WO2016113122A1

WO2016113122A1 - System for pumping highly viscous and firm compounds out of containers

Info

Publication number: WO2016113122A1
Application number: PCT/EP2016/000025
Authority: WO
Inventors: Ralf MÜLLER
Original assignee: MüLLER RALF
Priority date: 2015-01-14
Filing date: 2016-01-08
Publication date: 2016-07-21
Also published as: EP3245155A1; DE102015000410A1

Abstract

A method and device for pumping highly viscous and firm compounds out of a container, wherein the compound to be pumped is forced to and into the pump inlet by way of a bladed impeller which is rotatable below a plate, or by way of a rotatable, flat, obliquely mounted plate which may have one or more blades, and said compound is conveyed onward by the pump, wherein the pump presses with the weight thereof against the compound via the plate.

Description

SYSTEM FOR PUMPING HIGH VISISTS AND SAFE MASSES FROM CONTAINERS

The invention relates to a method for pumping highly viscous and puncture resistant masses from a container and the device therefor.

The system is intended as a competing product for barrel discharge pumps operating in conjunction with a press. It can also be used on liquid masses that do not require a press. It is also a competing product for pumps, which empty a hopper from below or into which hopper the mass to be pumped is poured. It can also replace systems in which a mass such. B. Butter first plasticized in a double-spindle pump and then pumped on. The system can also be used as an alternative to dumping by means of a lifting tipper. With these z. B. poured dough in a funnel pump. I am thinking in particular of the pumping of materials such as resin, silicone, pastes, grease, glue, bread, biscuit and pasta dough, marzipan, pastry fillings, my sealant, creams and butter at z. B. 5 ° C.

When a pump has pumped some mass, a negative pressure is created in the pump in the area of the pump inlet, whereby further mass is drawn in. This negative pressure is not always enough. Cavitation can occur, which is harmful to the mass to be pumped and can destroy the pump. Under certain circumstances, nothing can be funded.

For masses that can still flow by themselves (eg soft grease, adhesive or leveling compounds) you can immerse an eccentric screw pump with an extended pumping station - a so-called submerged pump - into the mass. The pump inlet is held with a short spacer close to the bottom of the tank. For a uniform depression of the mass to be pumped, a plate, which is also called a follower plate, can float on the mass. These plates are usually circular and have in the middle of a hole through which the pumping pump of the pump is pushed. The plate encloses it and is guided by it. As a result of the resulting negative pressure, the mass is pressed down evenly by the plate. However, the container bottom and the supports for the spacer form bottlenecks, which prevent tough masses from flowing. For masses that can not flow by themselves (eg petroleum jelly) or masses in which the pump can not be submerged (eg tomato paste), the plate can be fixed to the pump at the pump inlet , The air which is between the plate and the mass is sucked by a separate pump or pushed out by a valve before pumping the mass. The pump presses over the plate with its weight on the mass. As a result, the mass is pressed to the pump inlet. When pumping the mass, the pump is led down together with the plate. However, this is not enough for very tough masses. There is then an additional pressure required by a press to get the mass into the pump. The principle I have shown in Figure 1.

It is difficult to specify the maximum viscosity up to which it is possible to work without a press, since it depends on the weight of the pump, the size of the container and also on the delivery rate of the pump. At a low flow rate, the mass to be pumped has more time to flow than a high flow rate.

The presses are unnecessarily expensive, they can not be used mostly mobile, they have an unnecessarily high power consumption, and depending on the pressure very stable containers are needed. The pumps can only be mounted on a short, non-swiveling boom near the lifting column or between 2 columns. The containers to be emptied must either be placed on a platform of the press, or the entire system must be firmly anchored in the ground so that it is stable, otherwise the system itself would push itself high. The handling and the exact positioning are unnecessarily expensive, especially for large containers (eg 200 liter drum).

Alternatively, very viscous masses (eg dough) are poured in a further working step into a funnel pump with throat. For this purpose, mostly lift trucks are used. When decanting the mass, air can be trapped. The complete emptying of the funnel can be problematic. In general, something can hang not only on the sloping walls but also on vertical walls. In puncture-resistant masses a repressions can hardly be avoided and incompatible with the work safety. Some masses require bridge breakers and feed screws to get into the pump. Even in the containers in which the masses are mixed or delivered, remains some mass back. For them, production costs incurred, and they may have to be disposed of. For large quantities when using a lifting tipper a correspondingly large and stable hopper is required in which the slipping can be problematic due to unfavorable angles. Therefore, it may happen that only smaller quantities are mixed. The masses can be reloaded more evenly with my system, so that possibly larger quantities can be mixed. That leads to savings. My system is mobile and can be used at different heights of the following machines. The lifting tippers, on the other hand, are designed for a certain maximum height. Since the masses can be pumped directly from the barrels with my system, the system can also replace a lifting tipper and a hopper pump at the same time. The same naturally applies to masses, which an external manufacturer can then offer in larger containers.

From the document DE 33 46 564 AI it is known that a highly viscous mass of a rotatable pressure plate, which has conical surfaces and extending to the central opening ribs, can be conveyed to a suction channel. The plate presses on a large, unchanging surface. Therefore, the weight of the pump is not used optimally. It comes to friction between the plate and the container or at the edge of the container remains ground. The ribs run almost to the container wall. They transport the mass from the edge to the suction channel. The mass is sheared. Turbulences are brought in. This can be bad for sensitive masses. Due to the friction and turbulence, the energy required to turn the plate is unnecessarily high.

DE 10 2009 047 862 A1 describes a system in which the pump would cause an uneven level of the mass to be pumped below a follower plate. The level must therefore be lower than at the edge in the area of the pump inlet. This difference is compensated by a shaking movement, by causing friction by the rotation of the follower plate or by rotating a propeller below the follower plate. The propeller should move the mass from the edge to the center and only level out so that the follower plate can follow a changing level in the container. It is not described why the level is uneven. This would mean that the pump creates a vacuum below the plate without this leveling agent.

The following ideas apply in principle to all types of pumps suitable for container emptying. Progressive cavity pumps, screw conveyor drum pumps and reciprocating pumps are very often used. Other pump types may work also be taken. Because of the lowering into the container, a long pumping station may be advantageous, so that the connection lines can be easily carried.

Auger drum pumps are mostly used only for medium viscosity masses. They have no closed chambers. Therefore, they can not suck in so well, and the backflow is greater with them than with the progressing cavity pumps, whereby no such great pressure can be built up. These problems have become smaller with my solution.

For my target group, the viscosity of the mass is higher than usual. As a result, the mass in a screw conveyor barrel pump can not flow back so easily due to the back pressure even at a low speed. It can be built up a higher pressure. It is known that screw conveyors can transport dough when the dough is in them. It is also known from other masses when the feed screw of a throat pump pushes the mass to be pumped into the pumping station. Since the mass to be pumped is pushed with my development in the pump, auger barrel pumps with my development under certain circumstances z. B. also pump highly viscous masses of grease, glue, silicone, etc. Basically, the pumps do not have to suck in my solution. Therefore auger drum pumps may sometimes replace progressing cavity pumps.

A problem with auger barrel pumps may be that the friction of the mass to be pumped with the stator must be greater than the friction of the mass with the auger. Due to the changed conditions, the gap between the stator and the screw conveyor may possibly be larger than usual. Therefore, the surface of the stator may be rougher than usual. This increases the friction between the mass to be pumped and the stator. For a thorough cleaning you can rinse them or dismantle them if necessary. The problem with the friction does not exist with double spindle pumps, in which two counter-rotating spindles intermesh. For progressing cavity pumps and reciprocating pumps, this problem does not exist either.

The actual job of a pump is to pump the mass to the pump outlet. This creates a vacuum in - not before - the pump. This vacuum is limited to the size of the pump inlet and acts as an additional weight. This additional weight is significantly less than the weight due to the mass of the pump. The aspiration of the mass to be pumped is the flow of the mass into the pump due to the difference in pressure in the pump inlet and the pressure under which the mass to be pumped is before the pump inlet.

In all solution variants of my development, the mass to be pumped is pushed layer by layer from top to bottom to the pump inlet and also into the pump. The required force always acts only in a comparatively favorable angle to only a small amount of the mass to be pumped. But only a relatively small force is required. The rest may initially remain unchanged and is pushed with the further rotation of the plate or the impeller to and into the pump inlet.

From everyday life, you know that you can hardly deform a package of chilled butter if you press exactly perpendicular to the entire surface of one of the two larger surfaces. It will hardly be possible to allow such a mass, which is in a container, to rise up at a free point by pressing vertically on the remaining surface. This is also the case with systems that use vacuum and possibly support from a press. If in the known systems some mass to be pressed into the pump, then at the same time on the whole surface below the plate mass must be moved. It is not possible to push or suck off mass at one point only. A vacuum must be refilled immediately. The plate with the pump must go continuously to the bottom of the container.

A mass such. But butter can be deformed relatively easily if you only press on one edge. The force then acts on a much smaller area. The mass will dodge where there is room. If a flat plate is mounted slightly obliquely in a drum, then it presses with the weight of the pump only at one point on the outer edge of the mass to be pumped. At this point, the mass is pressed to the middle of the barrel and thus to and into the pump inlet.

Initially, the plate pushes only on the outer edge of the mass. With the turning of the plate, a conical cone forms in the tip of the pump. It is constantly pressed new mass to the pump inlet and thus into the pump. The plate is powered by its own motor. When turning the plate, it exerts a pressure on the mass in its front area. In the back area there is a discharge. It is a room free. The mass force acting on the mass can be broken down into a horizontal and a vertical component. The horizontal component pushes the mass to the pump inlet. The vertical component ensures that this gap is filled and the mass does not dodge upwards.

In this version, the plate must be slightly oval to fill the entire cross-section of the barrel. It may be advantageous if the upper part of the plate is horizontal (Fig. 2). The deformation of the mass is thereby limited. The same effect occurs when the plate is firmly fixed to the pump and it is rotated slightly obliquely in a circle. However, the gap between the plate and the container is larger. Therefore, this version will not be considered further. The advantage over the document DE 33 46 564 AI is that when turning the plate, the weight of the pump acts on a relatively small, constantly deforming surface. The weight of the pump is used more effectively, so that less energy is required to rotate the plate, and the mass to be pumped is not sheared so much.

If necessary, the container must be secured against turning. The pump must be safely suspended against twisting or tilting. It can promote until the lower outer edge of the plate has arrived at the bottom of the container. The pump inlet can reach into the mass. As a result, the mass that is immediately below the plate can be pressed more easily to the pump inlet (explanation see below). In addition, then the residual amount in the container is smaller by the volume of this part. The remainder of the container bottom will be the remaining cone. The volume of a straight circular cone arises

V = l / 3 * pi * r ² * h. A height difference of 1cm would therefore mean a flat residual amount with the height of about 3.4mm. If a cone is formed on only one side, then the remaining amount is about 6 to 7mm. If necessary, you can also make the horizontally shaped part of the plate in Figure 2 at a smaller angle slightly obliquely down and thereby reduce the amount remaining.

A further improvement can be achieved if one or more blades are attached to the plate. The effect is like going over butter (or margarine) with a knife to smear it on bread. You then push some butter in front of the knife so that it goes up. She deviates where there is room. In this case, the mass of the plate and the blades is directed into the pump. This can pump even firmer masses.

It is obvious that you can remove such solid masses layer by layer from top to bottom and can push to or into the pump inlet. The pump is guided as usual together with the plate from top to bottom.

The advantage over the known systems for pumping z. B. chilled butter, marzipan o. Ä. Is that the goods not in individual blocks, which must be cut, and unpacked again, must be stored. For cutting, packaging and unpacking, labor costs, material costs and costs for the goods hanging on the packaging are incurred. The manufacturer saves as well and can therefore sell cheaper. In my solution z. B. a 300 liter barrel. In addition, the technical effort for plasticizing and pumping the goods is lower.

The plate can also be stored horizontally. The occurring in the solution according to the document DE 33 46 564 AI friction between the container and the plate can be avoided by not the plate but a rotatably mounted paddle wheel is rotated below the plate. The paddle wheel is driven by a separate motor in Figure 3. The plate may have a sealing lip, which reduces the mass remaining on the container wall. For sensitive, very solid masses, the version with the obliquely rotating plate may be preferable, because it protects the mass to be pumped more.

With a consistently high paddle wheel from the inside out, more mass would be taken away on the outside than inside. This congestion can be reduced by the paddle wheel is shallower outside than inside. The plate can then be tilted slightly obliquely from inside to outside (Fig. 3). As a result, the mass to be pumped is also pushed more easily in the middle, since the weight of the pump hits it at a slight angle. It can be at different angles - so z. B. inside strongly sloping, outside only slightly inclined - be designed to keep the remaining amount as small as possible.

Even if the paddle wheel has arrived at the bottom of the container can be pumped a little further, as there is a back pressure in front of the blades even with the remaining amount. This pressure then decreases. Shutdown of the pump can be controlled by a sensor which measures it at a point in front of the paddle wheel. Alternatively, the pump may be turned off when in contact with the container bottom via a contact sensor. When the paddle wheel is driven by its own motor, it may be more advantageous to use a flat (only a few millimeters high) paddle wheel at a higher speed than a larger paddle wheel at a lower speed. The required torque and the residual amount in the container are thereby smaller.

For most masses such. As dough, glue or grease the paddle wheel does not need to go to the container wall, since they can be easily deformed. The paddle wheel can usually be very short. It just has to push as much mass into the pump as it can pump. This saves energy for the drive.

When the paddle wheel is rotated, it first tries to push the mass that is in front of the paddles ahead of them. This creates a dynamic pressure in front of the blades. The mass is pushed into the middle and from there into the pump, because there is room. Behind the blades, an empty space is created. This space is surrounded by the mass to be pumped on which the pump presses over the plate. The resulting behind the shovels empty space is thereby replenished. You can compare that to flattening a small lump of dough. Thus, it will be sufficient if the paddle wheel is only a few inches long, to empty even a large barrel with a high-viscosity mass. For pressing z. As cake dough, glue, grease, etc. in an empty space, no large pressure is required when the deformation takes place in the direction of pressure.

The vacuum will migrate horizontally over the entire surface, because that requires the smallest forces for very tough masses. The mass can always flow in a straight line. This is particularly advantageous for sensitive masses. There is only a very small difference in height required. Therefore, there is hiking even with very large systems. With them, however, the weight of the pump is distributed over a larger area, whereby the pressure on the mass is smaller, so that, if necessary, a larger paddle wheel must be selected. Alternatively, the plate can be made heavier. A pump can only deliver as much mass as it gets through the opening in the plate. In my system, the flow rate can be higher than in the known systems, because my system can set this amount more easily.

For this filling of the empty space in most masses only a pressure is required, which is significantly smaller than the pressure generated by the weight of the pump to the mass to be pumped. It is obvious that it is easier to put some mass down in the compression direction Press as they push through a force acting in the opposite direction in the opposite direction. For very tough masses that makes a lot, because with them, the shear forces are much greater than with relatively liquid masses. A container has a diameter of z. B. 70cm (= 3847cm ² ). The pump pushing on the mass weigh with accessories z. Eg 30kg. Thus, only about 7.8g / cm ² = 0.0078bar to the mass. But this is usually sufficient to compensate for different filling heights.

The paddle wheel consists of at least 2 blades. They are similar to a propeller arranged so that no bending moment occurs. Like a sickle, they should be bent slightly forward, or tilted at an angle to the direction of rotation, that is, slightly offset from the center, or fixed in a combination of these two possibilities, as the mass can be moved more easily if the blades strike it obliquely. Below the stator and possibly the plate, the blades are vertical, so they do not promote against them. In the area of the pump inlet, they should be tilted backwards so that the mass is pushed upwards into the pump. Ideally, the paddle wheel pushes just as much into the pump as it can pump.

According to the textbooks, the pressure in a closed container is the same everywhere. For very tough masses that's not true. It can take some time until the mass to be pumped is deformed and can exert a greater pressure on the walls. For chilled butter z. B. is that - as shown above - clearly visible. You can also see that when a mass is pressed into a pump. It is obvious that the pressure of the plate on the mass is greater than the pressure with which you can push through the hole, which requires a sufficiently large pressure.

The difference is explained by the fact that the pressure of the plate goes vertically down to the bottom of the container. From there, according to the 3rd Newtonian axiom, a counterpressure. These two forces meet. The crowd has to dodge to the side. It is thereby braked by the shear forces - ie by friction. Below the hole in the plate, the resulting, significantly weaker forces meet each other horizontally. From there, the mass must ascend vertically upwards into the pump, whereby shear forces again occur. The forces are always straightforward and not in a bow. They work the better the more straightforward the mass can flow. In the case of the widespread systems, the mass must rise into the pump against the forces transmitted via the plate. The counter-force that occurs when sucking, you can imagine, if you imagine the reverse process - so when the pump pumps the mass into the container. This is most obvious when the pump is near the bottom of the tank as it can not be pushed away. The impeller would cause in this view, that the mass is not pumped against the container bottom, but that it is deflected to the side. Further up it causes that already existing in the container mass does not have to be displaced. This counterforce exists with the opposite sign even when sucking. It can also be seen from this point of view that it is not sufficient if no paddle wheel is used and only the plate is funnel-shaped from the inside to the outside, since the counterforce during suction continues to occur, and the mass is pressed to the center only with a small force ,

In the known systems is the formation of a - apart from the steam pressure - actually existing vacuum below the plate (mass at the container edge stops, it passes only mass from the center of the container into the pump), in contrast to the representations of some manufacturers of pumps not possible because the resulting vacuum is stronger than the negative pressure generated by a pump. In addition, the gravity of the mass would have to be overcome. This can be easily recognized, if one imagines that the plate can not be moved down, so that there is a closed container with solid walls. It can then be pumped no liquid such as water. My system would be pumped as long as the paddle wheel is in bulk.

In an eccentric screw pump, the rotor is rotated about a center which is not the center of the rotor. However, most masses such as dough, glue or grease can very easily be pushed into an empty space - the pump inlet - when this happens in the direction of pressure. A short paddle wheel on the rotor will not generate a high torque so that it can be attached to it (Fig. 4). This makes the system easier to design. The additional motor is eliminated and the plate is less expensive.

In a screw conveyor barrel pump, the auger always rotates about its own axis so that its center remains unchanged. That's why you can easily mount a large paddle wheel on it, without there being a greater bending moment during operation. The same applies to double spindle pumps.

It is also possible to rotate the container instead of the paddle wheel or the plate. But that is not beneficial.

If the paddle wheel is attached to the rotor and does not extend beyond the outer edge of the stator, then the pumping station can be pushed through the hole in the plate. If the paddle wheel is larger, then the hole in the plate must be larger. The gap can be closed by another, fixed to the pumping station plate. The two plates must be positioned accordingly. The actual plate can then be placed first on the mass to be pumped. The trapped air can be pushed out of the hole by manual pressure on the plate. The masses that are preferably pumped with this system are so viscous that they do not flow so easily over the plate. Then the pump can be lowered onto the plate and properly positioned by a barrier. The plate can z. B. be attached to the pump with a chain to raise them together with the pump again. In that case no compressed air has to be pumped under the plate for lifting, which leads to further savings. Alternatively, the plate is firmly attached to the pump and the paddle wheel is finally mounted. The air must then either be sucked out before pumping or pushed out through a closable opening or be pumped or left to lift the pump again.

So far, I have shown ways how the mass to be pumped can be relatively easily promoted in the actual pump. In the progressing cavity pumps, auger barrel pumps and double spindle pumps, the mass flow in them is perpendicular to a wall which is the limit to the drive. The mass must be pressed perpendicular to the resulting back pressure in the pump outlet opening and from there into the connected lines. For masses such as grease, glue or similar, this is not a major problem. However, the flow of the mass can be improved. We have seen that it is not a problem to deform butter if the pressure acts obliquely on it. Accordingly, when pumping z. As dough, glue, grease, etc., the back pressure in the pump can be reduced if there is a slope on the wall to the motor or on the stator, which conducts the mass into the pump outlet opening (Fig. 5). The horizontal part of the slope in the drawing represents a bearing with seal. Ideally, this slope goes over the entire cross section. If this is not possible then the slope on the wall must be opposite to the pump outlet opening. From there, a pressure then goes perpendicular to the conveying direction, whereby the mass is directed into the pump outlet opening. This protects the pump, relieves the shaft seal and reduces energy costs. Alternatively, z. B. also the use of a Rotary pump to be tested. Of course, the container must be large enough for the pump to fit in with the impeller motor.

You do not have to pump most of the masses out of a round barrel. To better use the transport and storage capacities and possibly also to further reduce the set-up times due to larger containers you can possibly take square containers. Of course, the record will not be rotated. Although the impeller can then not go anywhere to the vessel wall, the mass not transported away by the blades is then under the weight of the pump under a relatively high pressure, so that most of the masses are thereby pressed from the edge to the center of the container.

The technical effort and the number of steps is lower in all variants of my solution than in the alternative known systems. It can be used mobile and thus flexible. The pump can be attached to a pivoting, long boom. It can also be a frame mounted on the edge of the container, wherein the pump is placed and guided by gravity down. The system can then be transported by hand. The barrels can stand on a pallet when emptying. Since the handling is simplified, larger barrels can be used. As a result, the setup times and the residual quantities in the containers can be smaller. Thus, natural resources are saved. The material price per kilogram or liter is usually lower for larger containers than for smaller containers. In addition, energy is saved.

Claims

claims

A method of pumping highly viscous and solid masses from a container, characterized in that the mass to be pumped by rotating a paddle wheel, which is close to the plate, or by rotating a flat, obliquely mounted plate, the one or more blades may have to pump inlet to this and pressed into this and further promoted by the pump. The pump presses over the plate on the mass, so that the resulting empty space is filled by surrounding mass.

2. An apparatus for pumping highly viscous and solid masses from a container, characterized in that the mass to be pumped is from a paddle wheel which is rotatable below the plate, or from a rotatable, flat, slanting plate which may have one or more paddles, is pressed to and into the pump inlet and further promoted by the pump, the pump presses with its weight on the plate to the mass.

3. A device for pumping highly viscous and puncture-resistant masses from a container according to claim 2, characterized in that a plate presses perpendicular to the mass to be pumped and the impeller is fixed to the rotor.

4. An apparatus for pumping highly viscous and puncture resistant masses from a container according to claim 2, characterized in that a plate presses perpendicular to the mass to be pumped and the impeller is driven by a separate motor.

5. An apparatus for pumping highly viscous and puncture-resistant masses from a container according to claim 2, characterized in that the rotatable flat, obliquely pressing on the mass to be pumped plate has a dodging the mass limiting horizontal or less oblique part and from a separate motor order the pump inlet is turned.