Patent Description:
It is known that, in many fields, for example in the medical field, it is necessary to prepare solutions according to well-specified dosages in order to carry out specific treatments. Such is for example the case of dialysis solution for dialysis treatment. The dialysis treatment is a process for purifying blood of a person whose kidney is not working normally.

Nowadays, the dialysis solution is often prepared just before dialysis sessions. To do so, solid substance for example in a form of powders, granules or tablets or mixtures thereof is placed in a container and can be dissolved by liquid, for example reverse osmosis (RO) water to obtain a solution which may be a dialysis solution or an intermediate solution for preparing the dialysis solution. For example, liquid concentrates like bicarbonate and sodium saturated solution can be prepared online from the corresponding solid substances. During the dissolving process, refilling of the liquid into the container is controlled to obtain a desired solution flow toward a downstream dialysate mixing path.

The container may be made of rigid or soft plastic material. For the soft container, the refilling process can be done by a pressure-controlled method. Specifically, the soft container is first filled with the liquid and followed by refilling cycles based on predetermined upper and lower fluid pressure set points.

However, the pressure-controlled method cannot be used for the rigid container in a closed hydraulic system design. When the liquid in the closed container is dispensed to the dialysate mixing path, excessive pressure change will act on a downstream liquid concentrate pump, which may damage the concentrate pump and lead to a mixing error.

Relevant prior art is for instance disclosed in document <CIT>.

In view of at least one of the problems existing in the prior art, an object of the present disclosure is to provide a pressure vessel for liquid mixing, a liquid mixing equipment comprising the pressure vessel, a liquid mixing system comprising the pressure vessel or the liquid mixing equipment, a method for preparing a solution using the pressure vessel, the liquid mixing equipment or the liquid mixing system, a corresponding control system and a corresponding computer readable program carrier.

For achieving this object, according to a first aspect, provided is a pressure vessel for liquid mixing, comprising: a housing; a deformable member configured to define a chamber in combination with at least one portion of the housing; an inlet port fluidly communicated with the chamber; an outlet port fluidly communicated with the chamber; an elastic biasing means configured to interact with the deformable member to make a volume of the chamber variable; and an air detection means configured to detect the presence of air within the chamber.

According to an optional embodiment of the present disclosure, the deformable member is formed by a flexible diaphragm; and/or the inlet port and the outlet port are disposed opposite to each other.

According to an optional embodiment of the present disclosure, the elastic biasing means comprises a spring, preferably a conical coil spring, or is configured in a manner of compressed gas, preferably compressed air; and/or the air detection means comprises a pair of air detection electrodes extending into the chamber.

According to an optional embodiment of the present disclosure, an inner space of the chamber is configured to generate a fluid flow for facilitating hygiene control in a cleaning and/or disinfection process; and/or the elastic biasing means is adjustable to regulate the volume of the chamber in operation.

According to an optional embodiment of the present disclosure, the inner space of the chamber is compressed by a force of the elastic biasing means to some extent at an initial stage; preferably, the inner space of the chamber is configured to have initially a U-shaped section along a direction of the elastic biasing means acting on the deformable member and extending the inlet port and the outlet port, and a bottom portion of the U-shaped section is defined by the deformable member.

According to an optional embodiment of the present disclosure, the air detection means is disposed adjacent to an outer end of a first leg of the U-shaped section; and/or the inlet port is disposed adjacent to a corner between the first leg and the bottom portion of the U-shaped section; and/or the outlet port is disposed adjacent to a middle point of a second leg of the U-shaped section opposite to the first leg.

According to a second aspect, provided is a liquid mixing equipment comprising the pressure vessel described above.

According to a third aspect, provided is a liquid mixing system comprising the pressure vessel described above or the liquid mixing equipment described above.

According to an optional embodiment of the present disclosure, the liquid mixing system further comprises: a canister, in particular a rigid canister, for receiving a substance to be dissolved or diluted by a first liquid to prepare a solution, preferably a saturated solution, wherein the outlet port of the pressure vessel is fluidly connected to the canister; and a mixing chamber fluidly connected to the canister to receive the solution; preferably, the inlet port of the pressure vessel is positioned higher than the outlet port of the pressure vessel in an operation state.

According to an optional embodiment of the present disclosure, the liquid mixing system further comprises: a first flow path fluidly connected to the inlet port of the pressure vessel to allow for filling the canister with the first liquid via the first flow path and the pressure vessel; and/or a second flow path fluidly connected to the canister to allow for filling the canister with a second liquid; and/or a third flow path fluidly connected to the canister to allow for transferring the solution to the mixing chamber; and/or a fourth flow path fluidly connected to the mixing chamber to supply a third liquid to the mixing chamber.

According to an optional embodiment of the present disclosure, the liquid mixing system further comprises: a pressure detection means configured to detect a pressure within the first flow path; a first valve disposed in the first flow path upstream of the pressure detection means; and an air exhausting means fluidly connected to the first flow path between the first valve and the pressure vessel.

According to an optional embodiment of the present disclosure, the air exhausting means comprises a second valve and an air outlet; and/or the canister has a top and a bottom in the operation state, and the pressure vessel is fluidly connected to a top inlet port of the canister to allow for filling the canister with the first liquid via the top of the canister.

According to an optional embodiment of the present disclosure, the liquid mixing system further comprises a third valve disposed in the second flow path; and/or the second flow path is configured to allow for filling the canister with the second liquid via the bottom of the canister.

According to an optional embodiment of the present disclosure, the liquid mixing system further comprises: a solution pump disposed in the third flow path to pump the solution to the mixing chamber; and/or a fourth valve, preferably a check valve, disposed in the fourth flow path.

According to an optional embodiment of the present disclosure, at least two of the first flow path, the second flow path and the fourth path are fluidly connected to a common liquid source; and/or at least one of the first liquid, the second liquid and the third liquid is reverse osmosis water; and/or the substance is in form of powder, granules, tablets or mixtures thereof; and/or the substance comprises sodium chloride and/or bicarbonate, in particular sodium bicarbonate.

According to a fourth aspect, provided is a method for preparing a solution by using the pressure vessel described above, the liquid mixing equipment described above or the liquid mixing system described above, comprising: detecting presence of air within the chamber of the pressure vessel; exhausting the air through the pressure vessel or out of the liquid mixing system in case of the presence of the air; and executing liquid supply through the pressure vessel to obtain the solution.

According to an optional embodiment of the present disclosure, the method further comprises: keeping a liquid pressure of the pressure vessel within a predetermined range.

According to an optional embodiment of the present disclosure, the method further comprises: stopping liquid supply toward the pressure vessel when the liquid pressure is within the predetermined range; and/or executing liquid supply toward the pressure vessel until the liquid pressure of the pressure vessel goes beyond the predetermined range.

According to a fifth aspect, provided is a control system configured to control the liquid mixing system described above to execute the method described above.

According to a sixth aspect, provided is a computer readable program carrier storing program instructions, wherein the method described above is implemented when the program instructions are executed by a processor.

According to the present disclosure, the solution pump can draw the solution in a substantially constant flow toward the mixing chamber so as to obtain the solution having a desired concentration. In addition, the solution pump can operate at a relatively stable pressure, which is very advantageous.

The disclosure and advantages thereof will be further understood by reading the following detailed description of some preferred exemplary embodiments with reference to the drawings in which:.

Some exemplary embodiments of the present disclosure will be described hereinafter in more details with reference to the drawings to better understand the basic concept of the present disclosure.

According to an aspect of the present disclosure, herein firstly proposed is a pressure vessel for liquid mixing.

<FIG> shows a schematic sectional view of the pressure vessel <NUM> according to an exemplary embodiment of the present disclosure in a non-operation state.

As shown in <FIG>, the pressure vessel <NUM> may comprise: a chamber <NUM>, an inlet port <NUM> fluidly communicated with the chamber <NUM>, an outlet port <NUM> fluidly communicated with the chamber <NUM>, an elastic biasing means <NUM> configured to interact with a deformable member <NUM> of the chamber <NUM> such that a volume of the chamber <NUM> is variable, and an air detection means <NUM> configured to detect the presence of air within the chamber <NUM>. By means of the air detection means <NUM>, it can be detected if the chamber <NUM> is filled fully with the liquid.

According to an exemplary embodiment of the present disclosure, the deformable member <NUM> of the chamber <NUM> may be formed by a flexible diaphragm. Preferably, the inlet port <NUM> and the outlet port <NUM> may be disposed opposite to each other, as shown in <FIG>.

As can be seen from <FIG>, the pressure vessel <NUM> may comprise a housing <NUM>, within which the deformable member <NUM> of the chamber <NUM> and the elastic biasing means <NUM> may be disposed, and the chamber <NUM> may be defined partially by a first portion <NUM> of the housing <NUM>. In particular, the chamber <NUM> may be defined commonly by the first portion <NUM> of the housing <NUM> and the deformable member <NUM> of the chamber <NUM>.

According to an exemplary embodiment of the present disclosure, the elastic biasing means <NUM> may be configured to comprise a spring <NUM>, preferably a conical coil spring, as shown in <FIG>.

As another exemplary embodiment of the present disclosure, the elastic biasing means <NUM> also may be configured in a manner of compressed gas, for example compressed air, filled into a chamber <NUM> defined by a second portion <NUM> of the housing <NUM> and the deformable member <NUM> of the chamber <NUM>.

According to an exemplary embodiment of the present disclosure, the air detection means <NUM> may be configured to comprise a pair of air detection electrodes <NUM> (only one of which is shown in <FIG>) extending into the chamber <NUM>. It is possible to detect presence of air within the chamber <NUM> by detecting conductivity within the chamber <NUM> using the pair of air detection electrodes <NUM>. Of course, it may be understood by the skilled person in the art that the air detection means <NUM> also may be configured based on different technical principles and thus the air detection means <NUM> is not limited thereto.

When liquid, for example RO water is filled into the chamber <NUM> so as to increase pressure within the chamber <NUM> through the inlet port <NUM>, the deformable member <NUM> will be displaced toward the elastic biasing means <NUM> so as to make the volume of the chamber <NUM> become bigger, and vice versa.

<FIG> shows a schematic sectional view of the pressure vessel <NUM> shown in <FIG> in an operation state.

As shown <FIG>, the deformable member <NUM> is displaced to a first position (schematically shown in a dashed line) when the pressure within the chamber <NUM> reaches a first pressure P1, for example <NUM> mbar, and the deformable member <NUM> is further displaced to a second position when the pressure within the chamber <NUM> further increases to a second pressure P2, for example <NUM> mbar, higher than the first pressure P1.

In particular for medical applications, it may be desired that the chamber <NUM> can be cleaned easily, for example before use. To this end, according to an exemplary embodiment of the present disclosure, an inner space of the chamber <NUM> may be configured to be able to generate a fluid flow for facilitating hygiene control in a cleaning and/or disinfection process. For example, the inner space of the chamber <NUM> may be configured to have no dead zone which cannot be cleaned easily.

<FIG> shows a sectional view of the pressure vessel <NUM> according to an exemplary embodiment of the present disclosure.

Preferably, the inner space of the chamber <NUM> may be compressed by a force of the elastic biasing means <NUM> to some extent at an initial stage.

As shown in <FIG>, the inner space of the chamber <NUM> may be configured to have initially a U-shaped section which is taken along a direction of the elastic biasing means <NUM> acting on the deformable member <NUM> of the chamber <NUM> and extends through the inlet port <NUM> and the outlet port <NUM>, and a bottom portion <NUM> of the U-shaped section may be defined by the deformable member <NUM> of the chamber <NUM>.

According to an exemplary embodiment of the present disclosure, as also can be seen from <FIG>, the air detection means <NUM> may be disposed adjacent to an outer end <NUM> of a first leg <NUM> of the U-shaped section. Also, the inlet port <NUM> may be disposed adjacent to a corner <NUM> between the first leg <NUM> and the bottom portion <NUM> of the U-shaped section. Further, the outlet port <NUM> may be disposed adjacent to a middle point of a second leg <NUM> of the U-shaped section opposite to the first leg <NUM>.

According to an exemplary embodiment of the present disclosure, the elastic biasing means <NUM> may be configured to be able to be adjusted to adjust the volume of the chamber <NUM> in operation. Specifically, elastic deformation characteristics of the elastic biasing means <NUM> can be adjusted so as to change deformation characteristics of the deformable member <NUM> at the same pressure within the chamber <NUM>, thereby changing the volume of the chamber <NUM> in operation.

As further shown in <FIG>, an adjusting screw <NUM> may be provided to adjust the elastic biasing means <NUM>.

<FIG> shows a left side view of the pressure vessel <NUM> as shown in <FIG>. The pair of air detection electrodes <NUM> can be seen in <FIG>.

According to another aspect of the present disclosure, further proposed is a liquid mixing system comprising the pressure vessel <NUM>.

Below, the liquid mixing system will be described.

<FIG> shows a schematic view of the liquid mixing system <NUM> using the pressure vessel <NUM> according to an exemplary embodiment of the present disclosure.

As shown in <FIG>, the liquid mixing system <NUM> may further comprise: a rigid canister <NUM> for receiving a substance, for example bicarbonate powder, to be dissolved by a first liquid so as to obtain a saturated liquid concentrate, wherein the outlet port <NUM> of the pressure vessel <NUM> is fluidly connected to the canister <NUM> and the inlet port <NUM> of the pressure vessel <NUM> is positioned higher than the outlet port <NUM> of the pressure vessel <NUM> in an operation state; and a mixing chamber <NUM> fluidly connected to the canister <NUM> to receive the liquid concentrate.

The substance may be in a form including powder, granules, tablets or mixtures thereof. Further, the substance may comprise bicarbonate, in particular sodium bicarbonate, and/or sodium chloride.

According to an exemplary embodiment of the present disclosure, the liquid mixing system <NUM> may further comprise a first flow path <NUM> fluidly connected to the inlet port <NUM> of the pressure vessel <NUM> to allow for filling the canister <NUM> with the first liquid via the first flow path <NUM> and the pressure vessel <NUM>. In the embodiment shown in <FIG>, the first liquid is transferred into the canister <NUM> from a source <NUM>.

According to an exemplary embodiment of the present disclosure, the liquid mixing system <NUM> may further comprise a second flow path <NUM> fluidly connected to the canister <NUM> to allow for filling the canister <NUM> with a second liquid.

According to an exemplary embodiment of the present disclosure, the liquid mixing system <NUM> may further comprise a third flow path <NUM> fluidly connected to the canister <NUM> to allow for transferring the liquid concentrate to the mixing chamber <NUM>.

According to an exemplary embodiment of the present disclosure, the liquid mixing system <NUM> may further comprise a fourth flow path <NUM> fluidly connected to the mixing chamber <NUM> to supply a third liquid to the mixing chamber <NUM>.

Preferably, at least one of the first liquid, the second liquid and the third liquid is water, for example RO water. When the first liquid, the second liquid and the third liquid are the same liquid, they can be supplied from the same source, for example the source <NUM>, as shown in <FIG>.

According to an exemplary embodiment of the present disclosure, the liquid mixing system <NUM> may further comprise: a pressure detection means <NUM> configured to detect a pressure within the first flow path <NUM>; a first valve <NUM> disposed in the first flow path <NUM> upstream of the pressure detection means <NUM>; and an air exhausting means <NUM> fluidly connected to the first flow path <NUM> between the first valve <NUM> and the pressure vessel <NUM>.

Preferably, the air exhausting means <NUM> may comprise a second valve <NUM> and an air outlet <NUM>. Air can be exhausted via the air outlet <NUM> by opening the second valve <NUM>.

According to an exemplary embodiment of the present disclosure, the canister <NUM> may have a top <NUM> and a bottom <NUM> in the operation state, and the pressure vessel <NUM> may be fluidly connected to a top inlet port <NUM> of the canister <NUM> to allow for filling the canister <NUM> with the first liquid via the top <NUM> of the canister <NUM>.

Preferably, the liquid mixing system <NUM> may further comprise a third valve <NUM> disposed in the second flow path <NUM>.

Preferably, the second flow path <NUM> may be configured to allow for filling the canister <NUM> with the second liquid via the bottom <NUM> of the canister <NUM>.

According to an exemplary embodiment of the present disclosure, the liquid mixing system <NUM> may further comprise a concentrate pump <NUM> disposed in the third flow path <NUM> to pump the liquid concentrate to the mixing chamber <NUM>.

Preferably, the liquid mixing system <NUM> may further comprise a fourth valve <NUM>, preferably a check valve, disposed in the fourth flow path <NUM>, in order to only allow for flowing of fluid toward the mixing chamber <NUM>.

The liquid mixing system <NUM> has been described above illustratively in connection with <FIG> and then it will be described how to operate the liquid mixing system <NUM>.

According to a further aspect of the present disclosure, proposed is a method for preparing a desired solution using the liquid mixing system <NUM>, at least comprising: detecting presence of air within the chamber <NUM> of the pressure vessel <NUM>; exhausting the air out of the liquid mixing system <NUM> in the presence of the air; and executing liquid supply through the pressure vessel <NUM> to obtain the desired solution.

According to an exemplary embodiment of the present disclosure, the method may further comprise: keeping a liquid pressure within the pressure vessel <NUM> within a predetermined range.

According to an exemplary embodiment of the present disclosure, the method may further comprise: stopping liquid supply toward the pressure vessel <NUM> when the liquid pressure within the pressure vessel <NUM> is within the predetermined range.

According to an exemplary embodiment of the present disclosure, the method may further comprise: executing liquid supply toward the pressure vessel <NUM> until the liquid pressure within the pressure vessel <NUM> reaches a upper limit, for example <NUM> mbar, of the predetermined range, when the liquid pressure within the pressure vessel <NUM> is below a lower limit, for example <NUM> mbar, of the predetermined range.

In order to better understand the operation of the liquid mixing system <NUM>, it will be described in connection with the embodiment as shown in <FIG>.

<FIG> shows a first operation phase of the liquid mixing system <NUM>. As shown in <FIG>, in the first operation phase, the second valve <NUM> and the third valve <NUM> are in an open state, the second liquid, for example RO water, is transferred firstly to the bottom <NUM> of the canister <NUM> through the second flow path <NUM> as shown in a first arrow A1 and rises in the canister <NUM> while dissolving the substance, for example bicarbonate, within the canister <NUM>. As the second liquid rises gradually within the canister <NUM>, air contained in the canister <NUM> is expelled toward the top <NUM> of the canister <NUM> and then into the chamber <NUM> of the pressure vessel <NUM> as shown in a second arrow A2. Finally, the air is exhausted via the second valve <NUM> and the air outlet <NUM>. When the air detection means <NUM> of the pressure vessel <NUM> detects the second liquid without any air, the second valve <NUM> and the third valve <NUM> are closed and then the first valve <NUM> is opened to transfer the first liquid, also for example RO water, into the chamber <NUM> of the pressure vessel <NUM> as shown in a third arrow A3, until the pressure detected by the pressure detection means <NUM> reaches the upper limit, for example <NUM> mbar, of the predetermined range.

In a second operation phase as shown in <FIG>, the concentrate pump <NUM> draws the saturated liquid concentrate from the bottom <NUM> of the canister <NUM> as shown in a fourth arrow A4 to the mixing chamber <NUM> to mix with the third liquid, also for example OS water, transferred into the mixing chamber <NUM> through the fourth flow path <NUM> as shown in a fifth arrow A5. At the same time, the same amount of the first liquid is dispensed from the pressure vessel <NUM> to fill the canister <NUM> from the top inlet port <NUM> of the canister <NUM> as shown in a sixth dashed line arrow A6. During the second operation phase, the pressure within the first flow path <NUM> is monitored by the pressure detection means <NUM>. When the pressure within the first flow path <NUM> drops to be below the lower limit, for example <NUM> mbar, of the predetermined range, the first valve <NUM> is opened to refill the chamber <NUM> of the pressure vessel <NUM> with the first liquid until the pressure within the first flow path <NUM> reaches the upper limit, for example <NUM> mbar, of the predetermined range. The above processes repeat to deliver the desired solution downstream from the mixing chamber <NUM>.

It may be understood from the above by the skilled person in the art that keeping the pressure within the first flow path <NUM> within the predetermined range can allow the concentrate pump <NUM> to draw the saturated liquid concentrate in a substantially constant flow toward the mixing chamber <NUM> so as to obtain the desired solution having a desired concentration. In addition, the concentrate pump <NUM> can operate at a relatively stable pressure, which is very advantageous.

According to a further aspect of the present disclosure, proposed is a control system configured to control the liquid mixing system <NUM> to execute the method described above.

According to another aspect of the present disclosure, proposed is a computer readable program carrier storing program instructions therein, wherein the method described above is achieved when the program instructions are executed by a processor.

Claim 1:
A pressure vessel (<NUM>) for liquid mixing, comprising:
a housing (<NUM>);
a deformable member (<NUM>) configured to define a chamber (<NUM>) in combination with at least one portion of the housing (<NUM>);
an inlet port (<NUM>) fluidly communicated with the chamber (<NUM>);
an outlet port (<NUM>) fluidly communicated with the chamber (<NUM>);
an elastic biasing means (<NUM>) configured to interact with the deformable member (<NUM>) to make a volume of the chamber (<NUM>) variable; and
an air detection means (<NUM>) configured to detect the presence of air within the chamber (<NUM>).