Method and apparatus for controlled production of fluid reaction products

Abstract

The invention relates to an apparatus and a method for producing a fluid product, for example a fluid reaction product. The invention comprises a reaction chamber and a receiving chamber and a control unit configured to control the flow of fluid into the reaction chamber through the one or more fluid connections. The invention further comprises a first quantity sensor and a second quantity sensor arranged to continuously or at least quasi-continuously determine the quantity of fluid components of the reaction chamber and the receiving chamber at least during the introduction of the fluid components.

Description

TECHNICAL FIELD

[0001] The present invention relates to an apparatus and a method for producing a fluid product, e.g. a fluid reaction product. The invention comprises a reaction chamber and a receiving chamber and a control unit configured to control the flow of fluid into the reaction chamber through the one or more fluid connections. The invention further comprises a first quantity sensor and a second quantity sensor arranged to continuously or at least quasi-continuously determine the quantity of fluid components of the reaction chamber and the receiving chamber at least during introduction of the fluid components. BACKGROUND

[0002] In some cases, chlorine dioxide (CIO2) is used to combat bacteria and pathogens, e.g. Legionella in building installations, and to disinfect drinking water in small cooling water systems or water plants or industrial processes.

[0003] The production of fluid products, such as CIO2, is usually carried out in a batch production mode. In this production mode, a batch is produced and transferred to a batch tank, after which a new batch is produced and stored ready to be transferred to the batch tank when needed.

[0004] Such a process, although fully operational, can suffer from the drawback that the produced fluid product deteriorates over time due to the fluid product being consumed by the customer for a long time. For example, if a batch of fluid product is consumed during a period of 1 month, then the last consumed quantity will have an age of 2 months since the batch was produced 2 months ago. The ageing can be estimated from the following. At t=0, a batch is produced and transferred to a batch tank from which fluid product is taken for consumption. Immediately after the transfer, a new batch is produced and stored ready to be used for transfer to the batch tank. Thus, the fluid product has aged 1 month when it is transferred to the batch tank and since the consumption is one batch per month, the last consumed quantity will have an age of 2 months.

[0005] Although these numbers are given somewhat arbitrarily to illustrate the principle and the ageing can be optimized based on the batch size, it has been accepted that the ageing of the fluid product with respect to the requirement to meet the need not to dry out the fluid product has been accepted, although this is undesirable, taking into account that it takes time to produce a new batch and that the consumption can vary over time.

[0006] US 2011 / 0278173 discloses an apparatus for manufacturing a fluid reaction product. The apparatus is located in a level sensor which allows for discrete filling levels, prompting a new batch to be produced immediately after a batch has been transferred to a storage.

[0007] Hence, an improved apparatus and method for producing a fluid product would be advantageous and in particular a more effective and / or reliable apparatus and method would be advantageous. SUMMARY

[0008] OBJECT OF THE INVENTION

[0009] It is a further object of the present invention to provide an alternative to the prior art.

[0010] In particular, it can be seen as an object of the present invention to provide an apparatus or method which addresses or at least mitigates the above-mentioned problems of the prior art relating to the aging of e.g. fluid products.

[0011] Hence, a first aspect of the present invention aims at achieving the above-mentioned objects and some other objects by providing an apparatus for producing a fluid product, such as a fluid reaction product, the apparatus comprising:

[0012] - a reaction chamber;

[0013] - one or more fluid connections extending from outside of the reaction chamber and into the reaction chamber for introducing fluid components into the reaction chamber;

[0014] - a receiving chamber;

[0015] - an activatable fluid transfer device providing a fluid connection between the reaction chamber and the receiving chamber, such that the receiving chamber receives the fluid product produced in the reaction chamber when the fluid activatable fluid transfer device is activated;

[0016] - an activatable discharge connection for discharging the fluid product from the receiving chamber,

[0017] - a control unit configured to control the flow of fluid into the reaction chamber through the one or more fluid connections;

[0018] - a first quantity sensor arranged to continuously or at least quasi-continuously determine the quantity of fluid components in the reaction chamber at least during the introduction of the fluid components, the first quantity sensor being operatively coupled to the control unit to communicate the determined quantity in the reaction chamber to the control unit by sensor readings;

[0019] - a second quantity sensor arranged to continuously or at least quasi-continuously determine the quantity of fluid product in the receiving chamber, the second quantity sensor being operatively coupled to the control unit to communicate the determined quantity of fluid product in the receiving chamber to the control unit by sensor readings.

[0020] Although it has been found that the present invention is generally useful for producing fluid products, in particular, it has been found that preferred embodiments of the present invention are useful for producing the following fluid products:

[0021] - ClO2, e.g. for drinking water use:

[0022] - Hydrochloric acid - chlorite - method:

[0023] 5 NaCI02+ 4 HCI -> 4 CIO2+ 5 NaCI + 2 H20

[0024] - peroxodisulfate-chlorite-method

[0025] Production of monochloramine (NH2CI):

[0026] - using ammonia (NH3) and hypochlorous acid (HCIO):

[0027] NH3+ HCIO -> NH2CI + H20

[0028] Compared to the prior art, the present invention has shown to provide optimization of the chemical process and / or to provide a flexible fluid product concentration (e.g. a user selected fluid product concentration) for the fluid product by means of a continuous level sensor. Some examples are:

[0029] To reduce by-products, the concentration can be reduced by reducing the amount of fluid component within the prescribed limits.

[0030] For temporary needs of a high concentration fluid product, the concentration can be increased by increasing the amount of fluid component within the safety limits.

[0031] The terms used herein are used in a manner which is ordinary to the skilled person. However, some of the terms used are detailed below:

[0032] As used herein, e.g. in "a first amount sensor arranged to continuously or at least quasi-continuously determine the amount of fluid component of the reaction chamber at least during introduction of the fluid component", "continuously or at least quasi-continuously" is generally used to refer to a sensor arrangement which is able to provide a sensor signal which provides a reading of the actual amount of fluid component in the reaction chamber and the actual amount of fluid product in the receiving chamber. Thus, "continuously" refers to a sensor arrangement which provides an indication of the actual content, "quasi-continuously" refers to a sensor arrangement which provides a stepwise reading relative to the actual amount, that is to say, the actual content is between two successive steps, e.g. between 100 [ml] and 101 [ml].

[0033] As used herein, the "hydraulic diameter" D h may preferably be determined as D h = 4 * cross-sectional area / length of the perimeter enclosing the cross-sectional area.

[0034] As used herein, the control unit generally refers to a computer comprising software and interfaces which configure the computer to receive readings from the sensors and to provide control signals to the elements (pumps, valves, etc.) of the apparatus and to perform the determinations disclosed herein.

[0035] In some preferred embodiments, the activatable fluid transfer device can comprise a pump, a valve or a combination thereof, wherein the pump, valve or combination thereof can be configured to be controlled by the control unit such that upon receipt of a control signal provided by the control unit, the pump, valve or combination thereof can be activated to transfer fluid.

[0036] In some embodiments, the activatable fluid transfer device can preferably comprise a siphon, which can comprise a downcomer and a riser arranged outside the downcomer, the riser having an inner diameter or hydraulic diameter larger than an outer diameter or hydraulic diameter of the downcomer to provide a gap between the downcomer and the riser, the downcomer can extend vertically within the reaction chamber from a bottom of the reaction chamber and having an upper inlet opening arranged at a distance from the bottom, the riser being closed at an upper end, the siphon can further comprise an opening at a lower end of the riser to provide a fluid passage into the gap, and an opening at an upper end of the downcomer between the gap and the inlet opening of the riser.

[0037] In some preferred embodiments, the device can further comprise a plurality of chemical storage containers, each chemical storage container being arranged in fluid connection with the reaction chamber via the one or more fluid connections, the fluid connections can comprise a pump, a valve or a combination thereof, wherein the pump, valve or combination thereof can be configured to be controlled by the control unit such that upon receipt of a control signal provided by the control unit, the pump, valve or combination thereof can be activated to selectively transfer a chemical from one or more of the chemical storage containers.

[0038] Some preferred embodiments of the device can further comprise a gas reservoir, preferably a volumetrically variable gas reservoir, fluidly connected to the interior of the receiving chamber.

[0039] In some preferred embodiments, the activatable discharge connection can comprise a pump in combination with a valve, the pump and valve can be configured to provide discharge of the fluid product upon receipt of a control signal provided by the control unit.

[0040] Preferably, the receiving chamber can further comprise a closable purge connection.

[0041] In some preferred embodiments, the device can further comprise a water reservoir fluidly connected to the reaction chamber via a conduit, the conduit preferably comprising a shut-off valve and / or a pump.

[0042] Preferably, the first amount sensor and / or the second amount sensor can comprise a float configured to provide an electrical signal representative of the liquid level, a weighing device configured to weigh the reaction chamber or the receiving chamber and provide an electrical signal representative of the weight, an optical sensor or an ultrasonic sensor configured to determine the liquid surface position in the reaction chamber or the receiving chamber (8) and provide a signal representative of the liquid surface position, or a pressure sensor configured to determine the liquid column pressure in the reaction chamber or the receiving chamber and provide a signal representative of the liquid column pressure.

[0043] In a second aspect, the present invention relates to a method for producing a chemical compound, such as CIO2, by using the apparatus according to any of the preceding claims, the method comprising

[0044] a) introducing a selected fluid component into the reaction chamber through one of the fluid connections, e.g. by using a pump, a valve or a combination thereof,

[0045] b) determining the total amount of fluid components in the reaction chamber based on readings from the first amount sensor and continuing steps a) and b) until the total amount of fluid components introduced has reached a prescribed total amount of fluid components, and

[0046] c) repeating steps a) and b) until all required selected fluid components have been introduced into the reaction chamber.

[0047] In some preferred embodiments, the method can further comprise during the introduction of the selected fluid components:

[0048] - determining an inflow rate of the selected fluid component by using the control unit and based on readings from the first amount sensor,

[0049] - comparing the inflow rate to a prescribed limit, and if the inflow rate is outside the prescribed limit:

[0050] - reducing the production capacity,

[0051] - adjusting the inflow rate to be within the prescribed limit,

[0052] - or reporting an error state.

[0053] Preferably, the prescribed limit can be a chemical reaction application limit.

[0054] Preferably, steps a) and b) can be repeated one fluid component at a time, wherein these steps can be repeated for one fluid component until the total amount of said fluid component has been introduced into the reaction chamber.

[0055] Preferably, the fluid product is CIO2, and the fluid components comprise sodium chlorite (NaCI02) and hydrochloric acid (HCI).

[0056] In a third aspect, the present invention relates to a method of initiating production of a compound, such as ClO2, by using the device according to the first aspect, the method preferably comprising:

[0057] - determining a minimum threshold amount of fluid product to be present in the receiving chamber,

[0058] - determining the amount of fluid product present in the receiving chamber based on readings from the second quantity sensor,

[0059] - initiating production of fluid product by using the method according to the first aspect if the amount of fluid product present in the receiving chamber is below the determined minimum threshold amount.

[0060] Preferably, the minimum threshold amount can be determined based on a historical time series of data comprising the amount of discharge as a function of time or by a user.

[0061] Preferably, the minimum threshold amount can be determined by:

[0062] - estimating the time of zero amount at which the amount of fluid product in the receiving chamber reaches zero, the estimation being made by approximating a historical time series of data, e.g. a recent historical time series, comprising the amount of discharge as a function of time,

[0063] - estimating the amount of time required to provide a certain amount of fluid product in the reaction chamber, and

[0064] - determining the minimum threshold amount as the amount of time for which the time required to provide a certain amount equals the time before the time of zero amount by approximating said time series of data.

[0065] In some preferred embodiments, the method can further comprise determining a transfer threshold amount and activating the activatable transfer device if the amount of fluid product present in the receiving chamber is below the transfer threshold amount.

[0066] Preferably, the transfer threshold amount is determined as the amount for which the transfer flow rate provided by the activatable fluid transfer device prevents the amount of fluid product in the receiving chamber from becoming zero.

[0067] In some preferred embodiments, the method can further comprise producing a plurality of batches of fluid product, wherein each batch can be a certain amount of fluid product produced and for each batch produced:

[0068] - recording the inflow rate of each selected fluid component,

[0069] - comparing the recorded inflow rates between batches, and

[0070] - providing a report thereof to a user if the compared inflow rates are not within a prescribed limit. Attached Figure Description

[0071] The invention and its preferred embodiments will now be described in more detail with reference to the accompanying drawings. The drawings illustrate ways in which the invention is implemented, but should not be construed as limiting other possible embodiments falling within the scope of the appended claims.

[0072] Figure 1 This is a cross-sectional view showing a conceptual representation of the device according to the first embodiment.

[0073] Figure 2 This is a system layout according to an embodiment of the present invention.

[0074] Figure 3 This is a schematic graph illustrating various detection possibilities according to a preferred embodiment of the invention.

[0075] Figure 4 This is a flowchart schematically illustrating the various steps performed during the introduction of the fluid component according to a preferred embodiment.

[0076] Figure 5 This is a schematic flowchart illustrating the start-up of the production of a compound in a reaction chamber according to a preferred embodiment.

[0077] Figure 6 This is a cross-sectional view of an embodiment where the activatable transfer device is in the form of a siphon tube.

[0078] Figure 7 This is a time diagram illustrating a preferred mode of operation according to a preferred embodiment of the present invention. Detailed Implementation

[0079] refer to Figure 1 This is a conceptual cross-sectional view of an apparatus according to a first embodiment of an apparatus 1 for producing a fluid product. As detailed herein, the fluid product may preferably be a fluid reaction product.

[0080] In the illustrated embodiment, device 1 includes a reaction chamber 2, which is a fluid-impermeable container configured to contain fluid components.

[0081] A fluid connector 3 is arranged to extend from the outside of the reaction chamber 2 and into the reaction chamber 2. This fluid connector is used to introduce fluid components into the reaction chamber 2. In the illustrated embodiment, the fluid components are stored in a first chemical reservoir 9 and a second chemical reservoir 10, both of which are in the form of containers. The fluid connector 3 includes a branch with a valve, wherein each branch leads to a separate chemical reservoir. The opening and closing of the valve is controlled by a control unit 5, as shown.

[0082] Thus, by opening the valves in the fluid connections 3, the fluid components can flow into the reaction chamber. Typically, the valves are opened one at a time to ensure that a chemical reaction takes place in the reaction chamber 2.

[0083] Although two reservoirs 9, 10 are shown, more reservoirs can be implemented. The reservoirs 9, 10 serve the purpose of holding fluid components that, when mixed, will result in a separate chemical process. In other embodiments, each reservoir 9, 10 is fluidly connected to the reaction chamber 2 by a separate fluid connection 3.

[0084] The receiving chamber 8 is arranged in fluid connection with the reaction chamber 2, such that fluid can flow from the reaction chamber 2 into the receiving chamber 8. The fluid connection between the reaction chamber 2 and the receiving chamber is implemented as an activatable fluid transfer device 4 that provides a fluid connection between the reaction chamber 2 and the receiving chamber 8, such that when the fluid activatable fluid transfer device 4 is activated, the receiving chamber 8 receives the fluid product produced in the reaction chamber 2. In the embodiment shown, this is provided by a pipe connecting the reaction chamber 2 and the receiving chamber 8 and a valve 23. The opening and closing of the valve 23 is controlled by the controller 5, such that when the valve 23 is open, fluid flows from the reaction chamber into the receiving chamber 8.

[0085] Thus, the production of a fluid product by the disclosed device 1 comprises introducing fluid components from the reservoirs 9, 10 into the reaction chamber 2 and allowing a reaction process to take place. Once the reaction process has ended, the fluid product can be transferred into the receiving chamber 8 by opening the valve 23.

[0086] An activatable discharge connection 15 for discharging the fluid product from the receiving chamber 8 is arranged at the bottom of the receiving chamber 8. In the disclosed embodiment, this discharge connection comprises a pipe with a valve 24. The opening and closing of the valve 24 is controlled by the control unit 5.

[0087] In order to monitor the amount of fluid present in the reaction chamber 2 and the receiving chamber 8, an amount sensor is arranged in the device 1.

[0088] As shown, a first amount sensor 6 is arranged to determine the amount of fluid components of the reaction chamber 2. The amount sensor is configured to determine the amount in the reaction chamber continuously or at least quasi-continuously at least during the introduction of the fluid components. In this way, the amount present in the reaction chamber is known as a function of time. The first amount sensor 6 is operatively coupled to the control unit 5 to communicate the determined amount in the reaction chamber 2 to the control unit 5 by sensor readings.

[0089] The second amount sensor 7 is arranged to determine the amount of fluid product in the receiving chamber 8. The second amount sensor 7 is configured to determine the amount continuously or at least quasi-continuously, such that the amount present in the receiving chamber 8 is known as a function of time. The second amount sensor 7 is operatively coupled to the control unit 5 to communicate the determined amount in the receiving chamber 8 to the control unit 5 by means of sensor readings.

[0090] As will be described in detail below, the continuous or at least quasi-continuous nature of these amount sensors makes it possible to monitor the discharge (consumption) of fluid product from the receiving chamber 8 in terms of time and to estimate the time at which the receiving chamber 8 will run dry. Based on the estimated dry-out time, it is possible to estimate when a new portion of fluid product will be produced to avoid the receiving chamber 8 running dry.

[0091] Although the fluid transfer device 4 is disclosed as a pipe with a valve, the fluid transfer device 4 can be implemented in other ways, for example comprising a pump, a valve or a combination thereof. Such a pump, valve or combination thereof is preferably configured to be controlled by the control unit 5, such that upon receipt of a control signal provided by said control unit 5, the pump, valve or combination thereof is activated to transfer fluid. Figure 1 The disclosed fluid transfer device 4 is disclosed as a pipe with a valve, but the fluid transfer device 4 can be implemented in other ways, for example comprising a pump, a valve or a combination thereof. Such a pump, valve or combination thereof is preferably configured to be controlled by the control unit 5, such that upon receipt of a control signal provided by said control unit 5, the pump, valve or combination thereof is activated to transfer fluid.

[0092] Instead of the setup disclosed in Figure 1 , the activatable fluid transfer device (4) can comprise a siphon 18 as shown in Figure 6 . As shown in Figure 6 , the siphon 18 comprises a lower pipe 19 and a standpipe 20 arranged outside the lower pipe 19. The lower pipe 19 opens into the interior of the receiving chamber 8 (not shown) and is sealed at the bottom of the reaction chamber 2. The standpipe 20 is arranged inside the reaction chamber, having an inner diameter or hydraulic diameter that is larger than the outer diameter or hydraulic diameter of the lower pipe 19, thereby providing a gap between the lower pipe 19 and the standpipe 20. As shown, the lower pipe 19 extends vertically inside the reaction chamber 2 from the bottom of the reaction chamber 2 and has an upper inlet opening 21 arranged at a distance from said bottom. The standpipe 20 is closed at the upper end. Due to the mutual arrangement of the standpipe 20 and the lower pipe, the siphon 18 is provided with an opening at the lower end of said standpipe 20 to provide a fluid passage into said gap, and the siphon 18 is provided with an opening at the upper end of said lower pipe 19 between said gap and the inlet opening of the standpipe 20.

[0093] Reference is made to Figure 2 , which schematically illustrates a system layout according to an embodiment of the application. Reference is made to Figure 1 , which schematically illustrates a system layout according to an embodiment of the application. Reference is made to Figure 2 , which schematically illustrates a system layout according to an embodiment of the application. Reference is made to Figure 2The device shown in the middle comprises a gas reservoir 16, which is preferably a variable volume gas reservoir, fluidly connected to the interior of the reaction chamber 2. By including such a gas reservoir, gas generated as a result of the reaction chamber 2 can be evacuated and enter the gas reservoir, which can be used, among other things, to control the pressure in the reaction chamber 2, for example to ensure that the pressure in the reaction chamber remains within predetermined limits.

[0094] As also Figure 2 shown in this embodiment, the activatable evacuation connection 15 is provided with a pump in combination with a valve. The pump and valve are configured to provide evacuation of fluid product upon receipt of a control signal provided by the control unit 5. The valve in the shown configuration is configured to provide safe evacuation of fluid product from the receiving chamber 8. Alternatively, the activatable evacuation connection 15 can be controlled by an external system.

[0095] It can be desirable to be able to, for example, clean the device or to discard the fluid in the receiving chamber 8. To achieve these and other purposes, the receiving chamber can also comprise a closable purge connection 22. As Figure 2 shown, such a closable purge connection 22 can be implemented as a pipe with a closable valve. By opening the valve, the fluid present in the receiving chamber can flow out of the receiving chamber 8 through a connection different from the evacuation connection 15. Cleaning can be done by introducing a cleaning fluid into the reaction chamber 2, which will eventually flow to the receiving chamber 8 and out through the purge connection 22.

[0096] In certain cases, it is desirable to control the concentration of a chemical in an aqueous solution. In accordance with this, the device 1 can also comprise a water reservoir 12, which is fluidly connected to the reaction chamber 2 by a pipe, which preferably comprises a shut-off valve 11 and / or a pump (not shown). As Figure 2 shown, the valve 11 and / or pump are controlled (opened and closed) by the control unit 5. It is noted that in the shown embodiment, the water is pressurized (for example by a tap water connection for the water reservoir 12), so that the flow can be controlled by the valve 11. If the water is to be pumped into the reaction chamber 2, a pump can be added for this purpose.

[0097] In Figure 1In the illustrated embodiment, the first and second quantity sensors 6, 7 comprise a float table. The float table comprises floats which, due to the buoyancy, float on the surface of the liquid in the reaction chamber 2 and in the receiving chamber 8. Each float is arranged on a rod which extends towards or even to the bottom of each of the reaction chamber 2 and the receiving chamber 8 as illustrated. The floats thus change with the gradually rising / falling fluid level in the chambers 2, 8. In one implementation, the float provides an electrical connection between two electrically conductive elements which extend along the rod, and thus the electrical resistance is a function of the position of the float relative to the longitudinal extension of the rod. The float table is thus configured to provide an electrical signal representative of the liquid (fluid) level by measuring the electrical resistance.

[0098] The first and second quantity sensors 6, 7 can alternatively or in combination with the above disclosure be implemented as a weighing device configured to weigh the reaction chamber 2 or the receiving chamber 8 and provide an electrical signal representative of the weight, an optical sensor or an ultrasonic sensor configured to determine the liquid level position in the reaction chamber 2 or the receiving chamber 8 and provide a signal representative of the liquid level position, or a pressure sensor configured to determine the liquid column pressure in the reaction chamber 2 or the receiving chamber 8 and provide a signal representative of the liquid column pressure.

[0099] Although the above description focuses on the hardware, the present invention also relates to a method for producing a compound such as CIO2 using the device according to the invention. The method aims to provide a production with a reduced age of the produced fluid product, but as will be described in detail below, the method aspect of the invention also has some other production benefits, e.g. in relation to diagnosing the production, e.g. fault diagnosis.

[0100] As Figure 3 illustrated, the method can comprise the steps of introducing water, chemical and water in sequence. Since the quantity sensors determine the quantities introduced in a continuous or at least quasi-continuous manner, the fluid flow into the reaction chamber can be determined. In some embodiments, the method makes use of a predetermined limit on the flow of the water intake, e.g. as Figure 3 illustrated, and a water inlet malfunction can be detected if the flow falls outside the predetermined limit. Figure 3 Other measures which can be implemented according to the invention are also illustrated and will be disclosed below.

[0101] Before detailing such measures, the method can be summarized as comprising the following steps:

[0102] a) introducing a selected fluid component into the reaction chamber 2 through one of the fluid connections 3, e.g. by using a pump, a valve or a combination thereof,

[0103] b) determining the total amount of fluid components in the reaction chamber 2 based on the readings from the first amount sensor 6, and continuing steps a) and b) until the total amount of fluid components introduced has reached the prescribed total amount of fluid components, and

[0104] c) repeating steps a) and b) until all the selected fluid components needed have been introduced into the reaction chamber 2.

[0105] By these steps, the desired fluid components are introduced into the reaction chamber in the desired amounts, and the reaction and fluid components can be provided in the reaction chamber 2.

[0106] In order to supervise the introduction of fluid components, and thereby at least indirectly the production of fluid products, the method can utilize the following further steps performed during the introduction of the selected fluid components:

[0107] - determining the inflow rate of the selected fluid components by using the control unit 5 based on the readings from the first amount sensor 6,

[0108] - comparing the inflow rate to a prescribed limit, and if the inflow rate is outside the prescribed limit:

[0109] - reducing the production capacity,

[0110] - adjusting the inflow rate to be within the prescribed limit,

[0111] - or reporting an error state.

[0112] In some embodiments, the lower inflow rate does not change, e.g. a chemical reaction, in which case the production capacity of the apparatus can be set to be lower. In other embodiments, it is important for the quality of the fluid products that, e.g. the correct amounts of chemical composition components are available during the production, in which case the prescribed limit is a chemical reaction application limit, setting e.g. a limit for the minimum flow of chemicals into the reaction chamber.

[0113] It is sometimes preferred that the fluid components are introduced into the reaction chamber 2 at a time, in which case steps a) and b) are repeated one fluid component at a time, where these steps are repeated for one fluid component until the total amount of said fluid component has been introduced into the reaction chamber 2. It should be noted that in this respect, one fluid component can be considered to be a mixture of two or more fluid components. The latter can be used in cases where two or more fluid components can be introduced simultaneously without seriously compromising the end product. In such cases, the two or more fluid components can be stored in separate storage containers and introduced into the reaction chamber simultaneously.

[0114] In Figure 3In the illustrated embodiment, the fluid product is CIO2, the fluid components include sodium chlorite (NaClO2) and hydrochloric acid (HC1), but Figure 3 The contents of the foregoing can be generalized to other fluid products.

[0115] With specific reference to Figure 3 A method of starting production of a compound such as CIO2 will be disclosed. It should be noted that Figure 3 includes an upper part showing the contents of the reaction chamber 2 as a function of time and a lower part showing the contents of the receiving chamber 8 as a function of time. Also as shown, the contents of the reaction chamber are zero until the customer intake minimum is reached, at which time production of the fluid product is started. In Figure 3 , the thin solid line represents the quantity, while the thick solid line represents an upper or lower limit within which the quantity as a function of time is expected to be. The dashed line is an auxiliary line. The specific example utilizes a siphon (as disclosed in connection with Figure 6 ), so the transfer from the reaction chamber 2 to the receiving chamber 8 is labeled "siphon transfer". Also as Figure 3 shown, once the siphon effect starts, no more water (or fluid) is added to the reaction chamber since the siphon is a self-propelled process. Also, it is noted that these quantities are given in percentages of the total quantity that will be present in the chamber; however, other units such as ml, kg, etc. can also be used.

[0116] The method of starting production of a compound typically involves the following steps:

[0117] - determining a minimum threshold quantity A of fluid product that will be present in the receiving chamber 8 t ,

[0118] - determining the quantity of fluid product present in the receiving chamber 8 based on readings from the second quantity sensor 7,

[0119] - if the quantity of fluid product present in the receiving chamber 8 is lower than the determined minimum threshold quantity A t , starting production of the fluid product by using the method disclosed above.

[0120] This is illustrated in Figure 3 , where the minimum threshold quantity A t is shown in the lower graph of Figure 3 and labeled "customer minimum reached".

[0121] The minimum threshold quantity can be determined in a number of ways, and in some embodiments the minimum threshold quantity A tis determined based on a historical time series of data comprising the amount drained as a function of time or is determined by the user. In the first case (historical time series), it is estimated when the receiving chamber is dry (at 0% in the lower graph of Fig. 1) and in the latter case (determined by the user), the minimum threshold amount A Figure 3 is determined by the user. t It can be set according to the user's needs for the minimum available amount.

[0122] The historical time series of data can be the most recent time series, e.g. data about the amount drained as a function of time in the most recent draining period, wherein the draining period is considered to be the period counted from when the receiving chamber was last filled to 100% to when the receiving chamber reaches the transfer threshold A a . If it is acceptable for the receiving chamber to dry out (0%), then the period considered can be extended from the transfer threshold A a to the time of 0%. If a higher statistical accuracy is targeted, then more time periods than the most recent one can be used and averaged.

[0123] In a practical implementation, this can be implemented as:

[0124] Amount in receiving chamber = -a* time + b

[0125] where a is the estimated slope and

[0126] b is the total amount in the receiving chamber

[0127] The historical data is used to estimate a. Although this represents a linear approximation, a higher order approximation can be used.

[0128] Another parameter used in determining the minimum threshold amount A t is the time required to produce the compound (production time t P ). This time is usually known due to chemical and system constraints, although deviations can occur.

[0129] Hence, once a is determined, the minimum threshold amount can be determined by solving the following equation:

[0130] A t = -a*(t total - t P ) + b

[0131] where t total is the time span of the draining period as described above.

[0132] If the time required to produce the compound t PIf not available, a preselected production time can be used. Such a preselected production time can be selected by the user during the setup of the routine as a time period long enough to ensure that the actual production time is less than the preselected production time.

[0133] Thus, with reference to Figure 3 , in the illustrated embodiment, the minimum threshold amount A t is determined by estimating the time t A0 at which the amount of fluid product in the receiving chamber 8 reaches zero (0%). While this represents a prediction and can be difficult to predict the actual time point, it has been shown in connection with the present invention that the estimation of the zero amount time point can effectively be made by an approximation based on a historical time series of data comprising the amount of discharge as a function of time. In such an embodiment, the approximation follows similar procedures as described above in connection with the linear approximation. However, once available as the most recent historical data, this most recent historical data is data obtained since the most recent filling of the receiving chamber 8.

[0134] As described above, the method generally requires the step of estimating the amount of time (i.e. the production time t P ) required to provide a specific amount of fluid product in the reaction chamber 8. And based thereon, by approximating a historical time series of said data, the minimum threshold amount A t is determined as the amount of time t P prior to which the time t A0 required to provide a specific amount equals the zero amount (t a ), as illustrated in Figure 3 .

[0135] In case it is not desired that the receiving chamber 8 dries out, the production and / or the transfer from the reaction chamber 2 to the receiving chamber 8 is adjusted in terms of time based on the determined transfer threshold amount Aa. In such an embodiment, the transfer threshold amount A a is determined, and the activatable transfer device 4 is activated if (and when) the amount of fluid product present in the receiving chamber 8 is below the transfer threshold amount A a .

[0136] In order to avoid that the receiving chamber 8 dries out, it can be necessary to take into account the transfer flow between the reaction chamber 2 and the receiving chamber 8, in particular in case a siphon is used, as such a siphon requires more water / fluid to be added to the reaction chamber 2 in order to start the transfer. However, when considering the transfer threshold, it is assumed that the production has already been completed. As illustrated in Figure 3 , the transfer threshold amount A a is determined as the amount at which the amount of fluid product in the receiving chamber is prevented from becoming zero by the transfer flow provided by the activatable fluid transfer device.

[0137] When using the apparatus and method, typically many batches are produced, wherein each such batch is a certain amount of fluid product produced.

[0138] According to the present invention, the following can be advantageously achieved. The inflow rate of each selected fluid component is recorded, the recorded inflow rates between production batches are compared, and if the compared inflow rates are not within a prescribed limit, a report thereof is provided to the user. Such a limit is indicated in Figure 3 by a thick solid line. This procedure can be used to ensure correct operation of the method and apparatus.

[0139] For example, if the amount of water to the reaction chamber is below a limit, this is typically a sign of a water inlet malfunction (see the notes in Figure 3 regarding "water 1"). As shown in Figure 3 , a warning is generated, identifying the observed malfunction, and if possible, a procedure to solve the malfunction, e.g. "please control inlet pressure". Furthermore, if the dose of a chemical is below a limit, a warning is generated to the user, and a possible cause can be communicated, e.g. "dose of air bubbles", "leak in pipe". Thereby, production and consumption can be monitored, and measures can be taken if production and consumption are not running as expected.

[0140] A further detection can be a leak detection and / or an external manipulation detection. This can for example be identified during a waiting time (e.g. reaction time or between water 2 and water 3, see Figure 3 ), during which the expected inflow rate (prescribed limit) is 0 l / h, so the content in the reaction chamber should be constant. If not, it can be a solenoid valve leak, or the system is externally manipulated. This typically involves the system reporting an error to the user.

[0141] A further advantageous feature of the present invention is that an automatic restart of the procedure (e.g. production, transfer, drain) after an error situation can be performed. After a power off or an internal malfunction, the current state (exact level, processing step, time stamp) is known. By comparison with the state before the error, the procedure can be continued automatically, without user intervention.

[0142] Optimization of the chemical procedure can be performed, since by using a continuous level sensor, the dose of different chemicals can be highly controlled, providing flexibility in the varying concentration of the fluid product between different batches. As an example in this regard, one can mention:

[0143] 1. To reduce by-products, the concentration can be reduced by reducing the amount of fluid components within a prescribed limit.

[0144] 2. For temporary needs of a situation of a high concentration fluid product, the concentration can be increased by increasing the amount of fluid components within a safety limit.

[0145] It is noted that although Figure 3 Many warnings, reasons, etc. are given, all of which need not be implemented. Thus, the present application can be designed to include one or more of those presented and Figure 4 others not presented in the detailed description.

[0146] Figure 3 A flow chart of a preferred embodiment of the method according to the present application is disclosed, which details the supervision of the production of the fluid product. As shown, the method determines the inflow rate into the reaction chamber 2 based on readings from the first quantity sensor. Based on this, it is assessed whether the inflow rate is within prescribed limits (as detailed with respect to Figure 5 the detailed description), and if not, it is decided whether the inflow rate is adjustable, typically to the extent of correcting the error. This process is carried out until the total amount of the selected fluid component has been reached. Thereafter, the process is performed for another fluid component.

[0147] Figure 7 A flow chart of a preferred embodiment of the initiation of the production of the fluid product is disclosed. As disclosed, the method is based on a minimum threshold amount and the amount of the fluid product present in the receiving chamber 8. When the amount present in the receiving chamber 8 drops below the minimum threshold amount, the production of the fluid product is initiated.

[0148] Figure 7 A timing diagram is disclosed, showing the preferred mode of operation in relation to the production of a ClO2 batch. Figure 7 The left hand side refers to the reaction chamber 2, the right hand side refers to the receiving chamber 8. Figure 7 The middle part refers to the control unit, which controls the apparatus. The arrows pointing to the control unit line indicate actions triggered by conditions in the receiving chamber 8. The time axis is vertically downwards in the figure. In Figure 7 T p refers to the waiting time before initiation of production, T s refers to the waiting time before transfer, during which no production is carried out.

[0149] As ​ shown, after transfer from the reaction chamber 2 to the receiving chamber 8, production is set to a waiting mode, which is terminated by having reached a threshold amount in the receiving chamber 8, and production of ClO2 is carried out. Transfer is initiated when the transfer threshold has been reached. As shown, a short waiting time for the fluid product in the reaction chamber 2 is accepted to allow the fluid product to be ready for transfer on demand. After transfer, production is put in a waiting mode until the minimum threshold amount in the receiving chamber 8 is reached, after which the method is repeated.

[0150] Although the application has been described in connection with the specified embodiments, it should not be construed as in any way limited to the presented examples. The scope of the application is set forth in the appended claims. In the context of the claims the term "comprising" does not exclude other possible elements or steps. Furthermore, it should be noted that the mention of prior art throughout the specification is not an admission that the prior art is specifically known or part of the common general knowledge of those working in the field of the application. Moreover, reference to something having been "discovered" is not an admission that the thing was previously unknown. In the context of the claims the term "comprising" does not exclude other possible elements or steps. Also, the mention of references in the description does not constitute an admission that the references are prior art to the application. Furthermore, the reference to a document in the description is not an admission that the document is prior art to the application. Moreover, the references to a document in the description are not an admission that the document is part of the common general knowledge of the skilled person in the field of the application. Also, the use of reference signs in the claims with or without prime notations is not to be construed as limiting the scope of the claims. Furthermore, individual features mentioned in different claims, can possibly be combined to provide different claims and the combination of features in the claims is not meant as an limitation unless otherwise indicated.

[0151] List of reference signs:

[0152] 1 device for producing a fluid reaction product

[0153] 2 reaction chamber

[0154] 3 fluid connection

[0155] 4 activatable fluid transfer device

[0156] 5 control unit

[0157] 6 first quantity sensor

[0158] 7 second quantity sensor

[0159] 8 receiving chamber

[0160] 9 first chemical storage container

[0161] 10 second chemical storage container

[0162] 11 water inlet control valve

[0163] 12 water reservoir

[0164] 13 pump

[0165] 14 pump

[0166] 15 activatable discharge connection (valve)

[0167] 16 gas reservoir

[0168] 17 absorption unit

[0169] 18 siphon

[0170] 19 downpipe

[0171] 20 riser pipe

[0172] 21 upper inlet opening

[0173] 22 clear connection

[0174] 23 valve

[0175] 24 valve

[0176] 25 level

[0177] A t minimum threshold amount

[0178] A a transfer threshold amount

[0179] t a0 time before zero amount

[0180] t a0 time before zero amount

[0181] T P waiting time before production

[0182] T S waiting time before transfer

Claims

1. A method for controlled production of a fluid reaction product, the method employing apparatus comprising: a reaction chamber (2); one or more fluid connections (3) extending from outside of the reaction chamber (2) and opening into the reaction chamber (2) for introducing fluid components into the reaction chamber (2); a receiving chamber (8); an activatable fluid transfer device (4) providing fluid connection between the reaction chamber (2) and the receiving chamber (8) such that the receiving chamber (8) receives fluid product produced in the reaction chamber (2) when the activatable fluid transfer device (4) is activated; an activatable discharge connection (15) for discharging fluid product from the receiving chamber (8); a control unit (5) configured to control fluid flow into the reaction chamber (2) through the one or more fluid connections (3); a first quantity sensor (6) arranged to determine, at least continuously or at least quasi-continuously, the quantity of fluid components in the reaction chamber (2) during introduction of the fluid components, the first quantity sensor (6) being operatively coupled to the control unit (5) to communicate the determined quantity in the reaction chamber (2) to the control unit (5) by sensor readings; a second quantity sensor (7) arranged to determine, continuously or at least quasi-continuously, the quantity of fluid product in the receiving chamber (8), the second quantity sensor (7) being operatively coupled to the control unit (5) to communicate the determined quantity of fluid product in the receiving chamber (8) to the control unit (5) by sensor readings, the method comprising: determining a minimum threshold amount A of fluid product to be present in the receiving chamber (8) t , determining the quantity of fluid product present in the receiving chamber (8) based on readings from the second quantity sensor (7), If the amount of fluid product present in the receiving chamber (8) is lower than a determined minimum threshold amount A t then the production of fluid product is started by: a) introducing a selected fluid component into the reaction chamber (2) through one of the fluid connections (3) by using a pump, a valve or a combination thereof, b) determining the total quantity of fluid components in the reaction chamber (2) based on readings from the first quantity sensor (6) and continuing steps a) and b) until the total quantity of introduced fluid components has reached a prescribed total quantity of fluid components, and c) repeating steps a) and b) until all required selected fluid components have been introduced into the reaction chamber (2), wherein the minimum threshold amount A t determined based on a historical time series of data, the data comprising the amount of discharge as a function of time, and wherein the minimum threshold amount A t is determined by: Estimating the time t of zero quantity A0 At this zero-quantity time, the amount of fluid product in the receiving chamber (8) reaches zero, and this estimation is made by approximating it using a historical time series of data including discharge volume as a function of time. estimating the amount of time required to provide a specific quantity of fluid product in the receiving chamber (8), and By approximating the time series of the data, a minimum threshold amount A t determined to provide a certain amount of time equal to zero amount t A0 the amount of time before.

2. The method of claim 1, further comprising: determining a transfer threshold amount A a and activating the activatable fluid transfer device (4) if the amount of fluid product present in the receiving chamber (8) is below the transfer threshold amount A a .

3. The method of claim 2, wherein, the transfer threshold amount A a An amount determined to prevent the amount of fluid product in the receiving chamber from becoming zero by the transfer flow rate provided by the activatable fluid transfer device.

4. The method of claim 1, further comprising: producing a plurality of batches of fluid product, wherein each batch is a certain quantity of fluid product produced, and for each batch produced: recording the inflow rate of each selected fluid component, comparing the recorded inflow rates between batches, and providing a report to a user if the compared inflow rates are not within prescribed limits.

5. The method according to any one of claims 1-4, further comprising during introduction of a selected fluid component: determining the inflow rate of the selected fluid component based on readings from the first quantity sensor (6) by using the control unit (5), comparing the inflow rate to prescribed limits, and if the inflow rate is outside the prescribed limits: reducing the production capacity, adjusting the inflow rate to be within the prescribed limits, or reporting an error state.

6. The method according to claim 5, wherein, the prescribed limits are chemical reaction application limits.

7. The method of any one of claims 1-4, wherein, Steps a) and b) are repeated one fluid component at a time, wherein these steps are repeated for one fluid component until the total amount of said fluid component has been introduced into the reaction chamber (2).

8. The method of any one of claims 1-4, wherein, The fluid product is CIO2, and the fluid components include sodium chlorite NaClO2 and hydrochloric acid HCl.

9. The method of any one of claims 1-4, wherein, The activatable fluid transfer device (4) comprises a pump, a valve or a combination thereof, wherein the pump, valve or combination thereof is configured to be controlled by the control unit (5) such that upon receiving a control signal provided by the control unit (5), the pump, valve or combination thereof is activated to transfer fluid.

10. The method of any one of claims 1-4, wherein, The activatable fluid transfer device (4) comprises a siphon (18) comprising a downcomer (19) and a riser (20) arranged outside the downcomer (19), the riser (20) having an inner diameter or hydraulic diameter larger than an outer diameter or hydraulic diameter of the downcomer (19) to provide a gap between the downcomer (19) and the riser (20), the downcomer (19) extending vertically within the reaction chamber (2) from a bottom of the reaction chamber and having an upper inlet opening (21) arranged at a distance from the bottom, the riser (20) being closed at an upper end, the siphon (18) further comprising an opening at a lower end of the riser (20) to provide fluid passage into the gap and comprising an opening at an upper end of the downcomer (19) between the gap and the inlet opening of the riser (20).

11. The method of any of claims 1-4, wherein the device further comprises: A plurality of chemical storage containers (9, 10) each fluidly connected to the reaction chamber (2) by the one or more fluid connections (3) comprising a pump (13, 14), a valve or a combination thereof, wherein the pump (13, 14), valve or combination thereof is configured to be controlled by the control unit (5) such that upon receiving a control signal provided by the control unit (5), the pump (13, 14), valve or combination thereof is activated to selectively transfer a chemical from one or more of the chemical storage containers (9, 10).

12. The method of any of claims 1-4, wherein the device further comprises: A gas reservoir (16) fluidly connected to the interior of the reaction chamber (2).

13. The method according to claim 12, wherein the gas reservoir (16) is a variable volume gas reservoir.

14. The method of any one of claims 1-4, wherein, The activatable discharge connection (15) comprises a pump in combination with a valve, the pump and valve being configured to provide discharge of the fluid product upon receiving a control signal provided by the control unit (5).

15. The method of any one of claims 1-4, wherein, The receiving chamber (8) further comprises a closable purge connection (22).

16. The method of any of claims 1-4, wherein the device further comprises: A water reservoir (12) fluidly connected to the reaction chamber (2) by a pipe.

17. The method according to claim 16, wherein the pipe comprises a stop valve (11) and / or a pump.

18. The method of any one of claims 1-4, wherein, The first and / or second quantity sensor (6, 7) comprises a float table configured to provide an electrical signal representative of the liquid level, a weighing device configured to weigh the reaction chamber (2) or the receiving chamber (8) and provide an electrical signal representative of the weight, an optical or ultrasonic sensor configured to determine the liquid surface position in the reaction chamber (2) or the receiving chamber (8) and provide a signal representative of the liquid surface position, or a pressure sensor configured to determine the liquid column pressure in the reaction chamber (2) or the receiving chamber (8) and provide a signal representative of the liquid column pressure.

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