CN1005962B

CN1005962B - Mixing pumps for conveying and efficiently mixing (homogenizing) two or more liquids (gases) in a constant but adjustable ratio of liquids

Info

Publication number: CN1005962B
Application number: CN85105455.2A
Authority: CN
Inventors: 阿如那·本徒·守古人
Original assignee: Modeling Science Of Ltd Branch
Current assignee: Modeling Science Of Ltd Branch
Priority date: 1985-07-17
Filing date: 1985-07-17
Publication date: 1989-12-06
Also published as: CN85105455A

Abstract

Mixing pump for delivering and mixing two or more liquids or gases in a constant ratio, comprising a double-acting pump adapted to displace liquid V in a first chamber at the end of piston 2 in the cylinder on its first stroke₁Is fed into the second cavity of the pump cylinder to make the liquid V₁With liquid V entering from the storage tank 5₂Mixing, double-acting pump for mixing liquid V in its second stroke₁＋Ｖ₂Into a storage tank other than the pump cylinder while supplying the liquid V₁Is sucked into the first cavity.

Description

Mixing for transporting and effectively mixing (homogenizing) two or more liquids (gases) in a constant but adjustable ratio

The invention relates to a mixing pump by which two or more liquids can be fed from a reservoir for each liquid component to a reservoir for a mixed product, while the liquids are mixed very effectively and the proportions of the various components in the liquids are constant and can be adjusted as desired.

In many industrial fields, in particular the chemical industry and the fuel industry, it is necessary to mix together two or more liquids effectively and to make the content ratio constant (adjustable). The requirements for truly efficient mixing (in microphase) and constant proportions (independent of capacity) are very stringent, which in the last few years have been achievable by means of technically careful design, but solutions to problems are often very complex and expensive.

It is evident that with modern advanced technology, a device with one or more of the following equipment such as measuring pumps, flow control elements, regulating valves, various mixing devices such as static mixers etc. and up-to-date technical data, the above requirements are achievable, but these devices are often very complex and expensive and are very vulnerable to damage due to minor operational errors.

The object of the present invention is to propose a mixing pump which in many cases is very simple and economical to solve and is very reliable.

It is often a complex matter to mix two or more liquids, and it is also relatively easy to mix two completely compatible, low viscosity liquids. More time-consuming people are faced with one or more of the following problems:

1. the viscosity of the liquid is very high and,

2. The temperature difference between the liquids is large

3. The liquids being immiscible

Even if the liquids are compatible, their viscosity is high or the temperature difference is large (1, and 2), efficient mixing is not easy.

Here, it is critical to "energy" because only sufficient energy is available to achieve very thorough mixing of the liquids of the various components in a short period of time.

In the case of liquids which are not compatible, special requirements are imposed on the equipment and the energy supply in order to obtain a satisfactory emulsion, which can be "coarse dispersed" or "fine dispersed" depending on the equipment and the energy supplied.

Some emulsions are stable (or nearly so), that is, they remain undisturbed for a long period of time.

Stability is related not only to the liquid itself, but also to the efficiency of the emulsification process (equipment, energy supply).

Other emulsions are very unstable and break down in a short period of time unless "emulsifiers" are added. (an emulsifier is a compound that acts to increase the stability of the emulsion).

Water-fuel emulsions and water-diesel emulsions are typical of the two emulsions that are well known.

The water-fuel emulsion has natural stability, and can be prepared into emulsion by using proper equipment and supplying proper energy (containing surfactant), and can be kept stable for several years.

The water-diesel emulsion is very unstable, and it breaks down in a short period of time, no matter how efficient the equipment is, and no matter how much energy is supplied.

Finally, it is pointed out that in many cases the liquids to be mixed are inherently inhomogeneous (for example fuel oil), so that the importance of an ideal mixing device exceeds that of the mixing method and care must be taken with respect to the conditions (homogeneity) of the liquids themselves.

The present invention provides a mixing pump that meets this need.

The above-mentioned problem relates to the efficiency of the mixing, which is an aspect of the complexity of the problem.

On the other hand the ratio of the liquids is not at all trivial, -this ratio is generally constant and independent of the ratio of the liquids produced. In addition, the adjustment of the liquid ratio should be easy.

Finally, the ratio must be constant, even in the case of 1:10 to 1:100.

All the problems mentioned above are solved by the mixing pump according to the invention, the method of which is not complex.

There are generally two different methods of making the mixture, one discontinuous, i.e., adding and mixing the appropriate amounts of the various liquids in the container, and the other continuous, i.e., continuously feeding the various liquids to the mixing device via metering pumps, flow control elements, flow measuring elements, nozzles, orifices, etc.

The mixing pump provided by the invention is to some extent intermediate between these two extreme cases, i.e. it works discontinuously-continuously, i.e. the mixing pump produces a small amount of mixture several times per minute and the proportions of the various components are adapted.

The displacement of the mixing pump is not only related to the size of the pump, but also depends on the number of infusions per minute and whether the pump is in operation.

These last two points make it possible for the displacement of the mixing pump to be between zero and maximum.

The present invention will be described in detail with reference to the accompanying drawings. Wherein:

FIG. 1 is a schematic cross-sectional view of a double acting pump cylinder. Showing the movement and flow of liquid during the first stroke of the piston.

Fig. 2 is the same as fig. 1 but shows the movement of the piston in the second stroke and the flow of liquid.

Fig. 3 is a schematic cross-sectional view showing one configuration of a mixing pump with a restriction element.

Fig. 4. A mixing pump configuration with a first restriction in a separate cylinder.

FIG. 5 is a block diagram of a single-acting, coupled pumping cylinder of the present invention.

A. for mixing two components

B. is used for mixing three components.

In fig. 1, the heart part of the mixing pump is a pump cylinder 1 with a piston 2, which is already used in piston pumps, steam engines and hydraulic drive systems. The cylinder is a double acting cylinder, i.e. both sides of the piston (right and left chambers) are involved in the pumping action, the cylinder working during both the piston coming and going (1 st and 2 nd stroke). In the two chambers separated by the piston are two mixing components.

This is the best structure of the invention.

This is because the construction has certain advantages and is very simple, requires little space and is not very tight, but the invention provides a construction which also includes separate, single-acting coupled cylinders, where each pump a separate liquid. This is preferably used for mixing, for example, two or more liquids.

Fig. 1 shows that on the stroke of the piston in the left direction, liquid V ₁ is pumped from the left chamber into liquid V ₂, while liquid V ₂ is sucked from its reservoir 5 into the right chamber.

Fig. 2, which is the case when the piston has moved to the right after the first stroke (second stroke), the mixture of V ₁+V₂ in the right chamber starts to exit the pump cylinder due to the action of the check valves (check valves) 7, 8 and 9 in the system, and the mixture is forced through the check valve 10 and the outlet pipe 11 into the reservoir of the mixture of V ₁+V₂. At the same time, liquid V ₁ is drawn from its reservoir 4 into the left chamber.

It is apparent that if all V ₁ liquid in the left chamber flows into the right chamber, then liquid V ₂ will not be able to enter the right chamber.

Mixing the two liquids and mixing them in the different ratios required, a certain amount of liquid V ₁ must flow back into the reservoir rather than into the right chamber.

The "isolation" of a certain amount of liquid V ₁ is accomplished with the regulating device 6 shown in fig. 1, 2, 3 and 4. This component of the mixing pump can be manufactured in a number of different ways depending on the use of the mixing pump in the actual application.

The adjustment means also need to be chosen according to whether the ratio of the various components in the liquid is constant (but still adjustable) or needs to be easily adjustable.

The regulating device (6) can be, for example, a pressure regulating valve or a flow control valve as shown in fig. 1,2,3, 4, but can also be just an orifice or nozzle, so that the V ₁ returned to the reservoir (4) has a constant displacement.

The above explanation and figures 1 and 2 solve the problems related to the constant (but still adjustable) ratio of the two (eventually more) liquids in the invention.

The invention is characterized in that the two-stroke piston mixing pump has a piston which moves from a far right end position (fig. 1, 2) to a far left end position and then returns to the far right end position to form a complete cycle, thereby generating a certain amount of mixed liquid of two or more components. Each cycle produces a mixture of two liquids in exactly the same proportion, the displacement of the mixing pump being related to the number of cycles per unit time.

Almost all ratios are available. It can be seen from fig. 1 and 2 that if the regulating element (6) connected to the reservoir (4) is fully opened, this will result in a V ₂ percent of the mixed liquor, whereas when the regulating element (6) is fully closed, the mixed liquor is almost V ₁ percent.

Ratios between these two extreme ratios are possible.

This is the contribution of the invention to obtaining a constant proportion of a mixture. Another part of the invention is the contribution to obtaining a highly efficient mixing of one or more liquids.

As mentioned previously, it is very difficult to mix liquids quickly and efficiently, depending on the composition of the liquids, especially if they are not uniform, and in any case energy is supplied.

Only enough energy is provided to overcome forces that attempt to hinder mixing, such as surface tension, shear forces, etc.

The mixing pump provided by the invention has absolute advantages in this respect, since it is structurally allowed to precisely supply the energy required for mixing. There is only one effect provided. Finally, there is a considerable problem of energy consumption.

The energy is used to force the liquid mixture through a high pressure drop, which requires a throttling element, on which a high pressure drop can be created.

Such a restriction element may be an orifice, a nozzle, a small hole, a sintered material, etc. There are a variety of configurations of throttling elements available in the homogenization process, and it is not important which throttling element is used in the present invention.

It is important that the pressure differential be high enough to allow efficient mixing of the liquids and eventually that the non-uniform composition be homogenized.

Fig. 3 and 4 show the throttling element in two different forms of the mixing pump structure.

In fig. 3, liquid V ₁ is sprayed through the cylinder wall into liquid V ₂, while in fig. 4V ₁ is sprayed into a separate chamber (pump cylinder).

These two structures are only two examples of the numerous possibilities of features of the invention, which do not exclude other structures based on the same principle.

In both fig. 3 and fig. 4, the liquid V ₁ is delivered to the liquid V ₂ by the throttling element 12 during the suction or flow of V ₂ into the cylinder (stroke 1).

Here, the miscible liquids are already well mixed.

If the two liquids are not compatible, V ₁ will spray as a mist into solution V ₂ and be present in the form of droplets in V ₂.

After the mixed emulsion has been pumped out of the cylinder (second stroke), it passes through a further throttling element (13), where a pressure drop is caused, where the soluble liquid mixture is finally thoroughly mixed and the insoluble liquid mixture is thoroughly homogenized.

This method is also effective for V ₂ if the liquid V ₂ is non-uniform from the beginning.

The mixing pump provided by the invention has advantages in mixing efficiency (emulsion and homogenization) and can meet the required mixing quality because the pressure difference passing through the throttling element can be freely regulated.

The pressure drop relates only to the damping of the throttling element and the piston speed, since the mixing cylinder (hydraulic cylinder is very suitable) is usually chosen to withstand a pressure of 200 bar, a suitable pressure difference can be found for each desired use.

In most cases, the pressure drop is determined after careful consideration of the mass of the mixture with respect to the energy consumption.

The subject matter described above primarily describes the mixing of two or more liquids.

Of course, one or all of the various liquids may be replaced by one or more gases in accordance with the principles of the invention.

It is also possible to mix one gas with one liquid (soluble or insoluble) or to mix two or more gases.

The explanation of the mixing of one or more gases according to the invention is the same as the explanation of the mixing of a liquid and is not repeated here.

For one or more gases, as well as the advantages of the mixed liquids, very effective mixing of the (homogeneous) gases with a certain (also adjustable) ratio of the various components is also obtained.

Hydraulic technology has now evolved to a very high level, the operation of double acting cylinders being very reliable and, because of its very rational construction, generally being the best choice.

The construction of the mixing pump according to the invention does not exclude the type of single-acting coupling cylinders which can be made separate. In some cases this structure is rather better, for example when more than two liquids/gases are to be mixed).

Fig. 5 shows the structure of two examples of separate and coupled cylinders.

Fig. 5a is an example of mixing two components, and fig. 5b is an example of mixing three components.

The explanations given above in relation to the double-acting cylinders apply literally equally to the explanations of two or more single-acting cylinders.

The mixing pump provided by the application can be used for completing various mixing tasks requiring constant proportion and effective mixing. The examples given below in no way limit the broad field of applicability that the application has.

Only one example of the addition of water to heavy fuel oil is given here, and only the effectiveness of the invention is demonstrated from this single field.

Examples

This is a well known example, where water is mixed with fuel to improve combustion and reduce particulate emissions.

The larger the water droplets emulsified into the fuel, the more uneven the fuel, and the more water needs to be added to get good combustion. With inefficient equipment, ten to twenty percent of water may need to be added.

With more efficient devices, this water proportion may be reduced to five percent, but even with such devices problems are encountered with fuel that is not well homogenized.

The following are the results of the mixing pump experiments performed according to the present invention.

The conditions are pressure jet, 550 kg oil/hr load, additional heavy fuel, (77 cm, 80 ℃) excess air:

contains 2.3% oxygen.

To better observe the above results, it is expressed in a simpler manner.

% Water

It can be seen that the pressure drop of the homogenization process and the amount of water in the oil have a great influence on the reduction of the particulate emissions.

It can also be seen that if the mixing pump is operated at a highly uniform pressure differential, a reduction in water content is possible, as a reduction of 0.08% water is important for water savings.

Finally, it should be noted that the movement of the piston in the mixing pump may be driven by a suitable power transmission method, for example, by an electric motor through a crankshaft, rack, screw or ball-bearing screw or by hydraulic, pneumatic or steam cylinders.

Claims

1. A mixing pump for effectively mixing at least a first liquid and a second liquid from respective liquid sources in a constant ratio and delivering the mixed liquid to a storage tank, the mixing pump comprising:

A cylinder having a piston slidably mounted therein, said piston being movable back and forth between a first position adjacent one end of the cylinder and a second position adjacent the other end;

A first fluid inlet located on the cylinder, the inlet communicating at least the first fluid source with the one end of the cylinder such that when the piston moves from the first position to the second position, a first fluid flows from the fluid source between the one end of the cylinder and the piston, and when the piston moves from the second position to the first position, a first fluid between the one end of the cylinder and the piston exits the cylinder;

A second liquid inlet located on the pump cylinder, the inlet communicating a second liquid source with the other end of the pump cylinder such that when the piston moves from the second position to the first position, a second liquid flows from its liquid source between the other end of the pump cylinder and the piston;

A liquid mixing tube connected between the first liquid inlet and the other end of the cylinder for receiving at least a first liquid exiting the cylinder from the first inlet and delivering it to the other end of the cylinder where the at least first liquid mixes with the second liquid as the piston moves from the second position to the first position;

And a mixed liquid outlet formed in the other end of the cylinder, the mixed liquid formed by the first liquid supplied from the liquid mixing pipe to the other end of the cylinder and the second liquid supplied to the other end of the cylinder through the second inlet being discharged from the cylinder through the outlet when the piston is moved from the first position to the second position.

2. The mixing pump of claim 1 wherein said pump cylinder comprises first and second adjacent pump cylinders, said piston comprising a first piston slidably mounted in the first pump cylinder and a second piston slidably mounted in the second pump cylinder, a piston rod connected between the first and second pistons;

The piston is movable back and forth between a first position in which the first piston is adjacent the first end of the first cylinder and the second piston is remote from the first end of the second cylinder, and a second position in which the first piston is remote from the first end of the first cylinder and the second piston is adjacent the first end of the second cylinder;

The first pump cylinder having a first fluid inlet communicating at least a first fluid source with a first end of the first pump cylinder, the first fluid being directed from the first fluid source between the first piston and the first end of the first pump cylinder when the piston moves from the first position to the second position, and the first fluid being directed from the first fluid source between the first piston and the first end of the first pump cylinder when the piston moves from the second position to the first position;

The second cylinder having a second fluid inlet communicating the second fluid source with the first end of the second cylinder for delivering at least a second fluid from the fluid source to between the second piston and the first end of the second cylinder as the piston moves from the second position to the first position;

the liquid mixing tube is connected between the first liquid inlet and the first end of the second pump cylinder, and receives at least the first liquid leaving the first pump cylinder and sends the first liquid to the first end of the second pump cylinder when the piston moves from the second position to the first position;

The mixed liquid outlet is positioned at the first end of the second pump cylinder, so that the mixed liquid of at least the first liquid fed into the first end of the second pump cylinder through the liquid mixing pipe and the second liquid entering the second pump cylinder through the second inlet leaves the second pump cylinder and flows to the storage tank.

3. The mixing pump of claim 2 wherein said first inlet has a regulator for returning a portion of at least a first liquid leaving the first cylinder from the first inlet to at least a first liquid source, said regulator being adjustable to vary said portion of liquid between 0% and 100% of the liquid leaving the first cylinder from the first inlet.

4. The mixing pump of claim 2, further comprising:

A first throttling element connected between said liquid mixing tube and the first end of the second cylinder for creating a pressure differential in the flow of at least a first liquid as it is being directed from the liquid mixing tube to the second cylinder and for dispersing the liquid in a second liquid directed to the first end of the second cylinder;

a second throttling element positioned between the first end of the second cylinder and the mixed liquor outlet for further mixing and homogenizing the mixed liquor of at least the first and second liquids as the mixed liquor flows from the second cylinder to the holding tank.

5. The mixing pump of claim 1 wherein said first inlet has a regulator which causes a portion of the first liquid to flow from the first inlet out of said pump cylinder back to the first liquid source when the piston moves from the second position to the first position, the regulator being adjustable such that the portion of the liquid varies from 0% to 100% of the first liquid exiting the pump cylinder from the first inlet.

6. The mixing pump of claim 1, further comprising:

A first throttling element connected between the liquid mixing tube and the other end of the pump cylinder, the throttling element creating a pressure differential in the flow of the first liquid as the first liquid is directed from the liquid mixing tube to the other end of the pump cylinder and dispersing the atomized liquid in a second liquid entering the other end of the pump cylinder through the second inlet;

A second throttling element positioned between the other end of the cylinder and the mixed liquor outlet for further mixing and homogenizing the mixed liquor of the at least first and second liquids as the mixed liquor flows from the other end of the cylinder to the storage tank.