DESC:EARLIEST PRIORITY DATE:
This Application claims priority from a Provisional patent application filed in India having Patent Application No. 202021048865, filed on November 09, 2020 and titled “SYSTEM AND METHOD FOR CONTROLLING ACIDITY OF A SCRUBBING SOLUTION IN A WET SCRUBBER”.
FIELD OF INVENTION
[0001] Embodiments of a present disclosure relate to acidity control of a scrubbing solution, and more particularly, to a system to control an acidity of a scrubbing solution in a wet scrubber.
BACKGROUND
[0002] For a wet scrubber-based emission control aiming at the reduction of the pollutants especially Sulphur oxides from the exhaust flue gases, solvent needs to be sprayed and recirculated in the device. The solvent is basically a water-based solution which is having a pH around 7 or a little more than 7. Recirculation of the solvent is required to minimize the water consumption rate during the operation of the emission control system. As desulphurization of the flue gases occurs due to the cooling of the flue gases when it comes in contact with the solvent. Upon cooling, the acidic dew point of the Sulphur is achieved and when it interacts with water it forms the sulphuric acid.
[0003] Especially in the case of the boilers fired by the furnace oil, it operates on the heavy Sulphur oil due to which the Sulphur oxide content in the exhaust is very high. The water in the tank becomes acidic after a certain amount of time. The solvent in the acidic state when recirculated will accelerate the corrosion and cause the damage to the material of the internal components of the emission control system. Thus, it is required to control the pH level of the solvent in order to prevent the material degradation of the emission control system.
[0004] Manual dozing of any kind of pH control agent will be a difficult task and it is difficult to control the dozing for an optimum level and control of pH level of the solvent. Further, in the simple pH control mechanism, where the pH agent is directly introduced to the solution the valve is used to control the flow of the pH control agent. As the agent can be powdered in nature, it hampers the functionality of the valve as it blocks the passage of the valve because of the coagulation of the pH agent when mixed with water to create an aqueous solution. In addition, slurry management is quite tough task in the existing system. No slurry removal or separation mechanism is available in the current existing systems of the flue gas desulphurization unit.
[0005] Hence, there is a need for an improved system to control an acidity of a scrubbing solution in a wet scrubber to address the aforementioned issue/s.
BRIEF DESCRIPTION
[0006] In accordance with one embodiment of the disclosure, a system to control an acidity of a scrubbing solution in a wet scrubber is provided. The system includes a scrubbing solution tank. The scrubbing solution tank is configured to store the scrubbing solution which will be recirculated in the wet scrubber of an emission control system, thereby converting the scrubbing solution into an acidic solution over a period. The system also includes a pH sensor. The pH sensor is configured to sense a pH of the scrubbing solution after every first pre-defined interval. The system also includes a water level sensor. The water level sensor is configured to sense a level of the scrubbing solution in the scrubbing solution tank. The system also includes an acidic solution circulation pump. The acidic solution circulation pump is configured to pump the scrubbing solution from the scrubbing solution tank to a reaction chamber via one or more spray nozzles when the scrubbing solution gets converted to the acidic solution. The reaction chamber includes an assembly of the one or more spray nozzles, one or more mandrels, and a slurry filter, wherein the one or more mandrels include pH control agent in a form of one or more cartridges. The system also includes a flow valve, wherein the flow valve is configured to allow a suction of the scrubbing solution by the acidic solution circulation pump. The system also includes a controlling unit. The controlling unit is configured to receive a first signal from the pH sensor via a transmitter. The controlling unit is also configured to receive a second signal from the water level sensor via the transmitter. The controlling unit is also configured to transmit an electrical actuation for the flow valve and the acidic solution circulation pump accordingly as per the logic to activate the flow valve and the acidic solution circulation pump for a second pre-defined interval.
[0007] To further clarify the advantages and features of the present disclosure, a more particular description of the disclosure will follow by reference to specific embodiments thereof, which are illustrated in the appended figures. It is to be appreciated that these figures depict only typical embodiments of the disclosure and are therefore not to be considered limiting in scope. The disclosure will be described and explained with additional specificity and detail with the appended figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure will be described and explained with additional specificity and detail with the accompanying figures in which:
[0008] FIG. 1 is a schematic representation of a front view of a system for controlling an acidity of a scrubbing solution in a wet scrubber in accordance with an embodiment of the present disclosure;
[0009] FIG. 2a is a schematic representation of a top view of one or more mandrels of the system for controlling the acidity of the scrubbing solution in the wet scrubber of FIG. 1 in accordance with an embodiment of the present disclosure; and
[0010] FIG. 2b is a schematic representation of a side view of the system for controlling the acidity of the scrubbing solution in the wet scrubber of FIG. 1 in accordance with an embodiment of the present disclosure.
[0011] Further, those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with details that will be readily apparent to those skilled in the art having the benefit of the description herein.
DETAILED DESCRIPTION
[0012] For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as would normally occur to those skilled in the art are to be construed as being within the scope of the present disclosure.
[0013] The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or method. Similarly, one or more devices or sub-systems or elements or structures or components preceded by "comprises... a" does not, without more constraints, preclude the existence of other devices, sub-systems, elements, structures, components, additional devices, additional sub-systems, additional elements, additional structures or additional components. Appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but not necessarily do, all refer to the same embodiment.
[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. The system, methods, and examples provided herein are only illustrative and not intended to be limiting.
[0015] In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings. The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.
[0016] Embodiments of the present disclosure relate to a system to control an acidity of a scrubbing solution in a wet scrubber. The system includes a scrubbing solution tank. The scrubbing solution tank is configured to store the scrubbing solution which will be recirculated in the wet scrubber of an emission control system, thereby converting the scrubbing solution into an acidic solution over a period. The system also includes a pH sensor. The pH sensor is configured to sense a pH of the scrubbing solution after every first pre-defined interval. The system also includes a water level sensor. The water level sensor is configured to sense a level of the scrubbing solution in the scrubbing solution tank. The system also includes an acidic solution circulation pump. The acidic solution circulation pump is configured to pump the scrubbing solution from the scrubbing solution tank to a reaction chamber via one or more spray nozzles when the scrubbing solution gets converted to the acidic solution. The reaction chamber includes an assembly of the one or more spray nozzles, one or more mandrels, and a slurry filter, wherein the one or more mandrels include pH control agent in a form of one or more cartridges. The system also includes a flow valve, wherein the flow valve is configured to allow a suction of the scrubbing solution by the acidic solution circulation pump. The system also includes a controlling unit. The controlling unit is configured to receive a first signal from the pH sensor via a transmitter. The controlling unit is also configured to receive a second signal from the water level sensor via the transmitter. The controlling unit is also configured to transmit an electrical actuation for the flow valve and the acidic solution circulation pump accordingly as per the logic to activate the flow valve and the acidic solution circulation pump for a second pre-defined interval.
[0017] FIG. 1 is a schematic representation of a front view of a system (10) for controlling an acidity of a scrubbing solution in a wet scrubber in accordance with an embodiment of the present disclosure. The acidity of the scrubbing solution may be defined by a pH level of the scrubbing solution. If the pH level of the scrubbing solution is greater than seven, then the scrubbing solution is an alkaline solution, if the pH level is less than seven then the scrubbing solution is an acidic solution, and if the pH level is equal to seven then the scrubbing solution is neutral.
[0018] The system (10) includes a scrubbing solution tank (20). The scrubbing solution tank (20) stores the scrubbing solution which will be recirculated in the wet scrubber of an emission control system, thereby converting the scrubbing solution into the acidic solution over a period. In one embodiment, the pH level of the scrubbing solution in the scrubbing solution is maintained a little basic rather than neutral. The system (10) also includes a pH sensor (30) operatively coupled to the scrubbing solution tank (20). The pH sensor (30) senses the pH of the scrubbing solution after every first pre-defined interval. The system (10) also includes a water level sensor (40) operatively coupled to the scrubbing solution tank (20). The water level sensor (40) is configured to sense a level of the scrubbing solution in the scrubbing solution tank (20). In one embodiment, the water level sensor (40) includes an electrically conductive type water level sensor.
[0019] The system (10) also includes an acidic solution circulation pump (50) operatively coupled to the scrubbing solution tank (20). The acidic solution circulation pump (50) pumps the scrubbing solution from the scrubbing solution tank to a reaction chamber (60) via one or more spray nozzles (70) when the scrubbing solution gets converted to the acidic solution. In one embodiment, the acidic solution circulation pump (50) is designed and manufactured specially to handle the acidic solution.
[0020] The reaction chamber (60) includes an assembly of the one or more spray nozzles (70), one or more mandrels (80), and a slurry filter (90), wherein the one or more mandrels (80) include a pH control agent in a form of one or more cartridges. In one embodiment, the reaction chamber (60) includes a transparent window (170) with a fiberglass type panel to get a check on the availability of the one or more cartridge in the one or more mandrels.
[0021] Further, in one embodiment, the pH control agent includes calcium hydroxide, calcium oxide, magnesium hydroxide, and the like. In one exemplary embodiment, the pH control agent available in a powdered form in the market. Further, the pH control agent may be made in the form of the one or more cartridges by casting and baking process. In one embodiment, the process of making the one or more cartridges varies depending upon the nature of the pH control agent.
[0022] Moreover, the one or more cartridges may ease refilling of the pH control agent in the one or more mandrels. Further, in one embodiment, the pH control agent is basic in nature and will react chemically with the acidic solution present received from the scrubbing solution tank and forms any kind of salt as a by-product. Further, various arrangements such as one of a series, a parallel, or a combination thereof may be used depending upon a required level of naturalization.
[0023] In one embodiment, the one or more spray nozzles (70) are used for atomization for the scrubbing solution which will interact with the pH control agent to create a buffer solution. Further, in one embodiment, the one or more mandrels (80) are housing for the one or more cartridges of the pH control agent. The one or more mandrels (80) may be placed in the reaction chamber with the required support. The one or more mandrels (80) may be a perforated housing with a pipe like structure which helps flow of the buffer solution through the pipe.
[0024] The system (10) also includes a flow valve (95), wherein the flow valve (95) allows the suction of the scrubbing solution by the acidic solution circulation pump (50). In one embodiment, a type of the flow valve (95) and the acidic solution circulation pump (50) may be chosen as per the application and the nature of the scrubbing solution.
[0025] The system (10) also includes a controlling unit (100). The controlling unit (100) receives a first signal from the pH sensor (30) via a first transmitter (110). In one embodiment, the first signal includes an analog signal transmitted from the pH sensor (30) to the controlling unit via the first transmitter (110). In one exemplary embodiment, the first signal includes a value of about 4 milliamperes (mA) to about 20 mA.
[0026] The controlling unit (100) also receives a second signal from the water level sensor (40) via a second transmitter (130). The controlling unit (100) also transmits an electrical actuation via an actuator (160) for the flow valve (95) and the acidic solution circulation pump (50) accordingly as per the logic to activate the flow valve (95) and the acidic solution circulation pump (50) for a second pre- defined interval.
[0027] In one embodiment, the controlling unit (100) includes a Programmable logic controller (PLC), one or more embedded systems, or the like. Further, in one embodiment, the system (10) also includes a timer (140) controlled by the controlling unit (100). The timer (140) may power the acidic solution circulation pump (50) for the second pre-defined interval when the controlling unit (100) receives the first signal representing the pH level is less than seven.
[0028] Further, in one embodiment, the system (10) the slurry filter (90) separates the by-product formed after the neutralization of the acidic solution received. The byproduct may also be called as slurry. The slurry filter (90) may be installed in an inclined manner at an angle such that the slurry may be moved to a slurry tank (120) by the action of gravity. The slurry filter (90) may be a wire-mesh type filter, a permeable membrane type filter, a mechanical component which provides a slurry removal action, or the like. A selection of the slurry filter (90) may depend on one or more properties and the nature of the by-product.
[0029] Furthermore, the system (10) also includes a spring-controlled valve (150). The spring-controlled valve (150) may also be termed as a weight-controlled valve. After the filtration of the slurry from the scrubbing solution, the slurry gets accumulated on the slurry filter (90). The spring-controlled valve (150) may include a torsional spring in a pre- tension to hold the spring-controlled valve (150) in a closed position. The spring-controlled valve (150) may be designed such that the weight of the spring-controlled valve (150) holds the spring-controlled valve (150) in the closed position. Further, ss the slurry filter is inclined at the angle, due to the action of the gravity the slurry exerts pressure on the spring- controlled valve (150) and as soon as it reaches above a limit the spring-controlled valve (150) will open and the slurry will move to the slurry tank (120).
[0030] Moreover, the slurry tank (120) may collect the slurry which is formed as the by- product during the neutralization of the acidic solution. The by-product may be separated and can be utilized for a plurality of applications. In one embodiment, the by-product includes calcium sulphate, magnesium sulphate, and the like. In one embodiment, the plurality of applications includes using the calcium sulphate for production of plaster of Paris and stucco, using one or more hydrates of the calcium sulphate acts as a coagulant in a plurality of food products, using the magnesium sulphate for medical purposes such as skin inflammation, eclampsia, and the like, using the magnesium sulphate in agriculture to increase magnesium content in soil, using magnesium sulphate as the coagulant in the plurality of food products, and the like.
[0031] Furthermore, the system (10) also includes a display unit. The display unit provides information about the current pH level of the scrubbing solution in the scrubbing solution tank (20) and also indicates the water level of the scrubbing solution in the scrubbing solution tank (20).
[0032] Furthermore, the system (10) also includes an alarm generation unit. The alarm generation unit generates an alarm when one of the pH level of the scrubbing solution in the scrubbing solution tank (20) reaches below a critical limit, the water level of scrubbing solution in the scrubbing solution tank (20) reaches below a critical limit, or a combination thereof. Further, the system (10) also includes a data logger, wherein the data logger stores information about one or more parameters involved during the operation of the system (10).
[0033] In one exemplary embodiment, one or more auxiliaries may also be added to the system (10) such as a remote monitoring system using servers, an online data storage system, or the like. In one embodiment, a by-product management system may also be integrated and automated accordingly for the utilization of the by-product formed during the neutralization of the acidic solution with the system (10).
[0034] In operation, the system (10) used in the emission control system for the desulphurization of one or more flue gases, the scrubbing solution present in the scrubbing solution tank (20) will become acidic after a certain amount of time because of the formation of Sulphuric acid when Sulphur oxides react with water. The pH sensor (30) senses the pH reading of the scrubbing solution present in the scrubbing solution tank (20) and the transmitter associated with it will send the first signal to the controlling unit (100). Further, the controlling unit (100) then activates the electrical actuation which further operates the flow valve (95) and powers on the acidic solution recirculation pump (50). The acidic solution recirculation pump (50) will recirculate the acidic solution time from/to the scrubbing solution tank (20) via the reaction chamber (60) in which the pH control agent in the form of the one or more cartridges is placed. The time of the recirculation will be calculated by the control logic depending upon the amount of the scrubbing solution in the scrubbing solution tank and the pH level of the scrubbing solution.
[0035] Further, the amount of the scrubbing solution available in the scrubbing solution tank (20) will be measured by the water level sensor (40) and the pH level of the scrubbing solution will be sensed by the pH level sensor (30). The scrubbing solution will be sprayed on the one or more cartridges by the one or more water spray nozzles (70) in the reaction chamber (60).
[0036] Furthermore, when the scrubbing solution interacts with a surface of the one or more cartridges, the pH control agent gets dissolved in one or more droplets which increases the pH level of the one or more droplets drastically. Further, the one or more droplets will act as the buffer solution which when mixed with the scrubbing solution in the scrubbing solution tank (20) increases the pH level of the scrubbing solution.
[0037] Consequently, the slurry filter (90) is provided in the reaction chamber (60) which will separate the slurry. It is installed in the inclined manner at the angle such that the slurry moves due to the gravity action. It will exert a force on the spring-controlled valve (150) which will tend to open the spring-controlled valve (150). As soon as it reaches above a limit the spring- controlled valve (150) will open and the slurry will move to the slurry tank (120). The slurry tank (120) is used to collect the slurry which is formed as the by-product during the neutralization of the acidic solution. It can be separated, and the by-product can be utilized for different applications. A perforated support mandrel is provided to hold the one or more cartridges in the reaction chamber (60). As soon as the pH level is maintained, the pH sensor (30) provides a third signal to the controlling unit (100) to stop the acidic solution circulation pump (50) and closes the flow valve (95).
[0038] FIG. 2a is a schematic representation of a top view of one or more mandrels (80) of the system (10) for controlling the acidity of the scrubbing solution in the wet scrubber of FIG. 1 in accordance with an embodiment of the present disclosure. FIG. 2b is a schematic representation of a side view of the system (10) for controlling the acidity of the scrubbing solution in the wet scrubber of FIG. 1 in accordance with an embodiment of the present disclosure.
[0039] Various embodiments of the present disclosure enable the prevention of scaling action because of the continuous recirculation of the scrubbing solution for pH control and scrubbing action. Also, the automation process provides precise control of the pH level. Further, due to the introduction of the one or more cartridges, the refilling of the pH control agent can be easily done by removing the one or more cartridges in the one or more mandrels. Further, a slurry removal system can be easily integrated in order to achieve the utilization of the by-product in different applications. Also, the inclined slurry filter separates the slurry due to the taction he of gravity and it will be moved to the slurry tank via the spring-controlled valve.
[0040] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person skilled in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.
[0041] The figures and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, order of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts need to be necessarily performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples.
,CLAIMS:1. A system (10) to control acidity of a scrubbing solution in a wet scrubber, wherein the system (10) comprises:
a scrubbing solution tank (20) configured to store scrubbing solution which will be recirculated in a wet scrubber of an emission control system, thereby converting the scrubbing solution into the acidic solution over a period;
a pH sensor (30) operatively coupled to the scrubbing solution tank (20), and configured to sense the pH of the scrubbing solution after every first pre-defined interval;
a water level sensor (40) operatively coupled to the scrubbing solution tank (20), and configured to sense a level of the scrubbing solution in the scrubbing solution tank (20);
an acidic solution circulation pump (50) operatively coupled to the scrubbing solution tank (20), and configured to pump the scrubbing solution from the scrubbing solution tank to a reaction chamber (60) via one or more spray nozzles (70) when the scrubbing solution gets converted to the acidic solution,
wherein the reaction chamber (60) comprises:
one or more spray nozzles (70) configured for atomization of the scrubbing solution which will interact with the pH control agent to create a buffer solution;
one or more mandrels (80) comprising a pH control agent in a form of one or more cartridges; and
a slurry filter (90) configured to separate the by-product formed after the neutralization of the acidic solution received;
a slurry tank (120) operatively coupled to the scrubbing solution tank (20), and configured to collect the slurry which is formed as the by- product during the neutralization of the acidic solution; and
a controlling unit (100) operatively coupled to the pH sensor (30) and the water level sensor (40), and configured to:
receive a first signal from the pH sensor (30) via a first transmitter (110);
receive a second signal from the water level sensor (40) via a second transmitter (130); and
transmit an electrical actuation via an actuator (160) for the flow valve (95) and the acidic solution circulation pump (50) accordingly as per the logic to activate the flow valve (95) and the acidic solution circulation pump (50) for a second pre-defined interval based on the first signal and the second signal.
2. The system as claimed in claim 1, wherein the reaction chamber (60) comprises a transparent window (170) with a fiberglass type panel, and configured to get a check on the availability of the one or more cartridge in the one or more mandrels.
3. The system as claimed in claim 1, wherein the pH control agent comprises at least one of calcium hydroxide, calcium oxide or magnesium hydroxide.
4. The system as claimed in claim 1, wherein the one or more mandrels (80) comprises a perforated housing comprising a pipe like structure which helps flow of the buffer solution through the pipe.
5. The system as claimed in claim 1, wherein the controlling unit (100) comprises a timer (140) configured to power the acidic solution circulation pump (50) for the second pre-defined interval when the controlling unit (100) receives the first signal representing the pH level is less than seven.
6. The system as claimed in claim 1, wherein the slurry filter (90) is installed in an inclined manner at an angle such that the slurry may be moved to a slurry tank (120) by the action of gravity.
7. The system as claimed in claim 1, comprising a display unit configured to:
display information associated to the current pH level of the scrubbing solution in the scrubbing solution tank (20); and
display the water level of the scrubbing solution in the scrubbing solution tank (20).
8. The system as claimed in claim 1, comprising an alarm generation unit operatively coupled to the controlling unit (100), and configured to generate an alarm when one of the pH level of the scrubbing solution in the scrubbing solution tank (20) reaches below a critical limit.

Dated this 28th day of May 2021

Signature

Harish Naidu
Patent Agent (IN/PA-2896)
Agent for the Applicant