DE102006055670A1 - Reactor for softening of water, comprises reactor housing, first pipe connection for supplying granular solid, second pipe connection intended at the reactor housing for removing pellets, and weighing device for measuring the reactor weight - Google Patents

Abstract

The reactor (1) for softening of water, comprises a reactor housing, a first pipe connection (5) for supplying a granular solid, a second pipe connection (7) intended at the reactor housing for removing pellets, and a weighing device (4) for measuring the reactor weight. The first pipe connection is intended at the reactor housing or at a water supply line (2) guided to the reactor. The reactor housing is arranged on the weighing device and a controller is intended to induce a removal of pellets via the second pipe connection in dependence of the measured reactor weight. The reactor (1) for softening of water, comprises a reactor housing, a first pipe connection (5) for supplying a granular solid, a second pipe connection (7) intended at the reactor housing for removing pellets, and a weighing device (4) for measuring the reactor weight. The first pipe connection is intended at the reactor housing or at a water supply line (2) guided to the reactor. The reactor housing is arranged on the weighing device and a controller is intended to induce a removal of pellets via the second pipe with respect to the measured reactor weight and to induce the entry of a solid quantity via the first pipe connection into the reactor. The controller is arranged in such a manner that during a fixed deviation of the measured reactor weight of a required weight or at outlet of a fixed time interval, a removal of the pellets is induced over the second pipe connection and the solid quantity refilled into the reactor is measured over a conversion factor. The reactor housing has a lower cone and an upper cone. The upper cone is directly joined to the lower cone and has a smaller expansion angle than the lower cone. An outlet line is attached at the second pipe connection and flows directly into a pellet silo. A reactor side- and a pellet-silo side valve are intended in the outlet line. A wastewater pipeline is mounted between the valves at the outlet line. A solid storage vessel arranged on the weighing device is intended and is connected over an injector, which has a water pipeline, with the first pipe connection of the housing. Independent claims are included for: (1) a device for softening of water; and (2) procedure for softening of water.

Description

The The invention relates to a reactor for softening water, with a Reactor housing, a first one on the reactor housing or at the water supply pipe feeding the reactor for feeding a grainy Solid and a second provided on the reactor housing pipe connection for removing pellets. Furthermore, the invention relates to a device for softening of water as well as a related matter Method.

The reduction in calcium or bicarbonate concentration, known as softening and decarbonization, has been a component of water treatment in waterworks for decades. In the so-called rapid chemical hardening, the water in a reactor is preferably admixed with a finely dispersed calcium hydroxide suspension (lime milk) and / or with sodium hydroxide solution, the calcium dissolved in the water precipitating as calcium carbonate (CaCO ₃ ) and remaining on solid particles in the reactor , which serve as crystallization nuclei, attaching to form calcium carbonate pellets. In general, the reactor is flowed through by the water to be softened in an upward flow from bottom to top, with the calcium carbonate pellets floating in the upward flow and lining down with increasing diameter. The reaction proceeds optimally for a given contact surface. This optimal contact surface corresponds to a known size distribution of the pellets a pellet mass. Too large pellet mass has a negative hydraulic effect. In extreme cases, the previously floating pellets sink so far that a bed settling results. In this case, if a pump presses a flow-controlled volume flow into the reactor, pulsation phenomena occur which cause a significant increase in turbidity in the softened water leaving the reactor.

Around an optimal softening result To achieve this, it is necessary to operate the reactor at constant operating parameters to work. Among other things, the optimal pellet mass is in To keep the reactor largely constant, which requires that the constantly forming and growing in diameter pellets regularly be withdrawn from the reactor. It is intended for the withdrawal of the pellets Pipe connection mounted on the reactor housing such that the in the upward flow of the to be softened Water floating pellet plug just above it so always the biggest pellets subtracted from. This ensures that on average always a constant Pellet volume prevails in the reactor.

From the prior art, various reactors are known which enable semi-automatic or fully automatic softening operation. Here, the operation is geared to the optimum pellet mass in the reactor to vary only slightly to the optimum in order to obtain an optimal and temporally constant softening result. In the in the German utility model DE 299 20 728.5 described water softening reactor is carried out at regular intervals an automatic or manually triggered removal of pellets, which are then introduced into a collecting container. The collection container itself is provided with a weighing device so that the amount of pellets introduced into it can be weighed and calculated therefrom over a predetermined conversion factor an equivalent amount of solids which is subsequently introduced into the reactor so as to maintain a continuous softening process in the reactor. The amount of pellets weighed in the collecting container is then removed from the collecting container via a withdrawal tube provided at the collecting container and introduced into a pellet silo for storage by means of an injector connected to a water conduit, so that the collecting container is again used for weighing out the amount of pellets to be withdrawn from the reactor in the next step is available.

The The reactor system described above initially has the advantage that at Use of an appropriate control a fully automatic operation possible is, the controller is a regular pellet withdrawal from the reactor performs and subsequently one equivalent each Introduces solid amount in the reactor. The decisive disadvantage is, however, that by weighing the pellets in the collection container no exact conclusions the actual Total lime content in the reactor to be taken at the time of pellet withdrawal can, as a certain lime content in the form of microcrystals in the softened water above of the pellet-graft is dispersed and as a micro-turbidity of the softened Makes water noticeable. The entire softening process is oriented So on the in the collection container certain weight of the in regular temporal intervals withdrawn from the reactor pellets with the result that the softening process over a longer period of operation can not run in an equilibrium state. This takes the micro-turbidity of the softened Water steadily increases, which in turn leads to an increasing burden the arranged behind the reactor filter units leads.

Based on this prior art, the invention is therefore an object of the invention to develop a reactor of the type mentioned, which also operates over a length period with constant operating parameters.

The Task is according to the invention with a Reactor for softening of water according to the preamble of claim 1 solved by that the reactor housing on a weighing device for Measurement of the reactor weight is arranged and provided a controller which is set up in dependence on the measured Reactor weight a withdrawal of the pellets via the second pipe connection initiate and then the entry of a quantity of solids via the first pipe connection into the reactor.

About one continuously weighing the contents of the content to be softened Water flowed through continuously Reactor leaves in a very simple way, the total lime content within the reactor determine at the respective weighing time. This can be an example act as a setpoint value from empirical values, with which each currently measured reactor weight in the provided according to the invention Control is compared in terms of a target-actual comparison. This Target-actual comparison in turn can be used directly as a criterion for the initiation of a pellet deduction and the subsequent Entry of a corresponding amount of solids can be used, in which case the total lime content within the reactor within selected limits also over a longer one Period can be kept constant on average. this in turn has, as described above, directly positive effects in terms of a constant quality of the withdrawn from the reactor softened Water.

Under the introduction of the pellet outlet from the reactor or the introduction the entry of a quantity of solids into the reactor is understood in accordance with the invention, that the control is the introduction of the pellet deduction or the entry a quantity of solids either independently in the sense of a fully automatic Operation triggers or outputs a signal, whereupon the operator initiates the Pellet deduction or the initiation of the entry of a quantity of solids triggers manually (semi-automatic operation).

According to one advantageous teaching of the invention is the control of the reactor operation arranged such that at a fixed deviation of the measured reactor weight of a target weight or after expiration a predetermined time interval deduction of the pellets over the second pipe connection and then via a conversion factor a quantity of solids to be replenished in the reactor and then the entry of the calculated amount of solids over the first pipe connection is introduced into the reactor.

Of the Use of such a controller allows, as already mentioned, the semi or fully automatic operation of the water softening reactor. Monitored in both operating modes the controller determines the current reactor weight and compares this with the previously set value, whereby in semi-automatic operation upon reaching a predetermined maximum deviation the operator a signal is given to initiate the pellet discharge while in the fully automatic operation this is done independently by the controller becomes. Alternatively, the controller may run at a specified time Time interval, a signal to initiate the pellet deduction output or make this independently. As a time interval, for example, a 24-hour interval can be selected.

In a combined operation based on a target-actual comparison and oriented at a fixed time interval, the signal becomes to initiate the pellet deduction then spent when the maximum value is reached within the time interval. Independent of Operating mode, beats the controller in semi-automatic operation, the pellet mass to trigger , which has grown since the previous withdrawal, and continues completed new trigger the counter for mass or time interval to "zero." In fully automatic Operation is the calculated deduction mass without correction options deducted.

It It goes without saying that the pellet extractor can also be introduced manually at any time and the deduction mass determined by the control manually editable is.

The Control uses a conversion factor from that in the reactor measured weight gain due to the Pelletwachstums to an equivalent Close solid amount. This conversion factor can be stored in the control as a percentage be. For example, this is Weight of the solid to be introduced into the reactor 3% of the previously withdrawn from the reactor pellet weight.

The reactor housing itself can be shaped differently. To be particularly advantageous, such a form has been found in which the reactor housing has a lower cone and an upper cone, wherein the upper cone directly adjacent to the lower cone and the upper cone has a smaller expansion angle than the lower cone. This design has the advantage that the water to be softened at the lower end of the lower cone quickly loses flow velocity in the comparatively strongly expanding lower cone, so that the flow path to the location of the largest, bottom layered pellets is short. However, the flow rate at the upper end of the lower cone is still sufficiently large to the pellet bed in the To hold the balance. The smaller widening angle of the upper cone ensures that no significant reverse flow flows, which would transport the pellets downwards and thus counteract classification, occur.

To Another teaching of the invention is that at the second Pipe connection a discharge line is connected, which immediately opens in a pellet silo. This embodiment of the invention has the advantage that the weight calcification in the context of determining the total weight the reactor is determined by the weighing device provided on the reactor, so that the known from the prior art with a weighing device provided collecting container for receiving the withdrawn from the reactor each pellets omitted can and the reactor over a discharge line to be connected directly to the pellet silo can. This simplification of equipment allows investment and maintenance costs to a considerable extent save on. Preferably, in the withdrawal line is a reactor-side and a pelletsilo-side valve is provided and between the valves an operating water line connected to the discharge line. hereby Is it possible the withdrawal line at regular intervals or even in acute disorders in different directions, namely on the one hand in the direction of the pellet silo with the reactor side valve closed and on the other hand in the direction of the reactor with closed pelletsiloseitigem valve, to wash.

To a further advantageous embodiment of the invention is at the reactor according to the invention one on a weighing device arranged solid storage tank provided, which has a Injector connected to a water pipe to the first pipe connection of the housing connected is. By arranged on a weighing device Solid reservoir can be any amount of the solid, for example, easier Sand, very precise to the reactor, what a prerequisite for an operation of the reactor with temporally constant operating parameters is.

The The object mentioned above is further by a device for softening dissolved by water, comprising a softening reactor, a solids reservoir, from which a granular solid is introduced into the reactor, and a pellet silo, in which the pellets withdrawn from the reactor are stored, wherein the reactor according to any one of claims 1 to 6 executed is.

The inventive device for softening of water is characterized by stable operation at steady water quality also over a longer one Period and is in particular compared to those of the prior art known devices particularly simple, since, for example between the reactor and the pellet silo no further containers and Conveyors, as pumps or injectors must be provided. This is on the one hand attributed to that according to the invention now a weighing the reactor itself and on the other hand that the reactor itself during the company constantly filled with water is so that the withdrawn pellets solely due to the pressure and without support an injector or a pump can be transported into the silo can.

The The object initially set is procedurally by a method for softening of water using a device according to any one of claims 1 to 6 solved, wherein the weight of the filled with the water-pellet mixture reactor over the weighing is weighed continuously, with a fixed deviation the measured reactor weight of a target weight or after expiration a predetermined time interval deduction of the pellets over the second pipe connection is carried out and followed by one via a Conversion factor calculated amount of granular solid over the first pipe connection is introduced into the reactor.

For the benefits the method according to the invention the above applies.

When Solid can different granular solids whose chemical composition is used in Drinking water allowed and in large quantities at low cost to disposal stand. In the simplest case, this is sand, however lime can also be used in ground form.

The Method can be semi-automatic or fully automatic, with in the case of semi-automatic operation by means of a controller at a fixed deviation of the measured reactor weight from a target weight or after a specified time interval a signal to manually initiate the withdrawal of the pellets and the entry the grainy Solid is output. In the case of fully automatic operation is controlled by a predetermined deviation of the measured reactor weight of a target weight or after expiration a defined time interval of withdrawal of the pellets over the second pipe connection and the subsequent entry of the calculated equivalent Amount of solids over introduced the first pipe connection in the reactor.

In the following the invention will be explained in more detail with reference to a drawing illustrating an embodiment. The only figure shows a device according to the invention for softening water.

The device for softening water shown in the figure comprises a reactor 1 with a housing, which in turn has a lower cone 1a and an upper cone 1b having. At its lower end, the reactor 1 a water supply 2 for supplying water to be softened and on its top a water drainage 3 for discharging the softened water.

According to the invention, the reactor 1 on a weighing device 4 with one or more - in this case two - pressure cells 4a and transducers 4b whose function will be described in detail below. Furthermore, the reactor has 1 via a first pipe connection 5 for feeding one in a storage container 6 stored granular solid, in this case sand, as well as a second pipe connection 7 for withdrawal of in the reactor 1 located calcium carbonate pellets. To the second pipe connection 7 is a withdrawal line 8th connected, which immediately in a pellet silo 8c in which the from the reactor 1 stored withdrawn pellets, flows. The discharge line is equipped with a reactor-side solenoid valve 8a and a pelletsilo-side solenoid valve 8b Mistake. Between the solenoid valves 8a . 8b is an operating water supply 9 connected to the discharge line, via which it can be rinsed in different directions.

The solid storage tank 6 itself is also on a pressure cell 10a and a transducer 10b comprehensive weighing device 10 arranged and via a sampling tube 11 with an injector 12 connected, which one via the weighing device 10 in terms of their weight metered amount of sand via a supply line 14 in the reactor 1 can transport. One acts via a water pipe 13 the injector 12 supplied water flow as a transport medium. The sampling tube 11 , the water pipe 13 as well as the supply line 14 are each via solenoid valves 11a . 12a . 14a closable.

In the operation of the reactor is now via the water supply 2 to be softened water at the bottom of the reactor 1 introduced into this, taking the water in an inlet nozzle 2a via a supply line 2 B a calcium hydroxide suspension (highly reactive milk of lime) is added. In the completely water-filled reactor 1 float, carried by the upward flow of the water to be softened, grains of sand of a defined mass, at which the calcium carbonate formed in the reaction between the water to be softened and the calcium hydroxide suspension accumulates to form pellets. As the reaction time increases, the pellets grow in diameter, with the largest and thus heaviest pellets sinking downwards, so that a classification of the pellets in terms of their diameter along the height of the reactor 1 he follows. It carries the special conical shape of the reactor 1 This will help to minimize pellet classification due to water backflow on the reactor wall. The connection 7 the withdrawal line 8th is arranged at such a height that the largest pellets float directly above it in the upward flow of the water to be softened.

Since calcium carbonate is constantly precipitated during the softening reaction, which accumulates on the one hand to form the pellets on the sand grains and on the other hand as micro-turbidity (microcrystals) is present in the water, in order to allow constant softening in the reactor at regular intervals pellets from the reactor 1 deducted and then new sand into the reactor 1 be registered.

In the reactor according to the invention 1 monitors a controller, not shown in the figure, by means of the weighing device connected to the controller 4 the current weight of the filled reactor 1 and compares this as an actual value with a previous or in the run-in operation of the reactor 1 setpoint. Due to the constantly precipitated calcium carbonate, the total weight of the reactor decreases 1 between two pellet removal operations constant, so that when reaching a predetermined maximum value, the control in the - selected here - fully automatic operation, the solenoid valves 8a . 8b in the withdrawal pipe 8th opens, whereby continuously pellets are withdrawn to the total weight of the reactor 1 has fallen back to the set point. The pellets are sent via the discharge line 8th in the pellet silo 8c initiated and stored there. As soon as the setpoint is reached, the controller closes the valves 8a and 8b and the deduction process is finished.

From the weight of the pellets withdrawn, the controller computes, over a predetermined conversion factor, an equivalent amount of sand to the reactor 1 must be returned to the pelletizer to ensure a constant operation of the reactor 1 maintain. At a percentage conversion factor of 3 Thus, the addition of 60 kg of sand is caused by a deduction of 2 t pellet mass. After calculating the amount of sand then the valves 11a . 12a . 13a opened and the injector 12 transports the calculated amount of sand into the reactor 1 , wherein the weight of the solid storage tank 6 via the also connected to the controller weighing apparatus 10 is monitored. The valves 11a . 12a . 13a After the calculated amount of sand has flowed out via the sampling tube 11 closed again, reducing the sand input to the reactor 1 is interrupted.

In the process described above, the pellet discharge is initiated precisely when the reactor weight has reached a maximum value, in which case so many pellets are withdrawn that the reactor weight drops back to the predetermined setpoint. In an alternative mode of operation, the pellet discharge is carried out at regular time intervals, with exactly the same amount of pellet being withdrawn as in the previous time interval in the reactor 1 originated. Also possible is a combined operation, wherein the pellet discharge is initiated upon reaching the maximum reactor weight, as far as this is achieved within the specified time interval. If the maximum value is not reached, then at the end of the time interval a pellet take-off is made in the amount of the weight of the lime precipitated in the past time interval.

Finally is it also possible to operate the reactor semi-automatic, by means of the controller when the maximum value is reached or after a specified time has elapsed Time interval a signal to manually initiate the deduction of Pellets and the subsequent Entry of the grainy Solid is output.

The particular advantage of the reactor according to the invention 1 is thus that in the measurement of the reactor weight, unlike the known from the prior art reactors, the lime content is taken into account, which does not precipitate in pellet form, but which is present as a micro-turbidity in the softened water. By this orientation on the actual lime content in the reactor 1 it is ensured that the reactor will continue to operate for a longer period of time 1 in the equilibrium state, ie at constant quality of the from the reactor 1 derived softened water, is guaranteed.

Claims (11)

Reactor ( 1 ) for softening water with a reactor housing, a first at the reactor housing or at the reactor ( 1 ) supplying water supply ( 2 ) provided pipe connection ( 5 ) for supplying a granular solid and a second pipe connection provided on the reactor housing ( 7 ) for the removal of pellets, characterized in that the reactor housing on a weighing device ( 4 ) is arranged for measuring the reactor weight and a controller is provided, which is adapted to a deduction of the pellets via the second pipe connection, depending on the measured reactor weight ( 7 ) and then the entry of a quantity of solids via the first pipe connection ( 5 ) in the reactor ( 1 ). Reactor ( 1 ) according to claim 1, characterized in that the controller is set up such that at a fixed deviation of the measured reactor weight from a target weight or after a predetermined time interval, a deduction of the pellets via the second pipe connection ( 7 ) and then via a conversion factor into the reactor ( 1 ) and then the entry of the calculated amount of solids over the first pipe connection ( 5 ) in the reactor ( 1 ) is initiated. Reactor ( 1 ) according to claim 1 or 2, characterized in that the reactor housing a lower cone ( 1a ) and an upper cone ( 1b ), wherein the upper cone ( 1b ) directly to the lower cone ( 1a ) and the upper cone ( 1b ) has a smaller expansion angle than the lower cone ( 1a ). Reactor ( 1 ) according to one of claims 1 to 3, characterized in that at the second pipe connection ( 7 ) a withdrawal line ( 8th ), which directly into a pellet silo ( 8c ) opens. Reactor ( 1 ) according to one of claims 1 to 4, characterized in that in the discharge line ( 8th ) a reactor-side and a pelletsilo-side valve ( 8a , b) is provided and between the valves ( 8a , b) an operating water line ( 9 ) to the withdrawal line ( 8th ) connected. Reactor ( 1 ) according to one of claims 1 to 5, characterized in that one on a weighing device ( 10 ) arranged solids reservoir ( 6 ) is provided, which via a with a water pipe ( 13 ) connected injector ( 12 ) with the first pipe connection ( 5 ) of the housing is connected. Device for softening water, comprising a water softening reactor ( 1 ), a solids reservoir ( 6 ) from which a granular solid enters the reactor ( 1 ), and a pellet silo ( 8c ), in which the from the reactor ( 1 ) withdrawn pellets, the reactor ( 1 ) is executed according to one of claims 1 to 6. A method for softening water using a device according to any one of claims 1 to 6, wherein the weight of the filled with the water-pellet mixture reactor ( 1 ) via the weighing device ( 4 . 10 ) weighed continuously with a defined deviation of the measured reactor weight from a target weight or after expiry of a specified time interval, a deduction of the pellets via the second pipe connection (FIG. 7 ) and wherein, following this, a quantity of granular solid calculated via a conversion factor via the first pipe connection ( 5 ) in the reactor ( 1 ) is initiated. Method according to claim 8, characterized in that that as a solid sand or ground lime is used. Method according to claim 8 or 9, characterized that the process is semi-automatic, using a controller at a fixed deviation of the measured reactor weight from a target weight or after a specified time interval a signal to manually initiate the withdrawal of the pellets and the Entry of the grainy Solid is output. A method according to claim 8 or 9, characterized in that the method is fully automatic, wherein by means of a control at a fixed deviation of the measured reactor weight of a target weight or after a predetermined time interval of the withdrawal of the pellets via the second pipe connection ( 7 ) and the subsequent entry of the calculated equivalent amount of solids over the first pipe connection ( 5 ) in the reactor ( 1 ) is initiated automatically.