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Title:
A SYSTEM AND METHOD FOR COLLECTING AND ANALYSING DATA RELATING TO AN OPERATING CONDITION IN A TOP-SUBMERGED LANCING INJECTOR REACTOR SYSTEM
Document Type and Number:
WIPO Patent Application WO/2016/103196
Kind Code:
A1
Abstract:
A system is provided for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system having a lance, the lower end of which is to be submerged in a molten bath during operation of the top- submerged lancing injector reactor system. The system includes: (a) at least two sensors configured to sense an indicator of the operating condition and to generate a sensed data signal, each sensor being of a different sensor type and at least one of the at least two sensors being a lance-based sensor; and (b) a central processing unit for receiving a plurality of sensed data signals and analysing the sensed data signals relating to at least two indicators of the operating condition to determine a current status of the operating condition.

Inventors:
MATUSEWICZ, Robert, Walter (27 Abbeygate Street, Oakleigh, Victoria 3166, 3166, AU)
Application Number:
IB2015/059906
Publication Date:
June 30, 2016
Filing Date:
December 23, 2015
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
OUTOTEC (FINLAND) OY (Rauhalanpuisto 9, Espoo, FI-02230, FI)
International Classes:
F27D3/16; C21C5/34; C21C5/35; F27D19/00; F27D21/00; F27D99/00
Domestic Patent References:
WO2011106023A12011-09-01
WO2014167532A12014-10-16
WO2011136729A12011-11-03
Foreign References:
DE102013208079A12014-08-14
US6923843B12005-08-02
FR2443509A11980-07-04
US5557631A1996-09-17
Other References:
None
Attorney, Agent or Firm:
BOCO IP OY AB (Itämerenkatu 5, Helsinki, 00180, FI)
Download PDF:
Claims:
CLAIMS

1 . A system for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system having a lance, the lower end of which is to be submerged in a molten bath during operation of the top-submerged lancing injector reactor system, the system including:

(a) at least two sensors configured to sense an indicator of the operating condition and to generate a sensed data signal, each sensor being of a different sensor type and at least one of the at least two sensors being a lance-based sensor; and

(b) a central processing unit for receiving a plurality of sensed data signals and analysing the sensed data signals relating to at least two indicators of the operating condition to determine a current status of the operating condition.

2. A system for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to claim 1 , wherein the lance-based sensor is mounted on the lance and/or configured to sense a mechanical interaction of the lance with the top-submerged lancing injector reactor system.

3. A system for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to claim 2, wherein the lance-based sensor is configured to sense a mechanical interaction of the lance with the top-submerged lancing injector reactor system in the form of an indicator relating to lance position, lance submergence or lance wear.

4. A system for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to claim 3, wherein the lance-based sensor is configured to sense a mechanical interaction of the lance with the top-submerged lancing injector reactor system by sensing a direct measure of the mechanical interaction.

5. A system for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to any one of claims 1 to 4, wherein the central processing unit compares the current status of the operating condition to an optimal operating condition to determine whether one or more process controls require adjustment to shift the current operating condition towards the optimal operating condition.

6. A system for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to any one of claims 1 to 5, wherein feedback regarding the current status of the operating condition is provided to an operator of the top-submerged lancing injector reactor system.

7. A system for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to any one of claims 1 to 5, wherein feedback regarding the current status of the operating condition is provided to a process control unit associated with the submerged lancing injector reactor system.

8. A system for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to claim 7, wherein the central processing unit communicates directly with the process control unit to adjust one or more process controls.

9. A system for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to any one of claims 1 to 8, wherein the system includes at least three sensors configured to each sense an operating condition indicator and generate a sensed data signal.

10. A system for collecting data relating to an operating condition in a top- submerged lancing injector reactor system according to any one of claims 1 to 8, wherein the at least two sensors are selected from at least two of the following sensor types: pressure, motion, sound, temperature and image.

1 1 . A system for collecting data relating to an operating condition in a top- submerged lancing injector reactor system according to claim 10, wherein at least one of the at least two sensors is configured to provide direct measurement of at least one of the following indicators of the operating condition: bath temperature, lance motion, lance position, or lance submergence.

12. A system for collecting data relating to an operating condition in a top- submerged lancing injector reactor system according to any one of claims 1 to 1 1 , wherein the operating condition that is indicated by the system relates to one or more of the following: bath temperature, slag condition, lance position, lance submergence or lance wear.

13. A method for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system having a lance, the lower end of which is to be submerged in a molten bath during operation of the top-submerged lancing injector reactor system, the method including the following steps:

(a) providing at least two sensors configured to sense an indicator of an operating condition during operation of the top-submerged lancing injector reactor system and generate a sensed data signal, each sensor being of a different sensor type and at least one of the at least two sensors being a lance-based sensor;

(b) transmitting the sensed data signals generated by the at least two sensors to a central processing unit; and

(c) analysing the sensed data signals relating to at least two indicators of an operating condition to determine a current status of the operating condition.

14. A method for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to claim 13, wherein the lance-based sensor is mounted on the lance and/or configured to sense a mechanical interaction of the lance with the top-submerged lancing injector reactor system.

15. A method for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to claim 13 or 14, wherein the lance-based sensor is configured to sense a mechanical interaction of the lance with the top-submerged lancing injector reactor system in the form of an indicator relating to lance position, lance submergence or lance wear.

16. A method for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to any one of claims 13 to

15, wherein the lance-based sensor is configured to sense a mechanical interaction of the lance with the top-submerged lancing injector reactor system in the form of an indicator relating to lance position, lance submergence or lance wear.

17. A method for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to any one of claims 13 to

16, further including the step of comparing the current status of the operating condition to an optimal operating condition; and determining whether one or more process controls require adjustment to shift the current operating condition towards the optimal operating condition.

18. A method for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to any one of claims 13 to

17, further including the step of providing feedback regarding the current status of the operating condition to an operator of the top-submerged lancing injector reactor system.

19. A method for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to any one of claims 13 to 17, further including the step of providing feedback regarding the current status of the operating condition to a process control unit associated with the submerged lancing injector reactor system.

20. A method for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to any one of claims 13 to 19, wherein the at least two sensors are selected from at least two of the following sensor types: pressure, motion, sound, temperature and image.

21 . A method for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to any one of claims 13 to 19, wherein the step of providing at least two sensors in the top-submerged lancing injector reactor system involves providing at least three sensors.

22. A system for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system according to any one of claims 13 to 21 , wherein at least one of the at least two sensors is configured to provide direct measurement of at least one of the following indicators of the operating condition: bath temperature, lance motion, lance position, or lance submergence.

23. A system for collecting data relating to an operating condition in a top- submerged lancing injector reactor system according to any one of claims 1 3 to 22, wherein the operating condition that is indicated by the method relates to one or more of the following: bath temperature, slag condition, lance position, lance submergence or lance wear.

Description:
A SYSTEM AND METHOD FOR COLLECTING AND ANALYSING DATA RELATING TO AN OPERATING CONDITION IN A TOP-SUBMERGED LANCING

INJECTOR REACTOR SYSTEM

Background to the Invention

[0001 ] Molten bath smelting or other pyrometallurgical operations which require interaction between the bath and a source of oxygen-containing gas utlilize several different arrangements for the supply of the gas. In general, these operations involve direct injection into the molten matte/metal. This maybe by bottom blowing tuyeres as in a Bessemer type furnace or side blowing tuyeres as in a Peirce-Smith type converter. Alternatively, the injection of gas may be by means of a lance to provide either top blowing or submerged injection. Examples of top blowing lance injection are the KALDO and BOP steel making plants in which pure oxygen is blown from above the bath to produce steel from molten iron. Another example of top blowing lance injection is the Mitsubishi copper process, in which lances cause jets of oxygen- containing gas such as an oxygen-enriched air, to impinge on and penetrate the top surface of the bath, respectively to produce and to convert copper matte. In the case of submerged lance injection, the lower end of the lance is submerged so that injection occurs within rather than from above the slag layer of the bath, to provide top submerged lancing (TSL) injection.

[0002] With both top blowing and TSL injection, the lance is subjected to intense prevailing bath temperatures. The top blowing in the Mitsubishi copper process uses a number of relatively small steel lances which have an inner pipe of about 50 mm diameter and an outer pipe of about 100 mm diameter. The inner pipe terminates at about the level of the furnace roof, well above the reaction zone. The outer pipe, which is rotatable to prevent it sticking to a water-cooled collar at the furnace roof, extends down into the gas space of the furnace to position its lower end about 500- 800 mm above the upper surface of the molten bath. Particulate feed entrained in air is blown through the inner pipe, while oxygen enriched air is blown through the annulus between the pipes. Despite the spacing of the lower end of the outer pipe above the bath surface, and any cooling of the lance by the gases passing through it, the outer pipe burns back by about 400 mm per day. The outer pipe therefore is slowly lowered and, when required, new sections are attached to the top of the outer, consumable pipe.

[0003] The lances employed for TSL injection are much larger than those for top blowing, such as in the Mitsubishi process described above. A TSL lance usually has at least an inner and an outer pipe, as assumed in the following, but may have at least one other pipe concentric with the inner and outer pipes. Typical large scale TSL lances have an outer pipe diameter of 200 to 500 mm, or larger. Also, the lance is much longer and extends down through the roof of a TSL reactor, which may be about 10 to 15 m tall, so that the lower end of the outer pipe is immersed to a depth of about 300 mm or more in a molten slag phase of the bath, but is protected by a coating of solidified slag formed and maintained on the outer surface of the outer pipe by the cooling action of the injected gas flow within. The inner pipe may terminate at about the same level as the outer pipe, or at a higher level of up to about 1000 mm above the lower end of the outer pipe. Thus, it can be the case that the lower end of only the outer pipe is submerged.

[0004] The inner pipe of a TSL lance may be used to supply feed materials, such as concentrate, fluxes and reductant to be injected into a slag layer of the bath, or it may be used for fuel. An oxygen containing gas, such as air or oxygen enriched air, is supplied through the annulus between the pipes. When submerged injection within the slag layer of the bath commences, oxygen-containing gas and fuel, such as fuel oil, fine coal or hydrocarbon gas, are supplied to the lance and a resultant oxygen/fuel mixture is fired to generate a flame jet which impinges into the slag. This causes the slag to slop within the bath resulting in significant bath movement. This bath movement, together with injection of gases or other materials via the lance results in movement of the lance due to induced forces. The range of motion to which a top submerged lance is subjected has the potential to provide important information regarding process operations occurring in the molten bath.

[0005] Since the contents of a top-submerged lancing injector reactor are not visible, it can be difficult for an operator to have any real appreciation of the operating conditions within the reactor. Data regarding operation of the reactor is collected using a standard range of equipment including devices such as thermocouples, flowmeters and the like which typically reside in or on the reactor casing or lining. As a result of the extremely inhospitable environment within the reactor, any instruments used to monitor operational conditions are invariably high cost and require frequent maintenance and/or replacement.

[0006] Conventional methods for monitoring operational conditions using standard equipment, tends to use collected data in an isolated and/or linear fashion. For example, the temperature of a molten slag bath might be measured using a thermocouple and the temperature measurement is used as an isolated reading in an attempt to deduce what is occurring within the reactor. This approach disregards the intrinsic interaction between factors affecting and/or indicating various operational conditions and makes it difficult to provide a plant operator with an accurate diagnosis regarding the operational conditions within the reactor.

[0007] The discussion of the background to the invention included herein including reference to documents, acts, materials, devices, articles and the like is intended to explain the context of the present invention. This is not to be taken as an admission or a suggestion that any of the material referred to was published, known or part of the common general knowledge in the patent area as at the priority date of the claims.

[0008] It would be desirable to provide one or more sensors for monitoring an operating condition in a molten slag bath.

Summary of the Invention

[0009] According to an aspect of the present invention, there is provided a system for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system having a lance, the lower end of which is to be submerged in a molten bath during operation of the top-submerged lancing injector reactor system, the system including:

(a) at least two sensors configured to sense an indicator of the operating condition and to generate a sensed data signal, each sensor being of a different sensor type and at least one of the two sensors being a lance-based sensor; and

(b) a central processing unit for receiving a plurality of sensed data signals and analysing the sensed data signals relating to at least two indicators of the operating condition to determine a current status of the operating condition. [00010] Combinations of various sensors including a variety of low cost sensors may be employed to implement the present invention. For example, temperature sensors, pressure sensors, motion sensors, position sensors, sound and/or image sensors may be employed. In the context of the present invention, it is requisite that the at least two sensors are of a different type such that they can be used to sense different but perhaps complimentary indicators of an operating condition. Moreover, at least one of the sensors is a lance-based sensor. For instance, if a first sensor is used to sense the motion of the lance and sensor signals indicate that the lance is not moving, then it is helpful to collect data from a second sensor type, for example that senses the position of the lance within the reactor, to confirm a diagnosis. For instance, if the position sensor indicates that the lance is not submerged in the bath, then the two independently sensed signals can be combined and analysed to provide an accurate diagnosis of the current operating condition, which is not possible relying on data collected using a single sensor type.

[0001 1 ] In the example provided, both the lance motion sensor and the lance position sensor constitute lance-based sensors, in that the lance motion sensor is mounted on the lance to sense movement thereof and the lance position sensor is configured to sense a mechanical interaction of the lance with the top-submerged lancing injector reactor system. However, it is to be understood that a status of the operating condition can be determined provided that one of the at least two sensors is a lance-based sensor.

[00012] A lance-based sensor may be configured to sense a mechanical interaction of the lance with the top-submerged lancing injector reactor system in the form of an indicator relating to a lance position, lance submergence or lance wear. Moreover, the lance-based sensor may be configured to sense the mechanical interaction by sensing a direct measure of the mechanical interaction.

[00013] In a particular embodiment, the central processing unit compares the current status of the operating condition to an optimal operating condition to determine whether one or more process controls require adjustment to shift the current operating condition towards an optimal operating condition. [00014] Feedback regarding the current status of the operating condition may be provided to an operator of the top-submerged lancing injector reactor system. That is, the operator may be provided with one or more instructions for manually adjusting the process controls to shift the current operating condition towards the optimal operating condition.

[00015] Alternatively, feedback regarding the current status of the operating condition may be provided directly to a process control unit associated with the submerged lancing injector reactor system. In this embodiment, the process control unit is provided instructions for autonomously adjusting process controls to shift the current operating condition towards the optimal operating condition. For instance, if a combination of sensors determine that the slag condition in the bath is undesirable, i.e. too thick and viscous due to a bath temperature that is too low, then the instruction to the operator or process control unit might be to increase the bath temperature in an attempt to shift the current operating condition towards a more fluid slag.

[00016] In a particular embodiment, at least three different types of sensors are provided to enable a variety of operational conditions to be detected.

[00017] The sensors may be selected from a variety of sensor types including pressure, motion, sound, temperature and image sensors. For example motion sensors may include orientation sensors generally, and more specifically accelerometers, gyroscopes, magnetometers, inertial measurement units, and the like. Such lance-based sensors sense the orientation of a lance for example, by detecting the magnitude and direction of lance movements, acceleration of the lance in various directions and/or the G-forces to which the lance is subjected. A position sensor may take the form of a position encoder which measures the position of the lance relative to the furnace hearth and may or may not be mounted on the lance. Sound and image sensors, e.g. in the form of a still or video camera, can provide useful data regarding slag viscosity for example, due to the sound of the molten splash patterns being generated. Similarly, there are certain characteristic sound frequencies that can be attributed to optimal operating conditions. If no bubbling frequency is registered for example, this is an indicator that the lance tip is not submerged in the bath, which may be supported by data signals generated by one or more other types of sensor.

[00018] Whilst some of the above mentioned sensor types, such as image and sound sensors, for example, are merely indicative of a particular operating condition, other sensor types are capable of providing direct measurement of an operating condition. Such sensor types include sensors for measuring bath temperature, lance motion, lance position, or lance submergence. At least one of these sensor types is preferably included in the system for collecting data relating to an operating condition.

[00019] The operating condition indicated by the sensed signals may relate to one or more of the following: bath temperature, slag condition, lance position, lance submergence or lance wear.

[00020] According to another aspect of the present invention, there is provided a method for collecting and analysing data relating to an operating condition in a top- submerged lancing injector reactor system having a lance, the lower end of which is to be submerged in a molten bath during operation of the top-submerged lancing injector reactor system, the method including the following steps:

(a) providing at least two sensors configured to sense an indicator of an operating condition during operation of the top-submerged lancing injector reactor system and generate a sensed data signal, each sensor being of a different sensor type and at least one of the at least two sensors being a lance-based sensor;

(b) transmitting the sensed data signals generated by the at least two sensors to a central processing unit; and

(c) analysing the sensed data signals relating to at least two indicators of an operating condition to determine a current status of the operating condition.

[00021 ] The lance-based sensor may be mounted on the lance and/or configured to sense a mechanical interaction of the lance with the top-submerged lancing injector reactor system. The lance-based sensor may further be configured to sense a mechanical interaction of the lance with the top-submerged lancing injector reactor system in the form of an indicator relating to lance position, lance submergence or lance wear. The mechanical interaction of the lance with the top-submerged lancing injector reactor system may sense an indicator relating to lance position, lance submergence or lance wear.

[00022] The method may further include the step of comparing the current status of the operating condition to an optimal operating condition; and determining whether one or more process controls require adjustment to shift the current operating condition towards the optimal operating condition.

[00023] In another embodiment, the method further includes the step of providing feedback regarding the current status of the operating condition to an operator of the top-submerged lancing injector reactor system.

[00024] Alternatively, the method further includes the step of providing feedback regarding the current status of the operating condition to a process control unit associated with the submerged lancing injector reactor system.

[00025] In one form of the present invention, the at least two sensors are selected from the following sensor types: pressure, motion, sound, temperature and image.

[00026] Optionally, the step of providing at least two sensors in the top-submerged lancing injector reactor system involves providing at least three sensors.

[00027] Preferably, at least one of the at least two sensors is configured to provide direct measurement of at least one of the following indicators of the operating condition: bath temperature, lance motion, lance position, or lance submergence.

[00028] The operating condition indicated by the method may relate to one or more of the following: bath temperature, slag condition, lance position, lance submergence or lance wear.

Brief Description of the Drawings

[00029] The present invention will now be described in greater detail with reference to the accompanying drawings. It is to be understood that the embodiments shown are examples only and are not to be taken as limiting the scope of the invention as defined in the claims appended hereto. [00030] Figure 1 is a partially cut away schematic of a molten bath smelting furnace including a top submerged lance in accordance with the prior art.

[00031 ] Figure 2 is a schematic showing a system for collecting and processing data relating to an operating condition in a top-submerged lancing injector reactor in accordance with an embodiment of the present invention.

[00032] Figure 3 is a table illustrating the inter relationship between various sensor types as indicators of various operating conditions in accordance with an embodiment of the present invention.

[00033] Figure 4 is a flowchart showing a method for collecting and processing data relating to an operating condition in a top-submerged lancing injector reactor system in accordance with an embodiment of the present invention.

Detailed Description

[00034] Referring firstly to Figure 1 , there is shown an exemplary top-submerged lancing injector reactor system 100. The reactor 102 has a cylindrical shell 104 closed at its top end by a roof 106 from which an off-take flue 108 projects upwardly to an off-gas boiler/heat exchanger 1 10. In Figure 1 , a section of the shell 104 has been removed to enable the interior of the reactor 102 to be viewed, although the shell 104 is circumferentially continuous at all levels in its height, apart from tap holes. The roof 106 has an inlet 1 12 down through which a top submerged injecting lance 1 14 extends so that a lower end portion of the lance 1 15 is submerged in the molten bath 1 16. The reactor 102 also has a feed port 1 18 opening through roof 106 to enable raw materials for a required pyro-metallurgical operation to be charged into bath 1 16, and a burner port 120 for enabling insertion of a burner 122 if required for heating the reactor. Lance 1 14 has connectors 124 that enable connection of lance 1 14 to separate sources of fuel/reductant and oxygen-containing gas, to enable the separate passage of these materials down through lance 1 14 and to mix at the lower, outlet end of lance to feed a combusting mixture. The combustion of the fuel and oxygen mixture generates a combustion zone in the molten bath 1 16 at the lower, outlet end of lance 1 15, as well as strong turbulence in the molten bath 1 16 that causes the raw materials charged through port 1 18 to be dispersed in the molten bath to give rise to the required pyro-metallurgical reactions therein. [00035] A top-submerged lancing injector reactor system 100 as illustrated in Figure 1 is typically operated by an operator who controls the position of the lance 1 14 within the reactor 102 by raising or lowering the lance relative to the bath by means of a lifting apparatus 126 attached to the lance Operators make various manual observations regarding the position of the lance and the movement of the lance, which over time leads the operator to developing an intuitive understanding of the range of motion of the lance that is indicative of optimal operating conditions in the reactor and a range of movement of the lance that is indicative of sub-optimal operating conditions within the reactor.

[00036] Referring now to Figure 2, the system of the present invention provides means for improved guidance of an operator with regard to how particular observations relate to operating conditions within the reactor and how an operator should appropriately respond to those operating conditions where they are sub- optimal. A system 200 for collecting, processing and analysing data relating to an operating condition in a top-submerged lancing injector reactor system 100 is provided. As shown in Figure 1 , the top-submerged lancing (hereinafter also referred to as "TSL") injector reactor system 100 has a lance 1 14, the lower end 1 15 of which is to be submerged in a molten bath 1 16 during operation of the TSL injector reactor system. Referring back to Figure 2, the system 200 includes at least two sensors 210, each of the at least two sensors being of a different sensor type and at least one of the at least two sensors is a lance-based sensor. Each sensor 210 is configured to sense an indicator of an operating condition and to generate a sensed data signal. A central processing unit 220 receives the sensed data signals. The central processing unit 220 then processes and analyses the sensed data signals to determine a current status of the operating condition.

[00037] Optionally, as shown in Figure 2, the central processing unit 220 is directly coupled directly to a process control unit 230. In this case, feedback regarding the current status of the operating condition is transmitted directly from the central processing unit 220 to the process control unit 230. The direct feedback can be translated into instructions for the process control unit 230 to adjust the reactor's process controls in an effort to adjust the current operating condition towards an optimal operating condition. [00038] Alternatively, where the central processing unit 220 is not coupled directly to a process control unit 230, feedback regarding the current operating conditions may be provided to the operator together with recommendations for adjustments to be made to the reactor's process controls in an effort to improve the operating conditions. In this case, the requisite adjustments are implemented manually by the operator in the usual manner.

[00039] As indicated, the system employs at least two sensors, each being of a different sensor type. At least one of the sensors is a lance-based sensor which is either mounted on the lance, for example in the form of a lance motion sensor, or configured to sense a mechanical interaction of the lance with the top-submerged lancing injector reactor system, for example in the form of a lance position sensor which need not necessarily be mounted on the lance per se, but senses the position of the lance with respect to the reactor. These sensors are selected from a wide variety of low cost sensors. An example of a suitable temperature sensor, which is also a lance-based sensor, is described in International PCT Application

PCT/IB2014/060638. Such a sensor is capable of direct measurement of bath temperature which can be indicative of a number of operating conditions occurring within the reactor, including the condition of the slag, i.e. fluid or viscous.

[00040] Pressure sensors are used, for example, to measure any restriction or blockage of fluids being injected via the lance. A pressure sensor or transmitter may be mounted in a suitable location on any of the fluid delivery lines, or could be a lance-based sensor mounted in proximity to the lance discharge point, i.e. the lance tip. That is, the pressure within any line feeding oxygen, air or fuel to the lance can be measured at any particular point. A change in the pressure reading at that particular point will typically indicate that a restriction or blockage has occurred. One obvious restriction or blockage occurs when the lance moves from above the bath to a submerged position due to the static pressure head which develops when the discharge point is below the molten slag surface. This means that a difference in the pressure head or back pressure reading, taken at the same point in the fluid flow line, can be an indicator of lance submergence as well as other potential blockages or restrictions that may occur during operation of the lance. Whether an increase in back pressure is due to lance submergence or some other restriction in the fluid flow line, is more readily determined with accuracy, when combined with reading from at least one other sensor, such as, for example, a lance position sensor, or a lance motion sensor which is also an indicator of whether the lance tip is submerged in the molten slag bath.

[00041 ] The injection of oxygen-containing gas and fuel into the molten bath causes the slag to slop in the bath. The slopping or bath movement together with forces induced by gases or other materials injected via the lance itself, cause various involuntary movements of the lance. The magnitude and direction of movement, together with the force and/or acceleration of a lance that is at least partially submerged in the molten bath is a reliable indicator of the operating conditions in the molten bath. These movements and forces are sensed by one or more motion sensors which may take the form of an orientation sensor, a magnetometer, a gyroscope, and accelerometer or an inertial measurement unit as disclosed in the copending application entitled "A Sensing Device for Determining an Operational Condition in a Molten Bath of a Top-Submerged Lance Injector Reactor System".

[00042] Other operational conditions that can be measured in relation to the lance are lance position and lance submergence. Lance position is an assumed measure of the lane tip position relative to the top surface of the furnace hearth and lance submergence is an actual measurement of the lance tip position relative to the molten bath surface.

[00043] Lance position can be measured by way of a position sensor which is attached to the lance hoist mechanism (for raising and lowering the lance within the reactor), or to the lance guide or trolley. Such a position sensor can be provided in the form of a position encoder. It should be noted that the actual position of the lance within the reactor can only be inferred from this measurement since it must be calibrated to each new lance and infers a lance tip position relative to the top of the furnace hearth. Accordingly, if the length of the lance changes, for example, by wearing of the lance tip through use, then the actual position of the lance tip with respect to the furnace hearth will also change. Knowledge of the position of the lance is typically insufficient to provide a measure of lance submergence since knowledge of the depth of the molten bath is required. Furthermore, the depth of the molten bath can vary due to a build-up of materials on the furnace hearth and the like. [00044] A measure of lance submergence can be determined by computation, using for example the lance position measurement together with a manual bath height measurement. An inferred measure of submergence can be discerned using a sound sensor, wherein a shift in the measured sound frequency is observed between an above bath and a submerged operation positon of the lance, to allow determination of the point where the lance becomes submerged. From this point on, the lance can be lowered a defined distance and hence the extent of submergence is known. Similarly, a measure of back pressure, as earlier described, can be used to determine the point where the lance becomes submerged.

[00045] Measurement of sound arising from TSL operation can also be an effective measure. Due to the low injection velocity of a typical TSL lance, a "bubble" frequency of approximately 3 Hz is considered characteristic. In simple terms, this means that injected fluids form bubbles and break away at the lance discharge end about three times per second. These result in characteristic bubbling sounds which can be measured. In its simplest form, if no bubbling sound is detected at all, then it can be inferred that the lance is not submerged in the bath. The characteristic and frequency of the sound will vary with slag condition. Moreover, splash patterns generated within the reactor can be captured on still or video image. If the volume and size of a normal splash indicative of optimal operating conditions is known, variations in the volume and size of the splashes can be used as an indicator of a change in conditions. For example, in the case of no splash to be seen, the lance is neither in the bath nor proximal to a surface of the bath. When the lance tip is barely submerged, the splash will be very fine. If the slag is very viscous, then the splashed slag tends to form plate-like, string-like or stream-like splashes. These variations in splash form are readily recognised through image analysis.

[00046] Bearing in mind the various operating condition that may be inferred and/or verified using different sensor types the system and method of the present invention will be best illustrated by means of examples.

[00047] For instance, in a first simple example, wherein a lance motion sensor is used to indicate whether a lance is moving in a normal or abnormal manner, if no lance movement is sensed, then the lance is most likely not submerged and being operated out of the molten slag bath. This diagnosis can be verified using a lance position or lance submergence measurement. However, in such a simple case, a lance operator will typically recognise and correct the problem from the lack of lance movement alone. In this case, both the lance motion sensor and the lance position sensor constitute lance-based sensors.

[00048] In a second more complex example, data signals generated by three different types of sensor can be used to determine an adverse operating condition: A lance motion sensor, a lance position sensor and a temperature sensor. In this case, the lance motion sensor measures excessive movement indicating an abnormal operating condition. On its own, this data could indicate one of a number of issues relating to process factors or problems with mechanical interaction within the reactor. So the following analysis is employed using data collected using all three sensor types to arrive at a comprehensive diagnosis:

1 . the lance motion sensor detects an abnormal movement condition indicating a higher degree of movement than is normal;

2. the lance position indicator shows the lance is in the correct position; and

3. the bath temperature indicates a low temperature condition.

[00049] In this case, both the lance motion sensor and the lance position sensor constitute lance-based sensors. The temperature sensor may be, but need not be, a lance-based sensor. The suggested course of action would be to increase the energy input to the system, for example by increasing the fuel addition rate via the lance.

[00050] In the second example, it may seem that the bath temperature indication alone could provide a solution. However, the third example uses the same three sensors in a circumstance where the bath temperature is also low. In this example the following indicators occur:

1 . the bath temperature is indicated as being low;

2. the lance is indicated as being at the correct position relative to the furnace; and

3. the lance motion sensor indicates that the lance is not moving. [00051 ] In this case, the combined sensor information indicates that the lance tip has worn back to the point where the lance is not submerged in the molten bath, but rather in a position above it. In this example, the course of action would be to remove the lance from service for repair of the lance tip and a path of adding more fuel would not rectify the problem and restore optimal operating conditions.

[00052] In a fourth example, sensors for sound measurement, lance position, lance backpressure and bath temperature are utilised. The indicators for these sensors show:

1 . Sound indicates abnormal operation;

2. Lance position is correct;

3. Bath temperature is in the correct range;

4. Lance backpressure is abnormal, indicating a high reading.

[00053] In this example, at least the lance position sensor and the lance backpressure sensor constitute lance-based sensors. The diagnosis is that the slag chemistry is not in the correct range and that an adjustment through slag chemistry modification is required.

[00054] The foregoing examples illustrate that analysing the data signals generated by at least two sensors of different types, where at least one of those two sensors is a lance-based sensor, is superior to relying on the operator to make an assessment of the signals from various sensors. Such a consolidated approach can provide consistency of operation as well as a more rapid response to process or mechanical changes which impact efficiency of the operation.

[00055] Referring now to Figure 3, there are shown some examples of possible interactions between various sensor types. The sensors can be grouped together depending on the application. Preferably, analysis of a minimum number of low cost sensors is combined to enable low cost operation and more stable plant operation.

[00056] Referring now to Figure 4, there is shown a flowchart illustrating the method 400 for collecting and analysing data relating to an operating condition in a top-submerged lancing injector reactor system having a lance, the lower end of which is to be submerged in a molten bath during operation of the top-submerged lancing injector reactor system. At 410, the method includes the step of providing at least two sensors, in the top-submerged lancing injector reactor system, each sensor being of a different sensor type and at least one of the two sensors being a lance-based sensor, each sensor configured to sense at least one operating condition indicator during operation of the top-submerged lancing injector reactor system. At step 420, the method includes the step of transmitting the sensed data signals generated by the at least two sensors to a central processing unit. At step 430, the sensed data signals relating to at least two operating condition indicators are analysed to determine a current status of the operating condition.

[00057] The method may further include the step of comparing the current status of the operating condition to an optimal operating condition; and determining whether one or more process controls require adjustment to shift the current operating condition towards the optimal operating condition.

[00058] The system of the present invention provides lower cost and more consistent operation of a top-submerged lance injection reactor using relatively low- cost sensors. The transmission of sensed signals determining a variety of operating factors to a central processing unit for processing and analysis enables the sensed signals to be analysed by an expert system module using proprietary algorithms to provide an improved diagnosis which can be used to guide operator action or directly instruct the plant control unit to make appropriate adjustments. This enables more consistent and stable plant operation between shifts and more efficient operation of the reactor.

[00059] While the invention has been described in conjunction with a limited number of embodiments, it will be appreciated by those skilled in the art that many alternative, modifications and variations in light of the foregoing description are possible. Accordingly, the present invention is intended to embrace all such alternative, modifications and variations as may fall within the spirit and scope of the invention as disclosed.