EP3723869A1

EP3723869A1 - Pre-flush unit for carrying out a pre-flush procedure in a breathing gas circuit of a recirculating breathing protection apparatus

Info

Publication number: EP3723869A1
Application number: EP18811737.8A
Authority: EP
Inventors: Kurt WENDEROTH
Original assignee: Draeger Safety AG and Co KGaA
Current assignee: Draeger Safety AG and Co KGaA
Priority date: 2017-12-15
Filing date: 2018-11-19
Publication date: 2020-10-21
Also published as: WO2019115162A1; AU2018383962B2; CN111491698A; CA3082940C; ZA202001806B; CN111491698B; CA3082940A1; US11738164B2; AU2018383962A1; DE102017011623A1; US20200398017A1

Abstract

The present invention relates to a pre-flush unit (10) for carrying out a pre-flush procedure in a breathing gas circuit (210) of a recirculating breathing protection apparatus (200), having a main body (20) with an inlet port (22) for the supply of breathing gas from a breathing gas reservoir (220) and with an outlet port (24) for the removal of breathing gas to the breathing gas circuit (210), wherein the inlet port (22) and the outlet port (24) are fluidically connected via a flow section (32) of a valve chamber (30) in the main body (20), and in the valve chamber (30) there is arranged a valve body (40) with a sealing face (42), the valve chamber (30) also containing an elastomer body (50) with a counter-sealing face (52) that separates the flow section (32) from a control section (34) in a fluid-tight manner and that consists of an elastic material which presses the counter-sealing face (52) against the sealing face (42) of the valve body (40) with a sealing force so as to seal the flow section (32), wherein moreover the main body (20) has a control port (26) for the controlled supply of breathing gas from the breathing gas reservoir (220) to the control section (34) for the purpose of pressure equalization between the flow section (32) and the control section (34).

Description

DESCRIPTION

Drägerwerk AG & Co. KGaA, Moislinger Allee 53-55, 23558 Luebeck, DE

Pre-purifying unit for carrying out a pre-purge operation in a breathing gas circuit of a circuit breathing apparatus

The present invention relates to a purging unit for carrying out a pre-purging operation in a breathing gas circuit of a circuit breathing apparatus, a gas-conducting device for a circuit breathing apparatus and a method for a pre-purging operation in such a gas-guiding apparatus.

Circulatory respirators are known to protect users of these devices from the inhalation of toxic gases in adverse environments. In order to ensure the longest possible use of the user, these circuit breathing apparatus are provided with a breathing gas circuit which supplies supply air to the mouth of the user and leads away exhaust air as exhaled air from the mouth of the user. In order to achieve the long service life, respiratory protection components are provided within the circuit breathing apparatus, which on the one hand serves to purify the exhaust air from the user's mouth and on the other hand can ensure supplementation of the purified breathing air with oxygen or normal air. This ensures that the reduction in the cleaning process is correlated by the removal of CO2 with a filling with oxygen and thus a long service life for the circulation operation of the circuit breathing apparatus is possible.

A disadvantage of the known solutions is that a relatively high effort has to be made in order to keep the respiratory gas circulation free of undesired gas residues at the beginning of the use of such a circulatory protection device. This relates in particular to an increased nitrogen content and / or one increased CO 2 content in the respiratory gas cycle. In order to avoid that the first breathings now proceed with an undesired gas mixture in the respiratory gas circulation, normative depending on the respective country of use is provided. wrote that a so-called pre-purging with the respiratory gas must be performed. The respiratory gas flowing through will displace residual gas remaining with unwanted gas mixtures from the breathing gas cycle during this pre-rinsing process and thus at the beginning of the application at the end of the pre-rinsing process be able to provide the user with a defined gas composition in the breathing gas circuit. To ensure this, so far complicated mechanical solutions with spring systems, but also electrical or electronic purging devices are known, which are designed correspondingly complex, expensive and large-volume.

It is an object of the present invention to at least partially overcome the disadvantages described above. In particular, it is an object of the present invention to be able to provide, in a cost-effective and simple manner, an as-automated pre-rinsing in a circuit-breathing device for the breathing-gas circuit.

The above object is achieved by a pre-rinsing unit having the features of claim 1, a gas-conducting apparatus having the features of claim 10 and a method having the features of claim 12. Further features and details of the invention will become apparent from the dependent claims, the description and the drawings. In this case, features and details described in connection with the purge unit according to the invention apply, of course, also in connection with the gas routing device according to the invention and the method according to the invention and in each case vice versa, so that with respect to the disclosure of the individual invention aspects always reciprocal reference is or can be taken.

According to the invention, a purging unit is used to carry out a purging operation in a breathing gas circuit of a circuit breathing apparatus. For this purpose, the purging unit has a base body with an inlet connection for the supply of breathing gas from a supply of breathing gas. In addition, an outlet connection for the discharge of breathing gas into the breathing gas circuit is provided on the base body. The input terminal and the output terminal are over a flow section of a valve chamber in the main body together in fluid idkommunizierender connection. In addition, a valve body with a sealing surface is arranged in this valve chamber. Furthermore, an elastomeric body is arranged in the valve chamber with a counter-sealing surface which separates the flow section in a fluid-tight manner from a control section and consists of an elastic material. Due to the elastic choice of material, the elastomer body, the counter-sealing surface, can act on the sealing surface of the valve body to seal the flow section with a sealing force. Furthermore, a control connection is provided on the main body for the controlled supply of breathing gas from the respiratory gas supply into the control section in order to be able to ensure a pressure equalization between the flow section and the control section.

The above explanation of the purging unit now makes it possible, independently of mechanical and / or electrical or electronic solutions, to be able to provide a pneumatic control, in particular a pneumatic control or a pneumatic control, of the purging operation. In order to be able to explain the relatively complex processes in more detail, the course of the pre-rinsing with a pre-rinsing unit according to the invention is explained in detail below.

At the beginning of the use of a circuit breathing apparatus, a corresponding supply of breathing gas must be provided. Such a breathing gas supply is usually arranged in a pressure bottle and has at a high pressure of, for example, about 200 bar oxygen as breathing gas. In order to be able to displace unwanted gas mixtures in a breathing gas circuit within the circuit breathing apparatus, the pre-rinsing process must be carried out. For this purpose, the breathing gas supply is connected to the breathing gas circuit and can spread in this way its pressure in the pre-rinsing unit. The respiratory gas and thus also the pressure, in particular via an upstream pressure reducer, passes via the inlet connection into the main body of the prefilter unit. The existing at this time or at this location mean pressure causes, contrary to the elastic biasing force of the elastomer body starting from the medium pressure of the respiratory gas, the elastomeric body moves outwardly into the control section and thus the counter-sealing surface of the elastomeric body lifts off from the sealing surface of the valve body. The seal, which between the counter-sealing surface of the valve body and the

Elastomer body and the sealing surface of the valve body was previously formed, is lifted in this way by the application of the mean pressure on the input terminal, so that now the breathing gas through the increased pressure medium through the valve chamber and there through the flow section can flow through to the outlet port. As will be explained later with reference to a gas guiding device according to the invention, the outlet connection now communicates with a respiratory gas circulation, so that at this point in time the respiratory gas flows via the priming unit and the opened flow section into the outlet connection via the outlet connection Breathing gas circulation can penetrate and displaces unwanted gas mixtures.

The beginning of the pre-rinsing described above shows how, as the respiratory gas penetrates it, it spreads into the respiratory gas circulation and displaces unwanted gas mixtures there. The second core idea of a purging unit according to the invention now serves the most automated possible termination of this pre-purging process, to ensure that not an unnecessarily large amount of breathing gas is used or wasted for the pre-rinsing process. For this purpose, the base body is equipped with the control connection. The control port is also supplied by breathing gas from the breathing gas supply, but is equipped with a lower rate of pressure rise. On the one hand, this can be provided by a defined smaller passage opening in the control connection, by correspondingly longer or smaller supply lines to the control interface or else by the dosing unit explained in greater detail below in such a control connection. While the medium pressure then continues rapidly via the inlet connection into the valve chamber and there into the flow section, a spread of the same mean pressure into the control connection and thus into the control section of the valve chamber will be much slower. Thus, at the beginning of the pre-rinsing process, the elastomeric body will bulge outwards, so that the control section will become dislodged. and increases the flow section to open the desired fluid-communicating connection to the output port. Over the course of the pre-rinsing process, more and more breathing gas now also enters the control section of the valve chamber via the control connection. Over time, therefore, pressure equalization will result between the internal pressure in the control section and the internal pressure in the flow section. As soon as the pressure, which is the same in both positions, since in both cases the respiratory gas is in communication with the medium-pressure connection of the respiratory gas supply, the

Move the elastomeric body back to its original position. In this initial position, the control section of the valve chamber has increased again and, accordingly, the flow section has been reduced by the same amount. By the pressure equalization is now the only force which still acts on the elastomer body, the elastic restoring force of the elastic material, so that now the counter-sealing surface is again pressed against the sealing surface of the valve body and in this way the flow section is sealed. This point in time defines the end of the pre-rinsing process, since the fluid-communicating connection to the outlet connection of the main body has now been interrupted by this sealing process, so that now further outflow of respiratory gas through the pre-rinsing unit is prevented.

As can be seen from the above procedures, pneumatic and automated control in the form of pre-purging control can be performed, dispensing with any electronic or electrical control or control, and without resorting to mechanical biasing units such as springs or similar valves. In a geometrical and constructive manner it can be predicted and set in a defined manner by the flow velocities or the corresponding volume flows at the control connection and at the input connection or at the output connection, how large the amount of breathing gas should be for the pre-rinsing process or for how long This pre-rinsing process is performed.

Based on the previously known very complex solutions thus a simple, inexpensive and small purging unit can be provided. In particular, due to the reduced complexity, the automation by means of the pneumatic control can be achieved simply and inexpensively as well as with high operational reliability.

It may be advantageous if, in a purging unit according to the invention, the input port and the output port have the same or essentially the same flow cross-section. This also applies in particular to the flow cross-section within the flow section, preferably in its fully open position at the beginning of the pre-rinse operation. By maintaining a flow cross-section over the course through the flow section of the body through unwanted flow resistance can be avoided, so that in particular defined and predictable manner, the time for the pre-purge and the pre-purge of breathing gas is defined predictable. Fast and, above all, safe and predefined pre-rinsing can be achieved effectively in this way.

A further advantage can be achieved if the elastomer body has a rotationally symmetrical counter-sealing surface, in particular rotationally symmetrical, in a pre-rinse unit according to the invention. A rotationally symmetrical design of the elastomer body allows a particularly simple and cost-effective production. In addition, the pressure distribution around a rotationally symmetrical elastomer body is particularly uniform, so that a corresponding sealing functionality can be provided in a simple, cost-effective manner and above all with a high level of safety. Preferably, the rotationally symmetrical design also leads to a full-scale application of the counter-sealing surface on the associated sealing surface of the valve body.

A further advantage can be achieved if in a pre-rinsing unit according to the invention the valve body has a rotationally symmetrical sealing surface, in particular is at least partially rotationally symmetrical. This embodiment is in particular combined with the purging unit according to the preceding paragraph. Again, the valve body can be made particularly simple and cost-effective. The flow geometry as well as the pressure In the case of the rotationally symmetrical configuration of the sealing surface, division is particularly advantageous. Last but not least, the full application of the counter-sealing surface in a rotationally symmetrical manner to the associated sealing surface of the valve body is again advantageous.

A further advantage may be if, in a pre-purifying unit according to the invention, the valve body, in particular as a valve cone, is arranged centrally or essentially centrally in the flow section. The central arrangement thus allows a full flow through, wherein the valve body is preferably formed along the flow axis within the flow section. Here, too, an improved circumferential flow can lead to a lower flow resistance, so that the predefined selection of the pre-wash process can be carried out with greater reliability. Unwanted flow turbulences are avoided or reduced to a minimum by the symmetrical and circumferential flow.

A further advantage can be achieved if, in a pre-rinsing unit according to the invention, the sealing surface is arranged on a widening sealing section of the valve body. This means that the valve body in front of the sealing portion and / or after the sealing portion preferably converges more closely in a conical manner. The space within the flow section is thereby spread, so that in particular the already described improved flow conditions with preferably constant free flow cross sections can be achieved with the flow section open.

A further advantage may be if, in a pre-purifying unit according to the invention, the main body has an additional connection in fluid-communicating connection with the control section for a fluid-communicating connection to an additional control volume. The control section, by virtue of its size on the one hand, and the control port through the supply speed and thus the propagation velocity of the mean pressure of the respiratory gas, on the other hand, exactly define when the end of the pre-purge operation is reached by the end of the pressure equalization. If an extension of this pre-rinse is desired, An additional additional control volume can now be made available via an additional connection according to this embodiment, so that, with the propagation velocity of the medium pressure remaining constant through the control connection, an extension is achieved until the end of the pressure equalization, since at a constant flow velocity now a larger Volume, al so also the additional control volume, can be filled with the corresponding mean pressure or must. Because different additional control volumes can now be used via the additional connection, a simple, flexible and, above all, cost-effective adaptation to different normative specifications in different countries is possible by selecting different additional control volumes.

It is also advantageous if, in a pre-purifying unit according to the invention, a metering unit is arranged in the control connection, in particular as a separate component, with a metering opening for the passage of respiratory gas from the respiratory gas supply into the control section. Such a dosing unit is designed in particular as a separate component and thus easily and inexpensively manufacturable with narrow tolerance ranges. In this case, the metering opening can be specific to the respective metering unit, so that different metering units with correspondingly different metering openings for different preliminary flushing specifications can be made available for different normative specifications. The use of the metering unit with a metering opening makes it possible to reduce the accuracy of precision for the production of the basic body and to be able to resort here to a cost-effective and simple method of production.

It may also be advantageous if fastening devices for a fluid-tight fastening of respiratory gas hoses are arranged in a pre-purge unit according to the invention at the input connection, at the output connection and / or at the control connection. These are, in particular, standardized fastening devices which, for example, can have plug-in connections and / or clamping connections. The fastening devices are preferably provided at all connections of the main body. Likewise provided by the present invention is a gas-conducting device for a circuit-breathing device, comprising a receiving connection for a respiratory gas supply. Next, a refill port is provided in the breathing gas circuit of the circuit breathing apparatus. The receiving connection is connected in a fluid-communicating manner via a pre-purge outlet to the input port and via a control outlet to the control port of a pre-purge unit. Furthermore, the output connection of the pre-purifying unit is connected in a fluid-communicating manner with the refilling connection. The connection to the refill connection is preferably provided by bypassing a corresponding refill valve arrangement, so that the desired prewash function can be ensured, in particular independently of a continuous refilling or a demand-based refilling by means of such a refill valve. By using a purging unit according to the invention, a gas-guiding device according to the invention now brings the same advantages as have been explained in detail with reference to a purging unit according to the invention.

A gas guiding device according to the invention can be further developed such that the receiving connection has a pressure reducing device for reducing the high pressure in the respiratory gas supply to a medium pressure. Within the supply of respiratory gas there is usually a high pressure of about 200 bar. By using a pressure reducing device, this high pressure can be reduced to an average pressure in order to be able to ensure the desired pre-purge function with a simple and cost-effective design of the individual components under the specifications of such a medium-pressure atmosphere.

A further subject matter of the present invention is a method for a pre-rinsing process in a gas-guiding device according to the invention, comprising the following steps:

Connecting the supply of breathing gas to the receiving connection,

Outflow of breathing gas via the pre-purge outlet through the inlet port of the pre-purge unit, through the flow section via the outlet port into the respiratory gas circuit, - Ingress of breathing gas via the control outlet and the control connection of the purging unit into the control section until pressure equalization with the flow section. By carrying out a gas-guiding device according to the invention, a method according to the invention brings about the same advantages as have been explained in detail with reference to a gas-guiding device according to the invention or with reference to a pre-rinsing unit according to the invention. The two steps of the outflow as well as of the inflow preferably proceed temporally parallel until they have reached a pneumatic end point, namely the pressure equalization between the flow section and the control section.

Further advantages, features and details of the invention will become apparent from the following description in which embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description may each be essential to the invention individually or in any desired combination. They show schematically:

1 shows a first embodiment of a purging unit according to the invention in a schematic perspective cross-section,

Fig. 2 shows the embodiment of Fig. 1 in a normal schematic

Cross section and

3 shows an embodiment of a gas guiding device according to the invention.

FIGS. 1 and 2 show schematically how a purging unit 10 can be configured. On the basis of these two representations, it is briefly explained again how the pre-rinsing process proceeds. As soon as the pressure, for example via a pressure reducer, is reduced to a medium pressure for the respiratory gas, For example, the respiratory gas can flow into the main body 20 via the fastening device 70 into the inlet connection 22. Once this medium pressure and thus the breathing gas has reached the valve chamber 30, the elastic biasing force of the elastomer body 50 is released by the high internal pressure, so that the counter-sealing surface 52 lifts from the sealing surface 42 of the valve body and the flow portion 32 is released. The respiratory gas thus continues to spread and flows via the outlet connection 24 and the associated fastening device 70 further into the respiratory gas circulation 210, as shown, for example, in FIG. 3.

At the same time, the respiratory gas and thus also the medium pressure are also applied via the fastening device 70 to the control connection 26 of the main body 20. As a result, a flow of the respiratory gas is now flowed through the metering unit 60 and there through a central and small metering opening 62 into the control section 34. As soon as the medium pressure continues to propagate into the control section 34 and the corresponding internal pressure increases there, the elastomeric body 50 will move back into its position, as shown in FIG. As soon as pressure equalization has taken place between the control section 34 and the flow section 32, the sealing position is again assumed by the elastomeric body 50, as shown in FIGS. 1 and 2. As soon as this sealing is completed, the flow passage through the valve chamber 30 and there through the flow section 32 is blocked again, so that the pre-rinsing process can be recognized as finished.

FIG. 3 shows schematically how such a purging unit 10 can be integrated in a respiratory breathing apparatus 200. Here, a gas guiding device 100 is provided, which can be connected to a fluid pressure component in the form of a breathing gas supply 220 by means of a receiving connection 1 10. In between, a pressure-reducing device is preferably connected. The reduced pressure of the respiratory gas can now propagate in the regular state via the refill port 120, for example in demand-controlled control via a refill valve 122 in the breathing gas circuit 210. In order to be able to specify the desired pre-rinse function at the beginning, the pre-rinse unit 10 is now For example, in the embodiment of Figs. 1 and 2 is provided. Starting from the receiving port 110 can now be applied via the pre-purge outlet 112 of the input port 22 of the pre-purge unit 10 with the respiratory gas. Concurrently with time and at the same time, the supply of breathing gas and thus the medium pressure is also effected at the control connection 26 via the control output 114 of the gas-conducting device 100. The functionality within the pre-purifying unit 10 is identical to that described with reference to FIGS. 1 and 2. The FIGS The preceding explanation of the embodiments describes the present invention purely by way of example. Of course, individual features of the embodiments, if technically expedient, can be freely combined with one another without departing from the scope of the present invention.

REFERENCE LIST Pre-rinse unit

body

input port

output port

control port

Second line

Valve chamber

flow section

counterfoil

Valve body

sealing surface

elastomer body

Against sealing surface

dosing

metering

Fastening device gas guiding device

receiving port

Vorspülausgang

control output

refill port

Refill valve circuit breathing apparatus

Breathing gas circuit

Breathing gas supply

Claims

A purging unit (10) for performing a purging operation on a breathing gas circuit (210) of a circuit breathing apparatus (200), comprising a body (20) having an inlet port (22) for the supply of breathing gas from a breathing gas reservoir (220) and having an outlet port (24) for the removal of breathing gas in the breathing gas circuit (210), wherein the input port (22) and the output port (24) via a flow section (32) of a valve chamber (30) in the main body (20) are connected in a fluid-communicating manner and in the valve chamber (30) a valve body (40) with a sealing surface (42) is arranged, further in the Ventilkam- mer (30) an elastomeric body (50) with a counter-sealing surface (52) the flow section (32) fluid-tight from a control section (34) separates and consists of an elastic material, which the counter-sealing surface (52) with a sealing force against the sealing surface (42) of the valve body (40) for sealing the S Furthermore, the main body (20) has a control port (26) for the controlled supply of breathing gas from the breathing gas supply (220) in the control section (34) for pressure equalization between the valve chamber (30) and the control section (34).

2. purge unit (10) according to claim 1, characterized in that the input port (22) and the output port (24) have an equal or substantially equal flow cross-section.

3. purging unit (10) according to any one of the preceding claims, characterized in that the elastomeric body (50) has a rotationally symmetrical counter-sealing surface (52), in particular is formed rotationally symmetrical.

4. purging unit (10) according to any one of the preceding claims, characterized in that the valve body (40) has a rotationally symmetrical sealing surface (42), in particular at least partially rotationally symmetrical.

5. purging unit (10) according to any one of the preceding claims, characterized in that the valve body (40), in particular as a valve cone, centrally or substantially centrally disposed in the flow section (32).

6. pre-rinsing unit (10) according to any one of the preceding claims, characterized in that the sealing surface (42) is arranged on a widening sealing portion of the valve body (40).

7. purging unit (10) according to any one of the preceding claims, characterized in that the base body (20) has an additional port (28) in fluidkommunizierender connection with the control section (34) for a fluid-communicating connection to an additional control volume.

8. purging unit (10) according to any one of the preceding claims, characterized in that in the control port (26) a metering unit (60) is arranged, in particular as a separate component, with a metering opening (62) for the passage of breathing gas from the breathing gas supply ( 220) in the control section (34).

9. purging unit (10) according to any one of the preceding claims, characterized in that at the input port (22), the output port (24) and / or the control port (26) fastening devices (70) are arranged for a fluid-tight attachment of breathing gas hoses.

10. A gas supply device (100) for a circuit respirator (200), comprising a breathing gas supply (110) and a refill port (120) into a breathing gas circuit (210) of the circuit-breaker (200), wherein the receiving port (110) via a Vorspülausgang (112) to the input terminal (22) and via a control output (114) to the control port (26) of a purging unit (10) having the features of one of claims 1 to 9 fluidly communicating connected, wherein the output port (24) of the purging unit (10) is fluidly communicating with the refill port (120).

The gas routing device (100) of claim 10, characterized in that the receiving port (110) comprises a pressure reducing device for reducing the high pressure in the breathing gas supply (220) to a medium pressure.

12. A method for a pre-purge operation in a gas-conducting device (10) with the features of one of claims 10 or 11, comprising the following steps:

- Connecting the breathing gas supply (220) to the receiving port

(110)

Outflow of breathing gas via the pre-purge outlet (112) through the inlet port (22) of the purging unit (10), through the flow section (32) via the outlet port (24) into the respiratory gas circuit (210),

- Ingress of breathing gas via the control outlet (114) and the control port (26) of the pre-rinsing unit (10) in the control section (34) to the pressure equalization with the flow section (32).