NL8000988A - FLUIDUM MIXER. - Google Patents

Description

* "1 Έ.0.28.777" "

Elul dumblng ing

The invention relates to a fluid mixing device and more particularly to a fluid mixing device which functions only under the influence of a fluid generated in the device itself, whereby the fluid mixing ratio can be adjusted in a simple manner.

In a known fluid mixing device, a fluid to be mixed is pressurized by pressure generating means such as a pump or the like and introduced through an inflow opening into a flow-through channel. Such a conventional fluid mixing device not only requires pressure-generating parts, but further it is difficult to control the mixing ratio and, as a result, the dimensions of the device itself become quite large.

Another known conventional fluid mixing device does not use pressure generating means but uses the so-called venturi effect, whereby the pressure in the flow-through channel is made lower than atmospheric pressure and a fluid to be mixed is introduced into the fluid by suction. flow channel.

In this conventional device problems arise with the suction if the pressure in the flow-through channel is higher. If the throttle ratio of the venturi tube is relatively large, then the suction of the fluid to be mixed can be carried out effectively. In this case, however, when the flow rate through the venturi tube is relatively large, the pressure drop will also be relatively large. Thus, in order to use the known device effectively, the optimum throttle ratio and the dimensions of the venturi must be changed in accordance with the flow rate. If the throttle ratio of the venturi tube is changed in accordance with the flow rate, then the optimum suction area in a venturi tube is very narrow and the suction state itself becomes unstable while further increasing the pressure drop through the venturi tube outside this optimum suction area.

That is, the range of the practically applicable flow rates is limited. In order to introduce an admixable fluid 55 under varying fluid pressures and varying flow rates by means of a venturi tube, a bridging pipe connection must be provided at the venturi tube 800 0 9 88 ά.

in the conventional device, whereby the fluid is introduced into the mixer with a flow rate suitable for being drawn through the venturi tube. However, in such a fluid mixer, a large number of valves 5 must be controlled at the same time to control the mixing state, and adjustment of the flow rate and mixing ratio is therefore very troublesome while the mixer itself is rather complicated. Furthermore, a bridging pipe connection is required, as a result of which the dimensions of the entire device increase and, as a result, a larger space is required for installing the device. When a device based on the use of a venturi tube and a bridging pipe connection is used for adding liquid fertilizer, for example for agricultural purposes, the mixing device becomes larger and it becomes difficult to install and operate the device because the device has a large space in a greenhouse and is equipped with a number of valves.

As a result of an extensive study of the problems associated with conventional fluid mixers, the invention now provides a fluid mixer that is small and lightweight and is capable of introducing an admixable fluid into a passage within a wide range range of flow rates even if the pressure in the passage is high while the fluid mixing ratio can be controlled as desired with a small pressure drop and without the need for a bridging pipe connection.

To this end, the invention provides a fluid mixing device comprising a mixing device body with a fluid inflow opening, a fluid outflow opening and a number of passages between the fluid inflow opening and the fluid outflow opening, wherein a mechanism is further provided in at least one of the number of passes for modifying the cross-sectional area THi the passages as desired and at least one inflow opening is provided for introducing a fluid to be admixed into at least one of the other passages by suction.

The invention will be described in detail below with reference to the illustrative embodiments shown in the figure, to which, however, the invention is not limited.

Fig. 1 shows a vertical section through a fluid mixing device according to a first embodiment of the invention.

Fig. 40 2 shows a section along the line II-II in FIG. 1.

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Fig. 3 is a sectional view taken on the line III - III in FIG. 1.

Fig. 4 shows a schematic view of an apparatus for mixing a liquid fertilizer for agricultural use carried out in accordance with the invention.

In Fig. 1, the body 1 of the mixing device is provided with a fluid inflow opening 1a and a fluid outflow opening 1b.

The passage through the mixing device 1 is separated by means of a dividing wall 2 into a variable flow-through channel 1c and a mixing channel 1d. A vertically movable valve 3 is arranged in the variable flow-through channel 1c and the cross-section of the flow-through opening of the channel 1c can be changed in the desired manner by moving the valve 3 in the vertical direction.

An inflow opening 4 for introducing a fluid to be mixed into the mixing channel 1d is arranged on the side of the mixing device 1 by means of a channel 4a opening into the mixing channel 1d.

The fluid introduced through the fluid inflow opening 1a is distributed by the dividing wall 2 and passes the variable flow-through channel 1c and the mixing channel 1d, which channels are separated by the dividing wall 2, and come together again in the fluid outflow opening 1b from where they are discharged from the body 1 of the mixer. The cross-section of the through-flow opening in the variable channel 1c is determined by the vertical position of the valve 3 which is arranged in the channel 1c, so that the amount of fluid 25 flowing through the variable through-flow channel 1c can be changed, with the result that also the amount of fluid flowing through mixing channel 1d can be changed. Thus, the flow rate in the mixing channel 1d can be controlled by the valve and the pressure in the mixing channel 1d can also be changed. In other words, the pressure in the mixing channel 1d is adjusted to a desired value such that a desired volume of the fluid to be mixed is introduced by suction through the inlet opening 4a.

According to the invention, the pressure in the mixing channel 1d can be adjusted in a simple manner to the pressure required for drawing in the fluid to be mixed by regulating the vertical position of the valve 3 in the variable flow channel 1c regardless of the amount of fluid which flows through the mixer and the fluid to be mixed can easily be introduced into the mixing channel by suction. lat means that the mixing ratio 40 of the fluid to be mixed can be controlled in a simple manner by operating only the valve 3 present in the variable flow channel 1c.

In the fluid mixing device of the device, the mixing channel 1d into which the fluid to be mixed is introduced is further separated from the variable flow channel 1c in which the through-flow quantity is controlled so that not only the suction condition but also the degree of suction can be stabilized can be easily varied within wide limits by controlling the flow rate through the variable flow channel 1c. Furthermore, the pressure drop in the backflow region can thereby be made smaller.

In the fluid mixing device according to the invention, the pressure in the mixing channel 1d can be controlled in a simple manner and the fluid to be mixed can not only be introduced into the mixing channel 1d by using the pressure difference between the fluid inflow opening 1a or the fluid outflow opening 1b and the mixing channel 1d, but also the pressure in the mixing channel 1d can be brought to a negative value (a pressure lower than the atmospheric pressure), so that the fluid to be mixed can be introduced into the mixing channel 1d by suction based only on the differential pressure with atmospheric pressure without the need for further energy sources.

Furthermore, the mixing process can be realized without any bridging pipe connections in the fluid mixing device according to the invention, so that the device can be made with smaller dimensions and a lighter weight and the installation of the device becomes very simple.

The fluid supplied via the fluid inflow opening 1a or via the inflow opening 4a in the mixing device according to the invention can be understood to mean a liquid, a gas, and a liquid or gas in which finely divided solid or liquid particles are present.

In the fluid mixing device according to the invention, the desired mixing can be achieved with at least one variable flow-through channel 1c, but the number of variable flow-through channels 1c is not limited, and in fact a number of 1 to 4 variable flow-through channels are preferred. The desired effect can also be achieved with 5 or more variable flow channels, but operating comfort is thereby reduced.

40 With at least one mixing channel 1d and at least one inflow opening 0a 9 88 5 the desired mixing process can be realized, but the number of mixing channels 1d and inflow openings 4a can be suitably selected depending on the number and types of fluid that must be mixed in. A quantity of inflow openings 4a 5 can be arranged in a single mixing channel 1d.

The cross-sectional shape of the mixing channel 1d is not limited to a particular embodiment, but a circular cross-section or a polygonal cross-section approximating a circular cross-section, for example a quadrilateral cross-section, is preferred for the cross-section of the mixing channel.

Particularly in the case where the fluid is a liquid, a sufficient mixing effect can be achieved with a straight tubular mixing channel 1d, but it is preferable that the diameter of the mixing channel gradually decreases from the inflow side of the mixing channel until at a certain position in the mixing channel a minimum cross-section is reached, s after which the cross-section gradually increases in the direction of the outflow end of the mixing channel, wherein the section with minimum cross-section is preferably a straight channel over a certain length. 20 section, and the length of this straight channel section with minimum cross section is less than twice the diameter of a circle having the same area as the surface of the minimum cross section of the straight section. If the length of the straight section with minimum cross section is greater than twice the diameter of a circle with the same area as the surface of the minimum cross section of the straight section, the pressure drop increases and the degree of suction decreases. It is preferable to choose the minimum cross-section between 5 - 100 mm 2

Mixing may still be possible below 5 nm, but the suction volume is too small and the pressure drop is too great. Above 100 mm, no suction is achieved if the fluid flow rate is too low.

The cross-sectional shape of the inflow opening 4a is not particularly limited. It is preferred that the cross-section 35 of the inflow opening 4a is selected at 10 - 90% of the cross-section of the mixing channel 1d or of the minimum cross-section of the mixing channel 1d if the mixing channel 1d is designed with a section with minimum intersection. Even if the cross-sectional area of the inflow opening 4a is less than 10% of the cross-sectional area of the mixing channel 1d, suction can be reached 80 0 0 9 88 b but the mixing volume is smaller and no high mixing ratio are achieved. If the cross-sectional area of the inflow opening 4a is more than 90% of the cross-sectional area of the mixing channel 1d, this is equivalent to the situation where the cross-sectional area of the mixing channel 1d has increased considerably, with the flow rate in the mixing channel 1d is reduced and mixing by suction is hardly achieved.

The variable flow channel 1c can have any cross-sectional shape in that the cross-sectional area can be varied as desired and the cross-sectional area of the variable flow channel 1c can be varied in any way, in that the cross-sectional area is continuous or stepped toward wish can be changed. A slide valve, a butterfly valve, a valve, a slide valve, a needle valve, etc. can be used, or the cross-sectional area can be changed, for example, by exchanging sections with a different cross-sectional area.

The length of the divider for dividing the total flow-through opening is not limited in any particular way, but it is preferred that the length be less than twice the diameter of a circle having the same area as the sectional area of the fluid. inflow opening 1a. If the length is more than twice the diameter, the device will produce a sufficient effect, but the dimensions of the devices will become larger.

In the fluid mixing device according to the invention, a flow meter, such as a flow meter, or pressure measuring means, can be applied to the inlet channel 4 so that the volume drawn is determined and the mixing ratio can be detected and controlled in a simple manner.

The fluid mixing device according to the invention has a complicated shape but can be easily manufactured by machining, casting, injection molding, a die-molding method or in another suitable manner, but by means of an injection molding process or a die-molding process the device can low cost and mass-produced with good accuracy.

The fluid mixer of the present invention can be effectively used for mixing and diluting liquid fertilizers and agricultural chemicals, for mixing an additive in a liquid fuel such as gasoline, for mixing and preparing lubricating oil, for mixing a additive 80 0 0 9 88 7 in a fuel gas and so on. The fluid mixing device is compact and easy to adjust to the operating mixing ratio and very economical compared to the conventional fluid mixing devices, because the fluid mixing device according to the invention functions only at the pressure generated by the passing fluid without that further pressure generating means or bridging pipe joints are required for mixing the fluid.

A particular embodiment of the fluid mixing device according to the invention intended for agricultural use will be described in the following text, it being noted that the invention is not limited to this embodiment.

A fluid mixer as shown in Fig. 1 was made of nylon by a normal injection molding process and was intended as a mixer for liquid fertilizers in agriculture with a total length of 200 mm. The dimensions of the respective elements in Fig. 1 are summarized in the table below.

Table 20 Elements Dimensions 1a diameter 50 mm 1b diameter 50 mm 1c length 50 mm 1d minimum diameter 6 mm 25 4a diameter 4 mm

A schematic view of the liquid fertilizer mixer is shown in Fig. 4, where 5 is a pipeline, 6 is a mixing body, 7 is a valve handle, 8 is a flow rate of 50 meters, 9 is a float element, 10 is a tap, 11 is a liquid fertilizer tank, 12 the liquid fertilizer, and 13 a stroke for supplying the liquid fertilizer by suction.

The flow rate in the variable flow-through channel is controlled with the valve and the flow rate meter 35 is arranged to detect the amount of liquid fertilizer introduced by suction. The tap 10 is arranged to control the amount of fertilizer introduced by suction.

If the variable flow opening 1c is completely closed by the valve, only water flows through the mixing channel 1d and the suction of the liquid fertilizer is started at a water flow rate of 80 0 0 9 88 8 with only the hose. 15 is inserted into the fertilizer hopper 11 and the maximum suction rate of the liquid fertilizer is 2.5 l / min. By gradually closing the tap 10, the amount drawn in can be adjusted to a desired amount below the maximum suction amount.

On the other hand, a large amount of water can pass through the variable through-flow opening by gradually opening the valve and in the fully opened state of the variable through-flow 1c, the water reaches a flow rate of 500 l / min, 10 but the liquid fertilizer is still introduced into the mixing channel 1d in this state with a pressure drop of only 0.5 kg / cm.

As can be seen from the above, the liquid fertilizer can be introduced in a desired mixing ratio within a wide flow range only by installing the mixing device according to the invention in a main water pipe, so that the mixing device according to the invention can thus be easily installed and operated .

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Claims (8)

9 "" - 1. Fluid mixing device provided with a body, a fluid inflow opening, a fluid outflow opening and a number of flow-through passages between the fluid inflow opening and the fluid outflow opening, characterized in that in at least one of said passages a mechanism is provided for modifying the cross-sectional area of the passage as desired, and further comprising at least one inflow opening for introducing a fluid to be admixed into at least one of the other passages by suction. 2. Fluid mixing device as claimed in claim 1, characterized in that the mixing passage, which is provided with at least one inflow opening for introducing the fluid to be mixed by suction, is designed such that the cross-sectional area 1. of the passage gradually decreases from the fluid inflow side in the downstream direction and an area of minimal cross section reaches at a particular position in the passage and then gradually expands from this position with minimal cross section toward the fluid outflow side the area of minimum cross section having a surface 2 on the order of 5 to 100 mm. 3. Fluid mixing device according to claim 1, characterized in that a flow quantity measuring device is provided for determining the suction quantity. 25 4. Fluid mixing device according to claim 1, characterized in that a slide valve, a butterfly valve, a tap, a slide valve valve, or a needle valve is used as a mechanism for changing the cross-sectional area of said passage. 30 Fluid mixing device according to claim 1, characterized in that the body of the mixing device is manufactured by injection molding, injection molding or mold molding. 6. Fluid mixing device according to claim 2, characterized in that the cross-sectional area of the inflow opening for introducing the fluid to be admixed is 10 to 90% of the minimum cross-sectional area of the mixing passage. 7. Fluid mixing device according to claim 1, characterized in that the fluid consists of a liquid. Fluid mixing device according to any one of the preceding claims, characterized in that the device is used for mixing in liquid fertilizer.