the concentration of hydrocarbons, or with respect to oxygen. It may be equipped with at least one sensor with the ability to directly detect the proportion of hydrocarbons.

As an example, at least one of the at least one sensor may be located in an additional space that communicates with the rotor space.

In embodiments, such additional space does not surround the centrifugal rotor.

Thus, the additional space can be a passage or chamber, such as a tube-shaped passage or chamber that is located outside the actual fixed frame, but communicates with the rotor space through at least one opening in the frame. This has the advantage of allowing easy access to at least one sensor.

Further, in the embodiment of the first aspect of the present invention, the centrifuge receives an input signal regarding a detected parameter regarding the concentration of flammable gas in the air in the rotor space, and adds the input signal based on the input signal. It further comprises a control unit configured to generate a signal to regulate the flow of compressed air.

This allows the flow of pressurized air, controlled by the detected parameters, that is, the ventilation of the centrifugal rotor. Therefore, the flow of ventilated air may be regulated by the detected parameters.

The control unit provides an input / output interface for communicating with the processor and the source of pressurized air, and for receiving information from at least one sensor about parameters regarding the concentration of flammable gas in the rotor space. Can be equipped with.

Adjusting can include increasing the flow of pressurized air when the detected parameters exceed the threshold. The threshold can be, for example, the ratio of hydrocarbons to oxygen in the rotor space, or the lower explosion limit for the specific concentration of hydrocarbons in the rotor space.

Adjusting may further include reducing the flow of pressurized air when the detected parameters are below the threshold.

Adjusting also includes using a regulating loop to keep the pressurized air flow at a constant level, activating or deactivating the pressurized air flow, or increasing the pressurized air flow. obtain. Therefore, the control unit may be configured to increase the flow of pressurized air during centrifuge pauses when there is liquid to be separated in the centrifuge rotor, i.e. the control unit is of the centrifuge. It may be further configured to receive information about the rotational speed and control the flow of pressurized air based on that information.

Therefore, the centrifuge may include pressure regulating means configured to supply air at a pressure above atmospheric pressure to at least one first air inlet. The pressure regulating means may include a valve. Therefore, the control unit may be arranged to generate a signal to be sent to the pressure regulating means.

In an embodiment of the first aspect of the invention, the frame further surrounds the drive member, thereby forming a drive space surrounding the drive member, and at least one arranged to provide fluid communication into the drive space. The centrifuge comprises two second air inlets and at least one second air outlet arranged to provide fluid communication out of the drive space, and the centrifuge has a second air from the second air inlet. Further provided with means for creating a flow of air towards the outlet and out through its second air outlet.

Means for creating a flow of air from the second air inlet to the second air outlet and out through the second air outlet may include, for example, a fan. The means for creating a flow of air from the second air inlet to the second air outlet and out through the second air outlet is the pressurization used to further ventilate the rotor space. It may be a source of pressurized air, such as a source of air. Therefore, at least one second air inlet may be arranged to be connected to a source of pressurized air. The at least one second air outlet may be arranged to allow the outflow of air from the drive space, such as a free outflow with no means of opposing pressure. Further, at least one second air inlet and at least one second air outlet are sized as previously detailed with respect to at least one first air inlet and at least one first air outlet. Can obtain or have such a size.

Therefore, the centrifuge may be further arranged to ventilate the drive space around the drive member, similar to the one described above for ventilation of the rotor space. The drive space may be in fluid communication with the rotor space or may be sealed from the rotor space. As an example, the centrifugal rotor may be placed above or below the drive member axially, and the rotor space and drive space use, for example, a liquid seal between the rotor space and the drive space axially. And may be sealed. The bearing device may be arranged in the drive space.

If there is no seal between the rotor space and the drive space, at least one first air inlet may be used to provide pressurized air to the drive space as well. At least one first air outlet ventilates the pressurized air supplied through at least one first air inlet through the drive space before leaving through at least one first outlet. As such, it may be arranged in a frame.

In addition, the centrifuge may include at least one sensor configured to detect parameters with respect to the concentration of flammable gas in the air in the drive space.

Therefore, the sensor arranged in the drive space can be a sensor as described above with respect to the rotor space.

In addition, at least one second gas inlet may be arranged to be connected to a source of pressurized air, and the centrifuge receives an input signal for the parameter and pressurizes based on the input signal. It further comprises a control unit configured to generate a signal to regulate the flow of air.

The control unit relates to a control unit for receiving signals from at least one sensor configured to detect parameters relating to the concentration of flammable gas in the rotor space, eg, for regulating the flow of pressurized air. It can be as described or can function as described.

The same control unit may be used to receive and control the flow of air in the rotor space and drive space.

In an embodiment of the first aspect of the invention, the centrifuge is provided with a set of sludge outlets around its outer periphery for the discharge of higher density components such as sludge or other solids in a fluid mixture. The frame further surrounds the solid collector for recovering the discharged components, and the centrifuge is configured to detect parameters related to the concentration of flammable gas in the air of the solid collector at least one sensor. Further prepare.

The sludge outlet may be configured to be opened intermittently or to be permanently opened, i.e. to form a nozzle. The solid collector may include a cyclone.

Placing at least one sensor in the solid collector may further increase the safety of the process, that is, it can also provide information about the concentration of flammable gas in the solid collector. If the centrifuge is equipped with a control unit as described above, the sensor in the solid collector may also be connected to the control unit so that the flow of ventilated air can be adjusted based on the information from the sensor in the solid collector. .. The sensors in the solids collector can function as described for the sensors in the rotor space and the drive space, respectively.

A second aspect of the present invention is a method for ventilating a centrifuge.
—— The step of providing a centrifuge according to the first aspect of the present invention,
--The step of feeding a fluid mixture containing at least two components of different densities to be separated into the separation space of the centrifugal rotor,
--With the steps of rotating rotating parts to provide separation of the fluid mixture,
--With the step of supplying pressurized air to at least one first air inlet, thereby ventilating the centrifuge,
Methods are provided that include.

The terms and definitions used with respect to the second aspect are the same as those detailed above in relation to the first aspect.

The fluid mixture to be separated can be a liquid mixture.

Depending on the application, the liquid mixture to be separated may have different temperatures, and if the liquid mixture to be separated contains gasoline, ethanol, or other volatile chemicals, the liquid mixture is substantially above room temperature. May begin to have a typical evaporation rate. Thus, as an example, the liquid mixture fed to the separator may be fed at room temperature. As a further example, the liquid mixture can have a temperature of at least 40 ° C, such as at least 50 ° C, at least 90 ° C, at least 95 ° C, at least 98 ° C.

The liquid mixture may be supplied to the separation space from above or below via a fixed inlet tube, or may be supplied via a mandrel, such as through a duct in a mandrel that rotates with the mandrel.

Therefore, the step of rotating the rotating component involves using a drive member to transfer torque to the mandrel so that the mandrel and centrifugal rotor rotate. The step of rotating the rotating component may include rotating the centrifugal rotor at a speed greater than 3000 rpm, such as greater than 3600 rpm.

The method may, of course, include the step of separating the fluid mixture into two or several phases, such as one or two liquid phases and a solid phase or sludge phase.

In the embodiment of the second aspect of the present invention, the fluid mixture to be separated comprises a flammable fluid.

The flammable fluid may contain oil. The oil can be selected from heavy fuel oil (HFO), lubricating oil, or crude oil. HFOs can be defined as in ISO 8217, Petroleum products --Fuels (class F) --Specifications of marine fuels. Editions 2005 and 2012. In addition, the fluid mixture to be separated can be heated to temperatures above 70 ° C, such as above 98 ° C, such as between 70 ° C and 98 ° C, before being fed into the separation space. .. This can increase the handling and separation of, for example, the oil mixture to be separated.

In an embodiment of a second aspect of the invention, the step of supplying pressurized air is for one period selected from start-up, pause, and the time period during which the rotational speed of the rotating component slows down to pause. At least implemented in.

This can be advantageous because the risk of flammable gas leaking into the rotor space can be greater when the liquid being processed has a longer retention time in the centrifuge rotor.

In the embodiment of the second aspect of the present invention, the steps of supplying pressurized air are carried out continuously.

Therefore, the rotor space can be continuously ventilated using pressurized air.

Alternatively, the step of supplying pressurized air may be performed intermittently. The step of supplying pressurized air can be triggered by time. Therefore, the time period during which the rotor space is ventilated, i.e. when pressurized air is supplied, and the time between such ventilation periods can be determined by a preset time period.

In the embodiment of the second aspect of the present invention, the step of supplying pressurized air is carried out so that the pressure in the rotor space is kept below 0.5 bar. This can be advantageous in that the frames of all separators do not have to be configured to withstand high pressures.

In an embodiment of the second aspect of the invention, the method is:
--Steps to detect parameters related to the concentration of flammable gas in the rotor space,
--Based on the detected parameters, the step of adjusting the flow of air from at least one first gas inlet to at least one first gas outlet and out through that first gas outlet,
Including further.

As detailed above in connection with the first aspect, the parameter can be the ratio of hydrocarbons to oxygen in the rotor space. The parameter may be the actual concentration of hydrocarbons.

Adjusting can include increasing the flow of pressurized air when the detected parameters exceed the threshold. The threshold can be, for example, the ratio of hydrocarbons to oxygen in the rotor space, or the lower explosion limit for the specific concentration of hydrocarbons in the rotor space.

Adjusting may further include reducing the flow of pressurized air when the detected parameters are below the threshold.

Adjusting can also include using a regulating loop to keep the flow of pressurized air at a constant level, or activating or deactivating the flow of pressurized air.

Therefore, in the embodiment of the second aspect of the present invention, the method is:
--Steps to detect parameters related to the concentration of flammable gas in the drive space surrounding the drive member,
--If the detected parameters exceed the threshold, the step of increasing the flow of air from at least one first gas inlet to at least one first gas outlet and out through that first gas outlet. ,
Including further.

Further, in the embodiment of the second aspect of the present invention, the method is:
--Steps to detect parameters related to the concentration of flammable gas in the solid collector,
--If the detected parameters exceed the threshold, the step of increasing the flow of air from at least one first gas inlet to at least one first gas outlet and out through that first gas outlet. ,
Including further.

The method, of course, is for flammable gas in both the rotor space and the drive space, in the rotor space, in the solid collector, or in all three of the rotor space, drive space, and solid collector. It may include the step of detecting parameters with respect to concentration.

It is a schematic diagram of an embodiment of a centrifuge that is ventilated using pressurized air. FIG. 6 is a schematic representation of an embodiment of a centrifuge that is ventilated using pressurized air and the sensor is used in additional space. FIG. 5 is a schematic representation of a further embodiment of a centrifuge that is ventilated using a stream of pressurized air. FIG. 5 is a schematic representation of an embodiment of a centrifuge ventilated using a flow of pressurized air regulated using a control unit.

The centrifuge according to the present disclosure is further illustrated by the following description of some embodiments with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a centrifuge 1 having a fixed frame 2 and a rotating component 4. The rotating part 4 includes a vertical mandrel 5 and a centrifugal rotor 6, and the actual separation occurs during the operation of the centrifuge 1. The liquid mixture to be separated can be introduced from above into the separation space (not shown) inside the centrifugal rotor 6 through a passage in the tube 33 during operation. Also, for example, one or two separated liquid phases, depending on the application, are discharged through the passage in this tube 33. The separation space further comprises a stack of truncated cone-shaped separation disks (not shown) to achieve effective separation of the liquid. Therefore, the overlap of the truncated cone separation disks is an example of an insert that expands the surface and is coaxially fitted to the centrifugal rotor 6 at the center. Further, the centrifugal rotor 6 is provided with a set of sludge outlets 19 around it, and the sludge outlet 19 is intermittently opened so as to discharge the separated sludge phase out from the centrifugal rotor 6 in the radial direction. obtain. The sludge phase is recovered in the solid collector 20 after discharge. In this case, the solid collector 20 is arranged radially outside the fixed frame 2.

The mandrel 5 is pivotally supported by the upper bearing 7a and the lower bearing 7b, and supports the centrifugal rotor 6 at its upper end above the upper bearing 7a. The rotating component 4 is rotatable around an axis of rotation X and is driven by a drive member 3, which in these examples comprises a screw gear. However, the drive may, of course, be equipped with an electric motor or belt drive as an alternative. Further, the driving member 3 may be arranged above the centrifugal rotor 6 in the axial direction.

The fixed frame 2 surrounds the centrifugal rotor 6 at a distance from the centrifugal rotor 6 so that the rotor space 8 is formed around the centrifugal rotor 6. As shown in the figure showing all the axis planes penetrating the frame 2, the rotor space 8 can be divided into a left portion 11 and a right portion 12 of the rotation axis X. The rotor space 8 may be divided into an upper portion 13 and a lower portion 14. The boundary between the upper portion 13 and the lower portion 14 can be, for example, a radial line through the sludge outlet 19, as indicated by the dashed line “Y” in the figure. Therefore, in the axial plane, the rotor space 8 may be divided into an upper right portion, an upper left portion, a lower right portion, and a lower left portion.

The first air inlet 9 is located on the fixed frame 2 in the upper left portion, while the first air outlet 10 is located in the fixed frame in the lower right portion. The first air inlet 9 and the first air outlet 10 are arranged in the frame as through holes with diameters between 5 and 10 mm, so that the air inlet 9, the air outlet 10, and the axis of rotation are all substantially the same. It is on the axis plane. The first air inlet 9 communicates with the pressurized air supply source 28 via the connection portion 29a. The source of pressurized air "P" is a common source of air found in almost all industrial environments and can therefore have a composition substantially equal to that of the atmosphere. The air flow at the connection 29a to the first air inlet 9 is regulated using the valve 30a. The first air outlet 10 does not have a liquid seal or the like that exerts opposite pressure, that is, is arranged so as to allow a substantially free flow of air exiting the rotor space 8.

Therefore, the air inlet 9 communicates with the upper left portion of the rotor space 8, while the air outlet 10 communicates with the lower right portion. However, the air inlet 9 may be arranged in the frame 2 so as to communicate with, for example, the upper right portion of the rotor space 8, while the air outlet 10 communicates with the lower left portion of the rotor space 8. It is understood that it may be placed in frame 2.

When the pressurized air is supplied to the first air inlet 9, the flow of ventilated air is formed through the rotor space, as indicated by the arrow "A" in the figure.

The fixed frame also comprises a lower component 16 that also surrounds the drive member 3 thereby forming a drive space 27 around the drive member 3. The drive space 27 and the rotor space 8 are not in fluid contact in this embodiment and may be separated using, for example, a water seal located above the upper bearing 7a. In this embodiment, the lower part 16 of the frame also has an air inlet and an air outlet, and in FIG. 1, the second portion communicating with the part of the drive space 27 to the left of the rotation axis X when viewed in the axial plane. The air inlet 17 and the second air outlet 18 communicating with the part of the drive space 27 to the right of the rotation axis X can be seen. Further, the separator 1 includes means (not shown) for generating an air flow through the drive space 27, such as a fan. Therefore, a flow of ventilated air that ventilates the drive space 27 during the operation of the centrifuge 1 can also be generated. This air flow exits from the second air inlet 17 to the second air outlet 18 through the second air outlet 18 in the drive space 27, as indicated by the arrow "B" in the figure. It flows like going.

However, when the rotor space 8 and the drive space 27 are in fluid contact, the second air inlet 17 and the first air outlet 10 can be extra and are supplied through the first air inlet 9. The flow of pressurized air can flow through both the rotor space 8 and the drive space 27 through an air outlet located at the bottom of the separator, the second air outlet 18. .. Therefore, both the rotor space and the drive space may be ventilated by the same flow of pressurized air supplied through the first air inlet 9.

Further, the centrifuge 1 includes a sensor 15a arranged in the rotor space 8, a sensor 15b arranged in the solid collector 20, and a sensor 15c arranged in the drive space 27. All these sensors can be sensors that detect parameters with respect to the concentration of flammable gas, such as the ratio of hydrocarbons to oxygen in the vicinity of the sensor. Thus, these sensors 15a-15c can provide information about the concentration of harmful or flammable gases, eg, satisfactory ventilation around the rotor and / or solid collector and / or drive member, or flammability. It can be used to ensure that the concentration of gas exceeds, for example, the lower limit of explosion in rotor space 8, solid collector 20, and / or drive space 27. By detecting the concentration of flammable gas above a certain limit, then, for example, shutting off the separator, i.e. stopping the feed of the mixture to be separated, and / or rotating the drive member 3 It can bring about a reduction.

However, the presence of pressurized air flow can add to the sensors 15a and 15b for detecting flammable gases. The flow of pressurized air can be set to a constant level to keep the concentration of flammable gas in the rotor space 8 and drive space 27 below a threshold, such as below the lower limit of explosion. As a supplement or alternative, the flow of pressurized air may be supplied over a specific preset time period, which may be set to ensure that the concentration of flammable gas is below a certain threshold. Also, the flow of pressurized air is during the start-up period of the centrifugal rotor, during the rest of the centrifugal rotor, and during the period during which the centrifuge decelerates from the operating speed to rest, that is, the liquid in the centrifugal rotor. Hold time is maximum, so at least one or more of the time during which the risk of flammable gas leaking out of the centrifugal rotor is maximum can be supplied.

FIG. 2 shows a further embodiment of the centrifuge 1. This centrifuge 1 functions as detailed in relation to the centrifuge of FIG. 1 above, the only difference being arranged to detect parameters related to the concentration of flammable gas in the rotor space 8. The sensor 15a is located in an additional space 21 that is in fluid contact with the rotor space 8. In this example, the additional space 21 is formed by the tube-shaped extension 34 of the frame 2. The tube-shaped extending portion 34 communicates with the rotor space through the through holes 22a and 22b of the fixed frame 2, but does not itself surround the centrifugal rotor 1. Due to the flow of air through the rotor space 8 and the through holes 22a and 22b, the concentration of flammable gas in the additional space 21 detected using the sensor 15a is the flammable gas in the rotor space 8. Represents the concentration of. Placing the sensor 15a in such an additional space is advantageous in that it allows easy access to the sensor.

FIG. 3 shows a further embodiment of the centrifuge 1. This centrifuge 1 has no sensor for detecting the concentration of flammable gas, except that the centrifuge 1 uses a flow of pressurized air to ventilate the rotor space 8 and the drive space 27. It functions as described in detail above in relation to the centrifuge of FIG. It uses connections 29a and 29b, which can be in the form of tubes or tubes, and both the first air inlet 9 and the second air inlet 17 are indicated by a "P" in the figure. This is achieved by connecting to a source of pressurized air. Air is drawn from the rotor space 8 and the drive space 27 through the first air outlet 10 and the second air outlet 18, respectively, as detailed in connection with FIG.

The source of pressurized air "P" is a common source of air found in almost every industrial environment. The air flow at the connection 29a to the first air inlet 9 is regulated using the valve 30a, while the air flow at the connection 29b to the second air inlet 17 uses the valve 30b. Is adjusted. Having a flow of pressurized air, such as a regular or intermittent flow of pressurized air, as detailed earlier in connection with FIG. 1, adds an extra sensor for detecting flammable gases. there is a possibility. In other words, the flow of pressurized air can be set to a level that keeps the concentration of flammable gas in the rotor space 8 and drive space 27 below a threshold, such as below the lower explosion limit.

FIG. 4 shows a further embodiment of the centrifuge 1. This centrifuge 1 functions as detailed in connection with the separator of FIG. 3, that is, the air inlets 9 and 17 are connected to the pressurized air source "P". In the embodiment, the adjustment of the air flow at the connections 29a and 29b is carried out using the information from the sensor for detecting the flammable gas. The centrifuge as shown in the embodiment of FIG. 4 is arranged in the sensor as detailed above in relation to FIG. 1, that is, the sensor 15a arranged in the rotor space 8 and the solid collector 20. The sensor 15b and the sensor 15c arranged in the drive space 27 are provided.

The sensor is connected to the control unit 23, which may be located within the centrifuge 1 or as a separate unit. By using the control unit 23, the valves 30a and 30b and the resulting air flow to ventilate can be controlled in an appropriate manner to obtain the required air flow. This is achieved using the connection 32a to the valve 30a and the connection 32b to the valve 30b.

The control unit 23 may further include a communication interface 26 such as a transmitter / receiver, through which the control unit receives data from sensors 15a, 15b, and 15c and further data to valves 30a and 30b. Can be sent.

For example, the received data may include data on measured parameters for the concentration of flammable gas, such as data on the ratio of hydrocarbons to oxygen. This is indicated by the connection 31a to the sensor 15a in the rotor space 8, the connection 31b to the sensor 15b in the solid collector 20, and the connection 31c to the sensor 15c in the drive space 27. The transmitted data may include, for example, control signals for controlling valves 30a and 30b.

The control unit 23 is further configured to perform a method for controlling the flow of pressurized air to the air inlets 9 and 17, according to the embodiments disclosed herein. For this purpose, the control unit 23 may include a processing unit 24, such as a central processing unit configured to execute computer code instructions that may be stored in the storage device 25, for example. Therefore, the storage device 25 may form a (non-temporary) computer-readable medium for storing such computer code instructions. Alternatively, the processing unit 24 may be in the form of hardware components such as application-specific integrated circuits, field programmable gate arrays, and the like.

Therefore, during the operation of the centrifuge as shown in FIG. 4, the control unit 23 receives information from various sensors 15a-15c and ventilates to the air inlets 9 and 17 based on the received information. The air flow can be regulated. For example, when the signal from the sensor 15a arranged in the rotor space 8 indicates that the concentration of the flammable gas in the rotor space 8 exceeds a specific threshold value such as exceeding the lower limit of explosion, the air flow will flow. The control unit 23 may adjust the valve 30a so that it can be increased. Next, even if the control unit 23 adjusts the valve 30a so that the air flow is reduced when the signal from the sensor 15a indicates that the concentration of the flammable gas in the rotor space 8 has decreased. Good.

Adjusting the valve 30a to reduce the flow of air may involve closing the valve 30a fully to prevent air from reaching the first air inlet 9.

Similarly, the control unit 23 may adjust the valve 30a to increase or decrease the flow of pressurized air based on information from sensors 15b located in the solid collector 20, or sensors 15a and 15b. The valve 30a may be adjusted to increase or decrease the flow of pressurized air based on information from both.

Further, the control unit 23 may adjust the valve 30b to increase or decrease the flow of pressurized air reaching the second air inlet 17 based on the information from the sensor 15c, and therefore may first adjust the valve 30b. Ventilation of drive space 27 may be regulated as described in detail in relation to ventilation of rotor space 8.

Therefore, the control unit 23 comprises an adjustment loop, that is, the control unit 23 has a first inlet 9 so that the concentration of flammable gas in the rotor space 8 and / or the drive space 27 is kept below a certain level. And / or may be configured to regulate the flow of air to the second air inlet 17.

The control unit receives information from other parts of the separator, such as from drive means 3, which can be an electric motor, and / or from a feed pump that regulates the feed of fluid mixture separated in centrifuge 1. It may be configured as follows. In this method, the control unit may adjust the flow of pressurized air to the first air inlet 9 and / or the second air inlet 17 based on that information. As an example, the control unit 23 may receive information that the centrifuge is dormant or that the supply to the centrifuge is cut off, so that the first air inlet 9a and / or the second. Valves 30a and 30b may be adjusted to reduce or increase the flow of pressurized air to the air inlet 9b.

The present invention is not limited to the disclosed embodiments, but may be modified and improved within the scope of the claims presented below. The present invention is not limited to the orientation of the axis of rotation (X) disclosed in the figure. The term "centrifuge" also includes centrifuges with substantially horizontally oriented axes of rotation.

1 Centrifuge
2 Fixed frame
3 Drive member
4 Rotating parts
5 mandrel
6 Centrifugal rotor
7a upper bearing
7b lower bearing
8 rotor space
9 First air inlet
10 1st air outlet
11 Left part
12 Right part
13 Upper part
14 Lower part
15a, 15b, 15c sensors
16 Lower parts
17 Second air inlet
18 Second air outlet
19 Sludge exit
20 Solid collector
21 Additional space
22a, 22b through hole
23 Control unit
24 processing unit
25 storage device
26 Communication interface
27 Drive space
28 Source of pressurized air
29a, 29b connection
30a, 30b valve
31a, 31b, 31c connections
32a, 32b connection
33 tubes
34 Tube shape extension
P Source of pressurized air
X rotation axis

Claims (12)

A centrifuge for separating at least two components of a fluid mixture of different densities, the fluid mixture containing a flammable fluid, the centrifuge.
With a fixed frame
A driving member configured to rotate a rotating component with respect to the fixed frame, wherein the rotating component includes a mandrel and a centrifugal rotor that surrounds a separation space, and the centrifugal rotor is a shaft of rotation. A drive member that is mounted on the mandrel to rotate around (X) with the mandrel, and the rotating component is supported by the fixed frame by at least one bearing device.
With
The fixed frame surrounds the centrifugal rotor, thereby forming a rotor space between the fixed frame and the centrifugal rotor, which provides fluid communication into the rotor space. It comprises at least one first air inlet arranged for the rotor space and at least one first air outlet arranged for providing fluid communication out of the rotor space.
The at least one first air inlet and the at least one first air outlet go from the at least one first air inlet to the at least one first air outlet and make the first air outlet. Arranged in the fixed frame to provide a flow of air through and out,
The at least one first air inlet is arranged to be connected to a source of pressurized air so that the at least one first air outlet allows air to flow out of the rotor space. Is located in
The centrifuge further comprises at least one sensor configured to detect parameters relating to the concentration of flammable gas in the air in the rotor space .
Flow of the air, during operation of the centrifuge, Ru is supplied so as to maintain the concentration of the flammable gas in the rotor space below a predetermined threshold value, the centrifuge. The at least one first air inlet is arranged in the frame so as to communicate with the left portion of the rotor space, and the at least one first air outlet communicates with the right portion of the rotor space. The centrifuge according to claim 1, wherein the centrifuge is arranged in such a frame, or they are reversed. The at least one first air inlet is arranged in the frame so as to communicate with the upper portion of the rotor space, and the at least one first air outlet communicates with the lower portion of the rotor space. The centrifuge according to claim 1 or 2, wherein the centrifuge is arranged in such a frame, or they are reversed. The centrifuge according to any one of claims 1 to 3, wherein the parameter is the ratio of hydrocarbons to oxygen in the air in the rotor space. The centrifuge according to any one of claims 1 to 4, wherein at least one of the at least one sensor is arranged in an additional space in fluid communication with the rotor space. The centrifuge further comprises a control unit configured to receive an input signal relating to the parameter and generate a signal to regulate the flow of pressurized air based on the input signal. The centrifuge according to any one of 5. The frame further surrounds the drive member, thereby forming a drive space surrounding the drive member, and further with at least one second air inlet arranged to provide fluid communication into the drive space. The centrifuge comprises at least one second air outlet arranged to provide fluid communication from the drive space to the outside, the centrifuge from the second air inlet to the second air outlet. The centrifuge according to any one of claims 1 to 6, further comprising means for creating a flow of air exiting through the second air outlet. A method for ventilating a centrifuge,
The step of providing the centrifuge according to any one of claims 1 to 7.
A step of feeding a fluid mixture containing at least two components of different densities into the separation space of the centrifuge rotator.
With the step of rotating the rotating part to provide separation of the fluid mixture,
A step of supplying pressurized air to the at least one first air inlet, thereby ventilating the centrifuge, wherein the fluid mixture to be separated contains a flammable fluid. Including, the method further comprises
The step of detecting the parameter related to the concentration of the flammable gas in the rotor space, and
A step of adjusting the flow of air from the at least one first gas inlet to the at least one first gas outlet and out through the first gas outlet based on the detected parameters. When,
How to include. The method of claim 8, wherein the fluid mixture to be separated is heated to a temperature above 70 ° C. before being fed into the separation space. The step of supplying pressurized air is performed during at least one period selected from starting, resting, and the time period during which the rotational speed of the rotating component slows down to rest, claim 8 or. The method described in 9. The method according to any one of claims 8 to 10, wherein the step of supplying pressurized air is carried out continuously. The method according to any one of claims 8 to 10, wherein the step of supplying pressurized air is performed intermittently.

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