WO2011003476A1

WO2011003476A1 - A dosing system and a cartridge

Info

Publication number: WO2011003476A1
Application number: PCT/EP2009/058873
Authority: WO
Inventors: Erik Cornelis Remijn
Original assignee: Ydroteq Nv
Priority date: 2009-07-10
Filing date: 2009-07-10
Publication date: 2011-01-13

Abstract

A dosing system (1) for dosing an additive (2) to a fluid flow comprises a fluid duct (6) for transporting a fluid and a container (9) which contains an additive (2). The container (9) is provided with an inlet (11) through which the container (9) communicates with the fluid duct (6) at a high-pressure location thereof for applying a pressure on the additive (2). The container (9) is also provided with an outlet (16-18) through which the container (9) communicates with the fluid duct (6) at a low-pressure location thereof for transferring a quantity of the additive (2) to the fluid duct (6). The fluid duct (6) is adapted such that under operating conditions the fluid pressure is lower at the low-pressure location than at the high-pressure location.

Description

A dosing system and a cartridge

The present invention relates to a dosing system for dosing an additive to a fluid flow.

Numerous dosing systems are known in the art. For example, a dosing system for adding an additive to tap water is known, but the system is complex and expensive.

The object of the invention is to provide a simple and low-cost dosing system.

This is achieved by the dosing system according to the invention which comprises a fluid duct for transporting a fluid, a container which contains an additive, wherein the container is provided with an inlet through which the container communicates with the fluid duct at a high-pressure location thereof for applying a pressure on the additive, and an outlet through which the container communicates with the fluid duct at a low-pressure location thereof for transferring a quantity of the additive to the fluid duct, wherein the fluid duct is adapted such that under operating conditions the fluid pressure is lower at the low-pressure location than at the high pressure location.

Under operating conditions there is a fluid flow through the fluid duct. Due to the pressure difference between the pressure on the additive and that at the low-pressure location under operating conditions the additive will be added to the fluid flow in the fluid duct. Thus, a pumping force for dosing the additive into the fluid duct is generated by the fluid flow itself. If there is no fluid flow the dosage of additive will be negligible because of the absence of a pressure difference. The advantage of the dosing system according to the invention is its simplicity because there are no moving parts and there is no requirement of electronic controls, for example. As a consequence, the dosing system can be manufactured at relatively low costs which is particularly beneficial in poor- countries which have water of low quality, for example.

The container may be adapted such that fluid from the inlet can mix with a substance in the container to form the additive. This means that under operating conditions the fluid that enters the container and mixes with the substance forms an additive that is injected into the fluid duct at the low- pressure location. When a quantity of the additive has left the container it will be automatically refilled by the fluid and a new quantity of additive will be prepared. In this case the fluid is both a pumping means and mixing means for preparing the additive. This is for example advantageous in case of a solid substance that partly solves in the fluid up to a certain

concentration in the fluid after which the additive in the form of a solved mixture is injected in the fluid duct whereas fresh fluid enters the container in which a remainder of the substance can solve.

The outlet may comprise a channel-shaped restriction and a dosing nozzle which communicates with the channel-shaped restriction and the fluid duct at the low-pressure location, and the channel-shaped restriction may have a length that is larger than twice, and preferably larger than five times its internal diameter. The channel-shaped restriction influences the quantity of additive injection on the basis of the pressure difference between the high pressure and low-pressure location, hence the mixing ratio of the fluid and the additive in the fluid duct. Furthermore, the channel -shaped restriction forms a storage for the additive to be injected at the low-pressure location such that the prepared additive is directly available upon starting a fluid flow through the fluid duct.

Preferably, the channel-shaped restriction has a spiral shape since this appears to be an efficient structure, A high ratio between channel length and volumetric space of the channel can be achieved. The spiral may be wound about the dosing nozzle and extend in a substantially flat plane, for example.

The flow-through area of the fluid duct at the low- pressure location may be smaller than the flow-through area at the high-pressure location. This is a simple way of creating a lower pressure at the low-pressure location than at the high- pressure location.

In practice, the high-pressure location will be

upstream of the low-pressure location since the injection of the additive is in fresh fluid in that case and not in fluid that already contains injected additive. Tne fluid duct may comprise a non-~return valve tc avoid a siι.uat.ion Lr.at return flow Ir. the fluid duct will create undcsircd dosage of adcitive.

In a preferred embodiment the container is part of a replaceable cartridge, because after consumption of the additive it is easy to replace the cartridge with a fresh one including the additive. In case of a substance that mixes with and/or solves in the f._uid under operating conditions the fresh

cartridge may only contain the substance.

The additive may be a scale inhibitor ir. order to prevent any installation from build up of deposits m tap water.

The additive may comprise a substance including an indication member for indicating the quantity of substance in tήe container and the dosing system is adapted sαch that the indication member is visible. In practice in case of a substance of grains or powder to which water is addeα m the container via the inlet thereof an indication member such as a ball will be adapted such that it sinKs to the bottom of the water part whicn coincides with the cop of the grains, powder glassy pearls, or the like. This provides the opportunity to monitor the substance level during use.

The invention is also related to a cartridge for use in a dosing system, which comprises a container for containing an additive, wherein the container is provided with an inlet for receiving a high pressure flαid for applying a pressure on the additive, and an outlet for transferring a quantity ot the additive to the outside of the container upon applying a

pressure on the additive.

The inlet may form one end of a channel which extends inside the container, whereas another end of the channel is located close to an inner wall of the container, preferably at a distance smaller than 5 mm.

The outlet may comprise a channel -shaped restriction ana a dosing nozzle, wherein the channel -shaped restriction may have a length that is larger than twice, and preferably larger than five times its internal diameter.

Preferably the channel-shaped restriction has a spiral shape as elucidated hereinbefore. The cartridge nay contain an additive which is a scale inhibitor, but alternative additives are conceivable. As stated hereinbefore the additive may be prepareα in the container itself by adding a fluid to the container which contains a substance that solves in the fluid.

The invention will hereafter be elucidated with

reference to the very schematic drawings showing embodiments of the invention by way of example.

Fig. 1 is a cross-sectional view of a.n embodiment of the dosing system according to the invention.

Fig. 2 is a cross-sectional view along the line Tl-II in Fig. 1.

Fig. 3 is an enlarged partial view of a slightly different embodiment of that according to Fig, 1.

Fig. 4 is a similar view as Fig. 1, but only showing an embodiment of the cartridge according to the invention.

Fig, 5 is a top view of the embodiment according to Fig. 4.

Figs. 1 and 2 show an embodiment of a dosing systeir 1 according to the invention, Ir- this embodiment the dosing system i is suitable for doling an additive 2 to water 3. The dosing system 1 is mounted in a water conduit 4 as a single unit. The additive 2 is a mixture of water and a. scale inhibitor 2a for preventing undesirable bu.i!d-up of deposits on equipment such as a boiler or for softening hard drinking water. The scale

inhibitor 2a is, for example, Ferrosil® or Siliphos®, possioly grains, powder, glassy pearls, or the like. Of course, numerous alternative additive are conceivable, for example phosphate (ortho- or poly phosphate, vitamin, fluoride, silicate (sodium, potassium, or potassium phosphate) .

The embodiment of the dosing system 1 comprises a housing 5 including a main water duct 6 for transporting water 3 through the dosing system 1. The housing 5 is adapted such that it can receive a cartridge holder 7 in which a replaceable cartridge 8 fits. The replaceable cartridge 8 includes a

container 9 which contains the adoifive 2. The cartridge holder 7 is releasably fitted to the housing 5 by a screw thread 10 which enables a user to replace the cartridge 8 Jn a simple manner when the additive has been consumed. Figs. 4 and 5 show the separate replaceable cartridge 8,

The container 9 of the cartridqe 8 comprises an inlet 11 Through which the container 9 communicates with the rrain 5 water duct 6 in assembled condition of the dosing system 1. This is possible since the cartridge 8 fits in the cartridge holder 7 by leaving open a relatively small slit between ^he cartridge holder 7 and the cartridge 8, At a bottom 12 of the cartridge 8 at least a protrusion 13 is provided so as to prevent the inlet

1C 11 from being obstructed by the cartridge holder 7. Under

operating conditions a relatively small quanta ty of water 3 can flow fron the main water duct G to the inlet 11, as illustrated by arrows A in Figs. 1-3, along the outer side of the cartridge 8. The cartridge 8 as shown m the Figs, is of a cylindrical

15 type, but alternative shapes are conceivable.

Tn the embodiment as shown in the Figs. 1-5 the container 9 comprises a channel 14 which extends upwardly from the inlet 11 and exits near a cover Ib of the container 9. The distance between the exit of the channel 14 and the cover Ib

/0 should be as small as possiole in order to avoid loss of the

substance 2a before the cartridge 8 is installed. The distance is smaller than the grain size in case of a substance 2a in the form of grains, or : t is smaller than 5 rrcn, for example. Under operating conditions water can flow from the inlet M through

25 the channel 14 further into the container 9 as illustrated by arrows A in Fig, 3. This means that in this embodiment the water mixes with the substance 2a to form the additive 2 which will be injected. In practice, the substance will partly solve m the water 3 such that the additive is a liquid mixture of water 3

30 and solved substance 2a. The container 9 may thus contain two phases: a liquid additive 2 and a solid substance 2a.

The container 9 is further provided with an outlet 16 through whicn the container 9 communicates with the main water duct 5. In the embodiment as shown in Fig, 3 the outlet 16 is

35 provided in the cover 15 of the container 9. The outlet 16

communicates with a dosing nozzle 17 located at the opposite side of the cover 15 via a channel-shaped restriction 18. In this embodiment the channel -shaped restrict:, on 18 has a spiral shape and is incorporated in the cover 15. The length of the channel is larger than the diameter thereof. For example,, the diameter may be 2 mm whereas the length between the outlet 16 and the dosing nozzle 17 may be 180 rrir . The advantage of the spiral shaped restriction is that a relatively Long channel 18 can be made within a limited space. Due to the relatively long channel 18 a prepared, additive, for example a solution of water 3 and the substance 2a is directly available near the dosing nozzle 17, The cover 15 may be made of two parts; a first part including a groove in a spiral shape and « second part covering the first part to form a spiral-shaped channel 18. The second part may have a flat surface that faces to the groove of the first part, see for example the embodiment of Fig. 3.

The cartridges 8 of the embodiments as shown in the Figs, comprise a rim 19 which protrudes αpward'y from the container 9 and which extends circumferer.t ially about the dosing nozzle 17, In assembled condition of the dosing system 1 the rim 13 contacts the housing 5 such that the main water duct 6 at the dosing no?zle 17 forms a smaller flow-trough area than at a location upstream thereof such that in case of a water flow L he water pressure is lower at the dosing nozzle 17 than at the location upstream thereof, hence forming a low-pressure location and a high-pressure location, respectively. The water fiow through the main duct 6 in the direction of the dosing nozzle 17 is indicated by arrows B in Figs. 1-3, The inlet 11 of the container 9 communicates with the high-pressure location which means that there is a pressure difference between the additive 2 in the container 9 and the exit of the dosing nozzle 1.7. This causes a flow of additive 2 from the container 9 into the main water duct 6, see arrows in Fig. 3. in case of no water flow through the main water duct 6 there is no pressure difference between the inlet of the container 9 and the main water cruet 6 at the exit of the dosing nozzle 17. Then the doεage of additive 2 is negligible. In the embodiment as shown in Fig. 2 it can be seen that the housing 5 is provided, with a plate 20. This plate 20 contacts the upper side of the rim 19 of the cartridge 8 so as to achieve a stable position of the cartridge 9 with respect to the housing 5.

The quantity of additive 2 that is metered to the water in the main water duct 6 depends on several parameters sαch as the flow restrictions of the channel -shapeα restriction 18 and the dosing nozzle 17 and the pressure difference in the main water duct 6 between the high-pressure location and the low- pressure location. Besides, the flow restrictions of the slit between the cartridge 8 and tr.e cartridge holder 7, the inlet 11 of the container 9 and the channel 14 are alεo influencing parameters. The latter flow restrictions further avoid a strong initial water flow into the container 9 after replacement of the cartridge 8.

The housing 5 comprises a non-return valve 21 aa shown in Figs . 1 and 2 ,

Tn the embodiments as shown in the drawings the container 9 contains a substance 2a being a powder, grains, glossy pearls, or the like. Water is able to enter the inlet 11 after which it mixes with the substance 2a. Under these

conditions the additive 2 above the substance 2a is prepared. Under operating conditions the water pressure at inlet 11 effects injection of the additive .? and supplies fresh water to the container 9 Lo mix with the substance 2a. In the container 9 a ball 22 for indication of the level of the substance 2a in the container 9 is present. The ball 2? sinks in the additive 2 which is present above the denser substance 2a and will rest on the suDstance 2a. For example, when the substance 2a comprises grains that solve in water up to a certain concentration the grains will become smaller and the upper level will decrease such that the ball 22 will bo lowered, as well. When the

cartridge holder 7 is translucent the user can monitor the additive consumption and replace the cartridge 8 in time.

The cartridge 8 can be made of a plastic, but alternative materials arc conceivable. The cartridge is able to withstand a fluid pressure of 10 bar, for example.

Furthermore, the applicant has discovered that when applying a dosing system. 1 according to the invention in a tap water circuit in combination with Ferrop.il® or Siliphos© as a substance in the cartridge for preparing the additive 2 upon mixing with water, adverse effects experienced by persons having skin diseases are relieved when they wash themselves with water coming from the dosing system. Therefore, FerrosilΘ can be used as a medicament, specifically for treating skin diseases. From the foregoing, it will be clear that the invent ior provides a relatively simple but effective dosing system.

The invention is not limited to the embodiments shown in the drawings and described hereinbefore, which may be varied in different manners within the scope of the claims and their technical equivalents. The dosxnσ nozzle and the outlet of the container are located at the centre line of the cylindrical container, but it is also possible to select an alternative location. The inlet of the container and the corresponding channel may also be located at an alternative location on the container. Alternatively, the additive could be contained in a collapsible bag being present in the container and on which the water from the inlet applies a pressure such that the water does not mix with the additive. Of course, water can be replaced by any other fluid.

Claims

1. A dosing system (1) for dosing an additive (2) to a fluid flow, comprising

a fluid duct (6} for transporting a fluid, a container {9} which contains an additive (2), the container (9) being provided with an inlet (11) through which the container (9) communicates with the fluid duct (6) at a high-pressure location thereof for applying a pressure on the additive (2), and an outlet (16-18) through which the container (9) communicates with the fluid duct (6) at a low-pressure location thereof for transferring a quantity of the additive (2) to the fluid duct (6), wherein the fluid duct (6) is adapted such that under operating conditions the fluid pressure is lower at the low-pressure location than at the high-pressure location.

2. A dosing system (1) according to claim 1, wherein the container (9) is adapted such that fluid from the inlet (11) can raix with a substance (2a) in the container to form the additive (2) .

3. A dosing system (1) according to claim 1 or 2, wherein the outlet comprises a channel-shaped restriction (18} and a dosing nozzle (17) which communicates with the channel- shaped restriction (18) and the fluid duct (6) at the low- pressure location, wherein the channel-shaped restriction (18) has a length that is larger than twice, and preferably larger than five times its internal diameter.

4. A dosing system (1) according to claim 3, wherein the channel -shaped restriction (18) has a spiral shape.

5. A dosing system (1) according to one of the preceding claims, wherein the flow-through area of the fluid duct at the low-pressure location is smaller than the flow- through area at the high-pressure location,

6. A dosing system (1) according to one of the preceding claims, wherein the high-pressure location is upstream of the low-pressure location.

7. A dosing system (1) according to one of the preceding claims, wherein the fluid duct (6) comprises a nonreturn valve (21) .

8. A dosing system (1) according to one of the preceding claims, wherein the container (9) is part of a

replaceable cartridge (8).

9. A dosing system (1) according to one of the preceding claims, wherein the additive (2) iε a scale inhibitor.

10. A dosing system (1) according to one of the preceding claims and claim 2, wherein t-he additive (2) comprises a substance (2a) including an indication member (22) for

indicating the quantity of substar.ee (2) in the container (9) and the dosing system (1) is adapted such that the indication member (22) is visible.

11. A cartridge (8) for use in a dosing system (1), comprising a container (9) for containing an additive (2), the container being provided with an inlet (11) for receiving a high pressure fluid for applying a pressure on the additive (2) , and an outlet (16-18) for transferring a quantity of the additive (2) to the outside of the container (9) upon applying a pressure on the additive (2).

12. A cartridge (8) according to claim 11, wherein the inlet (11) forms one end of a channel (14) which extends inside the container (3), whereas another end of the channel (14; is located close to an inner wall (15) of the container (9), preferably at a distance smaller than I mm,

13. A cartridge (8) according to claim 11 or 12, wherein tne outlet comprises a channel -shaped restriction (18) and a dosing nozzle (17), wherein the channel-shaped restriction (18) has a length that is larger than twice, ana preferably larger than five times its internal diameter.

14. A cartridge (8) according to claim 13, wherein the channel-shaped restriction (18) has a spiral shape.

15. A cartridge (8) according to one of the claims 11- 14, wherein the cartridge (8) contains an additive (2j which is a scale inhibitor.