This invention relates to a system and method for monitoring disinfectant levels in non-human animal drinking water and automatically adding disinfectant as needed to maintain a desired minimum level to ensure safety of the drinking water.
Animal farms draw water from different sources (such as rivers, ponds, or underground) for potable use for animals. These water sources can be contaminated by numerous pollutants, including disease-causing organisms, or pathogens. Pathogens in animal drinking water can lead to serious consequences, including weight loss, reduced productivity, sickness, death, or even transmission of the disease to human beings as the end user. To reduce risk, animal farms apply chemicals (disinfectants) to inactivate pathogens to ensure the drinking water safety.
Currently, animal farms use different types of disinfectants to treat drinking water, including chlorine, chlorine dioxide, ozone, and other disinfectants, The disinfecting capability in the water depends on not only disinfectant level, but also other physical and chemical factors, such as pH, temperature, and water hardness. Many farms only measure and monitor the disinfectant level in the water. This practice masks the real disinfecting capability of the water, which can cause disinfectant under-dose (resulting in an increase in pathogens in the animal drinking water) or over-dose (which is wasteful and can be harmful to the animals or cause the animals to stop drinking or ingest less water than needed). Inconsistency in disinfectant dosing may lead to biological safety issues on the farm.
The most popular water disinfection method is chlorination. Chlorine can be applied in many ways, including chlorine gas (Cl2), sodium hypochlorite (NaClO), or calcium chlorite (Ca(ClO2)2). When chlorine reacts with water, the reaction forms hypochlorous acid (HClO) and hypochlorite ion (ClO−), both of which play a key role in oxidation and disinfection. The activity of hypochlorous acid as a disinfectant is higher than that of the hypochlorite, being almost 80-100 times more powerful. The pH of the water is an important determinant in the ratio of hypochlorous acid and hypochlorite ions. The proportion of hypochlorous acid decreases from around 100% in a solution with a pH around 6.0 down to almost 0% at pH of around 9.0. The combination of hypochlorous acid and hypochlorite ions is called free chlorine. Free chlorine is widely measured and controlled as the primary parameter to indicate the disinfecting potential of the water. However, the water disinfecting capacity does not depend only on the levels of free chlorine, but also the pH level since it changes the distribution of hypochlorous acid and hypochlorite ions which impacts the disinfecting capacity significantly.
Oxidation-Reduction Potential (ORP) is an electronic measurement, in millivolts (mV), of the oxidizing capability in the water. Oxidizers remove electrons from microbial membranes which compromises the structure and rigidity of the membrane. This destabilizes the microbe, resulting in rapid death via cellular lysis. ORP is a reliable indicator of the real-time disinfecting capability of water. It is known to use ORP sensors in systems designed to control disinfectant or chlorine addition to non-drinking, circulating water systems, such as swimming pools, spas, and cooling towers. For example, U.S. Pat. No. 5,422,014 discloses a system that uses an ORP sensor, pH sensor, and a controller to measure the ORP and pH of a diverted portion of swimming pool water (around 5% of the total water flow circulating through the pool system is sent through a service loop for measurement and injection of chemicals) and inject chlorine and/or an acid to modify the pH based on the measurements. As another example, U.S. Pat. No. 6,423,234 discloses a method of controlling chloramine levels in an indoor swimming pool, both in the pool and in the air, using an ORP sensor and chemical additions, including a coagulating agent to reduce the amount of halogen donor when needed, in order to maintain the ORP reading at between 700 and 850 mv and to maintain the pool at the breakpoint chlorine level (super chlorinated). These systems and methods are unique to swimming pool and recirculating water systems and are not used for drinking water systems.
For drinking water, the World Health Organization has published Guidelines for Drinking-water Quality for human water sources (for drinking, bathing, and food preparation) which indicate an ORP measurement can be used in the operational monitoring of disinfection efficacy. The Guidelines state that it “is possible to define a minimum level of oxidation-reduction potential necessary to ensure effective disinfection [but this] value has to be determined on a case-by-case basis; universal values cannot be recommended.” As such, there is no known system or method that can reliably measure disinfectant levels for animal drinking water with integrated control of a disinfectant dosing system. There is a need for a system and method that can utilize (1) a universal parameter to indicate the disinfecting capacity of animal drinking water, and (2) apply an automatic control system to adjust disinfectant dosing and pH in a timely manner to ensure the quality of animal farm drinking water.
According to one preferred embodiment of the invention, a monitoring system and method uses ORP technology to automatically monitor and control disinfectant levels in animal farm drinking water by adding disinfectant as needed to maintain a desired minimum level of disinfectant in the drinking water to ensure animal drinking water safety. Preferably, the monitoring system comprises a controller and an in-line ORP sensor or probe. The in-line ORP sensor takes readings of the oxidation-reduction potential in the drinking water flowing through a supply line and sends signals to the controller indicating a measurement of the level of disinfectant in the drinking water. Most preferably, the ORP sensor is compatible with different types of disinfectants which have a positive co-relationship with ORP measurement including, without limitation, chlorine, sodium hypochlorite, calcium chlorite, chlorine dioxide, monochloramine, fluorine, bromine, potassium permanganate, iodine, and/or ozone. Most preferably, the measurement is in millivolts. According to another preferred embodiment, the controller converts the millivolt signal into a measurement in different units, such as a concentration of disinfectant.
According to another preferred embodiment, the controller compares the measurement (in millivolts or as converted into other units) to one or more predetermined thresholds or to one or more prior measurements to determine if the measured level of disinfectant is within a desired range, is below the desired range (or below a lower threshold), and/or is above a desired range (or above a high threshold),
According to another preferred embodiment, the monitoring system further comprises a disinfectant dosing system. One preferred embodiment of the disinfectant dosing system comprises a pump that is preferably controlled by the controller to activate the pump to add disinfectant from a container of disinfectant to the drinking water when a measurement or a comparison of a measurement indicates that additional disinfectant is needed. According to another preferred embodiment, the disinfectant dosing system comprises a valve that is controlled by the controller to open and dose to allow disinfectant to feed into the supply line from the container by gravity feed. Most preferably, the disinfectant is in a liquid/solution form that can be pumped or fed by gravity feed from the container, but solid forms with an added dissolution system to form a liquid solution may also be used. Most preferably, the disinfectant in the container is chlorine, sodium hypochlorite, calcium chlorite, chlorine dioxide, monochloramine, fluorine, bromine, potassium permanganate, iodine, and/or ozone.
According to another preferred embodiment, the ORP probe will monitor the ORP level in the animal drinking water and send a signal to the ORP controller. When the ORP value does not reach the desired level, the ORP controller will send a signal to turn on the chemical or disinfectant dosing system to dose more disinfectant into the water to promote an appropriate ORP level. Once the ORP probe detects that the ORP value has reached the desired level, the ORP controller will send a signal to turn off the chemical pumping system to stop the disinfectant dosing
According to another preferred embodiment, the monitoring system may comprise a pH adjustment system to monitor and adjust pH in order to optimize the disinfecting capacity of the water. Most preferably, the pH adjustment system comprises an in-line pH sensor/meter/probe that takes pH readings or measurements in the drinking water flowing through a supply line and sends signals to the controller indicating a measurement of the pH level of the drinking water. One preferred embodiment of the pH adjustment system further comprises a pump that is preferably controlled by the controller to activate the pump to add a pH adjusting agent from one or more containers to the drinking water when a pH measurement indicates that the pH should be raised or lowered to achieve optimal disinfection. According to another preferred embodiment, the pH adjustment system comprises a valve that is controlled by the controller to open and close to allow a pH adjusting agent from one or more containers to feed into the supply line from the container(s) by gravity feed. Most preferably, the pH adjusting agent comprise one or more acids in a first container and optionally one or more bases in a second container, in a liquid/solution form that can be pumped or fed by gravity feed from the container(s), but solid forms with an added dissolution system to form a liquid solution may also be used.
According to another preferred embodiment, the monitoring system comprises a flow switch indicating whether water is flowing or static in a supply line. Most preferably, the monitoring system is only active when the flow switch indicates water is flowing through the supply line.
Preferred embodiments of the invention ensure that animal drinking water has the correct ORP level to maintain the correct disinfecting capacity. Preferred embodiments have the advantage of automatic ORP monitoring and addition of disinfectant as needed to animal farm drinking water to maintain the ORP in a reasonable range to ensure proper disinfecting capacity. This invention measures the ORP level in a timely manner and controls the disinfectant dosing automatically, based on the ORP in-line reading. It has not previously been known to use ORP measurements to maintain a disinfectant level in animal drinking water.
The system of the invention is further described and explained in relation to the following figures wherein:
Referring to
Disinfectant dosing system 15 preferably comprises a pump 16 connected in fluid communication with a disinfectant container 18 connected in fluid communication with an injector 22 through a disinfectant discharge line 20. Alternatively, disinfectant dosing system 15 may comprise a valve disposed on container 18 or discharge line 20 to allow disinfectant to be fed by gravity feed from container 18, particularly if container 18 is disposed at an elevated position relative to supply line 42 and discharge line 20 is disposed at or near a bottom of container 18. Discharge line 20 is preferably connected to water supply line 42 at point 22, which may be an injection port, manifold, opening or other access point where disinfectant may be added to the water in line 22 by gravity, dripping, or pumping. As another alternative, point 22 may be directly into the water source, such as a water tower, rather than supply line 42, to allow disinfectant to be added to the water source. Most preferably, ORP sensor 14 is located on supply line 42 at least a distance D of 5 meters; more preferably at least a distance D of 10 meters from point 22 where disinfectant is added to the water.
An optional, but preferred pH adjustment system to monitor and adjust pH in order to optimize the disinfecting capacity of the water may also be used with monitoring system 10. A pH adjustment system could be configured to monitor the pH of the water in supply 42 or in the water source (such as a water tower), similar to the layout of disinfectant dosing system 15 shown in
Control system 12 preferably comprises a controller 28, a power switch 30, a wire relay 32, and integrated wire board 34, and a plurality of wires or connectors 36 to connect components of control system 12 to each other and to pump 16, ORP sensor 14, and flow switch 24. Wires or connectors 36 may include wire 36A connecting to pump 16, 36B connecting to a measuring electrode in ORP sensor 14, 36C connecting to a reference electrode used with or in ORP sensor 14, and 36D connecting to flow switch 24.
Controller 28 is preferably configured to receive signals (preferably in millivolts) from ORP sensor 14. Most preferably ORP sensor 14 has an internal timing mechanism to automatically take a measurement at periodic intervals, such as every 15-25 seconds, but the ORP sensor may be configured to also receive signals from controller 28 to activate a measurement or to alter the duration of the periodic intervals between measurements. ORP sensor 14 is used to measure the voltage between a measuring electrode (preferably platinum, but other non-oxidizable metal such as gold, palladium, or silver may also be used) and a reference electrode which represents the oxidation reduction potential of the water flowing through line 42. ORP sensor 14 is preferably disposed inline through a port installed on line 42 (not shown) to directly measure the water flowing through line 42. As an alternative, a portion of water may be diverted from line 42 to a sub-circuit into which ORP sensor 14 is installed with the diverted water being reintroduced into line 42 after measuring.
Controller 28 may optionally be configured to convert the signal from ORP sensor 14 into an ORP measurement using a different value conversion or scale, such as converting a millivolt signal from sensor 14 into a concentration of chlorine in line 42, if desired. Controller 28 is further configured to compare one or more ORP measurements (either as a raw signal or a converted measurement), most preferably each ORP measurement, to a predetermined threshold or range or to one or more prior ORP measurements. Most preferably, ORP system 10 has a lower predetermined threshold or a lower alarm ORP point and a higher predetermined threshold or higher alarm ORP point. Lower alarm ORP point is the minimum ORP level in the water to ensure sufficient disinfecting capacity. Most preferably, at a pH of around 7, the lower threshold is around 580 my to 720 my, more preferably 600 my to 700 mv, and most preferably 625 my to 675 mv or around 0.2 to 4 ppm, more preferably 0.25 to 3 ppm, and most preferably 0.6 to 1.8 ppm of chlorine (if converted to a chlorine concentration). The higher alarm ORP point is the maximum ORP level in the water to ensure the ORP level is not too high to have adverse effects on animal health. Most preferably, the higher threshold is around 825 mv to 875 mv, more preferably 835 mv to 865 mv, and most preferably 850 mv to 860 mv or around 2 to 10 ppm, more preferably 3 to 7 ppm, and most preferably 5 to 6 ppm of chlorine (if converted to a chlorine concentration).
If the comparison of an ORP measurement indicates that a level of disinfectant in line 42 is too low, controller 28 is further configured to send a signal to disinfectant dosing system 15 to allow disinfectant to be added to the water at point 22. Preferably, controller 28 sends a signal to pump 16 to activate pump 16 (or to a valve to open a valve for gravity feed of disinfectant) to deliver an amount of disinfectant stored in container 18 to the water flow line 42 (or to the water source) through an injector 22. Preferably, controller 28 activates pump 16 (or keeps valve open) until a comparison of ORP measurement indicates the disinfection level is above the lower threshold, more preferably until a comparison indicates the disinfection level has reached an intermediate level that is around 5-10% lower than the higher threshold. Alternatively, controller 28 may activate pump 16 (or keep a valve open) until the next comparison that meets or exceeds the higher threshold. As an additional alternative, controller 28 may be configured to determine an amount of disinfectant needed to bring the level up to a desired level above the lower threshold based on the flow rate through line 42 and the ORP measurement that triggers disinfectant addition and to activate pump 16 (or open a valve) for an amount of time based on pumping rate (or gravity feed rate) necessary to deliver the determined amount of disinfectant to achieve the desired ORP measurement level. Pump 16 (or a valve) may also be activated by controller 28 for a predetermined amount of time, such as using a timer. Although it is preferred that controller 28 automatically control the addition of disinfectant through disinfectant dosing system 15, controller may also be configured to send an alert to a user that disinfectant needs to be added or when sufficient disinfectant has been added so that the user can manually operate disinfectant dosing system 15.
Controller 28 is preferably configured to receive signals from a pH sensor in an optional pH adjustment system and to convert the signal to a pH reading if needed. Most preferably pH sensor has an internal timing mechanism to automatically take a measurement at periodic intervals, such as every 15-25 seconds, but the pH sensor may be configured to also receive signals from controller 28 to activate a measurement or to alter the duration of the periodic intervals between measurements. A pH sensor is used to measure the pH of the water flowing through line 42 or in the water source (such as a water tower). A pH sensor is preferably disposed inline through a port installed on line 42 to directly measure the water flowing through line 42. As an alternative, a portion of water may be diverted from line 42 to a sub-circuit into which a pH sensor is installed with the diverted water being reintroduced into line 42 after measuring.
Controller 28 can be further configured to compare one or more pH measurements (either as a raw signal or a converted measurement), most preferably each pH measurement, to a predetermined acceptable threshold or range based on the specific disinfectant use, or to one or more prior pH measurements. Most preferably, system 10 has a lower predetermined pH threshold or a lower alarm pH point and a higher predetermined pH threshold or higher alarm pH point. Lower alarm pH point is preferably the minimum desired pH level in the water to aid in optimizing disinfecting capacity without harming the animals or causing damage to the components of system 10. Upper alarm pH point is preferably the maximum desired pH level in the water to aid in optimizing disinfecting capacity without harming the animals. The optimal pH and the lower and upper pH thresholds are dependent on the preferred disinfectant and are predetermined and programmed into the controller as appropriate. Preferred ranges include chlorine derivatives (chlorine, sodium hypochlorite, calcium chlorite) at an optimal pH of 5 to 7.5, monochloramine at an optimal pH of 7 to 9, potassium permanganate at an optimal pH of 6 to 7, and bromine at an optimal pH of 6 to 8.
If the comparison of a pH measurement indicates that a pH level of the water in line 42 is too low, controller 28 is further configured to send a signal to pH adjustment system to allow a pH adjusting agent (a base if the pH is too low) to be added to the water at a pH adjustment injection or addition point, preferably near point 22 and more preferably upstream of point 22. Preferably, controller 28 sends a signal to a pump to activate the pump (or to a valve to open a valve for gravity feed of pH adjusting agent) to deliver an amount of pH adjusting agent stored in a container to the water flow line 42 (or to the water source) through an injector (like injector 22). Preferably, controller 28 activates a pump (or keeps valve open) until a comparison of pH measurement indicates the pH level is above the lower pH threshold, more preferably until a comparison indicates the pH level has reached an intermediate level between the low pH threshold and high pH threshold, such as between 5.5 to 7.5, more preferably between 6 to 7. Alternatively, controller 28 may activate a pump (or keep a valve open) until the next comparison that meets or exceeds the higher pH threshold. As an additional alternative, controller 28 may be configured to determine an amount of pH adjusting agent needed to bring the level up to a desired level above the lower threshold based on the flow rate through line 42 and the pH measurement that triggers pH adjusting agent addition and to activate a pump (or open a valve) for an amount of time based on pumping rate (or gravity feed rate) necessary to deliver the determined amount of pH adjusting agent to achieve the desired pH measurement level. A pump (or a valve) may also be activated by controller 28 for a predetermined amount of time, such as using a timer, to deliver pH adjusting agent. Although it is preferred that controller 28 automatically control the addition of pH adjusting agents through pH adjustment system, controller may also be configured to send an alert to a user that a pH adjusting agent needs to be added or when sufficient pH adjusting agent has been added so that the user can manually operate the pH adjustment system.
Controller 28 may also be configured to trigger an alert, such as an audible or visual alarm or to send a signal or message to a user, to indicate that an ORP or pH measurement is above or below one of the thresholds or range of thresholds; to store ORP or pH data and send or allow transfer of historic data to another device, such as a computer, tablet, or cell phone. Control system 12 also preferably comprises a user interface, preferably with a display screen 46 and one or more buttons 48 to allow user inputs. Most preferably, a user may view information regarding ORP system 10 on a display screen, such as ORP measurements, pH measurement, comparisons, activation of pump 16, and/or disinfectant dosage amounts added using pump 16, pH adjusting agent dosage amounts, and input data or instructions into system 10 using one or more buttons or a touch screen, such as instructions to recall information to be displayed, to change one of the thresholds, to manually activate pump or manually stop pump, and/or to turn system 10 on or off (which may also be done with power switch 30).
Controller 28 is preferably configured to receive a signal from flow switch 24 indicating whether water is flowing through drinking water flow line 42 (dynamic flow) or not flowing (static flow). If no water is flowing through line 42 (static water flow detected), then the ORP system 10 is preferably in a “pending” or inactive state. This will ensure the ORP system will not run idle when no water is flowing in the pipeline, such as during overnight hours when water is not typically consumed by farm animals. If dynamic water flow is detected, then the ORP system 10 will preferably be in an “active” state. When in a pending or inactive state, ORP system 10 preferably does not take any readings with sensor 14, or optionally convert signals from sensor 14 to measurements, or make any comparisons. When in an active state, a signal is sent from ORP sensor 14 to controller 28 preferably every 15-25 seconds.
Controller 28 may optionally be configured to alert a user of a low level of disinfectant in container 18 by sending a signal or message to a user or trigger an audible or visual alarm when a level of disinfectant in container 18 reaches a predetermined threshold or predetermined low level so that a user can be alerted that container 18 needs refilling or replacement. Disinfectant dosing system 15 may further comprise a level sensor disposed in or on container 18 and configured to send signals to controller 28 indicating the level in container 18. Alternatively, controller 28 may be configured to calculate and track the amount of disinfectant injected into line 42 and to compare it to an initial volume of disinfectant in container 18 to calculate a level of disinfectant remaining in container 18. Controller 28 may be configured to initiate a low level alert when the remaining volume of disinfectant in container 18 is below a predetermined threshold, such as 10% or 5% volume remaining to indicate the container is near empty (or actually empty, if desired) so that it may be refilled or replaced. According to yet another preferred embodiment, controller 28 also tracks inventory of replacement containers 18 or a replenishment volume of disinfectant to be added to refill container 18 and can provide an alert or automatically send a replacement order to replenish inventory of disinfectant when the supply of disinfectant at the treatment location is low. Controller 28 may similarly be configured to calculate and track amounts of pH adjusting agents used and inventory and to send alerts or replenishment orders.
Monitoring system 10 may also be used with a water supply system that has a preexisting disinfectant dosing or addition system, in which case monitoring system 10 does not comprise a disinfectant dosing system. In that case, controller 28 may be configured to send a signal to the external/preexisting dosing or addition system when a comparison of measurements indicates additional disinfectant is needed or to send an alert to a user to make the addition manually or using a separate control system for the external/preexisting disinfectant dosing or addition system.
Enclosure or housing 26 preferably protects controller 28 from incidental contact by untrained personnel, water, fire, and foreign objects. Enclosure or housing 26 also provides a certain degree of fire protection and water resistance. Most preferably, enclosure or housing 26 is waterproof to extend equipment life and decrease maintenance. Enclosure or housing 26 and components of the disinfectant dosing system are preferably disposed in a semi-sheltered environment, preferably under an overhead cover or roof. Enclosure or housing 26 is preferably compact in size. An exemplary size according to one preferred embodiment is around 400 mm×200 mm×570 mm.
Power switch 30 provides an electrical connection from a voltage source/ground to a load. It saves power across multiple voltage rails and protects subsystems from damage. Wire relay 32 preferably controls a high power/voltage circuit for pump 16 with a lower power circuit from the ORP controller 28. Galvanic isolation is desirable, but not required. Integrated wire board 34 integrates several components in system 10 which are inseparably associated and electrically interconnected. The wire board also aids the assembly of the whole system by coordinating the wire connections between several elements. Components 30, 32, and 34 are shown outside of enclosure 26 in
According to one preferred embodiment, a method of monitoring a level of disinfectant in animal drinking water comprises: (1) periodically obtaining an ORP measurement (and optionally a pH measurement), of water flowing as it flows through a supply line from a water source to a point of animal consumption using an ORP sensor (and optionally a pH sensor); (2) comparing one or more of the ORP (and/or optionally pH) measurements to a predetermined low value ORP (or pH) threshold, a predetermined high value ORP (or pH) threshold, a predetermined acceptable ORP (or pH) range, one or more prior ORP (or pH) measurements, or a combination thereof; and (3) adding disinfectant (or a pH adjusting agent) from one or more containers having an initial volume of disinfectant (or one or more pH adjusting agents) to an addition point in the supply line if the ORP (or pH) measurement is below the predetermined low value ORP (or pH) threshold or below the predetermined acceptable ORP (or pH) range. According to other preferred embodiments, the method further comprises one or more of the following steps: (4) deactivating the pump or closing the valve to stop adding disinfectant and/or pH adjusting agent once a new ORP or pH measurement is above the high value predetermined threshold or is within the predetermined acceptable range for ORP or pH, respectively; (5) determining whether water is flowing through the supply line or is static and carrying out the comparing step only when water is flowing through the supply line; (6) triggering a first alert when the ORP or pH measurement is below the predetermined low value threshold, above the predetermined high value threshold, or outside the predetermined acceptable range for the ORP or pH measurement, respectively; (7) determining a remaining volume of disinfectant or pH adjusting agent in the one or more containers, comparing the remaining volume to a predetermined volume level, and triggering a second alert when the remaining volume is below the predetermined volume level for the disinfectant or pH adjusting agent, respectively. According to another preferred embodiment, the adding step(s) comprises activating a pump to pump disinfectant or pH adjusting agent from the one or more containers through a discharge line to the addition point or opening a valve on the one or more containers or on one or more discharge lines connected to the container(s) to allow disinfectant or pH adjusting agent to flow by gravity feed from the container to the addition point. Most preferably, the methods of the invention are carried out using a preferred monitoring system, such as system 10.
References herein to animals include all animals raised for agricultural purposes, or as a source of foods for humans, such as livestock and aquatic species, but specifically exclude humans. References herein to drinking water are to drinking water for consumption by animals, not drinking water for human consumption.
References herein to measurements, reading, calculating or measuring a value, parameter, or property and the like are intended to include any form of direct measurement, converting data or a signal, making a calculation based on one or more data points or signals, or otherwise comparing, interpreting, correlating, or manipulating one or more data points or signals unless specifically excluded. Unless specifically excluded, any preferred features and optional components of system and/or method steps described herein may be used with any other embodiment, even if not specifically described herein with that particular embodiment. All dimensions, sizes, numerical rating, ratio, or percentages indicated herein as a range include each individual amount or ratio within those ranges and any and all subset combinations within ranges, including subsets that overlap from one preferred range to a more preferred range. Those of ordinary skill in the art will also appreciate upon reading this specification, including the examples contained herein, that modifications and alterations to the preferred embodiments of may be made within the scope of the invention and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventor is legally entitled.
This application claims the benefit of U.S. Provisional Application Ser. No. 63/114,885 filed on Nov. 17, 2020.
Number | Date | Country | |
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63114885 | Nov 2020 | US |