US20230287877A1

US20230287877A1 - Hose Pump

Info

Publication number: US20230287877A1
Application number: US18/200,499
Authority: US
Inventors: Erich Scheugenpflug
Original assignee: Dosmatix GmbH
Current assignee: Dosmatix GmbH
Priority date: 2020-11-24
Filing date: 2023-05-22
Publication date: 2023-09-14
Also published as: DE102020131083A1; JP2023550140A; WO2022112183A1; EP4251885A1

Abstract

A novel hose pump for viscous material includes a hose, a variator, a variator drive, a controller, a pressure-tight housing, and a negative pressure connection. The hose has an elastic circumferential wall and an inner cross-sectional area and is open at both ends. The hose includes a pressure-tight inlet opening and a pressure-tight outlet opening. A portion of the hose is enclosed within the pressure-tight housing. The negative pressure connection is coupled to the pressure-tight housing. The variator is adapted to compress the hose and thereby to reduce the inner cross-sectional area of the hose. The variator drive causes the variator to compress the hose at controlled locations along the hose. The controller controls the variator drive. The variator rotates and compresses the hose where the variator contacts the hose. Alternatively, multiple variators form pinch valves at fixed locations along the hose and compress the hose independently of one another.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application is filed under 35 U.S.C. § 111(a) and is based on and hereby claims priority under 35 U.S.C. § 120 and § 365(c) from International Application No. PCT/EP2021/082526, filed on Nov. 22, 2021, and published as WO 2022/112183 A1 on Jun. 2, 2022, which in turn claims priority from German Application No. 102020131083.8, filed in Germany on Nov. 24, 2020. This application is a continuation-in-part of International Application No. PCT/EP2021/082526, which is a continuation-in-part of German Application No. 102020131083.8. International Application No. PCT/EP2021/081528 is pending as of the filing date of this application, and the United States is an elected state in International Application No. PCT/EP2021/082526. This application claims the benefit under 35 U.S.C. § 119 from German Application No. 102020131083.8. The disclosure of each of the foregoing documents is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the flow and transportation of fluids or viscous substances in a transport line.

BACKGROUND

The transportation of especially viscous, pasty substances in pipelines is often difficult, since those substances build up a high flow resistance. In addition, these substances, which are required especially in electronics, cosmetics and adhesive technologies, can be either very sensitive and/or abrasive and/or adhesive, which makes handling them even more difficult. In principle, it is attempted to handle these materials without allowing them to enter gaps, such as between a valve body and a valve seat, or to enter other cavities where they can be deposited, or, in the case of curable materials, cured.
A typical problem in transporting such materials from a storage container, such as a barrel, cartridge, or a pretreatment unit, such as a mixer, to a consumer, e.g., a dosing unit for dispensing the materials in precisely specified (dosed) quantities. For this purpose, a certain minimum pressure often must be applied at the consumer of the materials, which should constantly be maintained during delivery. In order to avoid depositing, diaphragm pumps were used in the past for transporting in hose lines, in which a diaphragm driven in an oscillating manner allows the material to be conveyed to the consumer in portions. However, the displacement of such diaphragm pumps is often not sufficiently precise.
In addition, hose pumps are known, in which the transporting is performed through regular deformation of an elastic hose, which is a component of the line through which the material is conveyed. Problems are caused by using hose pumps to transport materials that are not subject to ambient pressure, but only to an extremely low residual pressure of a few millibars close to zero, which is always the case when the material has to be conveyed from a processing device or a container that is kept under vacuum so as to avoid the formation of air pockets.
In hose pumps, a cross-sectional variator is in contact with the elastic hose and is capable of reducing the cross-section of the hose and compressing the hose, if necessary down to zero, i.e., compressing it in a sealing manner, whereby the pressing point is usually moved along the hose and, as a result, the material in the hose is pushed in front of the pressing point by means of the cross-sectional variator. Typical cross-sectional variators comprise pressing bodies in the form of non-deformable rigid sliding shoes or rollers, which compress the hose in a transverse direction and then are moved longitudinally along the hose.
In addition, elastic pressing bodies are known, for example, in the form of a pressure sleeve arranged around the entire circumference of the hose or a pressure pad resting against it over only part of the circumference. These elastic pressing bodies are usually hollow and can be filled hydraulically or pneumatically, thereby compressing the hose.
It is therefore the object of the present invention to provide a hose pump as well as an output device equipped therewith that avoids the problems described above and, moreover, which is simple and inexpensive to manufacture and has a long service life. It is also an object to provide a method for operating such an output device.

SUMMARY

In order to be able to make use of a low cost hose pump as a feed pump to a user of the pumped material in an output device in which the air space in a reservoir is connected to a vacuum pump via a negative pressure connection, a negative pressure or even a vacuum likewise is used for the re-deformation of the hose after compression either on the outside of the hose in the internal space of the hose pump, or a mechanical deformation process is provided. The deformation of the hose can be performed by rigid pressing bodies or expansible press pads or press sleeves, preferably including individual chambers one behind the other.
A novel hose pump includes a hose, a cross-sectional variator, a variator drive, a controller, a pressure-tight housing, and a negative pressure connection. The hose has an elastic circumferential wall and an inner cross-sectional area and is open at both ends. The hose includes a pressure-tight inlet opening and a pressure-tight outlet opening. A portion of the hose is enclosed within the pressure-tight housing. The negative pressure connection is coupled to the pressure-tight housing. The material that is pumped flows through the hose in a direction of flow. The cross-sectional variator is adapted to compress the hose and thereby to reduce the inner cross-sectional area of the hose. The variator drive causes the cross-sectional variator to compress the hose at controlled locations along the hose. The controller controls the variator drive.
In one embodiment, the variator drive controls how the cross-sectional variator rotates and compresses the hose where the cross-sectional variator contacts the hose. In another embodiment, the cross-sectional variator is formed as a pinch valve that is capable of reducing the inner cross-sectional area of the hose to zero. The cross-sectional variator includes a pressing body that abuts the hose at a fixed position. The pressing body abuts the entire circumference of the hose as a press sleeve. The pressing body can include a plurality of chambers arranged along the hose, such that the chambers communicate with each other via throttle points and are driven using one common press-pressure connection.
A novel output device for outputting a viscous material includes a vacuum pump, a reservoir and a hose pump. The reservoir is adapted to contain the viscous material. The reservoir includes an outlet opening. A negative pressure is maintained in an air space in the reservoir above the viscous material using the vacuum pump. The hose pump includes a hose, a variator, a pressure-tight housing and a variator drive. The hose is connected to the outlet opening. A portion of the hose is enclosed within the pressure-tight housing. The variator is adapted to compress the hose. The negative pressure is maintained in the pressure-tight housing using the vacuum pump. The variator drive causes the variator to compress the hose at controlled locations along the hose.
In one embodiment, the output device includes a second hose pump and a controller. The first hose pump and the second hose pump are connected in parallel to the outlet opening. The controller is adapted to drive the first hose pump and the second hose pump in a phase-shifted manner.
Other embodiments and advantages are described in the detailed description below. This summary does not purport to define the invention. The invention is defined by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, where like numerals indicate like components, illustrate embodiments of the invention.

FIG. 1A shows a mechanical hose pump.

FIG. 1B and FIG. 1C are cross-sectional views through the hose in the hose pump as shown in FIG. 1A.

FIGS. 2A, 2B, 2C, 2D, 2E and 2F show a longitudinal section of a first construction form of a pneumatic or hydraulic hose pump along the hose in various functional states.

FIGS. 3A and 3B show a longitudinal section of a second construction form of a pneumatic or hydraulic hose pump along the hose in various functional states.

FIG. 4 shows additional mechanical equipment for a hose pump similar to FIG. 1A.

FIGS. 5A, 5B and 5C show cross-sectional views at various points through the hose pump according to FIG. 4 in different functional positions.

FIG. 6 shows a longitudinal section of a third construction form of a pneumatic or hydraulic hose pump along the hose.

FIG. 7 shows an output device with a reservoir for viscous or fluid material and a hose pump according to the invention.

DETAILED DESCRIPTION

Reference will now be made in detail to some embodiments of the invention, an example of which is illustrated in the accompanying drawing.
FIG. 1A shows a novel hose pump 1. With regard to hose pump 1, the object is solved by the fact that the hose pump has a pressure-tight housing around the hose 2 in the pumping section, i.e., the area where the pressing point is located or can move, and preferably around the entire hose pump.
The hose 2 can enter the housing 5 via a pressure-tight inlet opening 5 a and a pressure-tight outlet opening 5 b, and the housing has a pressure connection with which a desired pressure, in particular a negative pressure, can be adjusted in the housing, which thus prevails at the outer circumference of the hose. A negative pressure is a lower pressure than the surrounding pressure, such as the ambient pressure.
Such a design of the hose pump 1 allows a targeted adjustment of the ambient pressure around the hose 2 in the area of the hose pump 1 in relation to the pressure inside the hose.
The controller 30, which controls the entire hose pump 1 and also the pressure inside the housing 5, should be designed in such a way that it is able, via the pressure connection, to control the pressure in the housing, for example, in accordance with the pressure inside the hose pump and/or cause a negative pressure in the housing between the pressing operations of the hose pump vis-à-vis either the ambient pressure or also the pressure inside the hose 2.
It should be clarified that for a hose pump in general a partly elastic body, which is open on both sides and through which material can flow, is required, which herein is referred to as a hose, although the body need not have the typical appearance of a hose, i.e., neither a round cross-section nor a larger extension in the flow direction than in a transverse direction. The term hose shall be understood to mean all elastic hollow bodies with two openings.
Instead, or as a support, the elastic body through which material can flow can be designed such that it resumes its non-compressed initial state without external influence after the end of compression, due to the structure or material properties of its circumferential wall. Thus, the circumferential wall, for example, may be made of a so-called memory material, which either always or under certain physical conditions resumes its initial shape.
Another possibility is that the deformation back into the initial state is due to external influence. Thus, for example, in order to reduce its cross-sectional area, a force can be applied to the hose 2 in a first transverse direction relative to its longitudinal direction, but, for re-deformation into its initial state, a force is applied to the hose in a second transverse direction in particular perpendicular to the first transverse direction, thus facilitating re-deformation or making it possible at all. The application of force in the second re-deforming transverse direction can be effected by means of a pressing body 8 engaging on the hose 2 merely periodically, or, for example, also by way of a spring element abutting the hose 2, i.e., its outer or inner side, permanently.
For example, a compression spring arranged inside the hose 2, such as a spiral spring, can apply force to the hose radially outward, or also a spring acting on the outside of the hose. Such spring elements can also be provided only in sections in the longitudinal direction of the hose 2. In this way, re-deformation can be ensured, even if the ratio between the external and the internal pressure of the hose 2 is unfavorable for this.
In most construction forms of hose pumps, the cross-sectional variator 3 comprises a rigid pressing body 8, which mechanically compresses the hose 2.
However, especially for the present case, designs of cross-sectional variators are also suitable that are not rigid but can change their shape and are in particular elastic pressing bodies, e.g., are hollow bodies themselves. The internal pressure of the variators can be changed via corresponding connections, at least one corresponding connection. Such a non-rigid, in particular elastic, pressing body 8 can be in close contact to the hose 2 with part of its circumferential wall and, in applying pressure to the inside of such a cross-sectional variator 3, can press the circumferential wall of the cross-sectional variator against the circumferential wall of the hose and compress the latter.
The pinch point with the reduced cross-sectional area can also be moved in the flow direction of the hose 2, in particular without the cross-sectional variator 3 moving in this direction, solely by the fact that the point of greatest extension of the cross-sectional variator may wander transversely to the hose 2 in the longitudinal direction of the hose, i.e., the flow direction.
When the cross-sectional variator 3 is able to compress the inner cross-section of the hose 2 down to zero, so that the inner cross-section is closed and thus acts as a shut-off valve, this is referred to as a pinch valve.
The hose pump 1 according to the invention may also comprise consecutively, in the direction of flow, a plurality of cross-sectional variators, which then preferably have to be drivable in a phase-shifted manner or in a certain temporal correlation to one another.
Thus, the interior of the pressing body 8 may comprise a plurality of chambers arranged in a direction of flow in particular one behind the other, which extend one after the other transversely to the longitudinal axis of the hose 2 and compress the latter, and this in the direction of flow one after the other, thereby pushing forward the material in the hose in the direction of flow. The individual chambers may communicate with each other, with throttling points between the chambers, and in particular, there can be only one common pressure connection for the entire pressing body 8.
Alternatively, the individual chambers do not communicate with each other, i.e., they can be separate chambers, each of which has a separate pressure connection, to which pressure then is applied in accordance with this sequence. Preferably, at least the first chamber in the direction of flow is able to reduce the cross-sectional area of the hose 2 to zero in order to prevent a backflow of material into the hose. However, in the other chambers, it is advisable to compress the hose 2 down to a small but remaining residual cross-section so that no material is enclosed between the closed cross-section in the first chamber and a further closed cross-section in a second chamber, which would then be under very high pressure. In the case of existing residual cross-sections, the material can always evade away from the closed pressing point and thus in the direction of flow.
After the pressing points have been opened, material flows into the hose 2 from upstream, in particular if a pressing point again is arranged for this purpose also at the end of the section of pressing points not fully closed, which completely closes the cross-section of the hose 2 for this purpose, i.e., a further pinch valve. Also a sequence of pinch valves can be controlled in this way if the pieces of the hose 2 between them are able to withstand the pressure that occurs upon closing two adjacent pinch points one after the other.
Preferably, the hose pump 1 also includes a vacuum sensor 15 for measuring the negative pressure in the housing 5 around the hose 2 in order to be able to use it to control the variator drive or the vacuum pump for generating the negative pressure in the desired manner.
Since many viscous materials become more fluid with increasing temperature, a heater 16 can also be provided in particular with a temperature controller 17, by which the hose pump 1 is heated, i.e., either the interior of the housing 5 and/or the hose 2 itself, so that the material inside the hose heats up and thus flows more easily, and the force required to operate the hose pump 1 is reduced.
Furthermore, the pressure in the material can be monitored by a pressure sensor 19, which can be arranged, for example, upstream and/or downstream of the pumping longitudinal area, in which the cross-sectional area of the hose 2 is changed. Such a pressure sensor 19 need not necessarily be in connection with the material in the hose 2. The pressure sensor 19 can, for example, also measure the outer circumference or outer diameter of the hose 2 and draw conclusions from this about the pressure prevailing inside if the elasticity of the hose 2 at this point is known.
Likewise, in the situation in which pressure is applied to the interior of an elastic pressing body 8, the pressure inside the elastic pressing body can be measured by means of a pressure sensor. Based on the pressure inside the elastic pressing body 8 or equated with this, the controller 30 may draw conclusions on the pressure in the material inside the hose 2.
Since such a hose pump 1 is simple and inexpensive to manufacture and, depending on the hose material, also has a long service life, this may be a better solution compared to diaphragm pumps, also depending on the materials to be conveyed.
With regard to the output device 100, which includes a reservoir 101 for the material M with an outlet opening 5 b in its lower region, as well as a hose pump 1 which is fluidically connected to this outlet opening, the present task is solved in that the hose pump is configured as described above.
For the case primarily considered here that the material M in the reservoir 101 is subjected to negative pressure, i.e., due to the incompressibility of a viscous or fluid material, the air space above the material in the reservoir is subjected to negative pressure, the housing 5 of the hose pump 1 should be designed such that the same amount of negative pressure can be applied to its interior as to the air space in the reservoir. This eliminates the risk of the compressed hose 2 not being able to expand back to its original state after the pressing force is removed due to the negative pressure in its interior.
Preferably, a shut-off valve, which can completely block a free cross-section of the hose 2, in particular a pinch valve, is disposed between the reservoir 101 and the cross-sectional variator 3, whereby the shut-off valve can also be part of the hose pump 1.
In order to reduce the periodically rising and falling pressure generated by a hose pump 1 on the outlet of the hose pump with regard to the user of the material being pumped, two or even a plurality of hose pumps can be connected in parallel, either, if a control system is provided that is capable of operating those hose pumps in a phase-shifted manner, or, in the case of two hose pumps, driving them alternately, and/or simply driving the plurality of hose pumps merely by a common pump drive, and the phase shift is implemented by the corresponding mechanical configuration of the common pump drive.
This allows high-pressure phases at the outlet of one of the hose pumps to follow almost seamlessly high-pressure phases at the outlet of the other hose pump, and the outlet lines of the hose pumps can be combined to form a single delivery line to the user of the material being pumped.
With regard to the novel method of operating a hose pump 1, in particular within the context of an output device 100 as described above, the task is solved in that the inner space of the pressure-tight housing 5 around the pumping area of the hose 2 is kept under equal or even higher negative pressure than the air space in the reservoir 101 above the material M.
If a plurality of cross-sectional variators exist one behind the other in a flow direction abutting on the same hose 2, those variators are operated in a phase-shifted manner, and in particular, the individual cross-sectional variators are activated one behind the other in the direction of flow.
If there are several hose pumps which are connected in parallel and abut on different hoses, the periodic pressure fluctuations in the delivery line to the user of the material being pumped are reduced or eliminated in that the hose pumps are driven in a phase-shifted manner, and alternately especially in the case of two hoses.
FIG. 7 illustrates the problem underlying the invention and the operation of the output device 100. The control unit 130 of output device 100 controls the moving parts of the output device 100. The output device 100 includes a reservoir 101, which is refilled from a delivery container or other reservoir (not shown) and also serves for pretreating the material M stored therein. To pretreat the material M, a mixer can rotate in the reservoir 101 and/or a pumping over can be carried out and/or thin film degassing can be performed or other treatment steps can be executed. To prevent new air pockets from forming in the process, the air space in the reservoir 101 above the material M is put under a negative pressure close to a vacuum, approximately from 1 mbar to 50 mbar of absolute pressure generated by a vacuum pump 102, which suctions the air from the air space of the reservoir 101. From the reservoir, preferably at its lowest point, the material M is withdrawn from an outlet opening 101 a and fed to a user 104 of the material via a connecting line 103. In this case the user 104 is a doser 104 for outputting precisely dosed quantities of the material M, e.g., via a discharge nozzle 105.
So that this, usually intermittent, discharge from the discharge nozzle 105 can take place at any time, the material M must always be applied to the user 104 at a certain minimum pressure, pressure fluctuations above the minimum pressure being acceptable.
According to the invention, the pressure is maintained by a hose pump 1 in the connecting line 103, in this case connected directly to the outlet opening 101 a of the reservoir 101 instead of the diaphragm pumps or piston pumps otherwise provided at this point because hose pumps are available as simple standard parts that are simple to construct and can be purchased separately at low cost.
The problem with the prior art is that in a conventional hose pump, the hose is compressed at one or more pressing points with respect to its cross-section, and, after the pressing force is removed, is deformed back to its original, usually round cross-section, on the one hand due to the restoring force of the elastic material of the hose wall, but above all also due to the overpressure prevailing inside the hose in the material delivered in the hose.
However, since in the present case, the air space in the reservoir 101 is subjected to a quasi-vacuum, hereinafter referred to only as a vacuum, this also applies to the material M provided below the air space and thus also to the material M in the connecting line 103 so that the hose pump 1 lacks an essential parameter for the return from a compressed to a non-compressed cross-section of the hose 2, which, however, is essential for the functioning of a hose pump 1.
FIGS. 1A, 1B and 1C show an existing hose pump 1 that is equipped with additions according to the invention. A hose 2 made of an elastic material is guided through a housing 5 in a U-shape in one plane, the U-shape having the shape of a semicircle in the inverted region. A two-armed rotary lever 28 rotates in the center of the semicircular U-end as viewed perpendicular to the U-shaped plane U″ in which the hose 2 lies, as shown in FIG. 1A. The opposing lever arms of two-armed rotary lever 28 are of equal length and carry on their ends a pressing body 8, in this case in the form of a pressure roller 8. The pressure roller 8 is held on the rotary lever 28 so as to be rotatable about a pressure roller axis 8′, which is perpendicular to the U-shaped plane U″. The rotary lever 28 is driven by a variator drive 4 about a rotary lever axis 28′ perpendicular to the hose plane 2″ and controlled by a controller 30 of the hose pump 1. The controller 30 may be an integral part of a control unit 130 of the output device 100. The rotary lever 28 rotates in a specific rotation direction R, in this case counter-clockwise.
The lengths of the lever arms of the rotary lever 28 and the diameter of the two pressure rollers 8 are measured in such a way that each of the pressure rollers 8 presses radially from the inside to the outside against the hose 2 for slightly more than half of its rotation and compresses it in the radial direction of its cross-section 2″ because on the radially outer side of the U-shaped deflection area of the hose 2, the hose 2 is pressed against a mostly plate-shaped counterhold 21 extending over at least the semicircular deflection area of the hose 2, as is apparent from FIGS. 1C and 1C.
At the pressing point S in the direction of rotation at which the pressure roller 8 is currently acting on the hose 2, the hose wall 9 is preferably squeezed flat so that the inner free cross-section 2″ is zero or tends towards zero, as shown in FIG. 1C. As a result, the pressure roller 8 moving along the hose 2 pushes the material M contained in the hose 2 in front of it and transports it along the hose 2 in the flow direction 10.
The two ends of the hose 2 in the housing 5 are usually tightly connected with a flange-shaped inlet opening 5 a on the one hand and an outlet opening 5 b on the other hand, and thus the material is pushed out of the outlet opening 5 b. The openings 5 a and 5 b in turn are tightly connected to the housing 5.
In an existing hose pump, the hose resumes its original, unstressed cross-section, usually a circular cross-section, immediately behind the pinch point S, as shown in FIG. 1B. Due to the lack of internal pressure in the interior of hose 2, this would have to take place solely due to the restoring force of the wall 9 of hose 2, which would result in a little elastic hose, and thus a high force to be applied by the cross-sectional variator 3, here the rotary lever 28 with pressure rollers 8, would be required.
In order to avoid this, the inner space 6 of the housing 5, which is tightly closed, has a negative pressure connection 7, through which a negative pressure can be generated inside the housing by way of a vacuum pump 20, possibly even a lower pressure than the one prevailing inside the hose 2, so that a factor for hindering the re-deformation of the hose 2 is omitted, namely a higher external pressure than internal pressure with respect to the hose 2.
In case the hose pump 1 is utilized within the context of an outputting device 100 according to FIG. 7 , the negative pressure connection 7 of the vacuum pump 1 is connected via a vacuum line 106 preferably to the same vacuum pump 102 that also supplies the air space of the reservoir 101 with negative pressure. A vacuum sensor 15 can also be provided in the interior 6, which measures the pressure therein, i.e., negative pressure, for control purposes and reports this to the controller 30, which can then vary the application of negative pressure via the negative pressure connection 7. Furthermore, one or more pressure sensors 19 a, 19 b, 19 c may exist in the interior 6 to measure the pressure in the hose 2 and in particular along the hose 2.
Thus, near the inlet opening 5 a and the outlet opening 5 b in the housing 5 for the hose 2, a pressure sensor 19 b, 19 c can be arranged, respectively, on the outside of the hose 2, in particular in close contact with the hose 2, and can measure the pressure prevailing therein. The pressure in the hose 2 can be directly or indirectly measured via the shape of the cross-section of the hose 2.
Furthermore, a pressure sensor 19 a can be provided, approximately in the middle of the U-shaped bend of the hose 2, which is directed towards the radially inner region of the circumferential contour of the hose 2 and measures its position relative to the radially outer counterhold 21, in particular during the passage of pressure roller 8, and therefrom determining the pressure inside the hose 2.
In order to heat the material M conveyed in the hose 2 and thereby make it more fluid, a heater 16 is provided in the interior 6, for example by electrically heating the counterhold 21, especially if the latter is made of metal. Preferably, the heater 16 is equipped with a temperature controller 17, which is preferably part of the controller 30 of the hose pump 1.
FIG. 4 shows an alternative for return deforming the hose 2 downstream of its pinch point S instead of and/or in addition to the negative pressure connection 7. This alternative, however, is used primarily when the hose 2 runs straight within the area of the hose pump 1, i.e., less when the hose is laid in a U-shape according to FIG. 1A
The flat squeezed cross-section 2″ of the hose 2 is deformed back into the original round cross-sectional shape by means of passes from at least one further pressure roller 26, as is best shown in the cross-sectional illustrations of FIGS. 5A, 5B and 5C of the hose 2. FIG. 5A shows the unstressed, circular cross-section of the hose 2 at a slice sufficiently far away from the pinch point S. FIG. 5B shows the hose 2 in a quasi tightly compressed state of its cross-section 2″ at point S, but not squeezed between a pressure roller 8 and a counterhold 21, as in the case of the hose-pump shown in FIG. 1A, but between two, preferably identically shaped, pressure rollers 8, which engage at the hose 2 at the same pinch pint S from two opposite sides with respect to the cross-section of hose 2.
The pressure roller 8 is preferably fastened to the free end of a rotary lever 28 with merely one arm, and it is not a 2-armed drive lever 28 with a pressure roller 8 at each of its free ends. The reason for this is that after the two pressure rollers 8 compressing the hose 2 have passed the pressing point S, a further pair of pressure rollers 26 mounted on rotary levers 27, must be able to engage with the hose 2 in order to press it apart again into its original cross-sectional shape before the rotary levers 28 reach the pressing point S again.
While the two compressing rotary levers 28 rotate with the pressure rollers 8 in a plane of rotation 28″ containing the first transverse direction 11, the diverging rotary levers 27 rotate with their pressure rollers 26 in a plane of rotation 27″ containing the second transverse direction 12, which is transverse, preferably perpendicular, to the plane of rotation 28″, both planes of rotation containing the flow direction 10, i.e., the direction of the hose.
For this purpose, the circumferential groove 26 a of these pressure rollers 26 has a cross-section which is approximately semi-circular in shape with a radius which is slightly larger than or equal to the radius of the outer circumference of the undeformed hose 2 of FIG. 5A. By making the two pressure rollers 26 radially reach very close to each other in a maximum approaching position in which their rotary levers 27 face one another, as shown in FIG. 5C, leaving between them a free space which corresponds to the shape of the undeformed cross-section of the hose 2 or is only slightly larger than it, the hose 2 is again pressed apart into its original round cross-section.
In this way, the re-deformation takes place mechanically and at most additionally, but not necessarily, by the negative pressure applied to the outside of the hose according to the solution in FIG. 1A.
FIGS. 2A, 2B, 2C, 2D, 2E, 2F, 3A and 3B show solutions in which the hose 2 is not compressed in its cross-section by means of rigid pressing bodies 8 or 26, but by means of elastic hollow pressing bodies that are expandable in a cross-sectional direction of the hose 2 in the direction of its central longitudinal axis 2′. Those pressing bodies can be press sleeves 24 running around the longitudinal axis of the hose 2 in an annular manner, or press pads 23 arranged on merely one or two opposite sides of the cross-section of the hose 2, which are provided opposite one another, in particular at the same longitudinal position, in which case the two opposing pressure pads 23 then are always operated synchronically. Preferably, there are several press pads 23 or press sleeves 24 provided one behind the other in the flow direction 10.
The press pads 23 or press sleeves 24 are supported on their radial outer side on a fixed counterhold 21, in the case of a press sleeve 24, a counterhold tube 21 running around the longitudinal direction 2′ of the hose 2, and at least in the extended state not only abut on the outer circumference of the hose 2, but also compress its cross-section, if necessary down to zero. If, as shown in FIGS. 2A, 2B, 2C, 2D, 2E and 2F, the counterhold 21 is a component of the press pad 23 or of the pressing sleeve 24, the two must be tightly connected to each other.
In the first construction form according to FIG. 2A, of these press pads 23 or press sleeves 24, four of such in this case annular press pads are depicted with pressure chambers 18 a, 18 b, 18 c, 18 d, whereby their number can vary in practice. Between the chambers 18 a-d, in each case a tight fixation is then necessary between the diaphragm of press pad 23 or the press sleeve 24 and the counterhold 21.
Each of these pressure chambers 18 a-d, which are separated from each other in a pressure-tight manner, is equipped with its own press-pressure connection 14 a-d, the pressurization of which (mostly by opening and closing of valves not shown) is controlled by the controller 30 of the hose pump 1 in an exact time relation to each other in order to achieve the function described below.
To push the material M forward in the conveying direction 10, first the rearmost, first pinch point S1 in the desired conveying direction 10 is activated, i.e., the pressure chambers 18 a of the press sleeve 24 there are pressurized, so that their elastic wall which rests against the wall 9 of the hose 2, expands radially inward and squeezes the hose 2 radially, preferably, until its inner passage is closed.
As a result, the material M previously present in the hose at this pinch point S1, is displaced both in the conveying direction 10 and in the opposite direction.
While this pinch point S1 remains closed, as shown in FIG. 2A, the next adjacent pinch point S2 as shown in FIG. 2B is then activated chronologically, and there, too, the cross-section of the hose 2 is reduced, but the hose is not fully closed, so that the material displaced in this area can only exit through pinch point S2 in the conveying direction 10. Subsequently, according to FIGS. 2C, 2D, the next pinch point S3 in conveying direction 10 and thereafter also S4 are activated, the previously activated pinch points S1 and S2 remaining in their squeezing position and the already activated chambers 18 a, 18 b, 18 c, respectively lying upstream thereof, remaining in this state. In this way, a substantial amount of material is pushed downstream of the last activatable chamber, here 18 d, through the hose 2 in the direction of transport 10.
For the next conveying process, after activation of all existing chambers 18 a-d, the last chamber 18 d in conveying direction 10 is further pressurized and the hose 2 is thereby compressed at this last pinch point S4 down to a zero cross-section, i.e., closed and held.
From the closure of this last pinch point S4, the upstream pinch points S1, S2, S3 are deactivated one after the other chronologically, i.e., the cross-section of the hose is reopened, beginning with the most upstream pinch point S1 and then continuing with the respective next pinch points S2, S3 in the direction of transport 10. As a result, material from the upstream area is suctioned in the hose due to its interior becoming larger towards the fully closed pinch point S4.
The re-deformation of the hose can also be promoted in this case by negative pressure connections 7, which in each case in the area between the pinch points S1-S4 creates a negative pressure in the radial area between the diaphragm of the press sleeve 24 supported on the counterhold tube 21 and the hose 2. FIG. 2E shows the state shortly before deactivation of the last pinch point S3 in a conveying direction 10 before the closed pinch point S4. In FIG. 2F, all other pinch points S1-S3 upstream of the closed last pinch point S4 are already open and the hose has its unstressed, mostly circular, cross-section again at these pinch points S1-S3. Subsequently, the next conveying cycle can start again, beginning with the deactivation and closing of the most upstream pinch point S1 according to FIG. 2A.
Instead of configuring the first and last pressing point as a pinch valve, i.e., with the possibility of fully closing the cross-section of the hose, conventional shut-off valves can also be provided in the hose downstream and upstream of the hose pump, i.e., with a valve seat and valve body, for example, which, however, generally allows contact between the material and the joints between the valve seat and valve body, which is not desired due to an often adhesive effect of the material M.
While in FIGS. 2A-2F, the press-pressure chambers 18 a-d are not connected to one another in terms of pressure, FIGS. 3A-3B show in a longitudinal section along the hose 2 a second construction form in which these chambers 18 a-d are connected to one another in terms of pressure. However, chambers 18 a-d are provided by means of comparatively small connecting openings 29 a-c acting as throttles, which are preferably distributed over the circumference around the hose 2 as individual through-openings or as a single through-opening and not as a through-ring. The first chamber 18 a is again in communication with a press-pressure connection 14A, but downstream thereof at most the last press-pressure chamber 18 d is in communication with a further press-pressure connection 14B.
For conveying the material M forward inside the hose 2 in the length range of the hose pump (with the press-pressure connection 14B closed, if provided), only the press-pressure connection 14A must be subjected to press pressure, usually with compressed air, so that the chambers 18 a, 18 b, 18 c, 18 d then expand sequentially one after the other due to throttle points 29 a-c against the hose 2 and produce the same effect as in FIGS. 2A-2D.
FIG. 3B shows the state in which the chambers 18 a-b are already fully expanded and next chamber 18 c will expand radially inward (fully expanded meaning that in the fully expanded area of the chambers the cross-section of the hose 2 is reduced to zero and is closed) with the downstream beginning of the closed hose section moving in the conveying direction 10.
To draw up new material M inside the hose 2 in the longitudinal region of the hose pump 1, the pressure applied to the press-pressure connection 14 A is reduced, if necessary, down to ambient pressure or even into the vacuum range, as a result of which first the chamber 18 a contracts and subsequently also the downstream chambers 18 b, 18 c and 18 d. This causes the hose 2 to deform back into its original, open cross-section at the upstream pinch points S3, S2, S1, and material is replenished in the direction of the most downstream pinch point S4.
If press-pressure connection 14B is provided, it can be briefly pressurized with applied pressure and the chamber 18 d there can preferably completely close the cross-section 2″ of the hose 2, which favors the suction of material from the area upstream of the hose pump 1. Preferably, the pressurization of the press-pressure port 14B with overpressure is performed only when the upstream chambers 18 a-c have already all reached their fully contracted state.
FIG. 6 shows a third construction form of hose pump 1 similar to that of the first construction form of FIGS. 2A-2F. In contrast to prior constructions, here the hose 2 itself is already part of the annular circumferential press sleeve 24, which therefore does not have its own elastic diaphragm provided in addition to the hose 2. In the third construction of FIG. 6 , four circumferential press sleeves 24 are again provided in succession in the flow direction 10 and form annular circumferential chambers 18 a-d, the radial outer side of which is again formed by a tubular counterhold 21, along which the hose 2 runs. Here, too, each of the chambers 18 a-d can be pressurized via an individual pressure port 14 a-d on its own.
For conveying material, the chambers 18 a-d can be successively pressurized in the flow direction 10 as in the construction form of FIG. 2 , thereby reducing the free cross-section of the hose 2 at the individual pressing points S1 to S4, preferably to zero at the most upstream pressing point S1, while, for conveying, the subsequent pressing points are not completely closed.
FIG. 6 shows the situation in which the hose 2 is already tightly compressed at the first pressing point S1 and the hose is already compressed to a reasonable residual cross-section at pressing point S2, whereupon compression is carried out at the subsequent pressing points S3 and S4, preferably again to a reasonable residual cross-section. Since it is preferable not to damage the hose 2, its internal cross-section is kept open between the individual pressing points S1 to S4 and at the beginning and end of hose pump 1 by a support ring 22, which fits into the inner circumference of the hose 2 and is inserted into the hose there and which holds the outer circumference of the hose 2 in contact with the inner circumference of tubular counterhold 21. This means that no fixing, such as bonding, of the hose 2 with respect to counterhold 21 is necessary, which also allows minor compensating movements of the hose 2 in or against the direction of flow 10.
After a conveying stroke, the most downstream chamber 18 d may first remain activated to draw in material as described in FIGS. 2A-2F, while the pressing points S1, S2, S3 upstream thereof, preferably in this order, are vented or pressurized with negative pressure via the pressure connections, so that the hose cross-section opens at those points and material is drawn in up to the closed pressing point S4. This pressing point is preferably only vented or pressurized with negative pressure when or shortly before the first chamber 18 a is already pressurized for the next conveying stroke.

REFERENCE NUMERALS

1 hose pump
2 elastic body, hose
2′ central longitudinal axis
2′ cross-sectional area
2″ cross-sectional variator
4 variator drive
5 housing
5 a inlet opening
5 b outlet opening
6 internal space of 5
7 pressure connection, negative pressure connection
8 pressing body, pressure roller
8 a circumferential groove
8′ axis of rotation
9 wall
10 flow direction, direction of flow
11 first transverse direction
12 second transverse direction
13 pinch valve
14 a-d press-pressure connection
14A-B press-pressure connection
15 vacuum sensor
16 heater
17 temperature controller
18 interior
18 a, b, c chamber
19 pressure sensor
20 vacuum pump
21 counterhold, counterhold plate, counterhold tube
22 heater
23 press pad
24 press sleeve
25 fixing point, fixing circumference
26 press roller
27 rotary lever
28 rotary lever
29 a-c connection opening, throttle point
30 controller
100 output device
101 reservoir
101 a outlet opening
102 vacuum pump
103 connecting line
104 user, doser
105 discharge nozzle
106 negative pressure line
130 control unit
M material
R direction of rotation
S pinch point
U″ level of U-shape, hose level
Although the present invention has been described in connection with certain specific embodiments for instructional purposes, the present invention is not limited thereto. Accordingly, various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.

Claims

1-17. (canceled)

18. A hose pump comprising:

a hose having an elastic circumferential wall and an inner cross-sectional area, wherein the hose is open at both ends, wherein the hose includes a pressure-tight inlet opening and a pressure-tight outlet opening, and wherein a material can flow through the hose in a direction of flow;

a cross-sectional variator adapted to compress the hose and thereby to reduce the inner cross-sectional area of the hose;

a variator drive that causes the cross-sectional variator to compress the hose at controlled locations along the hose;

a controller that controls the variator drive;

a pressure-tight housing, wherein a portion of the hose is enclosed within the pressure-tight housing; and

a negative pressure connection coupled to the pressure-tight housing.

19. The hose pump of claim 18, wherein the variator drive controls how the cross-sectional variator rotates and compresses the hose where the cross-sectional variator contacts the hose.

20. The hose pump of claim 18, wherein the pressure-tight housing has an internal pressure that is controlled by the controller using the negative pressure connection.

21. The hose pump of claim 20, wherein the controller controls the internal pressure inside the pressure-tight housing to be lower than the pressure inside the hose.

22. The hose pump of claim 20, wherein the controller controls the internal pressure inside the pressure-tight housing to equal an average pressure existing inside the hose during operation of the hose pump.

23. The hose pump of claim 18, wherein each portion of the elastic circumferential wall of the hose reverts to its initial cross-sectional form after being compressed by the cross-sectional variator.

24. The hose pump of claim 23, wherein each portion of the elastic circumferential wall of the hose reverts to its initial cross-sectional form after being subjected to a first force that reduces its cross-sectional dimension in a first transverse direction and to a second force that reduces its cross-sectional dimension in a second transverse direction.

25. The hose pump of claim 18, wherein the elastic circumferential wall is made of a memory material that enables the hose to revert to its initial cross-sectional form after being compressed by the cross-sectional variator.

26. The hose pump of claim 18, wherein the cross-sectional variator is formed as a pinch valve that is capable of reducing the inner cross-sectional area of the hose to zero.

27. The hose pump of claim 18, wherein the cross-sectional variator is configured to move a pinch point at which the inner cross-sectional area of the hose is reduced in the direction of flow.

28. The hose pump of claim 18, wherein a plurality of cross-sectional variators are arranged along the hose and can compress the hose independently of one another.

29. The hose pump of claim 18, wherein the cross-sectional variator comprises a rigid, non-deformable pressing body configured to move along the hose in the direction of flow.

30. The hose pump of claim 18, wherein the cross-sectional variator comprises a pressing body that abuts the hose at a fixed position.

31. The hose pump of claim 30, wherein the pressing body abuts the entire circumference of the hose as a press sleeve.

32. The hose pump of claim 30, wherein the pressing body comprises a plurality of chambers arranged along the hose, and wherein the chambers communicate with each other via throttle points and are driven using one common press-pressure connection.

33. The hose pump of claim 18, wherein the cross-sectional variator comprises a plurality of chambers arranged along the hose, and wherein at least one of the plurality of chambers is configured to reduce the inner cross-sectional area of the hose to zero.

34. The hose pump of claim 18, further comprising:

a vacuum sensor configured to measure a negative pressure in the pressure-tight housing; and

a heater configured to heat the hose.

35. An output device for outputting a viscous material, comprising:

a vacuum pump;

a reservoir for the viscous material, wherein a negative pressure is maintained in an air space in the reservoir above the viscous material using the vacuum pump, and wherein the reservoir includes an outlet opening; and

a first hose pump that includes a hose, a variator and a pressure-tight housing, wherein the hose is connected to the outlet opening, wherein a portion of the hose is enclosed within the pressure-tight housing, wherein the variator adapted to compress the hose, and wherein the negative pressure is maintained in the pressure-tight housing using the vacuum pump.

36. The output device of claim 35, wherein the first hose pump further comprises a variator drive that causes the variator to compress the hose at controlled locations along the hose.

37. The output device of claim 35, further comprising:

a second hose pump, wherein the first hose pump and the second hose pump are connected in parallel to the outlet opening; and

a controller adapted to drive the first hose pump and the second hose pump in a phase-shifted manner.

38. The output device of claim 35, wherein the hose has an elastic circumferential wall and an inner cross-sectional area, wherein the hose is open at both ends, and wherein the variator is adapted to compress the hose by reducing the inner cross-sectional area of the hose.

39. The output device of claim 35, wherein the negative pressure that is maintained in the pressure-tight housing is lower than the negative pressure that is maintained in the air space in the reservoir above the viscous material.