EP3892364A1 - Dosing and mixing system for the preparation of a chlorine-containing solution or suspension of a chlorine-containing pourable solid, and method for operating the dosing and mixing system - Google Patents

Abstract

The invention relates to a metering and mixing system for producing a chlorine-containing solution or suspension from a chlorine-containing, free-flowing solid in a mixing container (100), the free-flowing solid being metered in by means of a suction device (17) via a suction line (6) and the metering through Connection of the mixing container (100) with the ambient air can be interrupted by means of a locking device (7). In order to better protect affected groups of people from health impairments and dangers, the dosing and mixing system according to the invention provides a controllable suction device (17), the suction device (17) being assigned an air filter (15) for filtering the sucked in air in the upstream or downstream is.

Description

The invention relates to a metering and mixing system for producing a chlorine-containing solution or suspension from a chlorine-containing, free-flowing solid according to the preamble of claim 1.

Such systems are required, among other things, for the production of calcium hypochlorite (CHC) suspensions for the disinfection of swimming and bathing pool water, whereby the water in public pools must have a legally prescribed chlorine content. For this purpose, the swimming pool or bathing pool water must be enriched with chlorine, which can be done, for example, by adding a chlorine-containing suspension solution to the swimming pool. The suspension solution is generated, for example, from water made up or taken from the swimming pool by adding calcium hypochlorite.

Such a chlorination system can typically have a storage tank with a free-flowing chlorine substance, in particular calcium hypochlorite or another hypochlorite, which is conveyed via a suction device into a mixing container for mixing with the water from the water used in the preparation or swimming pool, where the chlorine-containing substance is brought into solution or suspension by means of stirring devices, include. The treated or to be treated swimming pool water is circulated between the swimming pool and the mixing tank or metered out in a monodirectional manner.

Such a chlorination system is, for example, from US 2014 0269 153 A1 known.

The suspension treatment described above creates by-products that are poisonous for the human organism, such as exhaust air mixed with chlorine dust, which can represent an acute source of danger to the health of swimming pool personnel and visitors, especially in closed rooms. For swimming pool personnel of such chlorination systems, handling in particular open storage containers that have to be refilled or replaced is not beneficial in terms of health. To avoid clumping and to improve the solubility as well as to adjust a certain pH value, additives such as acids are often used in the preparation of the solution or suspension.

One object of the invention is therefore to provide an improved metering and mixing system with which swimming pool personnel and / or visitors can be better protected from health impairments and dangers. In addition, it should be possible to dispense with the use of additional operating media, in particular acids.

In the known systems for the preparation of calcium hypochlorite suspensions, suspensions with a sometimes high content of chlorine are also produced, with very high amounts of calcium being released which, if the solubility product in the water used is exceeded, in conjunction with anions present in the water , especially carbonates, precipitate as lime. The precipitated lime sediments on the bottom of the mixing tank in which the suspension is produced. This leads to deposits that are difficult to dissolve (so-called "chlorine sludge"), which can lead to clogging of the mixing and dosing system.

Another object of the invention is therefore to avoid the formation of difficult-to-dissolve deposits in the mixing container and in other assemblies of the metering and mixing system.

These objects are achieved with a metering and mixing system according to claim 1 and a method according to claim 13.

According to the invention, the metering and mixing system for producing a chlorine-containing solution or suspension from a chlorine-containing, free-flowing solid has a water inlet and a material inlet for the free-flowing solid having a mixing container and a storage container holding the free-flowing solid. Furthermore, a suction line connecting the mixing container and the storage container, a suction device attached to the mixing container for generating a suction pressure for conveying the free-flowing solid into the mixing container and a blocking device for selectively connecting the mixing container with the ambient air to interrupt the conveying of the free-flowing solid into the mixing container are provided .

The dosing and mixing system can stand in an essentially closed space.
According to the invention, the suction device sucks in air from the environment in order to control the suction of the free-flowing solid from the storage container and the suction device is assigned an air filter in the upstream or downstream, so that the air sucked in by the suction device from the environment is filtered and, in particular, of chlorine components can be released.

The term suction device is to be understood generically and means any device that can be used as a volume conveyor and / or vacuum source.

A control device for controlling the suction device and the locking device is also provided, the control device being set up to control the suction device and the locking device in a first operating mode essentially for conveying the free-flowing solid and in a second operating mode for exhaust air or room air treatment. The first operating mode takes place independently, in particular separated in time, from the second operating mode. The first operating mode is carried out with the locking device closed and the second operating mode with the locking device open.

In the second operating mode, in addition to the room air, the air from the mixing and storage container can also be exchanged and processed.

By being controlled in two operating modes, the dosing and mixing system can be used both for air treatment and for the production of suspensions.

The same or additional filters can be used to filter out other air components such as suspended matter or aerosols (humidity). As a result, the suction device in particular can be protected from moisture and increased wear.

By sucking in air from the environment, the suction behavior of the free-flowing solid from the storage container can be controlled, which in conjunction with the quickly switchable locking device and possibly a targeted control of the vacuum provided by the suction device, a targeted and precise setting of the Chlorine content in the solution or suspension is made possible. This can prevent overdosing and prevent or at least reduce the precipitation of lime in the solution or suspension. The air filter can remove harmful gases and / or unpleasant smells from the exhaust air or room air.

The air sucked in from the environment per unit of time can expediently be adjusted in order to achieve an exact dosage of the amount of chlorine in the suspension. This can be achieved, for example, by adjusting the suction power of the suction device, variable air inlet openings and / or specific cross-sectional designs of suction lines or suction line sections as well as other fluid mechanical means.

The air filter can also advantageously be designed as an activated carbon filter. An activated carbon filter has the peculiarity of binding chlorine gases and odorous substances to the activated carbon of the filter. This allows the cleaned air to be returned to the room. A separate air discharge leading out of the room can be dispensed with.

The blocking device is advantageously designed to be NO-logic (NO - normally open). This means that the locking device is open in the basic state and locks when energized. A safety-critical overdosing of solid matter in the event of a fault can in particular be avoided by means of a NO-logic blocking device.

The metering and mixing system can advantageously comprise means for providing the chlorine-containing solution or suspension as required. Provision is understood to mean the production of the solution or suspension in the mixing container. The means can include, for example, sensors for capturing a situation picture or water delivery devices.

The metering and mixing system can advantageously comprise means for providing room air conditioning as required. Room air treatment is indicated, for example, if a component of the ambient air (room air) of the dosing and mixing system exceeds a predetermined concentration:
The dosing and mixing system can have an air sensor for detecting at least one room air parameter. Depending on the recorded room air parameters, the dosing and mixing system can expediently start room air treatment by activating the suction device and opening the locking device (second operating mode), so that essentially no negative pressure arises to convey the free-flowing solid from the storage container into the mixing container. In this (second) operating mode, the sucked in air is passed over the air filter and thereby cleaned, in particular freed from chlorine. The air sensor can be designed as a Ch sensor, for example.

The dosing and mixing system can also have a mixing container sensor for detecting at least one mixing container parameter, e.g. a chlorine concentration of the suspension in the mixing container, and depending on the detected mixing container parameter, control the conveyance of the free-flowing solid from the storage container into the mixing container and, in particular, start it by the suction device is activated and the locking device is closed (first operating mode), so that there is essentially a sufficient negative pressure to convey the free-flowing solid material from the storage container into the mixing container. In the case of an NO-logic blocking device, the blocking device is closed by activation.

The metering and mixing system can be set up for the quasi-continuous provision (production) of a chlorine-containing solution or suspension. Quasi-continuous provision is to be understood as a demand-controlled preparation of the chlorine-containing solution or suspension in the mixing container, in which the mixing container is essentially never completely emptied during operation. In particular, for example, a residual volume of the chlorine-containing solution or suspension can be filled with fresh or swimming pool water up to a required level or above and the corresponding amount of the free-flowing solid can be conveyed into the mixing container to achieve the desired concentration of the suspension.

With a quasi-continuous provision, a batch-wise provision with predefined lot sizes can be avoided. Intermediate containers or stores, which temporarily store a lot size during a new production of a suspension or solution, can be saved as a result. Furthermore, the size or the capacity of the mixing container can be reduced accordingly.

The prepared solution or suspension is expediently fed into one or more swimming pools by means of a removal device. In the case of large volume flows, the extraction device particularly advantageously comprises at least one Venturi nozzle. As an alternative or in addition to the at least one Venturi nozzle, the extraction device can comprise at least one hose pump or another fluid delivery device.

In particular with several conveying devices such as a combination of one or more Venturi nozzles and one or more hose pumps, the dosing and mixing system can sometimes also be used to feed a large number of different and / or differently sized swimming pools with a chlorine-containing suspension solution at the same time. This enables the delivery rate to be adapted to the size of the swimming pool. The (majority of) Venturi nozzle (s) can be used when a large delivery rate is required and the peristaltic pumps can be used for lower dosing rates.

An air suction point of the metering and mixing system, via which the mixing container is connected to the suction device via a suction line, is advantageously arranged vertically elevated and horizontally offset with respect to the material and / or external air supply. In this way, unwanted suction of added solids can be prevented or at least reduced. Furthermore, the air flow can advantageously be directed in the mixing container via the elevated position of the air suction point, so that the condensation water that collects on the ceiling of the mixing container can be better discharged.

In an advantageous embodiment, the material inlet of the mixing container can be different from an air inlet of the mixing container, via which, for example, room air is conveyed into the mixing container, when the locking device is open.
In other words, the blocking device is not attached in or on the suction line. The mixing container has a separate air inlet. As a result, the air inlet can be designed free from boundary conditions of the suction line, for example by the air inlet having a different diameter than the suction line or the diameter of the material inlet. This makes it possible, among other things, to minimize frictional losses and / or to maximize volume throughputs in the second operating mode. Furthermore, contact of the locking device with the abrasive, free-flowing solid can be avoided.

In an advantageous, alternative embodiment, the material feed into the mixing container can be identical to the air feed when the locking device is open. In other words, the locking device is arranged directly in or on the suction line. With such an arrangement, the wet / dry transition from the mixing container to the suction line and the suction line itself or at least partial sections of the suction line can also be actively ventilated in the second operating mode. In this way, in particular, the formation of condensation in the suction line and thus the tendency for free-flowing solids to clump together in the suction line and the storage container can be reduced.

The blocking device, viewed in the direction of conveyance of the free-flowing solid, can advantageously be arranged at or just behind a geodetically highest point of the suction line. Compared to an arrangement of the blocking device in front of the geodetically highest point, this has the advantage that warm, moist air can continuously escape from the mixing container via the material inlet (and possibly via the blocking device which is open when the dosing and mixing system is idle) and not in the storage container precipitates. In an advantageous embodiment, the blocking device can be arranged directly on the mixing container, in particular directly on the top of the mixing container. This enables a compact design of the dosing and mixing system with short signal and power lines. The positioning on the mixing container is also acoustically advantageous, since noises caused by flow or vibration can be minimized.

The blocking device can preferably be assigned to the suction line via an air lock and spaced from it, the air lock dividing the suction line into two sections which are assigned to one another in the air lock, for example via a nozzle-funnel arrangement. An air lock is to be understood as a pressure-tight space in which two partial sections of the suction line are in fluid connection with one another in an open manner, for example as a nozzle-funnel arrangement. Due to the spatial distance of the blocking device from the suction line, direct contact of the blocking device with the conveyed solids can be avoided. The locking device is therefore more robust and less prone to failure. The air lock can also be used to implement different cross-sections of air and material accesses, the cross-section for the external air inlet being expediently larger than that of a first suction line section.

The suction line can have a uniform or variable cross section. A first section of the suction line can expediently have a smaller cross section and a second section a larger cross section.

The blocking device can preferably be designed as a solenoid valve, in particular as a valve that can be magnetically actuated by a tie rod. Very short reaction times can be achieved with solenoid valves, so that a high level of metering accuracy is possible for the solids being conveyed. However, other forms of locking device are also possible, such as a hydraulically, pneumatically or electromotive controlled locking device.

The metering and mixing system expediently has one or more level meters.

The dosing and mixing system can comprise at least one non-contact level meter for measuring the level of the suspension or solution located in the mixing container, in particular in the form of an ultrasonic sensor. Non-contact measuring principles are much more robust and less error-prone than e.g. mechanical measuring principles such as contact switches operated by floats and enable continuous monitoring of the fill level, i.e. for every fill level from 0 to 100%

The metering and mixing system can advantageously include a measuring device for recording the amount of free-flowing solid that has been removed from the storage container. With such a measuring device, an exact dosage of the free-flowing solid and thus a precise production of the desired suspension concentration is possible.

The measuring device can, for example, be designed as a weighing cell for measuring the weight of the free-flowing solid that is removed from the storage container or remains in it. The measuring device can, for example, record the weight of the storage container and determine the amount of free-flowing substance removed by calculating the difference in the weight measurement. Instead of a weight measurement, however, volumetric measurement methods can also be used.

The measuring device can be arranged directly on the storage container, in the suction line, at the material inlet of the mixing container or elsewhere. The measuring device is advantageously arranged directly on the storage container. This is next to the Determination of the withdrawn amount of free-flowing substance also allows determination of the weight of the storage container, so that if the storage container weight is known, it can be determined when the solid in the storage container is running low. The measuring device can advantageously be coupled to a container switchover described below.

The dosing and mixing system can advantageously include a vibration device to maintain the flowability of the flowable solid in the storage container. This can be designed, for example, as a vibration or knocking device, which can be driven electrically, pneumatically or electropneumatically, and is activated periodically and / or at certain times, e.g. before and / or when the free-flowing solid is removed from the storage container and the Solid matter in the storage container set in motion by vibrations or impulses. As a result, clumping of the solid can be prevented and / or the suction of the solid can be facilitated in the first operating mode. The vibration device can in particular be designed as an electric motor with an imbalance, which is attached to a receptacle of the storage container and additionally comprises a freely oscillating knocking device. As a result, both impulses (low frequency, high energy density) and vibrations (high frequency, low energy densities) can be transmitted to the storage container or the solid with just one actuator.

In a preferred embodiment, the dosing and mixing system comprises a suction lance which can be dipped into the storage container and which has a material suction opening at its submersible end for sucking in the free-flowing solid and an air suction opening spaced axially therefrom for sucking in air from the environment. This can be made possible, for example, by the fact that the suction lance comprises an inner pipe and an outer pipe, the inner pipe and the outer pipe being concentrically and radially spaced apart and axially displaceable relative to one another, and the inner pipe being used to suck in the free-flowing solid material from the storage container and air from the environment is sucked into the annular gap that forms between the inner tube and the outer tube. In this case, at least one air intake opening is expediently made in the outer pipe, in particular in an upper section, and at least one passage opening in the inner pipe, in particular in a lower portion, with air being sucked in from the environment through the air intake opening, which air enters the inner pipe through the passage opening can get. On the one hand, this ensures a uniform suction power and, on the other hand, enables the air that has been sucked in to be deflected through the through opening (s) in the inner tube. The resulting air turbulence in the inner pipe enables finely dosed suction of the solids and prevents the sucked-in solid particles from clogging the suction lance at the start of suction, especially when the suction device is tightened.

The positioning of the air intake opening on the suction lance means that air openings in optionally exchangeable storage containers can be dispensed with.

The air intake opening is expediently designed to be changeable, e.g. with a throttle slide that partially covers the air intake opening. The air intake opening can also have an air filter in order to prevent or at least reduce the entry of undesired foreign substances.

The inner tube and the outer tube of the suction lance can preferably be designed to be displaceable relative to one another in the axial direction. The inner and outer pipes thus form an annular air gap, so that when there is negative pressure in the suction line, air is sucked through the air intake opening and into the annular gap and which is swirled at the tip of the suction lance and sucked out again via the inner pipe. Material located at the suction lance tip can be carried away. The air vortex conditions can be advantageously adjusted by positioning the inner and outer tubes accordingly. In particular, the amount of air sucked in from the environment per unit of time can be adjusted by changing the cross section of the air intake opening by axially displacing the inner tube with respect to the outer tube. This enables precise dosing of the solids sucked into the mixing container. With a higher amount of air sucked in, the suction behavior is finer (less).

The suction lance is expediently movably mounted in or on the storage container. As a result, automatic tracking of the suction lance, in particular due to negative pressure or gravity, is possible.

In advantageous developments, the amount of air sucked in from the environment per unit of time can also be advantageously adjusted by means not described above. In one embodiment, between a suction line, which is arranged between the suction device and the mixing container, a throttle element for adjusting the suction Air volume and / or arranged to regulate the flow rate. The throttle element can advantageously be designed as a ball valve. In this way, operating errors can be avoided or at least reduced.

In an advantageous embodiment, the dosing and mixing system comprises at least two storage containers and an automatic container switchover, with the container switchover selecting a storage container from which free-flowing solid material is conveyed into the mixing container.

The metering and mixing system expediently has a mixing device for mixing the solution present in the mixing container. The mixing device could, for example, be designed with one or more propellors in a vertical or other construction. The mixing device is advantageously designed in such a way that it generates vertical turbulence with respect to the axis of rotation of the propeller (s) and as a result an approximately closed vortex field is established in the solution or concentrate, which in particular makes it difficult for chlorine sludge to deposit on the bottom of the storage container will.

A direction of rotation of the mixing device can expediently be configured to be switchable. In particular during the production of the chlorine-containing solution or suspension, the production process can be accelerated or the solubility of the chlorine-containing solid can be improved by a single or multiple change of direction.

In the method according to the invention for operating a dosing and mixing system, it is provided that the control device activates the suction device after opening the shut-off device or when the shut-off device is already open for room air conditioning at predetermined intervals and for a predetermined duration, the control device opening the locking device before activating the suction device . In this way, a constant indoor air quality, especially without hazardous gases and without odor nuisance, can be guaranteed. It can also be used to dehumidify storage and mixing containers. Time-controlled air preparation also manages without room air sensors for recording room air parameters, so that the method enables particularly cost-effective operation of the system.

The method according to the invention can provide intervals of 2 to 60 minutes, preferably 10 to 20 minutes, particularly preferably 12-15 minutes. The method according to the invention can provide durations of 5 to 120 seconds, preferably 10 to 60 seconds and particularly preferably 10-30 seconds. With such intervals and durations, the indoor air quality can be adjusted depending on the size of the room and the activity of the dosing and mixing system.

In an alternative method for operating a dosing and mixing system, it is provided that the dosing and mixing system has a room air sensor and the control device activates the suction device when the shut-off device for room air treatment is open, if a value determined by the room air sensor exceeds an (upper) threshold value and is expediently deactivated if the value determined by the room air sensor falls below a (lower) threshold value.

Advantageous forms and further features of the invention emerge from the accompanying figures and the following description of the figures. Reference can be made alternately to the subject matter according to the invention and the method according to the invention.

Fig. 1

eine erste Ausführungsform einer erfindungsgemäßen Dosier- und Mischanlage,

Fig. 2

eine zweite Ausführungsform einer erfindungsgemäßen Dosier- und Mischanlage, und

Fig. 3

eine Detaildarstellung der Sauglanze der Dosier- und Mischanlage gemäß den Figuren 1 und 2 sowie

Fig. 4

eine Detaildarstellung einer Sauglanze für die Dosier- und Mischanlage gemäß den Figuren 1 und 2 in einer weiteren Ausführungsform.

Show it

Fig. 1

a first embodiment of a dosing and mixing system according to the invention,

Fig. 2

a second embodiment of a metering and mixing system according to the invention, and

Fig. 3

a detailed representation of the suction lance of the dosing and mixing system according to the Figures 1 and 2 as

Fig. 4

a detailed representation of a suction lance for the dosing and mixing system according to the Figures 1 and 2 in a further embodiment.

Fig. 1 shows a metering and mixing system according to the invention for producing a chlorine-containing solution or suspension. The solution or suspension is prepared in a mixing container 100, the preparation being carried out by mixing water supplied via a water supply 90 and material supplied via a material supply 60 in the form of a free-flowing solid such as granular hypochlorite. The mixing container is designed, for example, as a cylindrical container. The material feed 60 and the water inlet 90 are arranged on the upper side of the mixing container 100 in this exemplary embodiment. In particular, the water inlet 90 could, however, also be arranged elsewhere, for example near the bottom of the mixing container 100. As a result, the water inlet could take place more calmly, in particular with less splashing water. At the same time, however, the delivery rate for the water supply would have to be increased by the amount of the hydrostatic pressure forces in the mixing container 100.

The terms “material” and “solid” are to be understood synonymously in the context of the entire description with the term “free-flowing solid” used in the claims.

The water is conveyed into the mixing container 100 via a fluid conveying device 9, designed here as a motive water pump. A corresponding metering in of the desired amount of water can take place, for example, using a volume measuring device located in the water supply line. The amount of water can, however, also be determined by means of power consumption or measurement of the rotational speed of the fluid delivery device. In the specific exemplary embodiment, the water supplied is determined by a non-contact fill level meter 12. The fill level meter 12 is designed here as an ultrasonic sensor and determines a distance between the fill level sensor and a water or fill level of the mixing container 100. The amount of water supplied can be determined comparatively precisely if the water and material are added sequentially, i.e. one after the other.

After water has been added, in this exemplary embodiment the free-flowing solid is added via the material inlet 60, the amount of material added being recorded by measuring the weight difference of the weight of the storage container 1. The free-flowing solid is stored in the storage container 1. The manner in which the solid is conveyed is described in more detail below. The weight difference is measured using a measuring device 4 located on a receptacle of the storage container 1. In the specific case of the exemplary embodiment, the measuring device is a capacitively operating load cell. However, other measuring devices with other measuring principles could also be used.

After the material has been added, water and material are stirred with one another via a mixing device 10, which is designed here as a stirrer. The metered solid goes into solution and / or suspension. Instead of an agitator, however, water and material could also be set in motion or circulated in the mixing container via a jet pump or some other fluid delivery device for blending and mixing.

The prepared solution or suspension is distributed as required via a removal device (not shown) comprising one or more discharge devices to appropriate sinks. The sinks can be intermediate storage for the temporary storage of the solution or suspension. In particular, several different solutions or suspensions, which differ in terms of their chlorine content, for example, could be stored through a large number of intermediate stores. The sinks can, however, also be one or more swimming pools, whereby depending on the pool volume different chlorination requirements and thus suspension or solution requirements can prevail, so that discharge devices preferably adapted to the sinks are connected to the dosing and mixing system. If there are several sinks (multi-circuit system), each sink can be provided with its own discharge device.

The metering and mixing system detects the withdrawal volume of the solution or suspension via the fill level meter 12, so that the fill level meter provides a signal by means of which a new production process for the production of another chlorine-containing suspension solution can be started.

To control the production of the solution or suspension, the metering and mixing system has a control device S, not shown in the figures, in which measurement signals from various internal or external measurement sensors and actuators can converge. The control device S can have means for automatic control of the individual actuators. The control device can also comprise a graphical or non-graphical user interface for the input of commands or the setting of automatic program sequences by a user. The control device S can, for example, be wirelessly connected to a local or non-local network (LAN or WAN) and can be reached via the network (web application, server). The control device S can have further interfaces for one-way or two-way communication with other devices, for example a bus connection.

The metering in of the free-flowing solid is described below. As already mentioned, the solid is located in a storage container 1. The storage container 1 can be, for example, a cylindrical delivery container. The storage container 1 is placed in a receptacle of the dosing and mixing system. In the receptacle, the storage container 1 can advantageously be inclined so that the solid, due to gravity, tends towards a "corner" of the storage container. This makes it easier to empty the residue.

The receptacle of the storage container 1 has the above-mentioned weighing cell 4, which detects the current weight of the storage container 1. This can be used in the above-mentioned manner to determine a metered in or withdrawn amount of solid matter. At the same time, a fill level of the storage container can also be determined via the weighing cell 4, so that the control device S can send a maintenance signal for the exchange of the storage container 1 at a given time.

Additionally or alternatively, the dosing and mixing system could include a second storage container and an automatic container switchover (not shown) which, when the first storage container is running low, switches the conveyance of the solid from the first storage container to the second (full) storage container. An automatic container switchover can be implemented, for example, by two holding devices equipped with load cells for the two storage containers, two 2-way valves that can be switched via the control device S, each storage container having a suction lance that is connected to that of the suction line. As a result, maintenance and replacement intervals can be reduced and personnel costs can be lowered.

Furthermore, the receptacle of the storage container 1 expediently has a vibration device 5 with which the material or solid in the storage container 1 can be made to vibrate in order to achieve a uniform distribution of the solid in the storage container.

A suction lance 2 is immersed in the storage container or its upper cover. The suction lance 2 comprises an outer tube 2b and an inner tube 2a, which are concentrically and radially spaced from one another and are arranged axially displaceable with respect to one another. Inner and outer tube 2a, 2b form an outer annular gap 21, which at the upper end has a Air intake 3 is connected atmospherically. The inner pipe 2a forms a suction pipe which is connected to the suction line 6.

In Figure 3 a preferred embodiment of the suction pipe 2 is shown in detail. The lower end of the inner tube 2a has a material suction opening 20. The upper end of the inner tube 2 a is connected to the suction line 6. Ambient air is sucked into the inner tube 2a through the material suction opening 20 via the air inlet 3 and the annular gap 21. The material suction opening 20 can expediently be spaced apart from the end of the outer tube 2b in the axial direction. This can prevent the inner tube 2a from touching down directly on a bottom section of the storage container 1 and from being able to get stuck.

In particular, the outer tube 2b can advantageously have a crown-like end or a crown-like attachment in order to prevent the outer tube 2b from being sucked into the bottom section of the storage container 1.

In order to avoid lump formation in the suction line 6, the suction lance 2 in the Figure 3 Have lump breakers, not shown in detail, at the tip of the suction lance 2. These can, for example, be designed as transverse webs in the inner tube 2a, in particular in the immediate vicinity of the material suction opening 20, and / or on the outer tube 2b. A lump breaker helps break up clumped solids. This can reduce the risk of a blockage in the suction line.

The inner tube 2a of the suction lance 2 can also have one or more through opening (s) 22, for example in the form of transverse bores or punctiform openings in the wall of the inner tube 2a, which creates a fluidic connection from the inside of the inner tube 2a to the annular gap 21.

The at least one passage opening 22 in the inner tube 2a allows air to flow through the inner tube 2a even in the event of a blockage of the material suction opening 20 of the suction lance 2, whereby the air flow creates a negative pressure in the inner tube 2a and a continuous suction force is maintained. This allows blockages that have arisen to be resolved. In addition, the through openings 22 can be a bring about advantageous turbulence of the air flow in the inner tube 2a or at the material suction opening 20.

As already mentioned, the inner tube 2a is axially displaceable with respect to the outer tube 2b. A corresponding mounting can be designed in the form of projections on the outer tube 2b and / or on the inner tube 2a that bridge the annular gap 21 and act as slide bearings. A fixing of the inner pipe 2a to the outer pipe 2b can be realized by the static friction adhering to the sliding bearing. However, separate locking mechanisms such as a locking screw can also be used.

To adjust the air flow rate (given the suction power of the suction device 17), the cross section of the air suction opening 3 of the suction lance 2 is expediently designed to be variable, so that the amount of air supplied per unit of time can be adjusted. In the in Figure 3 The illustrated embodiment of the suction lance 2, the adjustment of the size of the air intake opening 3 takes place by axial displacement of the inner tube 2a with respect to the outer tube 2b.

In the embodiment according to Fig. 3 the size of the air intake opening 3 is determined by the axial distance from the upper end of the outer tube 2b and a thickening 23 of the inner tube 2a. The smaller the axial distance between the thickening 23 and the upper end of the outer tube, the smaller the cross section of the air intake opening 3 and the smaller the amount of air conveyed through the annular gap 21.

The thickening 23 is firmly connected to the inner tube 2a or formed thereon. By axially adjusting the inner tube 2a relative to the outer tube 2b, the distance between the thickening 23 and the upper end of the outer tube 2b can be changed. In the event of an adjustment, the cross section of the air intake opening 3 and at the same time also the distance between the intake opening 20 and the lower end of the outer tube 2b change.

Alternatively, the thickening 23 can, however, also be fastened releasably or axially displaceably on the inner tube 2a, for example by means of a clamping screw. As a result, the cross section of the air intake opening 3 can be adjusted independently of the axial distance between the intake opening 20 and the lower end of the outer tube 2b.

The cross section of the air intake opening 3 can, however, alternatively also be changed via a throttle valve arranged in the air intake opening 3, a throttle valve or a throttle slide.

In an in Fig. 4 The illustrated variant of a suction lance or each air intake opening 3 can be designed invariably, for example as a radial bore in the outer tube. As a result, an axial displacement of the inner tube 2a relative to the outer tube 2b is possible without simultaneously changing the size / cross section of the air intake opening (s) 3. In the in Fig. 4 In the variant shown, the inner tube 2a and the outer tube 2b are connected to one another via a connector part 24. The connector part 24 is firmly connected to the outer tube 2b and the inner tube 2a is mounted in the connector part 24 so that it can move axially.

By regulating the air supply into the inner tube 2a of the suction lance 2, the suction force setting and thus the amount of material conveyed per unit of time can be set very precisely.

The solids are conveyed from the storage container 1 via the suction lance 2, the suction line 6 and the material inlet 60 into the mixing container 100 by negative pressure. The negative pressure is generated via a suction device 17. The suction device 17 has, for example, a suction turbine which is connected to the mixing container 100 via a suction line 14. When the suction device 17 is activated, a negative pressure is therefore generated in the mixing container 100. The negative pressure is propagated into the storage container 1 via the material inlet 60, the suction line 6 and the inner pipe 2a. In essentially equivalent alternative embodiments, the suction device 17 can also be designed quite generally as a vacuum device, and in particular as a side channel compressor.

Ambient air is sucked through the annular gap to the tip or material suction opening 20 of the suction lance 2 via the annular gap of the suction lance 2, which is atmospherically connected by the air intake opening 3. The sucked in air swirls the material located there and conveys the thus fluidized solid into the suction line 6 via the inner pipe 2a serving as a suction pipe.

In the first operating mode, material is conveyed through the suction lance 2 as long as the suction device 17 is activated or negative pressure prevails and this negative pressure also occurs in the suction lance 2 or the storage container 1 is available. A conveying of material can thus be interrupted by either deactivating the suction device 17 or canceling the negative pressure in the storage container 1 or the suction pipe 2a in some other way.

A blocking device 7 is provided for a quick interruption of the negative pressure in the suction line 6 and thus in the inner tube 2a of the suction lance 2. According to the embodiment of Fig. 1 this locking device 7 is arranged on the top of the mixing container 100. The blocking device 7 blocks the connection between the air inlet 80 of the mixing container 100 and the atmosphere or the ambient air.

If the locking device 7 is open, the interior volume of the mixing container is connected to the atmosphere via the air inlet 80. This results in a flow separation in the suction line 6, as a result of which the negative pressure in the suction line 6 is also eliminated. The conveyance or metering in of the material from the storage container 1 into the mixing container 100 is thereby abruptly interrupted.

If the suction device 17 continues to be operated with the locking device 7 open, (room) air is conveyed via the air inlet 80 through the mixing container into the suction line 14. The suction device 17 also has an air filter 15 for air conditioning. The air filter 15 can be an activated carbon filter which is combined with a particle filter for filtering out suspended matter and aerosols. As a result, the air in the inner container of the mixing container 100, in the storage container 1 and in the suction line 6 as well as the air sucked in from the outside (room) can be prepared, ie cleaned of odors, gases and suspended matter. The air filter is arranged here in the flow of the suction device 17. However, it would also be possible to arrange the air treatment by the filter 15 in the wake of the suction device 17, for which purpose the air filter can also be placed outside and downstream of the suction device 17. An air conditioning system placed in the lead has the advantage that in particular solid particles located in the suction flow are retained in the air filter and therefore cannot reach the suction device 17. As a result, damage or wear to the suction device 17 can be prevented or at least reduced.

After a certain delay time, the suction device 17 can be deactivated and the locking device 7 opened. The suction device can also be deactivated immediately when the desired metered quantity of material is reached, without any follow-up time

The metering and mixing system operated in this way can be used in the manner described above for conveying and metering material into the mixing container 100 (first operating mode).

The dosing and mixing system can, however, also be used to prepare room air via the air filter 15 (second operating mode). For this purpose, the blocking device 7 is opened before the suction device 17 is activated, so that air flows via the air inlet 80 through the mixing container 100 into the suction line 14 and the air filter 15. As a result, air treatment can also be achieved independently of material conveyance.

The air treatment can be operated as required, in particular periodically at intervals for a certain duration. With frequent suspension preparation and / or with small operating rooms of the dosing and mixing system, the intervals can be shorter and / or the durations D can be longer. For example, the intervals I range from 2 to 60 minutes and the durations from 5 to 120 seconds.

The locking device 7 is designed, for example, as a spring-loaded solenoid valve. Due to the short response times, a solenoid valve is suitable for rapid activation and thus very precise regulation of the dosing rate.

In the example, the blocking device 7 is designed to be NO-logic (normally open), i.e. it is always open in the idle state and is closed when energy is supplied.

Furthermore, the inlet of the suction line 14, ie the air suction point 13, in this embodiment is advantageously positioned higher and laterally offset than the material inlet 60 and just as advantageously higher and laterally offset than the air inlet 80 larger in the mixing container 100, which leads to a better exchange of air. When the locking device 7 is closed, the unwanted suction of material into the suction line 14 can be avoided while the material is being conveyed, since the increased air suction point 13 no or at least less material is sucked into the suction line 14 and the material safely sinks into the mixing container 100.

In an alternative embodiment according to Fig. 2 the locking device 7 is not designed with a separate air inlet 80 on the mixing container 100, but rather is designed in or on the suction line 6. The locking device 7 thus divides the suction line 6 into a first section 6a and a second section 6b. The locking device 7 can be placed at almost any point along the suction line 6.

By placing it in or on the suction line 6, the air flow generated during air conditioning (second operating mode) can remove condensation water not only from the mixing container 100, but also from the second section 6b. Furthermore, the locking device 7 can be spaced from the mixing container. As a result, the locking device 7 is in particular not exposed to any spray water and less moisture from the interior of the mixing container 100.

In the embodiment of Fig. 2 the blocking device 7 is also only indirectly connected to the suction line 6 via an air lock 70. The air lock 70 divides the suction line 6 into a first section 6a and a second section 6b. In an airtight chamber, the first section 6a and the second section 6b of the suction line 6 are fluidly connected to one another in an open manner, here in the form of a nozzle-funnel arrangement 71 Air lock 70 and the environment are established and thereby a flow separation in the first section 6a of the suction line 6 are caused. Correspondingly, the air from the environment is sucked in via the air lock 70 via the second section 6b and the air inlet 80 into the mixing container 100 and removed again via the suction line 14 and the air filter 15. As a result of the air lock 70, the locking device 7 essentially no longer comes into contact with the conveyed material. As a result, clogging of the locking device with free-flowing material or parts thereof (dust) can be largely prevented. In addition, the cross section of the air inlet 80 can also be selected independently of the cross section of the suction line 6. The blocking device 7 can also expediently be arranged at a highest point of the housing of the air lock 70. This allows warm, moist air to escape from the system when the locking device is open.

In contrast to the first exemplary embodiment, the air inlet 80 and the material inlet 60 are identical. As a result, the material inlet 60 is also cleaned during the air treatment without material conveyance, so that the suction line 6 or material inlet is cleaned of humidity or condensation and clogging or overgrowing of the material inlet with deposits can be prevented or at least reduced.

The nozzle-funnel arrangement 71 is arranged vertically in this exemplary embodiment. As a result, misdirection of the free-flowing solid can be avoided or at least reduced.

The metering and mixing system designed in this way can furthermore reduce a vacuum volume to be placed under vacuum for the conveyance of material, the housing of the mixing container 100 can be made more stable and thus the suction power of the suction device 17 can be reduced.

Furthermore, in this second exemplary embodiment, the air lock 71 is arranged downstream behind a highest point P of the suction line. If there is no negative pressure, material located upstream of point P falls back into the storage container 1, while material located downstream of point P falls into the mixing container 100 via the nozzle-funnel arrangement 72.

The rest of the structure of the dosing and mixing system is otherwise identical to the embodiment of FIG Fig. 1 . To convey the free-flowing solid, the blocking device 7 is correspondingly closed, so that when the suction device 17 is activated, the solid falls over the nozzle of the first section 6a into the second section 6b and is transported into the mixing container 100.

List of reference symbols:

1

Storage container

2

Suction lance

2a,

Inner tube of the suction lance

2 B

Outer tube of the suction lance

3

Air inlet suction lance

4th

Measuring device

5

Vibration device

6th

Suction line

6a

Suction line (first section)

6b

Suction line (second section)

7th

Locking device

9

Motive water pump water filling

10

Mixing device (agitator)

12th

Level meter

13th

Air extraction point

14th

Suction line

15th

Filters for exhaust air and room air treatment

17th

Suction device (vacuum generator)

20th

Material suction opening (of the inner tube 2a)

21

Annular gap

22nd

Passage opening (of the inner tube 2a)

23

Thickening (of the inner tube 2a)

24

Connection part (for inner and outer pipe 2a, 2b)

60

Material feed

70

Airlock

71

Connection funnel arrangement

80

Air inlet

90

Water inlet

100

Mixing tank

P.

geodetically highest point of the suction line

Claims (15)

Dosing and mixing system for the production of a chlorine-containing solution or suspension from a chlorine-containing, free-flowing solid, comprising a mixing container (100) with a water inlet (90) and a material inlet (60) for the free-flowing solid, a storage container (1) holding the free-flowing solid , a suction line (6) connecting the mixing container and the storage container (1), a suction device (17) attached to the mixing container for generating a suction pressure for conveying the free-flowing solid into the mixing container (100) and a blocking device (7) for the selective connection of the mixing container (100) with the ambient air to interrupt the conveyance of the free-flowing solid into the mixing container (100), as well as a control device (S) for controlling the suction device (17) and the locking device (7), the suction device (17) being air from the environment sucks, through which the suction of the free-flowing solid from the storage container it (1) is controllable, characterized in that
that the suction device (17) is assigned an air filter (15) in the upstream or downstream, so that the air sucked in by the suction device can be filtered and, in particular, freed from chlorine components, and
that the control device (S) for controlling the suction device (17) and the locking device (7) in a first operating mode for conveying the free-flowing solid when the locking device (7) is closed and a second operating mode for processing the room air and the container air when the locking device is open (7 ) is set up, wherein the first operating mode can take place independently of the second operating mode. Dosing and mixing system according to Claim 1, characterized in that the mixing container has an air inlet (80) into the mixing container (100) and that the material inlet (60) into the mixing container (100) is identical to the air inlet (80). Dosing and mixing system according to Claim 1 or 2, characterized in that the blocking device (7) is arranged behind a highest reversal point (P) of the suction line (6), seen in the direction of conveyance of the free-flowing solid. Dosing and mixing system according to one of the preceding claims, characterized in that the blocking device (7) is assigned to the suction line (6) via an air lock (70) and is arranged at a distance from the suction line (6), the air lock (70) being the suction line (6) divides into two sections (6a, 6b). Dosing and mixing system according to Claim 4, characterized in that the subsections (6a, 6b) of the suction line (6) in the air lock (70) are assigned to one another via a nozzle-funnel arrangement (71), one subsection of the suction line has a connecting piece and the other section comprises a funnel which is arranged below the connecting piece and at a distance therefrom. Dosing and mixing system according to one of the preceding claims, characterized in that the locking device (7) is designed as a switchable valve, in particular as a valve which can be magnetically actuated by a tie rod. Dosing and mixing system according to one of the preceding claims, characterized in that the dosing and mixing system contains a receptacle in which the storage container (1) can be adjusted in particular at an angle, the receptacle preferably being coupled to a vibration device (5). Dosing and mixing system according to one of the preceding claims, characterized in that the dosing and mixing system comprises a suction lance (2) which can be immersed in the storage container (1) and which has a material suction opening (20) at its immersible end for sucking in the free-flowing solid and axially at a distance therefrom has an air intake opening (3) for drawing in air from the environment. Dosing and mixing system according to claim 8, characterized in that the suction lance (2) comprises an inner pipe (2a) and an outer pipe (2b), the inner pipe (2a) and the outer pipe (2b) being concentrically and radially spaced from one another and axially The inner tube (2a) is used to suck in the free-flowing solid from the storage container (1) and air from the environment is sucked into the annular gap (21) formed between the inner tube (2a) and the outer tube (2b) will. Dosing and mixing system according to claim 8 or 9, characterized in that in the outer pipe (2b), in particular in an upper section, at least one air intake opening (3) and in the inner pipe (2a), in particular in a lower section, at least one passage opening (22) is introduced, air being sucked in from the environment through the air intake opening (3), which air can enter the inner tube (2a) through the passage opening (22). Dosing and mixing system according to one of the preceding claims, wherein the amount of air sucked in from the environment per unit of time is adjustable, in particular with a throttle element arranged in a suction line (14) between the mixing container (100) and the suction device (17). Dosing and mixing system according to one of the preceding claims, characterized in that the dosing and mixing system comprises at least two storage containers and a container switch, whereby the container switch controls the storage container from which pourable solid is conveyed into the mixing container. Dosing and mixing system according to one of the preceding claims, characterized in that the dosing and mixing system has a room air sensor. Method for operating a dosing and mixing system according to one of the preceding claims, characterized in that the locking device (7) is opened or is opened before the control device (S) controls the suction device (17) with the locking device (7) open for conditioning the room air and the container air is activated at predetermined intervals and for a predetermined duration. Method according to Claim 14, characterized in that the predetermined intervals are 2 to 60 minutes, in particular 10 to 20 minutes, and the predetermined duration is 5 to 120 seconds, preferably 10 to 30 seconds.

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