WO1993007960A1

WO1993007960A1 - Suction/mixing device

Info

Publication number: WO1993007960A1
Application number: PCT/DE1992/000877
Authority: WO
Inventors: Hansbernd Berzheim
Original assignee: Atp Advanced Technologies Promotion Ltd.; DÖRING, Wolfgang
Priority date: 1991-10-25
Filing date: 1992-10-21
Publication date: 1993-04-29
Also published as: DE4208442A1

Abstract

In a suction/mixing device, a primary fluid flowing through a main channel (3) sucks a secondary fluid flowing through a secondary channel (5). The suction/mixing zone (11) has at its mouth a narrow cross-sectional shape and the cross-sectional surface at the mouth lies in the size range of the smallest effective cross-sectional surface in the primary fluid flow system. A laminar flow generating zone is arranged upstream of the mouth, in the direction of flow of the primary fluid, and the secondary channel is formed at the mouth by a plurality of uniformly distributed supply channels (7). High suction power and performance, as well as fine mixing and homogenizing, are thus obtained. Some of the most important domains of application are the domestic services technology, heating, laboratory, engine, cleaning, gardening and aquarium-building technologies.

Description

Suction / mixing device

The present invention relates to a suction / mixing device with a main channel through which a primary fluid flows, with a suction / mixing zone and with a secondary channel through which a secondary fluid flows, which opens into the main channel in the suction / mixing zone.

Such suction / mixing devices are known. These devices make use of the principle that the secondary fluid flowing in the secondary channel is sucked in by the primary fluid flowing in the main channel, introduced into the main channel and mixed with the flowing primary fluid. By narrowing the hollow body through which the primary fluid flows, the flow velocity of the primary fluid and thus its suction power is increased.

In such devices of the prior art, the cross section of the suction / mixing zone at the suction point is generally circular. There are also known crescent-shaped, crescent-shaped or circular section-shaped cross sections. For example, DE 3930709 AI describes a device for suction and Mixing of additives into a liquid flow, in which a stopper protrudes into the through-channel approximately at right angles to the liquid flow and blocks a large part of the liquid flow but can be flowed around laterally. The cross-sectional areas for the flow of the primary fluid are each designed in the form of a circular section. The secondary channel opens into the main channel on the side of the plug facing the flowing flow.

All known devices have in common that the cross section of the suction / mixing zone at the mouth of the secondary channel has a relatively small ratio of area / area. In other words, only the part of the fluid which flows in the edge regions of the cross section contributes to the exertion of the suction force, while the fluid flowing in the middle of the cross section flows through the channel without having exerted suction force. It is understood that only imperfect suction / mixing effects are achieved.

The invention has for its object to provide a device of the specified type in which suction power, suction power and / or suction efficiency are optimized.

This object is achieved in a device of the type specified by the characterizing features of patent claim 1.

According to the invention, not any indefinite cross-sectional area is selected at the suction or outlet point, but the physically optimal cross-sectional area, which is characterized in that it is in the size range of the smallest effective cross-sectional area that occurs in the flow system of the primary fluid, but in no way smaller is. According to the invention, the suction or A cross-sectional shape with a large ratio U circumference or boundary line / surface area is chosen. Examples of such a cross-sectional shape are the ring shape, partial ring shape, slot shape, U-slot shape, V-slot shape. According to the invention, a laminarization zone for the primary fluid of different lengths, depending on the field of application, is preferably provided in front of the suction or outlet point. In this laminarization zone there is a so-called “flow between plates”, which is particularly favorable for laminarization, ie the smoothing of vertebrae, for physical reasons.

An optimal suction effect is further achieved by the fact that not a single secondary channel opens into the main channel, but instead a large number of uniformly distributed at one or both parallel sections of the boundary line of the cross-sectional area of the suction / mixing zone at the mouth, preferably in one, at the mouth Level arranged, supply channels is provided. This large number of channels ensures a uniform introduction of the secondary fluid into the primary fluid over its entire flow area, whereby the special narrow cross-sectional shape of the suction / mixing zone ensures that suction forces of the same magnitude are exerted in the area of each supply channel, so that the same proportions over the whole Flow cross section of the primary fluid can be achieved.

The present invention thus creates optimal conditions with regard to the suction effect to be achieved. The optimum cross-sectional area at the mouth and, in addition, the optimal laminarization zone in front of the mouth ensure that the physically highest possible speed of the primary fluid and thus the highest physically possible suction power is achieved. The special cross-sectional shape at the suction point ensures that not just a part, but the entire primary fluid can develop its suction power. As a result, the physically highest possible suction power and the highest possible suction efficiency of the primary fluid are achieved.

In addition to the influence on the speed of the primary fluid, the optimal laminarization zone also causes the flow system to be stable in relation to the mounting, for example, which changes with the installation, and thus to fluctuations in suction power. In contrast, the device designed according to the invention has a precisely defined suction power and suction power.

The device designed according to the invention can be used either as a pure suction device or as a combined suction / mixing device. In the former case, the secondary fluid is also the

Primary fluid admixed, but it is not important here to produce a homogeneous mixture in which the secondary fluid is admixed with the primary fluid in finest distribution. An example of such an application is the suction of a secondary fluid that is identical to the primary fluid. However, there is also enough

Use cases where it is only a question of the suction of the

Secondary fluids and not achieving a good mixing effect is important.

When implemented as a pure suction device (example water jet pump), a particularly high suction power is achieved with the solution according to the invention, ie a large amount of secondary fluid is sucked in per unit volume of primary fluid. This reduces the consumption of primary fluid. The particularly high suction power is due to the combination of the features listed in the characterizing part of the main claim achieved, in this embodiment the number of supply channels is kept rather low, since it is not important here that the secondary fluid is mixed in a finely divided manner with the primary fluid. It is only important that the feed channels are evenly distributed over one or both sections of the boundary line of the cross-sectional area of the suction / mixing zone at the mouth and have the smallest possible distances from one another, so that the entire circumference of the cross-sectional area of the suction / mixing zone is used to draw in secondary fluid.

If the device designed according to the invention is used as a suction / mixing device, the number of supply channels is kept as large as possible in order to obtain a mixture of primary fluid and secondary fluid in which the secondary fluid is mixed with the primary fluid in a very fine distribution. This "fineness" can be varied depending on the number of feed channels provided and can be adapted to the respective requirements. The advantages listed above in connection with the use as a suction device, in particular high suction power, homogeneous admixture, are retained, so that additional measures required for this in the prior art can be dispensed with. The large number of supply channels therefore increases the surface area of the secondary fluid flows.

As mentioned above, in both embodiments the cross-sectional area at the mouth must be in the size range of the smallest effective cross-sectional area that occurs in the flow system of the primary fluid. By "effective cross-sectional area" is meant the actual flow cross-section in a pipe. This flow cross section can be smaller than the geometric cross section (pipe cross section), in particular after pipe curvatures. The Cross-sectional area at the mouth should preferably be identical to the smallest effective cross-sectional area. The larger it is, the more the flow velocity drops in the main channel, which has an unfavorable effect on the suction effect. If it is smaller, a throttling effect occurs. If there are points with variable cross-sectional areas in the entire flow system, for example valves, etc., the largest possible cross-sectional areas or those that are most important for the respective application are preferably calculated.

The length of the laminarization zone is to be selected in accordance with the particular application and in particular in accordance with the respective primary fluid so that turbulence is reduced in the primary fluid, ideally until complete laminarization. All cross-sections of the laminarization zone are the same in shape and area. It is understood that the laminarization zone merges into the suction / mixing zone.

The device according to the invention is positioned as an intermediate piece in the course of a hollow body (for example a pipe) in which the primary fluid flows. To better understand the explanations below, a few terms are briefly defined below. There is an entry point at which the primary fluid flows into the device and an exit point at which it flows out of the device. The connection between the inlet and outlet point through which the primary fluid flows within the device according to the invention is called the main channel. This main channel consists of a series of zones. In the direction of flow of the primary fluid follow one another: an inlet zone, a laminarization zone, a transition zone, a suction / mixing zone and an outlet zone. In the suction / mixing zone, the secondary fluid is sucked in through the primary fluid through a plurality of feed channels opening into it and possibly in this finely divided. The Pipe section outside the device according to the invention up to the input position of the device is called the input pipe. The pipe section outside the device according to the invention from the starting point of the device is referred to as the starting pipe. The cross-sectional area in the main channel means any area between the entry point and exit point which lies perpendicular to the direction of flow of the primary fluid.

The cross-sectional area of the outlet pipe is preferably larger than the cross-sectional area of the inlet pipe. The ratio of the cross-sectional areas of the outlet and inlet pipe is preferably equal to the ratio of the volumes of the primary fluid plus the sucked and mixed secondary fluid on the one hand and the primary fluid alone on the other.

The cross-sectional shapes of the laminarization zone, the transition zone and the suction / mixing zone are the same, but not their cross-sectional areas.

The cross section of the suction / mixing zone is preferably designed as follows:

The cross section can correspond to a geometric figure made up of a flat rectangle, i.e. a rectangle with a large length / width ratio, and two equal semicircles. The diameter of the semicircles is equal to the width of the rectangle. The two semicircles lie with their straight sides on the two broad sides of the rectangle.

The cross section can also be designed as a narrow circular ring. In a further embodiment, the cross section is a geometric figure, which is composed of a narrow circular ring sector and two semicircles that are identical to one another. The diameter of the semicircles is equal to the width of the circular ring sector. The semicircles lie with their straight sides at the two ends of the circular ring sector. The central angle of the circular ring sector is preferably at least 180 °.

In the inlet zone, the sequence of the geometric shapes of the cross sections in the flow direction of the primary fluid is designed such that there is a continuous transition from the cross section of the entry point to the cross section of the laminarization zone. In the outlet zone, the sequence of the geometric shapes of the cross sections in the direction of flow of the primary fluid is designed such that there is a continuous or discontinuous transition from the cross section of the

Suction / mixing zone to the cross-section of the exit point results. The exact sequence of the cross-sections in the inlet zone on the one hand and the outlet zone on the other hand can be found in test series or by computer simulation, taking into account the fluids used for a specific application. The aim here is to obtain the smallest possible differences in the flow velocities of the primary fluid over a cross section and to cause the lowest possible turbulence.

The cross-sectional area of the laminarization zone is greater than or at least equal to the cross-sectional area of the suction / mixing zone. It is preferably equal to the cross-sectional area of the inlet pipe.

As mentioned, the cross-sectional area of the suction / mixing zone is in the range of the smallest effective cross-sectional area, which is in the entire flow System of the primary fluid occurs, in which the device according to the invention is inserted. If there are points with variable cross-sectional areas in the entire flow system, for example valves etc., their largest possible cross-sectional areas or the most important cross-sectional areas in the respective application are preferably calculated. In the transition zone, the sequence of cross-sectional areas in the flow direction of the primary fluid is designed in such a way that there is a continuous transition from the cross-sectional area of the laminarization zone to the cross-sectional area of the suction / mixing zone in the sense of the most streamlined design.

The feed channels for the secondary fluid are guided so that they open into the main channel of the primary fluid in the suction / mixing zone. Viewed in cross-section of the suction / mixing zone, each feed channel preferably opens into the suction / mixing zone of the main channel perpendicular to the circumference of the cross-sectional area. Viewed in longitudinal section of the suction / mixing zone, each feed channel opens into the suction / mixing zone of the main channel perpendicular to the direction of flow or obliquely in the direction of flow of the primary fluid.

The mouths of the feed channels are either all on one of the long sides of the cross section of the suction / mixing zone or on both long sides. In the second case, they are preferably offset from one another (on a gap). The openings preferably have the same spacing on one long side or on each of the two long sides.

In a special embodiment, the supply channels connect the ignition points in the suction / mixing zone of the main channel to a central memory in such a way that each supply channel is supplied with the secondary fluid as evenly as possible and all supply channels to the same extent. In an alternative embodiment the supply channels connect the confluence points with two or more independent stores from which they are supplied with two or more secondary fluids.

In the suction / mixing device, the cross section of the feed channels is very small in relation to that of the main channel. The feed channels preferably all have the same or, more preferably, a circular cross section. The smaller the cross section, the greater the number of feed channels. Preferably, the part of each feed channel at the point of entry into the suction / mixing zone which has the very small cross section should be as short as is technically possible in the respective application.

The terms "primary fluid" and "secondary fluid" used here refer to flowable or flowable media, ie liquids or gases. Both fluids can be liquid or gaseous. However, one fluid can also be liquid and the other can be gaseous.

A shut-off or dosing valve is preferably provided for supplying and shutting off or dosing the secondary fluid. If there is more than one store, each store is preferably assigned a shut-off or metering valve in order to shut off or meter the special secondary fluid.

According to a further embodiment of the invention, at least a section of the boundary line of the suction / mixing zone at the mouth point can be displaced parallel to the opposite boundary line section. This allows the cross-sectional area of the suction / mixing zone, but not its cross-sectional shape, to be changed. The cross-sectional areas of the laminarization zone, the transition zone and the suction / mixing zone can also be designed to be mutually variable. A special embodiment of the invention is characterized in that the suction / mixing zone is ring-shaped at the mouth, the inner circumference of which is formed by a cylindrical central body, on the circumferential surface of which the mouths of the feed channels are provided. These supply channels start from a central chamber in the central body, into which the secondary channel opens. The secondary duct is preferably guided obliquely as a tube through the main duct to the outside thereof. In a special embodiment, the central body is elongated and at the same time forms the laminarization zone upstream of the suction / mixing zone. It is preferably spherical at its upstream end and preferably approximately conical at its downstream end. The central body is held on the hollow body of the main channel via individual holders which penetrate the suction / mixing zone or laminarization zone.

As far as the distance between the feed channels is concerned, they are preferably arranged at a distance of 10 - 30 ° from one another, the opening area of the feed channels preferably extending in each case over 10 ° of the central body circumference (assuming customary tube sizes).

In the special embodiment described above, the feed channels extend radially outward from the inside into the suction / mixing zone. However, the invention also includes an embodiment in which the feed channels radially inwards from the outside into the

Suction / mixing zone run. In this case, for example, an annular part is provided which surrounds the tubular body of the main channel and contains the individual feed channels.

The device designed according to the invention can be used in a variety of ways

fersa become. For example, it can be installed in a heating system with liquid or gaseous fuel. Here it is installed in the fuel line between the fuel / dispenser and the burner, preferably integrated as close as possible to the burner or in the burner. The primary fluid is the fuel; while the secondary fluid is air. The air can be preheated to a predetermined temperature either by hot exhaust gases and / or electrically and / or in some other way.

The invention can also be used in a heating system in which the primary fluid is air and the secondary fluid is fuel. The air is blown into a combustion chamber via a fan or compressor. It can be preheated by hot exhaust gases and / or in some other way. The device according to the invention is installed between preheating and compressor on the one hand and the combustion chamber on the other. Part of the exhaust gas is preferably returned to the primary fluid upstream or downstream of the compressor, but upstream of the device according to the invention.

In a further application of the device according to the invention, it is installed in an internal combustion engine with liquid or gaseous fuel (preferably a diesel engine or a turbine). The device according to the invention is hereby installed in the fuel line between the fuel storage device and the combustion chamber, preferably as close as possible to the combustion chamber. The primary fluid is the fuel, the secondary fluid is air. The air can be preheated by exhaust gases and / or in some other way.

In a further application, the device according to the invention is installed in an internal combustion engine with fuel injection. she is placed directly in front of the injection valve or integrated into it. The primary fluid is the fuel, the secondary fluid is air. The air is not taken from the atmosphere, but from the combustion chamber via a line.

The device according to the invention is further characterized in that it is particularly tolerant of manufacturing inaccuracies.

In general it can be said that the device according to the invention designed as a suction / mixing device can be used wherever a liquid with another liquid, a liquid with a gas, a gas with a liquid or a gas with another gas is as intimate as possible should be mixed. The efficiency of the mixture in the respective field of application is directly dependent on the intimacy of the mixture. The more intimate the mixture, e.g. the more pearly a gas is mixed in a liquid, the larger the surface of the active ingredient and the greater the chemical and physical effectiveness per volume used. The higher the efficiency, the greater the immediate savings in carrier substance, active substance and pump energy. In addition to the advantages of saving valuable substances and energy, there are regular additional environmental benefits, such as reducing or avoiding pollutants in the air, water and soil.

Other areas of application are high-pressure cleaners, car care facilities, washing machines and dishwashers, dosing systems for garden hoses, dosing systems for showers, kitchen sinks, seawater and freshwater aquariums, suction and disposal systems for hazardous vapors etc., the mixing in of C0 _? in water to precipitate lime or to achieve fertilization effects. The invention further relates to a suction / mixing device with a suction pump for the primary fluid arranged downstream of the suction / mixing zone in the main channel. Such a case is given, for example, in the case of an oil heater in which the device is arranged in the oil line leading to the burner of an oil heater, air being admixed with the oil as the secondary fluid. The aim here is to introduce air in a very pearly form into the oil flow of the heater behind the oil filter and in front of the burner by means of a device according to the invention. This oil-air mixture is pressurized by the burner pump (suction pump) with a pressure of up to 14 bar.

Another area of application is diesel engines.

The admixture of air with the device designed according to the invention achieves significant advantages with regard to oil combustion. When the oil emerges from the burner nozzle, the pressure suddenly drops to normal pressure. The dissolved parts of the air suddenly gas out of the oil and the compressed air bubbles "explode". This causes the oil to spray, which is more finely divided than is normally the case. The proportion of gasified oil is also higher. As a side effect it is achieved that a small part of the combustion air is transported directly in the oil and does not have to be mixed in after the burner nozzle. Both effects increase the combustion efficiency. This reduces the consumption and emission of harmful gases. The soot number is reduced and sooty combustion plants are burnt free.

Experiments have shown that the presence of a suction pump (burner pump) means that appropriate modifications must be carried out on the device according to the invention in order to achieve an optimum How it works. Due to the suction effect generated by the pump, there is a risk that the suction effect on the secondary fluid is not only generated in terms of flow dynamics by the flowing primary fluid, but mainly by that generated by the suction pump. Vacuum. The suction pump exerts a suction effect on the primary fluid on the one hand and on the other hand an equally large suction effect on the secondary fluid at the mixing point. In addition, there is the fluid dynamic suction effect on the secondary fluid.

In order to prevent an increased intake of secondary fluid (air) in the form of "air hoses" in this constellation, the invention proposes that each feed channel, seen in the longitudinal section of the suction / mixing zone, opens into the suction / mixing zone obliquely against the direction of flow of the primary fluid. In other words, the feed channel or channels have a negative angle of attack with respect to the

Flow direction of the primary fluid. As a result, the influence of the dynamic pressure is increased and the influence of the suction effect is increased in the oscillation "secondary fluid-primary fluid-secondary fluid-primary fluid" caused by the interaction between the suction action on the secondary fluid and the dynamic pressure of the flowing primary fluid. The negative angle of attack of the feed channels causes an increase in the dynamic pressure to the detriment of the suction effect. Experiments have shown that the above-described negative effect of pulling in "air hoses" or the air-oil oscillation is significantly reduced.

A further improvement is achieved in an embodiment in which the main channel in the area of the suction / mixing zone has an annular elevation on the outside thereof, the supply channels opening into the upstream-facing rising side. This will make one more

Spare sheet greater shift in the ratio between suction and dynamic pressure in favor of the dynamic pressure and disadvantageous suction is achieved, and the frequency of the above-mentioned oscillation is further increased.

In longitudinal section, the annular elevation preferably has an upstream straight rising side. Even more preferably, there is a downstream straight ascending side. Both rising sides form an edge. The feed channels open into the upstream rising side. This rising side is preferably arranged at an angle of 30-90 ° to the surface line of the main channel. A preferred value is 30 °. If necessary, the angle of this rising side can be increased up to 90 °. The larger this angle, the smaller the negative angle of attack of the feed channels.

It has already been mentioned that the cross-sectional area of the suction / mixing zone can be varied at the mouth. One embodiment of the invention provides that the ring-shaped elevation can also be displaced at the mouth point to reduce or enlarge the cross-sectional area of the suction / mixing zone.

The main channel can be designed as a tube, but also as a box. In the latter case, the central body is preferably arranged on the underside of the main channel, extends to the sides of the main channel and is approximately wavy in longitudinal section. In longitudinal section it has approximately the shape of a half rotationally symmetrical central body, which is used in embodiments with a tubular main channel. Only the transition from the bottom of the main channel to the central body is continuous. The invention is explained in detail below using exemplary embodiments in conjunction with the drawing. Show it:

Figure 1 a shows a longitudinal section through a suction / mixing device;

Figure 1 b is a plan view of part of the device;

Figure 1 c shows a cross section through the device at the mouth of the feed channels;

Figure 1 d shows a partial longitudinal section according to Figure 1 a, which shows the formation of the downstream end of the central body;

Figure 1 e shows a longitudinal section through the upstream part of the central body;

Figure 1 f shows a cross section through the central body at the mouth of the feed channels;

Figure 1 g shows a cross section through the central body on its assembly parts in the main channel; and

Figure 2 a shows a longitudinal section through a further embodiment of a suction / mixing device;

Figure 2 b is a partial longitudinal section through the device of Figure 1, showing the central body;

Figure 2 c shows a cross section through the central body at the mouth of the feed channels; Figure 2 d shows a cross section through the central body at the assembly point in the main channel;

Figure 3 a shows a longitudinal section through a further embodiment of a suction / mixing device;

Figure 3 b shows a section along line A-A in Figure 3 a;

Figure 3 c shows a section along line B-B in Figure 3 a;

FIG. 4 shows a longitudinal section through yet another embodiment of a suction / mixing device;

FIG. 5 shows a longitudinal and cross section through an embodiment of a device in which a suction pump is arranged downstream;

6 shows a longitudinal and cross section of a further device with a suction pump, similar to FIG. 5;

FIGS. 7 and 8 still further embodiments of devices with a suction pump in longitudinal and cross-section; and

Figure 9 shows an embodiment of a device with a suction pump in longitudinal section, the device having a box-shaped main channel. The device 1, 20 designed according to the invention and shown in FIGS. 1 and 2 is arranged as an intermediate piece in the course of a tube 2, which forms a main channel 3, in which flows a primary fluid which is to be mixed with a secondary fluid. The primary fluid flows into the device at an entry point and out of the device at an exit point. Arranged within the main channel 3 is a central body 4, which has an approximately cylindrical shape and is spherical at its upstream end and approximately conical at its downstream end. To accommodate the central body 4, the tube 2 expands accordingly, the main channel 35 in the region of the central body changing from a circular cross-sectional shape to an annular cross-sectional shape. In the area of this annular cross-sectional area, seen in the direction of flow, there is a laminarization zone, which is followed by a suction and mixing zone 11. In this embodiment, the cross-sectional shape and the Q cross-sectional area of the laminarization zone 10 and the mixing zone 11

5 identical. After the mixing zone 11, the ring cross section widens gradually and changes again at about 12 into the usual circular cross section of the tube 2. The start of the circular cross-section is indicated at 9.

A secondary fluid is introduced into the main channel 3 via the central body 4 and mixed there with the primary fluid. For this purpose, the central body is connected via a pipe 5 with a smaller cross section than the pipe 2 of the primary fluid to a secondary channel 14, through which the secondary fluid is supplied. The tube 5 extends obliquely through the main channel 3 at a location downstream of the mixing zone 11 in the direction of flow of the primary fluid. The corresponding angle is, for example, 45 °. The secondary duct 14 opens into a central chamber 6 within the central body, from which a plurality of supply ducts 7 extend radially outwards and opens into the main duct on the peripheral surface of the central body in the region of the mixing zone 11. This can be seen, for example, in FIG. 1 c. The feed channels 7 are arranged at equal intervals over the circumference of the mixing part within a cross-sectional plane and run perpendicular to the longitudinal axis of the main channel 3. The distances between the individual feed channels, the cross section of which extends, for example, over an angle of 10 °, is preferably 10 up to 30 °.

The central body 4 is fastened to the inside of the tube 2 via short rod-shaped elements 8, which are arranged at a distance of 120 °.

The device works in such a way that the primary fluid flowing at an increased speed in the region of the mixing zone 11 as a result of the narrowed cross section causes the secondary fluid to flow via the feed channels 7 central chamber 6 and the secondary channel 14 sucks. The primary fluid previously calmed in the laminarization zone 10 exerts a uniform suction effect over the entire circumference of the mixing part 4, all flow areas of the primary fluid contributing to this suction effect due to the narrow cross-sectional area. As a result, the secondary fluid is mixed evenly distributed over the entire circumference of the mixing part 4 of the primary fluid, so that a particularly good mixing result can be achieved. As a result of the large number of feed channels, the secondary fluid is distributed very finely in the primary fluid.

Figure 2 shows a further embodiment of a suction / mixing device 20. This suction / mixing device is constructed essentially as the device shown in Figure 1, so that the same reference numerals as in Figure 1 have been used to designate the individual parts.

The only difference compared to the embodiment in FIG. 1 is that the central body 4 is designed to be substantially longer than in the embodiment in FIG. 1 and has a bulge in the area of the suction / mixing zone 11 in relation to its cross section in the laminating zone 10. This bulge leads to a circular ring cross-section in the area of the mouths of the feed channels (suction / mixing zone), which is narrower than the circular ring cross-section in the area of the laminarization zone 10. This constriction increases the flow rate of the primary fluid compared to the laminarization zone, thereby achieving an increased suction effect . For the rest, the feed channels 7 are again distributed uniformly over the circumference of the central body, so that a uniform and fine-pearled admixture of the secondary fluid takes place via the chamber and the secondary channel 5. FIG. 2 b shows a central body 4, which is extended behind the suction / mixing zone 11 in the flow direction compared to the central body shown in FIG. 2 a. Such an embodiment is also possible.

FIG. 3 shows a further embodiment of a suction / mixing device. Here, the device is designed as a pipe intermediate piece 2, which is composed of an inlet part 32 and an outlet part 31. Both parts are screwed together (thread 37, sealed against air) and sealed on the end face via an O-ring 36. A spacer sleeve 38 is inserted into an enlarged bore part of the two parts 31 and 32.

The pipe adapter 2 forms a main channel 3 for the primary fluid. In the main channel there is a central body 4, which is approximately cylindrical in shape and has an end piece 33 of spherical design on its upstream end. At its downstream end, the central body 4 is approximately conical. Between the conical and cylindrical section, the central body 4 has a thickened area through which the main channel 3 is narrowed. At this point (suction / mixing zone II), a multiplicity of feed channels 7, which are inclined in the flow direction, open out from the outside and extend upstream from an annular chamber into which a secondary channel 14 extends. The secondary duct 14 extends through a pipe socket 5 which is fixed to the outlet part 31 of the intermediate pipe section 2 via O-ring seals and a sleeve 34.

The central body 4 is held by webs in the main channel 3, as shown in Figure 3 c. FIG. 3 b shows the large number of feed channels 7 opening into the suction / mixing zone 11. FIG. 4 shows yet another embodiment of a suction / mixing device 20 in a longitudinal section. In this embodiment, the intermediate pipe section 2 is essentially designed to adapt to a central body 4, ie it widens in the flow direction of the primary fluid in the main channel 3 and then has a constant cross section

(Laminarization zone), then widens again (transition zone) and reaches a suction / mixing zone 11. Then the cross section gradually narrows to the outlet point. In this embodiment, too, the secondary fluid is fed into the suction / mixing zone 11 from the outside, a large number of feed channels 7 being connected via an annular chamber to a secondary channel 14 located in a pipe section 5. This embodiment is characterized in that the ring cross section of the suction / mixing zone 11 can be varied by displacing the central body 4 in the axial direction within the pipe section 2. In order to enable such a displacement, the central body 4 has a web 31 which engages in a spiral groove 30 formed on the inside of the intermediate tube piece 2. By rotating the rotationally symmetrical central body 4 there is thus an axial displacement thereof, depending on whether the cross section of the suction / mixing zone 11 is to be reduced or expanded. Such rotation can be carried out in the disassembled state or in the assembled state. In the latter case, for example, part of the web 31 extends through the wall of the intermediate tube piece 2, so that guidance from the outside is possible. Suitable seals ensure that no fluid can escape. Figure 5 shows an embodiment of a suction / mixing device in longitudinal and cross section, which is used in cooperation with a downstream suction pump. This can be, for example, the oil supply line for the burner of an oil heater. The device is designed as a pipe section 1, which is installed in the oil supply line. The oil supply line forms the main channel 3, in which a central body 4 is arranged, which is designed correspondingly as in the embodiments described above. The introduction of the secondary fluid, here air, into the main channel 3 takes place in the area of the narrowest point between the tube wall and the central body via a

A plurality of feed channels 7 provided in the tube wall, which are arranged at regular intervals around the circumference of the tube piece 1. These feed channels open into a corresponding suction / mixing zone 11 of the main channel.

The feed channels 7 have a negative angle of attack to the direction of flow of the oil, which in this embodiment is 30 °. This largely prevents the negative effects caused by the suction effect of the pump in relation to the admixture of air (formation of long air hoses, etc.).

A further improved effect is achieved with the embodiment shown in FIG. 6. This is essentially identical to the embodiment of FIG. 5, except for an annular elevation 40 on the inside of the pipe section in the area of the suction / mixing zone 11. This annular elevation creates an increased dynamic pressure of the oil, which has the adverse effect on the admixture the air is largely canceled out by the suction effect of the pump.

he annular elevation 40 is approximately roof-shaped in longitudinal section formed and has two flat increase surfaces 41 and 42. The feed channels 7 with a negative angle of attack open into the upstream rising surface 41. The angle of the two rising sides 41 and 42 to the surface line of the main channel is in each case 30 °.

In the embodiments shown in FIGS. 7 and 8, the annular elevation 40 is modified accordingly, while the other embodiments are essentially identical to those in FIGS. 5 and 6. According to Figure 7, the upstream rising surface 41 is arranged substantially perpendicular to the surface line of the main channel 3, while the downstream rising surface 42 is inclined at an angle of 30 °. The feed channels 7 in turn open into the main channel on the upstream rising surface 41. A further increase in the dynamic pressure is achieved by this embodiment.

In FIG. 8, the jacket body forming the pipe section 1 is formed in two parts, the part 43 of the jacket body having a smaller inside diameter and thus narrowing the main channel 3. The feed channels 7 are milled into the free conical end edge of part 43, so that in this embodiment they no longer have to be drilled. The area of the conical end face of the part 43 which is exposed compared to the part with a larger inner diameter of the pipe section 1 forms the upstream rising side 41 of the annular elevation 40. This rising side extends at an angle counter to the direction of flow of the oil and ends in a corresponding Pmg edge.

FIG. 9 shows an embodiment of the device with a suction pump, in which the main channel 3 has a box-shaped cross section. The top of the box is here by three wall parts 1, 44 and 45 formed, of which the middle part 44 can be displaced obliquely relative to the other two parts in order to change the cross-sectional area of the suction / mixing zone 11 accordingly. The feed channels 7 and the ring-shaped elevation are designed in a corresponding manner as in the embodiment in FIG. 8.

On the underside of the box there is a central body 4, which is not designed as a rotationally symmetrical body. Rather, this body extends over the entire bottom 46 of the box to its side walls. In longitudinal section it is designed approximately as one half of the rotationally symmetrical central body described above, although it continuously merges into the underside 46 of the box at an upstream section. It is understood that the displaceable wall part 44 can also be made longer downstream. It can also be moved perpendicular to the direction of flow, while the wall part 1 can be moved parallel to the direction of flow in order to enlarge or reduce the cross section of the suction / mixing zone 11.

Claims

1. Suction / mixing device with a main channel through which a primary fluid flows with a suction / mixing zone and a secondary channel through which a secondary fluid flows, which opens into the suction / mixing zone into the main channel, characterized in that the suction / mixing zone (11) at the outlet point has a narrow cross-sectional shape with a closed center line having two end points and two sections of the boundary line parallel to it, the ratio of the total length of the boundary lines or boundary line sections to the area of the

Cross-sectional area of the suction / mixing zone (11) is as large as possible, taking into account the frictional resistance of the flow, the cross-sectional area at the mouth is in the size range of the smallest effective cross-sectional area ever found in the flow system of the primary fluid, and the secondary channel (14) at the mouth through a A plurality of feed channels (7) is formed which are distributed uniformly over one or both sections of the boundary line of the cross-sectional area of the suction / mixing zone (11) at the mouth.

Spare sheet

2. Device according to claim 1, characterized in that in the main channel (3) upstream of the mouth a laminarization zone (10) is provided for the primary fluid with the same cross-sectional shape and cross-sectional area, the same cross-sectional area>, the cross-sectional area of the suction / Mixing zone (11) is at the mouth.

3. Apparatus according to claim 2, characterized in that the cross-sectional shape of the laminarization zone (10) corresponds to the cross-sectional shape of the suction / mixing zone (11).

4. Device according to one of the preceding claims, characterized in that the suction / mixing zone (11) is ring-shaped or te ring-shaped at the mouth.

5. Device according to one of the preceding claims, characterized gekenn¬ characterized in that each feed channel (7) seen in cross section of the suction / mixing zone (11) opens perpendicular to the circumference of the cross-sectional area in the suction / mixing zone (11).

6. Device according to one of the preceding claims, characterized gekenn¬ characterized in that each feed channel (7) seen in the longitudinal section of the suction / Misch¬ zone (11) perpendicular to the flow direction or obliquely in the flow direction of the primary fluid in the suction / mixing zone (11) .

7. Device according to one of the preceding claims, characterized gekenn¬ characterized in that the dimensions of the mouth surfaces of the feed channels (7) in the circumferential direction of the main channel (3) are larger than the same in the axial direction.

8. Device according to one of the preceding claims, characterized gekenn¬ characterized in that the feed channels (7) are provided on both parallel sections of the boundary line of the cross-sectional area of the suction / mixing zone (11), the feed channels (7) offset on the one boundary line which are arranged on the other boundary line.

9. Device according to one of the preceding claims, characterized gekenn¬ characterized in that the feed channels (7) are arranged at a circumferential distance of 10 - 30 ° from each other.

10. Device according to one of claims 1 to 6 or 8, 9, characterized in that the feed channels (7) have a circular cross section.

11. Device according to one of the preceding claims, characterized gekenn¬ characterized in that the feed channels (7) are connected to two or more independent memories from which they are supplied with two or more secondary fluids.

12. Device according to one of the preceding claims, characterized gekenn¬ characterized in that at least one of the parallel sections of the boundary line of the suction / mixing zone (11) at the mouth while maintaining the parallelism relative to the opposite section to reduce or enlarge the cross-sectional area of the suction / Mixing zone (11) is displaceable at the mouth.

13. Device according to one of the preceding claims, characterized gekenn¬ characterized in that the suction / mixing zone (11) is annular at the mouth, the inner circumference by an approximately cylindrical

Spare sheet gene central body (4) is formed, on the circumferential surface of the mouths of the feed channels (7) are provided.

14. The apparatus according to claim 13, characterized in that the feed channels (7) emanate from a central chamber (6) in the central body (4) into which the secondary channel (14) opens.

15. The apparatus of claim 13 or 14, characterized in that the central body (4) is elongated and the laminarization zone (10) upstream of the suction / mixing zone (11).

16. The device according to one of claims 13 to 15, characterized gekennzeich¬ net that the opening area of the feed channels (7) extends over 10 ° of the central body circumference.

17. The device according to one of claims 13 to 16, characterized gekennzeich¬ net that the central body (4) is spherical at its upstream end and approximately conical at its downstream end.

18. Device according to one of claims 13 to 17, characterized gekennzeich¬ net that the central body (4) in the suction / mixing zone (11) with respect to its upstream portion has a thickening (13).

19. Device according to one of the preceding claims, characterized gekenn¬ characterized in that the feed channels (7) are as short as technically possible, d. H. expand a short distance upstream of their mouth.

20. Device according to one of claims 13 to 19, characterized in is characterized in that the cross-sectional area of the suction / mixing zone (11) can be reduced or enlarged at the mouth by axial displacement of the central body (4).

21. The apparatus according to claim 20, characterized in that the central body (4) engages with a web (31) in a spiral groove (30) on the inside of the tube forming the main channel (3) and is axially displaceable by rotation.

22. Device according to one of claims 1 to 5 or 7 to 21 with a suction pump arranged downstream of the suction / mixing zone in the main channel for the primary fluid, characterized in that each feed channel (7) seen obliquely in the longitudinal section of the suction / mixing zone (11) the direction of flow of the primary fluid opens into the suction / mixing zone (11).

23. The device according to one of claims 1 to 5 or 7 to 22, characterized in that a throttle is formed in the secondary channel.

24. Device according to one of claims 1 to 5 or 7 to 23, characterized in that the main channel (3) in the region of the suction / mixing zone

(11) has an annular elevation (40) on its outside, in whose upstream rising side (41) the feed channels (7) open.

25. The device according to claim 24, characterized in that the annular elevation (40) has two flat rising sides (41, 42).

26. The apparatus according to claim 25, characterized in that the angle of the upstream rising side (41) to the surface line of the main channel (3) is 30-90 °.

Replacement sheet

27. The device according to one of claims 24 to 26, characterized gekenn¬ characterized in that the annular elevation (40) for reducing or enlarging the cross-sectional area of the suction / mixing zone (11) is displaceable at the mouth. y-

28. Device according to one of claims 22 to 27, characterized in that it is arranged in the oil line leading to the burner of an oil heater, in particular directly at the inlet of the oil pump, air being added to the oil as the secondary fluid.

29. Device according to one of the preceding claims, characterized gekenn¬ characterized in that the main channel (3) has a box-shaped cross section.

30. The device according to claim 29, characterized in that the

Central body (4) is arranged on the underside of the main channel (3), extends to the sides of the main channel (3) and is approximately wavy in longitudinal section.