MIXING INSTALLATION WITH A DOSING DEVICE

A mixing installation is provided for mixing a first agent to a liquid. The mixing installation includes a dosing assembly and a first agent supply conduit. The dosing assembly includes a venturi arrangement and a first dosing device between the first agent supply conduit and the venturi arrangement. The first dosing device includes a first agent passage and a first dosing mandrel having a first dosing pin that extends in the first agent passage, wherein the first dosing mandrel is axially slidable in its axial direction with respect to the first main body over a first release stroke by pulling between a dosing position in which the first dosing pin extends inside the first agent passage to define a first ring shaped dosing channel around the first dosing pin, and a retracted position in which the first ring shaped dosing channel is cancelled.

BACKGROUND

The invention relates to a mixing installation with a dosing assembly for dosing an agent to a liquid. The agent is for example a disinfectant that is added to a high pressure water flow, for example for cleaning or disinfecting animal stables or barns, for example cattle stables, pig stables or chicken barns.

A known mixing installation for dosing an agent to a water flow for that purpose comprises a high pressure water pump that feeds the water flow into a venturi assembly. The venturi causes an under pressure that draws the agent from an agent container into the passing water flow. The dosage is for example set by means of an internal choke pipe.

SUMMARY OF THE INVENTION

A disadvantage of the known mixing installation is that the mixing installation is that in practice it works only very well with agents that are free of any particle containing dirt. When the agent accidentally contains some hard particles, for example sand that is present in an animal breeding environment, the choke pipe may become clogged. When this is not noticed by the operator, the water flow lacks the required disinfecting properties. The stable or barn may therefore not meet the prescribed sanitary requirements.

It is an object of the present invention to provide a mixing installation with a dosing assembly for dosing an agent to a liquid, that can be operated in animal stables or barns, for example cattle stables, pig stables or chicken barns.

According to a first aspect, the invention provides a mixing installation for mixing a first agent to a liquid, wherein the mixing installation comprises a liquid supply conduit, a mixture discharge conduit, a dosing assembly between the liquid supply conduit and the mixture discharge conduit, a first agent container, and a first agent supply conduit between the first agent container and the dosing assembly, wherein the dosing assembly comprises a venturi arrangement between the liquid supply conduit and the mixture discharge conduit, and a first dosing device between the first agent supply conduit and the venturi arrangement, wherein the first dosing device comprises a first main body with a first agent passage that is in fluid communication with the first agent supply conduit and the venturi arrangement, and a first dosing mandrel having a first dosing pin that extends in the first agent passage, wherein the first dosing mandrel is reciprocally slidable in its axial direction with respect to the first main body over a first release stroke between a dosing position in which the first dosing pin extends inside the first agent passage to define a first ring shaped dosing channel around the first dosing pin with a constant first radial flow height around the circumference of the first dosing pin, and a retracted release position in which the first ring shaped dosing channel is cancelled.

The mixing installation according to the invention comprises a first dosing device having a first ring shaped dosing channel with a defined first radial flow height around the circumference of the first dosing pin to set the feed of agent to the venturi arrangement with high accuracy. However, when the first agent contains some dirt, for example sand, it may get stuck and accumulate in front of or inside the first ring shaped dosing channel. The accumulated dirt can easily be released an removed by sliding the dosing mandrel from the dosing position into the retracted release position whereby the entire first agent passage is cancelled to allow the accumulated dirt to escape via the venturi assembly. This can be performed regularly to ensure a proper dosage of the first agent.

In an embodiment the first ring shaped dosing channel has the constant first radial height over the length of the first ring shaped dosing channel in the flow direction of the first agent passage, whereby the dosage can be set very accurately.

In an embodiment the first radial flow height is the smallest flow width as from the first agent container to the mixture discharge conduit, whereby it is guaranteed that the released dirt can escape via the venturi arrangement.

In an embodiment the first dosing device comprises a first spring that biases the first dosing mandrel over its entire first release stroke to the dosing position, whereby the first dosing pin can be pulled out of the first agent passage to release dirt, whereafter it can snap back to be ready for dosing again. This can be performed very quickly during the work in the stable environment, without having to take care of the dosage setting.

In an embodiment the first dosing device comprises a first linear slide bearing between the first main body and the first dosing mandrel for guiding the sliding movement of the first dosing mandrel with respect to the first main body over its first release stroke. A slide bearing allows the first dosing mandrel to slide with respect to the first main body while maintaining its orientation, that is without axial rotation.

In an embodiment the first dosing device comprises a first pull knob on the first dosing mandrel for manual pulling the first dosing mandrel into the retracted release position. The accumulated dirt can then very easily be removed by manually pulling on the first pull knob. This can be done for example when the first agent container is replaced.

In an embodiment the dosing assembly comprises a first check valve between the first dosing device and the venturi arrangement that prevents a backflow of the first agent from the venturi arrangement to the first dosing device.

In an embodiment the mixing installation comprises a first dirt filter before or inside the first agent supply conduit to prevent the entry of dirt having particles that are for example larger than that can pass the venturi arrangement. In this manner the entire flow path as from the first agent container to the mixture discharge conduit is protected against entry and accumulation of particles that cannot be released anymore by retraction of the first dosing mandrel.

In an embodiment the mixing installation comprises a container holder for insertion and holding the first agent container, whereby the first agent container can be embodied as a disposable or single use container, such as a jerrycan.

In an embodiment the mixing installation comprises a vertical support above the container holder, wherein the dosing assembly is vertically slidable along the vertical support between a low position in which the first agent supply conduit extends through a top opening of the first agent container, and a high position in which the first agent supply conduit is fully retracted from the first agent container. The vertical support can ensure that the inlet end of the first agent supply conduit remains free from a dirty floor.

In an embodiment the mixing installation comprises a second agent container and a second agent supply conduit between the second agent container and the dosing assembly, wherein the dosing assembly comprises a second dosing device between the second agent supply conduit and the venturi arrangement, wherein the second dosing device comprises a second main body with a second agent passage that is in fluid communication with the second agent supply conduit and the venturi arrangement, and a second dosing mandrel having a second dosing pin that extends in the second agent passage, wherein the second dosing mandrel is reciprocally slidable in its axial direction with respect to the second main body over a second release stroke between a dosing position in which the second dosing pin extends inside the second agent passage to define a second ring shaped dosing channel around the second dosing pin with a constant second radial flow height around the circumference of the second dosing pin, and a retracted release position in which the second ring shaped dosing channel is cancelled.

The mixing installation according to this embodiment is suitable for mixing two different agents to the liquid flow, for example a cleaning agent and a disinfection agent. The second dosing device may have the same features and advantages as the first dosing device.

In an embodiment thereof the second ring shaped dosing channel has the constant second radial height over the length of the second ring shaped dosing channel in the flow direction of the second agent passage.

In an embodiment the second radial flow height is the smallest flow width as from the second agent container to the mixture discharge conduit.

In an embodiment the second dosing device comprises a second spring that biases the second dosing mandrel over its entire second release stroke to the dosing position.

In an embodiment the second dosing device comprises a second linear slide bearing between the second main body and the second dosing mandrel for guiding the sliding movement of the second dosing mandrel with respect to the second main body over its second release stroke.

In an embodiment the second dosing device comprises a second pull knob on the second dosing mandrel for manual pulling the second dosing mandrel into the retracted release position.

In an embodiment the dosing assembly comprises a second check valve between the second dosing device and the venturi arrangement that prevents a backflow of the second agent from the venturi arrangement to the second dosing device.

In an embodiment the mixing installation comprises a second dirt filter before or inside the second agent supply conduit.

In an embodiment the mixing installation comprises a container holder for insertion and holding the first agent container and the second agent container, whereby both the first agent container and the second agent container can be embodied as a disposable or single use container, such as a jerrycan.

In an embodiment thereof the mixing installation comprises a vertical support above the container holder, wherein the dosing assembly is vertically slidable along the vertical support between a low position in which the first agent supply conduit and the second agent supply conduit extend through top openings of the first agent container and second agent container, and a high position in which the first agent supply conduit and the second agent supply conduit are fully retracted from the first agent container and the second agent container.

In an embodiment the mixing installation comprises a high pressure water pump that is connected with the liquid supply conduit.

In an embodiment the mixing installation comprises a high pressure water gun that is connected with the mixture discharge conduit for manually cleaning by means of the mixing installation according to the invention.

According to a second aspect, the invention provides a dosing assembly for use in a mixing installation according to the invention.

The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, in particular the aspects and features described in the attached dependent claims, can be made subject of divisional patent applications.

DETAILED DESCRIPTION OF THE INVENTION

FIG.1shows a mixing installation1that comprises a metal container holder2with in this example a first agent container10that contains in this example a liquid cleaning agent, and a second agent container15that contains in this example a liquid disinfection agent. The container holder2comprises a bottom wall3, a back wall4, a top wall5that is partially cut out for illustration only, and two connecting side walls6that bound an insert opening7for insertion of the first agent container10and the second agent container15in direction A. The first agent container10and the second agent container15are both embodied as jerrycans, and comprise respectively a first screw connection11and a second screw connection16of which the screw caps have been removed for access via the respective first opening13and the second opening17inside the container holder2. Alternatively, the first agent container10and the second agent container15comprise a closure that can be pierced or teared off for access to the contained agent.

The mixing installation1comprises a metal dosing assembly holder21having a vertical support22that is connected to the container holder2. The dosing assembly holder21comprises a slider24that is slidable in a vertical direction B along two parallel elongated slots23in the vertical support22. The mixing installation1comprises a dosing assembly30that is mounted on the slider24.

The dosing assembly30is shown in more detail inFIGS.2A-2C, and comprises a metal casing31having a block-shaped casing base32that merges into a cylindrical fluid inlet section33in which an inlet connector40is screwed, and a cylindrical fluid outlet section34in which an outlet connector41is screwed. The dosing assembly30comprises a selection switch45having a ring section46that extends around the inlet section33, and a handle47that projects from the casing base32and that can toggle in direction C with respect to the inlet section33.

The dosing assembly30comprises a first agent supply conduit150for the first agent container10and a second agent supply conduit160for the second agent container15that are symmetrically shaped. The first agent supply conduit150is formed with a tube, and comprises a first straight section151that merges into a first transition section153that is mounted to the casing base32. The first agent supply conduit150comprises a first inlet filter holder152on the end of the first straight section151in which a not-shown first dirt filter is enclosed, and a first stop154at the merger of the first straight section151and the first transition section153. The second agent supply conduit160is formed with a tube, and comprises a second straight section161that merges into a second transition section163that is mounted to the casing base32. The second agent supply conduit160comprises a second inlet filter holder162at the end of the second straight section161in which a not-shown second dirt filter is enclosed, and a second stop164at the merger of the second straight section161and the second transition section163.

The first inlet filter holder152and the second inlet filter holder162are moveable in the vertical direction B by means of the slider24over a limited stroke between the fully retracted position as shown inFIG.1in which the first agent container10and the second agent container15can be placed into the container holder2, and a fully lowered position in which the first stop154and the second stop164abut the top wall5whereby the first filter holder152and the second filter holder162are in contact with, or just a few millimeters spaced apart from the bottoms of the first agent container10and the second agent container15.

As shown inFIG.1, the inlet connector40is via a liquid supply conduit170connected with a high pressure water pump171that can supply water at a pressure of more than 100 bar, preferably more than 200 bar. In this example the outlet connector41is via a mixture discharge conduit173connected with a high pressure water gun174.FIGS.1and2Ashow the handle47in its neutral position in which the water passes without agent dosage. When the handle47is set in direction C from the neutral position into a first or left position the dosing assembly30doses agent from the first agent container10to the passing water, and when the handle47is set in direction C from the neutral position into a second or right position, the dosing assembly30doses agent from the second agent container15to the passing water, both at a precisely defined dedicated dosage or mixing ratio for each agent.

As shown inFIG.2Cthe casing base32of the dosing assembly30encloses a venturi arrangement60between the inlet connector40and the outlet connector41. The venturi arrangement60defines in series an inlet channel61that merges into a venturi nozzle62, and a venturi channel64opposite to the venturi nozzle62that conically widens towards the outlet connector41.

As best shown inFIG.2B, the casing base32comprises a plunger channel50that at the ends merges into a first outlet channel51and a second outlet channel52with a smaller diameter than the plunger channel50. The dosing assembly30comprises a switch plunger55that can slide through the plunger channel50in an axial sliding direction D between the first outlet channel51and the second outlet channel52. The switch plunger55comprises an elongated plunger body56and a projecting notch54that is internally engaged by the selection switch45. The plunger body56carries a first end seal57for sealing off the first outlet51and a second end seal58for scaling off the second outlet52depending on its position in the sliding direction D as set by the selection switch45. The switching plunger55comprises two seals59around the plunger body56that seal off against the plunger channel50.

The casing base32comprises a first inlet channel155that is connected to the first agent supply conduit150and that debouches between the first outlet channel51and the adjacent seal59of the switching plunger55. The casing base32comprises a second inlet channel156that is connected to the second agent supply conduit160and that debouches between the second outlet channel52and the adjacent seal59of the switching plunger55. The casing base32comprises a first intermediate channel157that extends between the first outlet51and a first insert channel70, and a second intermediate channel158that extends between the second outlet52and a second insert channel71. The first insert channel70and the second insert channel72both debouche aside the venturi nozzle62and are in fluid communication therewith.

In this example the plunger channel50is a blind bore in the casing base32that is at one side closed by an screw cap53that comprises the first outlet channel51and a part of the first intermediate channel157. The first intermediate channel157and the second intermediate channel158are blind bores that are closed off by screws74. The first insert channel70and the second insert channel70are stepped bores in the casing base32.

The casing31comprises a not-shown venturi bypass channel for bypassing the venturi arrangement60, and a closing arrangement for the venturi bypass channel that is operated by the selection switch45. The closing arrangement closes off the venturi bypass channel in the first and second position of the handle47, and opens the venturi bypass channel when the handle47is in its neutral position as shown inFIGS.1and2A.

The dosing assembly30comprises a first dosing device80and a first check valve120in series therewith that are inserted in the first insert channel70, and a second dosing device81and a second check valve121in series therewith that are inserted in the second insert channel71. The first dosing device80and the second dosing device81are identical and are therefore described hereafter under reference to the first dosing device80as shown inFIGS.3A and3B.

The first dosing device80has a main body82that comprises a proximal side83with an internal cylindrical bearing passage84that merges via a first cylindrical guide chamber93and a widening abutment edge85into a wider cylindrical guide chamber86. The main body82comprises a distal end87with an internal cylindrical agent passage88. The bearing passage84and the agent passage88are aligned on the center line S of the first dosing device80. The main body82comprises a ring-shaped inlet89that is in fluid connection with the end of the first intermediate channel157. The ring-shaped inlet89merges via an internal conical wall90into the agent passage88. The agent passage88merges into an outlet91of the distal end87of the main body82.

The first dosing device80comprises a dosing mandrel100inside the main body82. The dosing mandrel100comprises a cylindrical bearing section101that extends through the bearing passage84to guide a sliding reciprocal movement of the dosing mandrel100in direction E, and a radially projecting collar102inside the guide chamber86that can come in abutment with the abutment edge85. The dosing mandrel100comprises a seal chamber103in which a seal104is enclosed to seal off against the wall of the first cylindrical guide chamber93. The dosing mandrel100comprises a distal end106that is bound by an external conical wall107that extends around its circumference parallel to the internal conical wall90of the main body82. The external conical wall107merges into a cylindrical dosing pin108. When the dosing mandrel100is in its dosing position as shown inFIG.3A, the collar102is in abutment with the abutment edge85and the dosing pin82extends centered through the agent passage88to define a ring shaped dosing channel110around the dosing pin82with a constant radial flow height around the circumference of the ring shaped dosing channel110and a constant radial flow height over the axial length of the ring shaped dosing channel110.

The first dosing device80comprises a screw cap112with a passage113for the dosing mandrel100. The screw cap112confines a push spring115that biases the dosing mandrel100via the collar102to its dosing position. The dosing mandrel100comprises a threaded end114to which a pull knob116is mounted by which the dosing mandrel100can be pulled in direction E against the bias of the push spring115to a temporal retracted release position in which the dosing pin82is fully retracted from the agent passage88whereby the ring shaped dosing channel110is temporally cancelled.

When during the operation of the pump171the handle47is in its neutral position, the pressurized water bypasses the venturi arrangement60whereby it is not active. When the handle47is in the selected first position or second position, the venturi bypass channel is closed, whereby the venturi nozzle62and the venturi channel64together cause an under pressure. The selected agent is sucked in via the first dirt filter or the second dirt filter and subsequently passes in the respective flow direction F, G the ring-shaped inlet89and the ring shaped dosing channel110of the respective first dosing device80or second dosing device81to enter the common venturi channel64via the respective first check valve120or second check valve121. In these flow paths the first dirt filter and the second dirt filter prevent entry of debris having a particle size that is larger than the cross section of the venturi nozzle62or that is larger than the smallest passage of the high pressure water gun174.

The ring shaped dosing channels110have a radial height or smallest flow width in the radial direction and the axial direction that is smaller than the cross section of the venturi nozzle62, which is necessary to obtain the precisely defined dosage or mixing ratio for each agent. The smaller particles of the debris that has passed the first dirt filter or the second dirt filter passes the ring shaped dosing channels110, while the larger particles may stick and accumulate at the entrance of the ring shaped dosing channels110. These accumulated particles can be released regularly by pulling on the knob116, whereby the dosing mandrel100is brought into its temporal retracted release position in which the dosing pin108is outside the agent passage88to release and flush away the accumulated particles via the venturi channel64.

The mixing installation1is very suitable to be used in animal stables or barns, for example cattle stables, pig stables or chicken barns that are regularly cleaned and disinfected by means of the high pressure water gun174. In those environments it is inevitable that some debris enters mixing installation1, for example during exchange of the agent containers10,15, or because the agents in the agent containers10,15is slightly polluted by sand for example which does not adversely affect the quality of the contained agent. The debris remains behind the first dirt filter or the second debris filter, or it is regularly released from the ring shaped dosing channels110to exit the mixing installation1via the venturi assembly60and the high pressure water gun174. As accumulated dirt in front of the ring shaped dosing channels110is regularly released, a practically constant correct dosage of the agent to the water flow is guaranteed.