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Patent Searching and Data


Title:
PUMPING DEVICE
Document Type and Number:
WIPO Patent Application WO/2010/100626
Kind Code:
A1
Abstract:
The pumping device comprises a central body (1) closed by a couple of headers (2, 3) and is internally provided with a separating disk (4), suitable to divide the inner space into a first and a second chamber (10, 11) separated. The device further comprises a shaft (5) passing through the said body (1) and the said headers (2, 3) in an eccentric position and connected at one end to an actuator (200); a first and a second impeller (6, 7) arranged respectively into the said first and second chamber (10, 11) and integral to the said shaft (5). The first and second chamber (10, 11) are connected to a recycling duct (16) of the suctioned, mixed, heated and pumped material, suitable to make the flow of the material more homogeneous during the steps of mixing and heating.

Inventors:
STORCHI VILIAM (IT)
DALLA VECCHIA FRANCO (IT)
MOLINARI FULVIO (IT)
Application Number:
PCT/IB2010/050966
Publication Date:
September 10, 2010
Filing Date:
March 05, 2010
Export Citation:
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Assignee:
VUZETA BREVETTI S R L (IT)
STORCHI VILIAM (IT)
DALLA VECCHIA FRANCO (IT)
MOLINARI FULVIO (IT)
International Classes:
F04D19/02; B01F25/60
Foreign References:
EP0667386A11995-08-16
US2477929A1949-08-02
Other References:
None
Attorney, Agent or Firm:
MANZELLA & ASSOCIATI S.A.S. (Bologna, IT)
Download PDF:
Claims:
Claims

[Claim 1] Apparatus for pumping, comprising a central body (1), closed by a couple of heads (2, 3) and having internally at least one separating disk (4), suitable to divide the inner space into at least a first chamber and a second chamber (10, 11) separated; a shaft (5) passing through said body (1) and said heads (2, 3) in an eccentric position, and connected at one end to an actuator (200); at least a first and a second impeller (6, 7) arranged respectively into said at least first and second chamber (10, 11) and integral to said shaft (5), characterized in that said first and second chamber (10, 11) are connected by a recycling duct (16) of the suctioned, mixed, heated and pumped material, suitable to make the flow of the material more homogeneous, during the steps of mixing and heating said material.

[Claim 2] Apparatus according to the claim 1, characterized in that said shaft (5) is supported at the heads (2, 3) by means of suitable bearings, arranged inside said chambers (10, 11), in respective housings kept closed and insulated by suitable protecting and sealing means, and kept at a pressure which at least equals the pressure inside said chambers (10, 11) by means of a closed loop oil circulation system, in order to allow the cooling thereof, in an effective manner.

[Claim 3] Apparatus according to the claim 1, characterized in that said impellers (6, 7) are made integral to said shaft (5) through hot-cold interference coupling and through shear pins.

Description:
Description

Title of Invention: PUMPING DEVICE

Technical Field

[1] The present invention regards a high performance mixing, heating and pumping device, suitable to find a particular use in the chemical and petrochemical type process plants.

Background Art

[2] Devices used to perform the mixing and pumping of mixed material, usually constituted by a liquid base and solid fraction of various type, in the circuits of the chemical and petrochemical type process plants, have been known for a while. In particular, such pumping devices are usually used to mix such materials in an homogeneous manner, and to perform the forwarding thereof in reservoirs or components such as reactors, distillation columns and the like.

[3] For example, German patent application DE 10 2005 056 735.5 illustrates a high power pumping and mixing chamber device, comprising a cylindrical outer wrapping which contains two inner chambers, in which rotate two respective impellers, keyed to a single motor shaft, which axially passes through both the aforesaid inner chambers in an eccentric position, and is actuated by an outer electric actuator.

[4] The described device attains the scope of performing the pumping of mixed materials, that is, materials which comprise oil, liquid substances, solids of various nature and granulometry, usually used in the petrochemical plants, and in particular in the plants dedicated to the treatment and to the conversion of waste materials.

[5] The described pumping device further enables to perform the heating of treated materials until reaching high temperatures, by means of the conversion of the kinetic energy of the impellers, in order to facilitate the chemical reactions that occur downstream in the plant.

[6] Nevertheless is complained the scarce efficiency of the known type pumping devices, and in particular the difficulty to efficiently control the temperature of the materials exiting from the same pumping devices.

[7] Furthermore, it has been observed that the geometry of the currently used mixing and pumping devices determines the development of cavitation phenomena, which reduce the yield and cause a fast wear and tear of the device. It has been further observed that the difficult operating conditions of the mixing and pumping systems of the described type, in particular the high temperature and speed, the presence of solid residual products such as glass, sand, metals and the like in the treated fluid, the high number of hours of required functioning, determine the low reliability and duration of such systems. In particular it has been observed that the low reliability encountered mainly depends on some constructive characteristics of the known systems, among which the system for blocking and positioning the impellers on the shaft, the system used for supporting the shaft, the system for transmitting the motion and the geometry of the ducts.

Disclosure of Invention

Disclosure

[8] The task of the present invention is that of solving the aforementioned problems, devising a mixing and pumping device that allows to increase the yield, reduce the damaging cavitation phenomena, and easily control the temperature of the exiting fluid.

[9] A further object of the present invention is that of providing a mixing and pumping device which has high reliability and duration.

[10] Another object of the present invention is that of providing a pumping device having a simple conception, a securely reliable functioning and versatile use, as well as relatively economic cost.

[11] The above mentioned scopes are attained, according to the present invention, by the pumping device according to claim 1. Description Of Drawings

[12] Details of the invention shall be more apparent from the detailed description of a preferred embodiment of the mixing and pumping device according to the invention, illustrated for indicative purposes in the attached drawings, wherein:

[13] figure 1 shows a plan view of the mixing and pumping device according to the invention;

[14] figure 2 shows a front view of the device;

[15] figure 3 shows an axonometric view of the device.

Best Mode

[16] With particular reference to such figures, the mixing and pumping device is indicated in its entirety with 100. The pumping device 100 comprises a central body 1, substantially cylindrical, made of special steel adapted to the use, to which are peripherally connected a couple of headers 2, 3, with the interposition of suitable seal means.

[17] The central body 1 comprises a separating disk 4, suitable to divide the space internal to the body 1 into two separated chambers 10, 11. The disk 4 is provided with a plurality of through holes 41, suitable to allow the passage of the fluid from the first chamber 10 to the second chamber 11.

[18] The device 100 further comprises a motor shaft 5, axially inserted in the body 1 in a slightly eccentric position. The shaft 5 passes through the body 1 and the headers 2, 3 in an eccentric position, and is connected at one end to a known type actuator 200, for example an electrical motor.

[19] The shaft 5 is supported in correspondence of the headers 2, 3 by suitable bearings, of the mixed rolling and axial thrust bearings type, or of the brass type. In order to enable the cooling thereof in an effective manner, the support means are arranged outside the chambers 10, 11, in respective housings kept closed and insulated by suitable protecting and sealing means, of the stuffing box, puddening, bellows type and the like. The housings of the support means are kept at a pressure which at least equals the pressure inside the chambers 10, 11 by means of a closed loop oil circulation system, which also allows to keep the support means temperature within predetermined values.

[20] The transmission of the motion between the actuator and the shaft 5 can be made through mechanical joint or magnetic dragging, with the possible interposition of moto-reducer means, according to the exigencies.

[21] The shaft 5 carries keyed two impellers 6, 7, which respectively occupy the chambers

10, 11. The impellers 6, 7 can be of various shape and typology as a function of the characteristics of the fluid to be treated, in particular they can be of the straight spoke, curved spoke, concave vane type and the like. The impellers 6, 7 are made integral to the shaft 5 through hot-cold interference coupling, and through shear pins.

[22] The headers 2, 3 respectively comprise a suction gate 12 and a delivery gate 13. Furthermore, the headers 2, 3 further provide for two recycling gates 14, 15, connected by a recycling duct 16.

[23] The functioning of the mixing and pumping device according to the invention is described in the following.

[24] After a first starting step, the rotation speed of the device is brought to values comprised between 450 and 1600 rpm. The speed is then kept constant during the functioning, The fluids to be treated, preheated through known type systems, are introduced in the device at an inlet temperature of about 300 0 C, varying as a function of the type of introduced material. The exercise temperature of the turbine is variable between 280 and 400 0 C, as a function of the set rotation speed. The fluid to be treated enters the first chamber 10 through the suction gate, and enters in contact with the first impeller 6 in rotation. The contact with the vanes of the first impeller 6 causes the mixing and an increase of temperature of the fluid. Successively, the fluid travels through the holes present in the disk 4, and reaches the second chamber 11, where it enters in contact with the second impeller 7 in rotation. The contact with the vanes of the second impeller 7 causes a further mixing and an increase of the temperature of the fluid.

[25] In the following, part of the fluid is sent in exit to the delivery gate 13. Part of the fluid is instead recycled, through the gate 14, the duct 16 and the gate 15, into the first chamber 10.

[26] It is to be underlined that the exit temperature of the fluid turns out to be more elevated with respect to the entry temperature, because of the contact between the fluid and the moving impellers, determining the transformation of part of the kinetic energy of the vanes into thermal energy of the fluid. Furthermore, the increase of the temperature of the fluid is favoured by the passage through the holes 41 of the separating disk 4.

[27] It has been experimentally verified that the presence of the recycling duct 16 enables to obtain the effect of making the turbine less subject to cavitation, and therefore more efficient. Furthermore, the flow inside the device is made more homogeneous, thus facilitating the mixing and the uniform heating of the fluid. The experimental analysis have also evidenced that the absence or a different positioning of the duct 16 creates counter- flows noxious to the correct functioning of the device.

[28] Furthermore, to enhance the efficiency of the mixing and of the thermal exchange in order to heat the introduced material, the inner walls of the body 1 can be usefully provided with protrusions or counter-fins, not shown.

[29] Furthermore, the inner walls of the body 1 can be also usefully provided with a coating made of ceramic material.

[30] In a further embodiment of the invention, not represented in the attached drawings, the central body 1 comprises a plurality of separating disks 4, suitable to divide the inner space of the body 1 in more separated chambers. The disks 4 are provided with a plurality of through holes 41, suitable to allow the passage of the fluid between the adjacent chambers. Each chamber is suitable to internally contain an impeller, and so constitutes a stage of a multistage pumping system. The use of the described multistage system usefully enables to extend the permanence time of the fluid inside the device, in compliance with the required specifications.

[31] The mixing and pumping device in hand attains the scope of increasing the yield, reducing the damaging cavitation phenomena, and easily controlling the temperature of the exiting fluid.

[32] An advantage of the device according to the present invention is given by the fact that it provides a mixing and pumping device having high reliability and duration, due to the presence of the recycling duct 16 and to the particular embodiment of the supporting and cooling system of the bearings 5.

[33] In practice, the embodiment of the invention, the materials used, as well as the shape and dimensions, may vary depending on the requirements.

[34] Should the technical characteristics mentioned in each claim be followed byreference signs, such reference signs were included strictly with the aim of enhancing the under- standing the claims and hence they shall not be deemed restrictive in any manner whatsoever on the scope of each element identified for exemplifying purposes by such reference signs.