BE1026892B1 - SYSTEM FOR PROCESSING LAGERED BEER TO PASTEURIZED CLEAR BEER - Google Patents

Abstract

A system (100, 200, 300) for processing aged beer into pasteurized clear beer, comprising: - two or more flow elements (114) connected in parallel, comprising a lager tank (101), a line (115) with shut-off unit (103) , and a measuring unit (102) to measure the static pressure (112); - a filter unit (105); - a pasteurization unit (106); - a clear beer tank (107), characterized in that: - the pasteurization unit (106) is placed downstream and in line with said filter unit (105), and - the system (100, 200, 300) further comprises: - a controllable pump (104); - a control unit (108) comprising a calculation module (110) adapted to calculate for each of the flow elements (114) a set value (113) for the pump (104), based on the static pressure (112) of each measuring unit (102) ).

Description

-1- SYSTEM FOR PROCESSING LAGERED BEER INTO SceolsssTs

PASTURIZED BRIGHT BEER Technical Area

The present invention generally relates to the processing of aged beer into pasteurized clear beer. In particular, the invention provides a solution for converting aged beer to pasteurized clear beer that allows to produce a high-quality beer in a cost-efficient and reliable manner. Background of the Invention

[02] When brewing beer, the beer is pumped after fermentation to lager tanks, where a second fermentation takes place in closed tanks. After lagering, the beer still contains substances, including cloudy and yeast, that affect the clarity and shelf life of the beer. To remove these substances and thus clear (clarify) the beer, the beer is filtered. Kiezelguhr (diatomaceous earth) is often used as a filtration medium, which essentially consists of skeletons of unicellular diatom algae. This porous material is used in horizontal or vertical filter elements, or in a candle filter. After filtration, we speak of clear beer. The beer is then pasteurized to prevent bacterial spoilage. Pasteurization involves rapid, short heating, killing any bacteria or yeast present and denaturing yeast enzymes. When this takes place before bottling, this is done using a so-called flash pasteurizer. Finally, the beer is bottled using a bottle filling machine.

[03] In the process of processing beer after lagering into pasteurized clear beer, brewers are faced with a number of problems arising from the stable process conditions that require both filtering and pasteurisation.

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[04] For example, does filtering require a stable supply pressure for the filter? 2919/5078 to avoid disturbing the Kiezelguhr filter layer. The beer to be filtered is supplied from different lager beer tanks, which in turn supply beer (of the same or different type) to the filtration. These tanks each have a different supply pressure, on the one hand due to a different pressure of the propellant (necessary to keep carbon dioxide in the beer), on the other hand because of the different height at which the beer is supplied. However, filtration is not stopped during the switch from one tank to another. As a result, when switching between lager beer tanks, a pressure surge occurs in the filter, which poses a great risk of disturbing the Kiezelguhr filter layer. Once this layer is disrupted, yeast, cloudy and Kiezelguhr will break down, which will adversely affect the quality of the beer and may even lead to production stopping. During this standstill, the filter should be cleaned, rinsed, sterilized, cooled, etc. Such a malfunction entails a lot of costs (beer loss, man hours, energy, water, ...) and is detrimental for breweries that only have a small amount of beer in stock.

[05] In addition, pasteurization also needs stable process conditions. For example, a flash pasteur should always have sufficient pre-pressure to prevent the beer from degassing and foaming occurring in the beer circuit. Flash pasteurization is also a continuous process that requires a continuously stable flow rate. If the decrease comes to a halt due to a problem downstream of the pasteurizer, there is a risk of over-pasteurization, which adversely affects quality and may even lead to beer being destroyed.

[06] Consequently, there is a general need for a solution to process aged beer into pasteurized clear beer, ensuring beer quality and reliability during filtering and pasteurisation.

[07] The use of buffer tanks is known, which makes it possible to store beer in the interim and thus separate process steps from each other. For example,

-3- in a classic solution the clear beer after filtration collected in a 1998 clear beer tank. The flash pasteurization receives beer from this clear beer tank, after which it is bottled in a filling line. In this way a stable pre-pressure on the pasteurizer can easily be maintained. However, a filling line is regularly subject to malfunctions. In the event of such a failure, beer cannot be taken from the pasteurizer, resulting in over-pasteurization and large beer loss. Here, too, a buffer tank (between pasteurizer and filling line) can be used to decouple both process steps. However, an extra buffer tank is not a cost-effective solution given the costs associated with maintaining and keeping such a tank operational (e.g. consumption of CO2 to keep the buffered beer under pressure).

[08] Another known solution is to create stable process conditions by controlling the pressure. It is known, for example, to use a back pressure valve. Such a valve can be placed upwardly from the filter unit to smooth out the pressure fluctuation resulting from switching between lager beer tanks. However, such a valve reacts too slowly to realize a perfectly flat pressure, so that the filter still experiences a fluctuation in pressure with the risk of disturbing the Kiezelguhr layer. In addition, such a back pressure valve introduces additional flow losses, requiring a heavier pump with higher energy consumption to pump the beer.

[09] Also known is the use of a controllable pump, which allows to control the downward pressure via control of the pump. Such a beer pressure regulator is described, for example, in DE538191. The system described in DE538191 consists of a piston pump which is controlled on the basis of a measured beer pressure downstream of the pump. This is a pure feedback control, which only comes into effect when a pressure change downstream of the pump is actually detected. When switching between lager beer tanks, such control will therefore react too late and cannot realize a completely flat pressure level upstream of the filter.

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[10] It is an object of the present invention to describe a system and 9190918 method for converting aged beer to pasteurized clear beer that overcomes the above-described drawbacks of prior art solutions. More specifically, it is an object of the present invention to describe a system and method for converting aged beer to pasteurized clear beer that allows to produce a high quality beer in a cost efficient and reliable manner.

Summary of the Invention

[11] According to the present invention, the objects identified above are achieved by a system of processing aged beer into pasteurized clear beer, as defined by claim 1, the system comprising: - two or more parallel flow elements, each of the flow elements includes: o a lager beer tank; o a pipe with shut-off unit which allows to activate the respective flow element by opening the shut-off unit: o a measuring unit adapted to measure the static pressure at a point in said flow element; - a filter unit; - a pasteurization unit; - a clear beer tank, characterized in that: - the pasteurization unit is placed downstream and in line with the filter unit, and - the system further comprises: o a pump placed between the parallel-connected flow elements and said filter unit, the pump being controllable is; o a control unit adapted to control the pump, the control unit comprising:

-5- "an input module adapted to receive the measured static pressure 0190918 from each unit of measurement;» a calculation module adapted to calculate a setting value for the pump for each of the flow elements, based on the measured static pressure; and = »a control module adapted to control the pump, upon activation of one of said flow elements, to the set value calculated for the activated flow element.

In other words, the invention relates to a system for processing aged beer into pasteurized clear beer comprising flow elements connected in parallel. A flow element includes a lager beer tank and a conduit. Each pipe can be closed using a shut-off unit, for example an on / off-controlled shut-off valve. The flow elements connected in parallel each supply beer in turn to a filter unit. In this case, one flow element is activated (i.e. the closing unit is opened), while the other flow elements have a closed closing unit. Filtration is not stopped during switching from one tank to another. The tanks contain beer with beers, where each tank can contain the same type of beer or different tanks can contain different types of beer. For example, the filter unit uses Kiezelguhr or diatomaceous earth as a filtration agent, in horizontal or vertical filter elements, or in a candle filter. After filtration, the filtered beer is passed through a pasteurization unit in which it is heated for a short time, and then stored in a clear beer tank. After the clear beer tank, the pasteurized clear beer is led to a filling installation or bottling line where it is transferred, for example, in bottles or barrels. In particular, within this invention, the pasteurization unit is placed in line with the filter unit, which means that pasteurization follows immediately after filtering and takes place before the clear beer tank. This has the advantage that the pasteurization is not hindered by the filling installation. Since a filling installation is regularly subject to malfunctions, this prevents over-pasteurisation at a time when the filling installation

-6- freezes and no beer can take off from the pasteurizer. Also, with the occurrence of 9190918, such a failure will only lose a limited amount of beer. This contributes to the reliability of the solution and to obtaining a high-quality beer. Also, the invention does not include an additional buffer tank, except for the clear beer tank. This contributes to a cost-efficient solution.

[13] Furthermore, the system according to the invention comprises a pump which pumps the beer coming from the active lager beer tank to the filter unit. This pump is adjustable. For example, it is a frequency-controlled centrifugal pump, in which the speed of the pump is adjustable by a frequency control on the driving electric motor. Controlling this pump, for example by adjusting the speed of the pump, allows to adjust the pressure downstream of the pump, i.e. upward of the filter unit. Such a pump therefore makes it possible to control the supply pressure for the filter unit in an accurate and efficient manner.

[14] The system also includes a control unit intended to control the adjustable pump. The control unit includes an input module that receives static pressures. The static pressure is measured using a unit of measure, for example an analog pressure gauge, on the pipe from the lager tank. Each flow element has such a pressure measurement. The measured static pressures may be different for each flow element, due to different propellant pressures in the tanks, different heights at which the tanks are arranged, or differences in the fill level of the tanks.

[15] The control unit further comprises a calculation module. Here a calculation is made of a set value of the pump, for example the speed of this pump. The calculation is done for each of the flow elements, and takes into account the measured static pressure for each of the flow elements. Since these pressures are different, the pump must deliver a different delivery head (and therefore rotate at a different speed, for example) in order to obtain the same pressure level downstream. The control unit further comprises a control module, which controls the pump at a set value (for example a calculated speed). Depending on which flow element

-7- is active, the pump is controlled at the setpoint calculated in accordance with ait 9190918 flow element within the calculator. When switching between tanks, the pump is immediately set to the other setting value. This makes it possible to determine predictively how the pump is to be adjusted in order to obtain a desired value of the downward pressure as soon as another flow element becomes active. This desired value of the downward pressure is, for example, a constant value which is optimal as the supply pressure for the filter. In this way, optimum control is obtained over the supply pressure for the filter unit. This makes it possible to keep this supply pressure perfectly stable: when switching to a different tank, the pump is immediately adjusted, ie. even before the pressure change is felt after the pump. In this way, the filter unit does not experience any pressure shock or pressure fluctuation, so that the Kiezelguhr layer is not disturbed when switching between lager beer tanks. This contributes to the reliability of the solution and the guarantee of high beer quality. In addition, by realizing a constant pressure level after the pump, it is also avoided that a pressure surge or fluctuation leads to fluctuating pasteurisation units, or that a pressure wave from pasteuriser towards filter is also created as a result of a reaction of the control of the pasteurizer ( which would burden the Kiezelguhr layer even more).

[16] Optionally, as defined by claim 2, the calculator is further configured to determine the pump setpoint for a flow element by: - Calculating a dynamic pressure at the input of the pump, based on the received static pressure and flow losses in the conduit of the flow element.

- Calculating a set value for the pump, based on this dynamic pressure, such that a fixed set value for the pressure is obtained at the output of the pump.

[17] In this way, the pump is controlled to a fixed set value for the pressure at the outlet of the pump, and thus a fixed supply pressure for the filter unit. By in addition to the differences in static pressures between

-8- flow elements also taking into account the occurring 99918 flow losses, the set value for the pump can be determined more precisely. After all, as a result of flow losses, a pressure drop will occur in the pipes, so that at the inlet of the pump a dynamic pressure applies that is lower than the static pressure. Flow losses depend on piping characteristics and flow velocity. The flow losses are calculated, for example, per flow element, taking into account the corresponding pipe characteristics. The dynamic pressure therefore provides a better estimate of the pressure at the inlet of the pump. Consequently, this allows a more precise calculation of the pump setpoint to obtain a fixed pressure setpoint downstream of the pump when switching between lager beer tanks. This contributes to the realization of a perfectly flat supply pressure for the filter unit, and thus to a higher operational reliability and to guarantee quality beer.

[18] Optionally, as defined by claim 3, the arithmetic module is further configured to calculate the flow losses for a flow element based on one or more pipe sizes and based on a flow rate or flow in this pipe. Relevant pipe dimensions are, for example, a pipe diameter and length. For the flow rate or flow rate, for example, a fixed (set point) value can be used in the calculation of the flow losses, or a measured value in the pipe. Taking these parameters into account contributes to a more accurate calculation of the flow losses, and thus a more precise control of the pump.

[19] Optionally, as defined by claim 4, the set value of the pump is the speed of the pump. For example, the pump is a frequency-controlled centrifugal pump and the speed is controlled via a frequency control on the driving electric motor. Its operating point changes by adjusting the pump speed. In particular, at constant flow, the delivery head will increase as the speed increases. Such a speed control allows to adjust the speed

-9- Delivered pressure by fine-tuning the pump to perfectly control the 7919/5916 filter supply pressure.

[20] Optionally, as defined by claim 5, the calculation module is further adapted to determine the setpoint for the pump based on the pump characteristic of the pump. For example, the pump characteristic of a centrifugal pump is given as a relationship between the delivery pressure and the flow rate. Such a relationship applies at a specific speed of the pump; at a different speed, a different relationship applies. The pump characteristic allows to determine how much the speed should be adjusted to achieve a desired rise or fall in the delivery head. For each flow element it can therefore be determined what the speed must be in order to obtain a fixed set value for the pressure at the output of the pump, at a known (dynamic) pressure at the pump inlet. This makes it possible to calculate such a speed (set value) predictively for each branch, and to immediately adjust the speed to the set value applicable to the relevant flow element when another flow element is activated. This contributes to the realization of a constant filter supply pressure and thus to the reliability of the solution and the delivery of high-quality beer.

[21] Optionally, as defined by claim 6, the system according to the invention further comprises: - an adjustable pasteurization pump placed between the filter unit and the pasteurization unit; a measuring unit adapted to measure a pasteurizer pre-pressure in the flow between the filter unit and the pasteurization pump; a second control unit, said second control unit comprising: an input module adapted to receive the measured pasteur pre-pressure; o a calculation module adapted to determine a setting value for the pasteurisation pump on the basis of this measured pasteurising pressure, and

-10- o a control module adapted to control the pasteurisation pump at 0018 the calculated set value.

In other words, in addition to the pump upstream of the filter unit, the system as defined by claim 6 also includes a pasteurization pump placed between the filter unit and the pasteurization unit. This pump is adjustable. The filter will gradually become fouled during filtration, causing an increasing pressure drop in the flow. Since the filter unit and pasteurization unit are placed in line within the system according to the invention, the flow at the entrance of the pasteurizer is affected by the varying flow conditions due to the upward filter unit. The provision of a pasteurisation pump between the filter unit and the pasteurisation unit makes it possible, by controlling the pump, to better control the flow conditions at the entrance of the pasteurizer. Consequently, this contributes to achieving the desired stable flow conditions for pasteurization, which contributes to high quality of the beer produced and the reliability of the solution.

The system as defined by claim 6 further comprises a second control unit intended to control the pasteurization pump. This second control unit comprises an input module which receives a pasteurizing pre-pressure measured by a measuring unit between the filter unit and the pasteurisation pump. The second control unit also comprises a calculation module adapted to determine a setting value for the pasteurisation pump on the basis of the measured pasteurizing pre-pressure. The set value is, for example, the speed of the pasteurisation pump. The second control unit further comprises a control module which controls the pasteurization pump to the calculated set value. This makes it possible to control the pre-pressure of the pasteurization unit. For example, if the pasteurizer pressure threatens to become too low as a result of contamination in the filter unit, there is a risk of degassing the beer. The second control unit can detect that the pasteurizing pressure falls below a predefined value, and then adjust the setting value of the pasteurizing pump (e.g. the speed

-11- float) to increase the delivery head. In this way, in-line filtering and pasteurization in line, the pasteur pre-pressure always remains sufficiently high, which contributes to the production of high-quality beer.

[24] Optionally, as defined by claim 7, the set value is the speed of the pasteurization pump. For example, the pasteurization pump is a frequency controlled centrifugal pump in which the speed is controlled by a frequency control on the driving electric motor.

[25] Optionally, as defined by claim 8, the second control unit is further adapted to receive a flow measured by a measurement unit between the pasteurization unit and the clear beer tank. Furthermore, the calculation module in the second control unit is adapted to determine the set value for the pasteurization pump on the basis of the measured flow rate, otherwise on the basis of the measured pasteur pre-pressure, if the measured pasteurine pre-pressure is higher than a predetermined pressure setpoint. The predetermined pressure desired value is, for example, a minimum pre-pressure for the pasteurization unit, which is necessary to prevent degassing of the beer. If the filter unit is already heavily contaminated, with an increased pressure drop across the filter, as a result of which the pasteurising pressure threatens to fall below the minimum permitted value, the pasteurisation pump is controlled in such a way as to maintain the pasteurising pressure. However, if the filter unit is not yet very dirty, and there is still no risk of pasteur pre-pressure being too low, the pasteurization pump is controlled on the basis of the measured flow rate downstream of the pasteurizer. After all, the delivered flow rate determines the production capacity.

[26] Optionally, as defined by claim 9, the calculation module in the second control unit is adapted to determine the set value for the pasteurization pump, if the measured pasteur pre-pressure is higher than the predetermined pressure desired value (for example a minimum pasteur pre-pressure). so that the flow rate downstream of the pasteurization unit is equal to a predetermined flow rate target value. If the measured pressure after the filter unit is higher than the predetermined desired pressure level (for example a minimum

-12- Pasteur pre-pressure), the set value for the pasteurization pump 2919/5078 is calculated so that the pasteur pre-pressure is equal to the predetermined pressure setpoint. In this way, as long as the filter unit is not too dirty, the pasteurization pump is controlled to a fixed flow rate downstream of the pasteurizer. This means that, starting from a clean filter, with gradual filter contamination and gradual decrease of the flow through the filter, for example, the speed of the pasteurisation pump is increased in order to be able to maintain a constant flow through the pasteurizer. This contributes to the realization of stable process conditions throughout the pasteurizer, and allows to obtain a maximum production capacity. However, once the filter unit is heavily contaminated, and the pasteurization pre-pressure has fallen, the pasteurization pump is controlled on the basis of the measured pasteur pre-pressure, so that no degassing can occur. At that moment, the set value of the pasteurisation pump is determined in order to realize sufficient delivery pressure, but the flow rate of the pump may be lower than the flow target value previously used. This reduces the production capacity, but the quality of the beer produced is guaranteed.

Optionally, as defined by claim 10, in the control unit adapted to drive the pump upstream of the filter unit, the input module is adapted to receive the measured pasteurizing pre-pressure. Furthermore, the calculation module within this control unit has been adapted to determine a setting value for the pump, based on the measured pasteur pre-pressure. The control module within this control unit is also adapted to control the pump to the determined set value. This means that the measured pasteurizing pre-pressure is not only used to control the pasteurization pump, but also to control the pump upstream of the filter unit. This allows, during filtration of beer from a given lager beer tank, the flow conditions at the level of the in-line filter and pasteurization unit to also be adjusted by the pump upstream of the filter unit. In this way, this pump not only has a function when switching between lager beer tanks, but also during the process of filtering and pasteurizing. In particular, this pump can run during this process

-13- can be regulated taking into account the measured pasteur pre-pressure, ie 0190918 with the gradual contamination of the filter. This contributes to the realization of stable process conditions for filter and pasteurizer.

Optionally, as defined by claim 11, the calculation module within the controller is adapted to determine, if the pasteurine pre-pressure is less than a predetermined pressure setpoint, the set value for the pump based on the pasteurine pre-pressure. The predetermined pressure desired value is, for example, a minimum pre-pressure for the pasteurization unit, which is necessary to prevent degassing of the beer. If the pasteurising pressure threatens to become too low due to heavy contamination of the filter, the pasteurisation pump is controlled on the pasteurising pressure, and no longer on flow. At that moment, the flow rate that the pasteurization pump can deliver decreases. By controlling the pump upwards from the filter (for example increasing the speed), this pump can at that moment supply extra energy to the flow, so that it is ensured that the desired (maximum) flow rate is maintained for longer. This contributes to the realization of a high production capacity.

Optionally, as defined by claim 12, the control module input module is further adapted to receive a filter pre-pressure measured in the flow between the pump and the filter unit. Furthermore, the calculation module within the control unit is adapted to determine the set value for the pump on the basis of the pasteur pre-pressure and the filter pre-pressure, if the pasteur pre-pressure is lower than the predetermined pressure setpoint. Measuring the filter pre-pressure can prevent it from rising too high. After all, a too high filter pre-pressure can lead to leaks in the filter. By also taking the filter pre-pressure into account when controlling the pump on the basis of the pasteurisation pre-pressure, a high flow rate can be maintained for as long as possible, but with the limitation that the filter pre-pressure must never become too high. In this way, we strive for maximum production capacity, but without creating the risk of leakage in the filter. This contributes to the reliability of the solution and the production of high-quality beer.

“14 - BE2018 / 5918

[30] In addition to a system for processing aged beer into pasteurized clear beer, the present invention also relates to a similar method as defined by claim 13, wherein this method comprises the following steps: - supplying aged beer from two or more in flow elements connected in parallel, each flow element comprising: o a lager beer tank; o a pipe with shut-off unit; o a measurement unit adapted to measure the static pressure at a point in the flow element; - activating one of the flow elements by opening the closing unit; - filtering the aged beer in a filter unit, resulting in clear beer; - pasteurizing the clear beer in a pasteurization unit, resulting in said pasteurized clear beer; - storing the pasteurized clear beer in a clear beer tank, characterized in that: - the pasteurization unit is placed downstream and in line with the filter unit, and - the method further comprises: o pumping the aged beer using a pump positioned between the parallel-connected flow elements and the filter unit, the pump being controllable; o controlling the pump by means of a control unit, comprising the following steps performed by the control unit: = »receiving the static pressure for each of the flow elements; = »Calculating, for each of the flow elements, a set value for the pump, based on the static pressure; and

-15- =, when one of the flow elements is activated, 99918 of the pump adjusts to the set value calculated for the activated flow element. Brief Description of the Drawings

[31] FIG. 1 is a block diagram of the system of the invention, according to a first Embodiment.

[32] FIG. 2 is a block diagram of the system of the invention, according to a second Embodiment.

[33] FIG. 3 is a block diagram of the system according to the invention, according to a third embodiment.

[34] FIG. 4 is a block diagram of the successive installations used in processing aged beer into pasteurized clear beer, in a prior art system.

[35] FIG. 5 is a block diagram of the successive installations used in processing aged beer into pasteurized clear beer, in a system according to the invention.

Detailed Description of the Embodiments

[36] FIG. 1 depicts a system (100) for processing aged beer into pasteurized clear beer according to an embodiment of the invention. In fig. 1, two lager beer tanks (101) are connected in parallel. In the figure, two flow elements (114) are visible, each of which comprises a lager beer tank (101) and a pipe (115) with shut-off unit (103). Downstream of the parallel-connected flow elements (114) is the filter unit (105), in which the supplied aged beer is filtered (resulting in clear beer). The filter unit (105) becomes direct

- 16 - followed by the pasteurization unit (106), in which the beer is briefly heated 0199918 After pasteurization, the pasteurized clear beer is temporarily stored in a clear beer tank (107). A filling installation (500) draws beer from the clear beer tank (107).

[37] In Fig. 5, the installations for processing aged beer into pasteurized clear beer according to the invention are shown again. For clarity of representation, only one lager beer tank (101) is suggested here. In fig. 4 shows another solution for processing aged beer into pasteurized clear beer, as known in the art. In the solution of FIG. 4, aged beer is supplied from a lager beer tank (400) (or lager beer tanks (400) connected in parallel) to a filter unit (401). The filtered beer (clear beer) is temporarily stored in a clear beer tank (402).

It is then pasteurized (flash pasteurization) in a pasteurization unit (403). After the pasteurization unit, a filling installation (404) follows, where the beer is placed, for example, in bottles or kegs. Unlike in the system (100) of the invention, in the prior art solution, the pasteurization unit and filter unit are not connected in line.

Since the filling installation (404) directly draws beer from the pasteurization unit, stable pasteurization conditions are disturbed when the filling installation (404) comes to a standstill. If necessary, this can be remedied by switching an additional buffer tank (405). However, this entails additional costs for keeping and maintaining such a buffer tank (405) operational.

In contrast, in the invention as shown in FIG. The filter unit (105) and pasteurization unit (106) are connected in line, so that the pasteurization unit (106) is not affected by the filling installation (500). This is important because such a filling installation is regularly subject to faults, which are difficult to avoid in practice.

[38] In Fig. 1, aged beer is supplied from a lager beer tank (101) during filtering. In order to have a continuous supply, we work with several lager beer tanks. Different tanks can be the same

-17- type of beer, or each a different kind. They can also each contain a different 99978 volume. There may also be a parallel-connected water tank, which supplies water to flush the pipes. Each lager beer tank (101) has a pipe (115), where besides the shut-off unit (103), other facilities may also be present, for example a vent valve. The shut-off unit (103) is, for example, an on / off-controlled shut-off valve. During filtering, one flow element (114) is active each time, which means that the closing unit (103) of that flow element (114) is open, while the other closing units (103) are closed. When one tank (101) is (almost) empty, it switches to another tank (101). The switchover can be done, for example, by an operator, or a PLC can calculate when a tank will be empty (based on, for example, a flow measurement or flow target value). A minimum contact or minimum probe can also be used to determine that a tank is (almost) empty. Switching is done, for example, via a change-over head or a cutting head.

[39] For example, the lager beer tanks (101) may be at different heights, and may contain a different level of beer. Within a lager beer tank (101), the beer is kept under pressure using a propellant (for example CO2) (for example 1.5 to 2 bar), in order to retain carbon dioxide in the beer. The propellant pressures may also be different in the different tanks (101). A measuring unit (102) in each of the flow elements (114) allows to measure the static pressure (112). A measurement unit (102) is, for example, an analog pressure measurement. The measured static pressures (112) are used by the control unit (108) (see description below), but can also be used for control purposes (e.g. to verify that not all shut-off units (103) are closed, or that the propellant pressure is in order in all tanks (101)). The static pressures (112) measured in the multiple flow elements (114) are different because of, for example, differences in the height of the beer column or differences in the propellant gas pressure. For example, at a propellant pressure of 1.8 bar in both tanks (101), and a beer column of 10 M in a flow element, approximately 2.8 bar of static pressure is measured, while at a beer column of 4 m

In another flow element a static pressure of about 2.2 bar is measured 190918.

[40] This means that when beer is supplied from one tank (101), and is switched to another tank (101) during filtering, a sudden pressure change or pressure surge occurs at the level of the filter, if no measures are taken taken. The filter unit is, for example, a window filter with Kieselguhr, whereby the Kieselguhr layer must remain intact for the purpose of filtering. A cleaning cycle follows each filter cycle. A pressure impact on the filter during filtering gives a great risk of breakdown of the Kiezelguhr layer. In addition, the occurrence of a sudden pressure change also disrupts the stable flow conditions at the pasteurization unit (106). This is a flash pasteur, where the beer is heated briefly. The temperature and duration of the heating depend on the type of beer (for example 30 sec at 72 ° C). In order to properly control this heating, a stable flow rate through the pasteurization unit (106) and stable pressures at the inlet and outlet of the pasteurization unit (106) must be aimed for.

[41] An adjustable pump (104) is used within the system (100) to avoid the above-mentioned pressure surge. This is, for example, a frequency-controlled centrifugal pump. It is placed downstream of the point where the flow elements (114) meet and upstream of the filter unit (105). The pump (104) has an adjustable speed. The setting value (113) for this speed is determined by a control unit (108), which for example is part of a PLC or process computer. The control unit (108) includes an input module (109) where the measured static pressures (112) are read, ie. one per flow element (114). Within a calculation module (110), a speed setting value (113) is calculated based on the measured static pressure (112). This means that with two flow units (114) connected in parallel, two speeds are calculated. Also, based on the difference in measured pressures (112), there can be a relative increase or decrease in speed

-19-

are determined.

With an active flow element (114), the set value 99978 (113) calculated according to this flow element (114) is applied to the pump (104). This is done via a control module (111), which communicates with the pump (104). If another flow element (114) is activated by switching between tanks (101), the other speed is immediately sent to the pump as the set value (113).

This means that the speed of the pump is immediately adjusted in order to regulate the differential pressure at the inlet of the pump (104).

Optionally, to calculate the speed within the calculator (110), the dynamic pressure at the inlet of the pump is calculated, i.e. the measured static pressure (112) less the pressure drop due to flow losses in the lines (115). For example, the measured static pressure is 2.2 bar, and at a calculated pressure drop of 0.7 bar due to flow losses, a dynamic pressure of 1.5 bar applies.

For example, the flow losses are calculated using a formula that uses the piping characteristics (for example, a pipe diameter and length, a material characteristics, etc.) and a flow rate (for example, a measured velocity or a velocity calculated from a flow setpoint or from a measured flow) as input parameters .

Such formula or specific dependencies can, for example, be looked up in the literature or documentation of manufacturers or can be determined experimentally.

The calculator (110) further takes into account a desired pressure downstream of the pump.

For example, this can be a desired pressure that is optimal already pre-pressure for the filter.

The calculation module determines a set value (for example speed) (113) which allows, at a given dynamic pressure at the input of the pump (104), to establish the desired pressure value at the output of the pump (104).

Optionally, use can be made of a pump characteristic for this purpose, for instance in the form of a head-flow rate connection at a certain speed or frequency.

From the calculated dynamic pressure at the inlet, and the desired pressure at the outlet, it is determined what the necessary head is to be supplied by the pump (104), and it is then determined via the pump characteristic which speed or frequency should be applied.

For example, at a desired pressure at the outlet of the pump (104) of 5 bar, and a dynamic one

-20- pressure at the inlet of the pump (104) of 2 bar, a head 95916 of 3 bar is required and a frequency of 40 Hz. With a dynamic pressure at the inlet of the pump (104) of 1.5 bar, a head of 3.5 bar is required and, for example, a frequency of 50 Hz. The set value (113) can be calculated in absolute terms or as a relative increase or decrease. Within the calculation module, it is thus continuously predictively determined what the setting value (113) should be when another flow element (114) is activated, in order to keep the same pressure downwards. Thus, unlike a feedback control, it is not necessary to wait for an effective downward pressure change to be made to adjust the pump (104).

[42] In FIG. 2 shows a system (200) according to another embodiment of the invention. Here, a measuring unit (202) and a pasteurization pump (201) are placed between the filter unit (105) and the pasteurization unit (106). The measuring unit (202) allows to measure the pasteurizing pre-pressure (208). This is also the pressure downstream of the filter unit (105). In the embodiment shown in FIG. 2, the feed module (205) also receives a flow rate (209) measured by a measuring unit (203) after the pasteurization unit (106). The pasteurization pump (201) is adjustable, for example it is a fregquency controlled centrifugal pump. The pasteurization pump (201) is controlled by a second control unit (204), which is, for example, part of a PLC or process computer. The second control unit (204) and the control unit (108) can be separate entities, or both can be integrated in the same PLC or process computer. The second control unit (204) includes an input module (205) that receives the measured pasteurizer pre-pressure (208), and an arithmetic module (206) that determines a setting value (210) (e.g., a speed or frequency) for the pasteurization pump (201). A control module (207) communicates with the pasteurization pump (201) to apply the set value (210).

[43] The calculation module (206) uses the measured pasteurizing pre-pressure (208) and optionally also the measured flow rate (209) to determine the set value (210) of the pasteurization pump (201). For example, one becomes in advance

-21- set pressure value (for example 1.7 bar) which must apply at least at the entrance of the pasteurisation unit (106) in order to avoid degassing of the beer. Also, a flow rate target value (e.g. 90 hl / h) for the flow rate through the pasteurization unit (106) can be established, thereby achieving optimum production capacity. For example, as long as the measured pasteurizing pre-pressure (208) is still above the pressure desired value (for example 1.7 bar), the set value (210) is determined on the basis of the measured flow rate (209). This means that, starting from a clean filter, when the filter is gradually soiled and the flow through the filter is gradually decreased, for example, the speed of the pasteurization pump (201) is increased, downstream of the pasteurization unit (106), desired flow rate (e.g. 90 hl / h). However, once the filter becomes heavily contaminated, and the pasteurizing pre-pressure (208) has fallen to the pressure setpoint (e.g. 1.7 bar), the speed of the pasteurisation pump (201) is determined on the basis of the measured pasteurising pre-pressure (208 ) (for example adjusting the speed to adjust the delivery head of the pasteurisation pump (201)). At that moment the flow falls below the initially set flow target value (for example 90 hl / h).

[44] In Fig. 3 shows a system (300) according to another embodiment of the invention. The measured pasteurizing pre-pressure (208) is in this embodiment also passed on to the control unit (108) which controls the pump (104). On the one hand, this allows the set value (303) of the pump (104) to be determined on the basis of the measured static pressure (112) of the active flow element (114), but can furthermore be adjusted in function of the measured pasteur pre-pressure. (208). When the pasteurizing pre-pressure (208) has fallen to the predetermined setpoint (e.g. 1.7 bar) and the pasteurization pump (201) can no longer supply the flow rate setpoint (e.g. 90 hl / h), the pump (104) can be adjusted (e.g. increase speed) to supply additional energy to the flow. In this way, the flow rate (209) can be kept longer at the desired value (for example 90 hl / h). Optionally, a filter pre-pressure (302), measured, is also taken into account within this control

-22- upward from the filter unit (105) through a measuring unit (301). This allows 1190918 to poorly increase the speed of the pump (104) to a level that achieves a maximum pressure at the inlet of the filter unit (e.g. 6 bar). In this way it can be prevented that leaks in the filter would arise as a result of too high an inlet pressure.

[45] Although the present invention has been illustrated by specific embodiments, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be practiced with various modifications and adaptations without leaving the scope of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being described by the appended claims and not by the foregoing description, and any changes falling within the meaning and scope of the claims, are therefore included here. In other words, it is understood to include any changes, variations or equivalents that fall within the scope of the underlying basic principles and whose essential attributes are claimed in this patent application. In addition, the reader of this patent application will understand that the words "comprising" or "comprising" do not exclude other elements or steps, that the word "a" does not exclude plural. Any references in the claims should not be construed as limiting the claims in question. The terms "first", "second", "third", "a", "b", "c" and the like, when used in the description or in the claims, are used to distinguish between similar elements or steps and do not necessarily describe a sequential or chronological order. Likewise, the terms "top", "bottom", "over", "under" and the like are used for description and do not necessarily refer to relative positions. it is understood that those terms are interchangeable under the appropriate conditions and that embodiments of the invention are capable of

-23- Da | BE2018 / 5918 function according to the present invention in orders or orientations other than those described or illustrated above.

Claims (13)

'24 - CONCLUSIONS BE2018 / 5918 A system (100, 200, 300) for processing aged beer into pasteurized clear beer, comprising: - two or more flow elements (114) connected in parallel, each of said flow elements (114) comprising: o a lager beer tank (101 ); o a conduit (115) with shut-off unit (103) allowing to activate the respective flow element (114) by opening said shut-off unit (103); o a measuring unit (102) adapted to measure the static pressure (112) at a point in said flow element; - a filter unit (105); - a pasteurization unit (106): - a clear beer tank (107), characterized in that: - said pasteurization unit (106) is placed downstream and in line with said filter unit (105), and - said system (100, 200, 300) further comprises: o a pump (104) interposed between said paralleled flow elements (114) and said filter unit (105), said pump (104) being controllable; o a control unit (108) comprising: 2 an input module (109) adapted to receive said static pressure (112) from each said measuring unit (102); = »A calculation module (110) adapted to calculate a setting value (113) for said pump (104) for each of said flow elements (114), based on said static pressure (112); and 2, a control module (111) adapted to control, upon activation of one of said flow elements (114), said pump (104) to said set value (113) calculated for the activated flow element. -25- BE2018 / 5918 A system (100, 200, 300) according to claim 1, wherein said calculation module (110) is configured to determine said setting value (113) for said flow element (114) by: - calculating a dynamic pressure at the input of said pump (104), based on said received static pressure (112) and flow losses in said conduit (115) of said flow element (114); - calculating said setting value (113) for said pump (104), based on said dynamic pressure at the input of said pump (104), such that at the output of said pump (104) a fixed desired value for the pressure is obtained is going to be; A system (100, 200, 300) according to claim 2, wherein said calculation module (110) is configured to calculate said flow losses based on one or more dimensions of said conduit (115) and based on a flow rate or flow rate in said conduit (115). A system (100, 200, 300) according to any preceding claim, wherein said setting value (113) is the speed of said pump (104). A system (100, 200, 300) according to claim 4, wherein said calculation module (110) is configured to determine said set value (113) based on the pump characteristic of said pump (104). A system (200, 300) according to any preceding claim, wherein said system further comprises: - an adjustable pasteurization pump (201) placed between said filter unit (105) and said pasteurization unit (106); - BE2018 / 5918 - a measuring unit (202) adapted to measure a pasteurizer pre-pressure (208) in the flow between said filter unit (105) and said pasteurization pump (201); - a second control unit (204), said second control unit (204) comprising: - an input module (205) adapted to receive said pasteurizer pre-pressure (208); - a calculation module (206) adapted to determine a setting value (210) for said pasteurization pump (201), based on said pasteurizing pre-pressure (208); - a control module (207) adapted to control said pasteurization pump (201) to said set value (210). A system (200, 300) according to claim 6, wherein said set value (210) is the speed of said pasteurization pump (201). A system (200, 300) according to claim 6, wherein said input module (205) in said second control unit (204) is adapted to further receive a flow rate (209) measured by a measuring unit (203) between said pasteurization unit (106) and said bright beer tank (107), and wherein said arithmetic module (206) in said second control unit (204) is adapted to, if said pasteur pre-pressure (208) is higher than a predetermined pressure setpoint, said setting value (210) for determine said pasteurization pump (201) based on said flow rate (209), otherwise based on said pasteurization pre-pressure (208). A system (200, 300) according to claim 8, wherein said calculating module (206) in said second control unit (204) is adapted to, if said pasteur pre-pressure (208) is higher than said predetermined pressure setpoint, said setting value "27 - (210) for said pasteurization pump (201) so that said 99918 flow rate (209) equals a predetermined flow rate value, otherwise differentiate said setting value (210) for said pasteurization pump (201) so that the pasteurizing pressure (208 ) is equal to a predetermined pressure setpoint. A system (300) according to claim 6, wherein in said control unit (108): - said input module (109) is adapted to receive said pasteurizer pre-pressure (208); - said calculation module (110) is adapted to determine a setting value (303) for said pump (104), based on said pasteurizing pressure (208); and - said control module (111) is adapted to control said pump (104) to said set value (303). A system (300) according to claim 10, wherein said calculation module (110) in said control unit (108) is adapted to, if said pasteur pre-pressure (208) is less than said predetermined pressure setpoint, said setting value (303) for said pump (104) based on said pasteurizing pre-pressure (208). A system (300) according to claim 11, wherein said input module (109) is further adapted to receive a filter pre-pressure (302) measured in the flow between said pump (104) and said filter unit (105), and said calculation module (110) is adapted to determine, if said pasteur pre-pressure (208) is less than said predetermined pressure setpoint, said setting value (303) for said pump (104) based on said pasteur pre-pressure (208) and said filter pre-pressure (302). -28- 13. A method for processing aged beer into pasteurized 95919 clear beer, comprising the following steps: - supplying said aged beer from two or more flow elements (114) connected in parallel, each flow element (114) comprising: o a beer tank ( 101); o a conduit (115) with shut-off unit (103); o a measuring unit (102) adapted to measure the static pressure (112) at a point in said flow element (114); - activating one of said flow elements (114) by opening said closing unit (103); - filtering said aged beer in a filter unit (105), resulting in clear beer; - pasteurizing said clear beer into a pasteurization unit (106), resulting in said pasteurized clear beer; - storing said pasteurized clear beer in a clear beer tank (107), characterized in that: - said pasteurization unit (106) is placed downstream and in line with said filter unit (105), and - said method further comprises: o pumping said aged beer using a pump (104) interposed between said parallel-connected flow elements (114) and said filter unit (105), said pump (104) being controllable; o controlling said pump (104) by means of a control unit (108), comprising the following steps performed by said control unit (108): = »receiving said static pressure (112) for each of said flow elements (114); = »Calculating, for each of said flow elements (114), a set value (113) for said pump (104), based on said static pressures (112); and -29- =, when one of said 99918 flow elements (114) is activated, controlling said pump (104) to said set value (113) calculated for the activated flow element (114).