WO2007074492A1 - Ventilation machine for active mud purification plants - Google Patents

Ventilation machine for active mud purification plants Download PDF

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Publication number
WO2007074492A1
WO2007074492A1 PCT/IT2006/000868 IT2006000868W WO2007074492A1 WO 2007074492 A1 WO2007074492 A1 WO 2007074492A1 IT 2006000868 W IT2006000868 W IT 2006000868W WO 2007074492 A1 WO2007074492 A1 WO 2007074492A1
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WO
WIPO (PCT)
Prior art keywords
nozzle
liquid
air
machine
diffuser
Prior art date
Application number
PCT/IT2006/000868
Other languages
French (fr)
Inventor
Guerriero Romani
Original Assignee
Faggiolati Pumps S.P.A.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Faggiolati Pumps S.P.A. filed Critical Faggiolati Pumps S.P.A.
Priority to EP06832370A priority Critical patent/EP1969233A1/en
Publication of WO2007074492A1 publication Critical patent/WO2007074492A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20—Mixing gases with liquids
    • B01F23/23—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/232—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using flow-mixing means for introducing the gases, e.g. baffles
    • B01F23/2326—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using flow-mixing means for introducing the gases, e.g. baffles adding the flowing main component by suction means, e.g. using an ejector
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D31/00—Pumping liquids and elastic fluids at the same time
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20—Mixing gases with liquids
    • B01F23/23—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/232—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using flow-mixing means for introducing the gases, e.g. baffles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/40—Mixing liquids with liquids; Emulsifying
    • B01F23/45—Mixing liquids with liquids; Emulsifying using flow mixing
    • B01F23/454—Mixing liquids with liquids; Emulsifying using flow mixing by injecting a mixture of liquid and gas
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/20—Jet mixers, i.e. mixers using high-speed fluid streams
    • B01F25/21—Jet mixers, i.e. mixers using high-speed fluid streams with submerged injectors, e.g. nozzles, for injecting high-pressure jets into a large volume or into mixing chambers
    • B01F25/211—Jet mixers, i.e. mixers using high-speed fluid streams with submerged injectors, e.g. nozzles, for injecting high-pressure jets into a large volume or into mixing chambers the injectors being surrounded by guiding tubes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
    • F04D29/44—Fluid-guiding means, e.g. diffusers
    • F04D29/445—Fluid-guiding means, e.g. diffusers especially adapted for liquid pumps
    • F04D29/448—Fluid-guiding means, e.g. diffusers especially adapted for liquid pumps bladed diffusers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
    • B01F27/25—Mixers with both stirrer and drive unit submerged in the material being mixed

Definitions

  • Ventilation machine for active mud purification plants Ventilation machine for active mud purification plants.
  • the present invention refers to a ventilation machine for active mud purification plants.
  • oxygen is continuously blown in this type of plants, because when the oxygen level drops below the critical threshold tolerated by aerobic bacteria, death of aerobic bacterial flora occurs and anaerobic bacterial flora proliferates, with consequent, undesired production of sulphuretted compounds and methane.
  • the efficacy of a ventilation system is measured with a parameter, the so-called alpha coefficient, defined by the ratio between the quantity of blown oxygen and the quantity of dissolved oxygen in standard conditions.
  • the alpha coefficient is generally tabled according to the quantity of blown air and the blowing depth.
  • the alpha coefficient is not sufficient to determine the energetic efficiency of the plant and therefore specific consumption must be measured, that is to say the kWh necessary to blow a kilogram of oxygen every hour, in standard environmental conditions (760 mmHg atmospheric pressure and 20° temperature).
  • mud active purification plants ventilation is mainly carried out with atmospheric air and provided with different methods, divided into two main groups, the so-called “surface systems” and “bottom systems”, according to whether oxygen is introduced on the surface or bottom of the oxidation tank.
  • a first method included in the so-called surface systems, fixed means are used to raise the sludge to the air in order to oxygenate it.
  • the said means consist in radial-blade rotors, with low rotational speed, driven by electrical motors by means of gear reducers.
  • the rotor is partially immersed in the oxidation tank and raises the sludge that falls back into the tank in a typical umbrella-like shape, with consequent air contact and oxygen transfer.
  • a second method included in the so-called bottom systems, uses mobile means provided with depression hydraulic ejectors, known as Venturi pipes. They basically consist in submergible electrical pumps, whose outlet is provided with a submerged liquid-air ejector.
  • the chamber maintained under depression by the jet delivered by the pump is connected to the air by a vertical pipe that reaches the surface of the tank.
  • the pump When the pump is started, the liquid flooding the air suction pipe is emptied and air is brought into the depression chamber. In the suction chamber the air gets in contact with the jet that drives it at high speed into a cylindrical mixing pipe where air bubbles are ejected together with the active mud mass.
  • a third method, included in the so-called bottom systems, uses mobile means provided with a dynamic compressor with liquid piston; this method is universally known and defined by technicians as Frings system.
  • the system includes submerged rotating machines that are laid on the bottom of the tank.
  • These machines are composed of a watertight electrical motor, of the same type as the one used for submergible electrical pumps, and by a sort of centrifugal rotor that rotates in the centre of a radial diffuser, having a series of internal fixed blades forming an annular series of channels.
  • the rotor is characterised by a special configuration of the frames.
  • the partial gap between contiguous blades allows the rotor to pump liquid and air simultaneously.
  • the air flows on the back side of the blades with respect to the movement direction and the liquid flows on the front side of the blades.
  • the suction orifice of the rotor operates in a chamber connected to a pipe that reaches the surface of the tank.
  • the rotor When the motor is started, the rotor ejects the liquid flooding the suction chamber, and then the liquid is pushed by the front side of the blades, being in permanent contact with it because of submersion, and the air flows continuously on the back side of the blades, being loaded from the suction chamber.
  • the liquid pushed by the front side of the blades leaves the periphery of the rotor with strong rotation and, when meeting a contiguous pair of fixed blades contained inside the diffuser, is divided in discreet volumes that, upon entering the channel, trap and compress the air released by the back side of the preceding rotating blade.
  • the effect is the effect produced by as many pulsating ejectors as the number of channels in the diffuser.
  • a fifth method included in the so-called bottom systems, uses a fixed installation with pressurised hydraulic ejectors.
  • the said installation comprises one or more pairs of overlapped pipes, the first one fed with the mud to be oxygenated and the second one fed with air.
  • This pair of pipes is laid on the bottom of the tank along its entire length.
  • All pipes with liquid to be oxygenated are connected to a manifold fed by a submergible or surface electrical pump at one end, and are closed at the other end.
  • All pipes with air are connected to a manifold fed by a compressor at one end, and are closed at the other end.
  • the two pipes forming the aforementioned pair are connected by mixers consisting in two coaxial nozzles, with the internal nozzle fed by the pipe with pressurised liquid, and the external nozzle fed by the pipe with pressurised air.
  • mixers are equally spaced and deliver from both sides of the pipes.
  • the nozzles are configured in such a way that the air is absorbed in an area with formation of high turbulence on the internal wall of the external nozzle, producing a very fine air dispersion that is considerably higher than the one obtained with static micro bubble diffusers.
  • a sixth method included in the so-called bottom systems, uses mobile means provided with rotating mixers with radial blades with nozzles for compressed air dispersion.
  • a seventh method included in the so-called bottom systems, uses mobile means provided with pressurised hydraulic ejectors, such as in the case of the installations described above.
  • this is a variant of the latter method, with basically one main difference, consisting in the fact that only a trunk of the said fixed installation is used, being installed on a vertical slides that supports a submergible feeding pump, in addition to the double pipes.
  • this mobile system can be easily extracted from the tank.
  • the purpose of the present invention is to devise a ventilation machine for active mud purification plants, suitable to be operated and moved on the bottom of the tank, having a compact structure, partially similar to the machines used in Frings systems, provided with pressurised hydraulic ejectors, of the type used in the last two methods described above, in order to take advantage of the benefits offered by the Frings system and of the benefits that are typical of installations with pressurised hydraulic nozzles, without relevant disadvantages.
  • the introduction of oxygen can be easily modulated according to the specific need, operating the compressor intermittently.
  • the alpha coefficient value is about 0.7-0.85, while the specific consumption value is high.
  • the present invention refers to a ventilation machine for active mud purification plants that comprises a centrifugal pump actuated by a submergible motor, and a special diffuser formed of a series of several different channels, through which the liquid ejected by the pump reaches a corresponding series of radial truncated-conical nozzles supported by corresponding nozzle-holder nozzles distributed along the external perimeter of the special diffuser.
  • Compressed air is introduced in an annular chamber that completely embraces the said channels, which are internally crossed by the liquid and externally grazed by compressed air.
  • the machine of the invention is able to eliminate the pairs of overlapped pipes that characterise the installations with pressurised hydraulic nozzles as described above, having the same alpha coefficient value and a low specific consumption value, due to the elimination of load losses in the pipes.
  • the machine of the invention is compact and easy to carry, combining the advantages of installations with pressurised hydraulic ejectors with the advantages of Frings systems, without being impaired by the relevant disadvantages.
  • - fig. 2 is a view of the machine of fig. 1 sectioned with a plane passing through the rotation axis of the rotor of the centrifugal pump;
  • - fig. 3 is a view of the diffuser of the centrifugal pump sectioned with a horizontal plane Ill-Ill of fig. 2;
  • - fig. 4 is an exploded view of the machine of the invention sectioned with a plane passing through the rotation axis of the rotor of the centrifugal pump;
  • - fig. 5 is an enlarged cross-section of a nozzle with relevant nozzle-holder nozzle
  • FIG. 6 is a perspective view of the diffuser and rotor sectioned with a vertical plane passing through the rotation axis of the rotor and with a horizontal plane passing through the nozzle axis.
  • the machine of the invention comprises a body (1), a submergible electrical pump (2), a manifold (3) for compressed air, a perimeter series of nozzle-holder nozzles (4) and corresponding nozzles (5) for radial delivery of the liquid-air mixed jet.
  • the body (1) is formed of three pieces:
  • a special diffuser (6) composed of a radial pattern of different channels (6a), specifically twelve channels;
  • the upper flange (7) supports the rotor of the submergible pump and the compressed air manifold (3), having an overtumed-Y profile, with forked sections inserted onto corresponding nozzles with vertical axis (7a) provided on the upper flange (7).
  • the compressed air is brought into a sealed gap (11 ) comprised between the diffuser (6) and the lower closing flange (8). From the said gap (11 ) the compressed air arrives inside the nozzle-holder nozzles (4) passing through holes (6c) drilled on the lateral wall of the diffuser
  • the rotor (2a) of the submergible electrical pump (2) occupies the internal part of the diffuser (6), in such a way that the liquid suctioned axially through the suction pipe (2b) is centrifuged inside the pipes (6a) that convey it towards the delivery nozzles (5).
  • the suction pipe (2b) is supported by the diffuser (6) and provided with a gap adjustment system with respect to the rotor (2a).
  • each channel (6a) of the diffuser (6) is designed to divide the output delivered by the rotor (2a) in as many parts as the nozzles, driving it from the exit direction from the rotor blades to a direction coaxial to the radial nozzles (5).
  • each nozzle-holder nozzle (4) contains two additional nozzles, and specifically the air nozzle (12) and the liquid nozzle (13), both being coaxial with the longitudinal axis of the radial nozzle (5), but with opposite profile, i.e. with the divergent air nozzle (12) that contains the convergent liquid nozzle (13).
  • a slot (12a) is obtained in the lower part of the air nozzle (12) and is used to transfer the compressed air from the holes (6c) into the nozzle-holder nozzle (4) inside the air nozzle (12).
  • Each nozzle (5) is crossed by a central jet of pressurised liquid (L) surrounded by an annular jet of compressed air (A), which both accelerate as they move towards the exit mouth, whose cross-section is practically identical to the choked exit of the liquid nozzle (13). Because of this, the so-called limit layer is formed in the final section (5a) of the acceleration nozzle (5), i.e. in the area with high turbulence that favours the incorporation of a very high number of micro air bubbles in the liquid jet
  • the liquid assumes the said helicoidal trajectory because it travels according to curvilinear trajectories on two orthogonal planes.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Aeration Devices For Treatment Of Activated Polluted Sludge (AREA)

Abstract

The present invention refers to a ventilation machine for active mud purification plants, which comprises a body, a manifold for the delivery of compressed air and a submergible electrical pump whose rotor is housed in the centre of a diffuser feeding a series of radial nozzles that eject a mixed liquid-air jet.

Description

Ventilation machine for active mud purification plants.
The present invention refers to a ventilation machine for active mud purification plants.
As it is known, oxygen is continuously blown in this type of plants, because when the oxygen level drops below the critical threshold tolerated by aerobic bacteria, death of aerobic bacterial flora occurs and anaerobic bacterial flora proliferates, with consequent, undesired production of sulphuretted compounds and methane.
The efficacy of a ventilation system is measured with a parameter, the so- called alpha coefficient, defined by the ratio between the quantity of blown oxygen and the quantity of dissolved oxygen in standard conditions.
The alpha coefficient is generally tabled according to the quantity of blown air and the blowing depth.
The alpha coefficient is not sufficient to determine the energetic efficiency of the plant and therefore specific consumption must be measured, that is to say the kWh necessary to blow a kilogram of oxygen every hour, in standard environmental conditions (760 mmHg atmospheric pressure and 20° temperature).
In mud active purification plants ventilation is mainly carried out with atmospheric air and provided with different methods, divided into two main groups, the so-called "surface systems" and "bottom systems", according to whether oxygen is introduced on the surface or bottom of the oxidation tank. According to a first method, included in the so-called surface systems, fixed means are used to raise the sludge to the air in order to oxygenate it. The said means consist in radial-blade rotors, with low rotational speed, driven by electrical motors by means of gear reducers.
The rotor is partially immersed in the oxidation tank and raises the sludge that falls back into the tank in a typical umbrella-like shape, with consequent air contact and oxygen transfer. These plants are especially appreciated for low installation cost and low specific consumption, although they are impaired by the fact that they produce aerosol substances that are transported by the wind, with consequent health problems. For this reason, they are not very popular and are only used in large plants far away from inhabited towns.
A second method, included in the so-called bottom systems, uses mobile means provided with depression hydraulic ejectors, known as Venturi pipes. They basically consist in submergible electrical pumps, whose outlet is provided with a submerged liquid-air ejector. The chamber maintained under depression by the jet delivered by the pump is connected to the air by a vertical pipe that reaches the surface of the tank. When the pump is started, the liquid flooding the air suction pipe is emptied and air is brought into the depression chamber. In the suction chamber the air gets in contact with the jet that drives it at high speed into a cylindrical mixing pipe where air bubbles are ejected together with the active mud mass.
A third method, included in the so-called bottom systems, uses mobile means provided with a dynamic compressor with liquid piston; this method is universally known and defined by technicians as Frings system. The system includes submerged rotating machines that are laid on the bottom of the tank.
These machines are composed of a watertight electrical motor, of the same type as the one used for submergible electrical pumps, and by a sort of centrifugal rotor that rotates in the centre of a radial diffuser, having a series of internal fixed blades forming an annular series of channels.
Although it is very similar to the rotor of an ordinary centrifugal pump, the rotor is characterised by a special configuration of the frames. The partial gap between contiguous blades allows the rotor to pump liquid and air simultaneously. In particular, the air flows on the back side of the blades with respect to the movement direction and the liquid flows on the front side of the blades. The suction orifice of the rotor operates in a chamber connected to a pipe that reaches the surface of the tank.
When the motor is started, the rotor ejects the liquid flooding the suction chamber, and then the liquid is pushed by the front side of the blades, being in permanent contact with it because of submersion, and the air flows continuously on the back side of the blades, being loaded from the suction chamber.
The liquid pushed by the front side of the blades leaves the periphery of the rotor with strong rotation and, when meeting a contiguous pair of fixed blades contained inside the diffuser, is divided in discreet volumes that, upon entering the channel, trap and compress the air released by the back side of the preceding rotating blade.
The effect is the effect produced by as many pulsating ejectors as the number of channels in the diffuser.
A fifth method, included in the so-called bottom systems, uses a fixed installation with pressurised hydraulic ejectors.
The said installation comprises one or more pairs of overlapped pipes, the first one fed with the mud to be oxygenated and the second one fed with air.
This pair of pipes is laid on the bottom of the tank along its entire length.
The number of overlapped pipe pairs depends on the width of the tank. All pipes with liquid to be oxygenated are connected to a manifold fed by a submergible or surface electrical pump at one end, and are closed at the other end.
All pipes with air are connected to a manifold fed by a compressor at one end, and are closed at the other end. The two pipes forming the aforementioned pair are connected by mixers consisting in two coaxial nozzles, with the internal nozzle fed by the pipe with pressurised liquid, and the external nozzle fed by the pipe with pressurised air.
Normally, mixers are equally spaced and deliver from both sides of the pipes. The nozzles are configured in such a way that the air is absorbed in an area with formation of high turbulence on the internal wall of the external nozzle, producing a very fine air dispersion that is considerably higher than the one obtained with static micro bubble diffusers.
A sixth method, included in the so-called bottom systems, uses mobile means provided with rotating mixers with radial blades with nozzles for compressed air dispersion. A seventh method, included in the so-called bottom systems, uses mobile means provided with pressurised hydraulic ejectors, such as in the case of the installations described above.
In reality, this is a variant of the latter method, with basically one main difference, consisting in the fact that only a trunk of the said fixed installation is used, being installed on a vertical slides that supports a submergible feeding pump, in addition to the double pipes.
Although not very compact, this mobile system can be easily extracted from the tank.
The purpose of the present invention is to devise a ventilation machine for active mud purification plants, suitable to be operated and moved on the bottom of the tank, having a compact structure, partially similar to the machines used in Frings systems, provided with pressurised hydraulic ejectors, of the type used in the last two methods described above, in order to take advantage of the benefits offered by the Frings system and of the benefits that are typical of installations with pressurised hydraulic nozzles, without relevant disadvantages.
Following is a description of the advantages and disadvantages of installations with pressurised hydraulic ejectors, characterised by the fact that they use a compressor and a pump that recirculates the active mud to be oxygenated.
First of all, the use of a pump allows for higher oxygen outputs compared to static diffusers, while the strong mixing action avoids mud sedimentation.
The introduction of oxygen can be easily modulated according to the specific need, operating the compressor intermittently. The alpha coefficient value is about 0.7-0.85, while the specific consumption value is high.
Moreover, installations with pressurised hydraulic ejectors are impaired by higher costs than installations with static diffusers, both for the presence of the pump-compressor assembly and the need to use composite materials that guarantee resistance to abrasion and corrosion. Nevertheless, the biggest drawback of the said installations consists in the fact that, due to constructional reasons, pipes need to be rectilinear and this negatively affects compactness and easy handling in case of large output. Due to constructional reasons, the pipe with liquid flow and the pipe with air flow must be welded, thus causing the difficult replacement of worn-out nozzles. The machines used in Frings system-based installations are characterised by high compactness, versatility of use and easy handling, together with high alpha values of 0.7-0.8.
The present invention refers to a ventilation machine for active mud purification plants that comprises a centrifugal pump actuated by a submergible motor, and a special diffuser formed of a series of several different channels, through which the liquid ejected by the pump reaches a corresponding series of radial truncated-conical nozzles supported by corresponding nozzle-holder nozzles distributed along the external perimeter of the special diffuser. Compressed air is introduced in an annular chamber that completely embraces the said channels, which are internally crossed by the liquid and externally grazed by compressed air.
The air reaches the nozzles through holes suitably drilled on the lower part of the diffuser, on whose perimeter the nozzle-holder nozzles are fitted. It appears evident that the machine of the invention is able to eliminate the pairs of overlapped pipes that characterise the installations with pressurised hydraulic nozzles as described above, having the same alpha coefficient value and a low specific consumption value, due to the elimination of load losses in the pipes. The machine of the invention is compact and easy to carry, combining the advantages of installations with pressurised hydraulic ejectors with the advantages of Frings systems, without being impaired by the relevant disadvantages.
For major clarity, the description of the machine of the invention continues with reference to the enclosed drawings, which are only for illustrative, not limitative purposes, whereby: - fig. 1 is an axonometric view of the machine of the invention;
- fig. 2 is a view of the machine of fig. 1 sectioned with a plane passing through the rotation axis of the rotor of the centrifugal pump;
- fig. 3 is a view of the diffuser of the centrifugal pump sectioned with a horizontal plane Ill-Ill of fig. 2; - fig. 4 is an exploded view of the machine of the invention sectioned with a plane passing through the rotation axis of the rotor of the centrifugal pump;
- fig. 5 is an enlarged cross-section of a nozzle with relevant nozzle-holder nozzle;
- fig. 6 is a perspective view of the diffuser and rotor sectioned with a vertical plane passing through the rotation axis of the rotor and with a horizontal plane passing through the nozzle axis.
With reference to the aforementioned figures, the machine of the invention comprises a body (1), a submergible electrical pump (2), a manifold (3) for compressed air, a perimeter series of nozzle-holder nozzles (4) and corresponding nozzles (5) for radial delivery of the liquid-air mixed jet. The body (1) is formed of three pieces:
- a special diffuser (6) composed of a radial pattern of different channels (6a), specifically twelve channels;
- an upper annular flange (7) with vaulted profile section; - a lower annular closing flange (8), under which the feet (9) of the machine of the invention are fitted.
By means of the liquid chamber the upper flange (7) supports the rotor of the submergible pump and the compressed air manifold (3), having an overtumed-Y profile, with forked sections inserted onto corresponding nozzles with vertical axis (7a) provided on the upper flange (7).
The compressed air introduced into the upper annular flange (7) is brought under the diffuser (6) due to the presence of a series of holes (6a) drilled on the diffuser in intermediate position with respect to the series of channels
(6a).
The compressed air is brought into a sealed gap (11 ) comprised between the diffuser (6) and the lower closing flange (8). From the said gap (11 ) the compressed air arrives inside the nozzle-holder nozzles (4) passing through holes (6c) drilled on the lateral wall of the diffuser
(6), immediately under each channel (6a), as shown in fig. 2.
The rotor (2a) of the submergible electrical pump (2) occupies the internal part of the diffuser (6), in such a way that the liquid suctioned axially through the suction pipe (2b) is centrifuged inside the pipes (6a) that convey it towards the delivery nozzles (5).
The suction pipe (2b) is supported by the diffuser (6) and provided with a gap adjustment system with respect to the rotor (2a).
In practical terms, each channel (6a) of the diffuser (6) is designed to divide the output delivered by the rotor (2a) in as many parts as the nozzles, driving it from the exit direction from the rotor blades to a direction coaxial to the radial nozzles (5).
With reference to fig. 5, this description continues by explaining how the air and liquid suctioned by the electrical pump (2) are mixed inside the nozzles (5).
First of all, each nozzle-holder nozzle (4) contains two additional nozzles, and specifically the air nozzle (12) and the liquid nozzle (13), both being coaxial with the longitudinal axis of the radial nozzle (5), but with opposite profile, i.e. with the divergent air nozzle (12) that contains the convergent liquid nozzle (13).
A slot (12a) is obtained in the lower part of the air nozzle (12) and is used to transfer the compressed air from the holes (6c) into the nozzle-holder nozzle (4) inside the air nozzle (12).
Each nozzle (5) is crossed by a central jet of pressurised liquid (L) surrounded by an annular jet of compressed air (A), which both accelerate as they move towards the exit mouth, whose cross-section is practically identical to the choked exit of the liquid nozzle (13). Because of this, the so-called limit layer is formed in the final section (5a) of the acceleration nozzle (5), i.e. in the area with high turbulence that favours the incorporation of a very high number of micro air bubbles in the liquid jet
(L). Finally, it must be noted that due to the special configuration of the channels (6a) of the diffuser (6), the liquid reaches the inside of the liquid nozzle (13) with a radial translation and rotation motion, thus moving along helicoidal trajectories and favouring better mixing with air in the final section (5a) of the acceleration nozzle (5). The said helicoidal trajectory (E) is shown in fig. 6.
It must be noted that the liquid assumes the said helicoidal trajectory because it travels according to curvilinear trajectories on two orthogonal planes.

Claims

Claims
1 ) Ventilation machine for active mud purification plants, characterised in that it comprises a body (1), a compressed air manifold (3) and a submergible electrical pump (2), whose rotor (2a) is housed in the centre of a diffuser (6) composed or a radial pattern of different channels (6a) feeding a corresponding series of radial nozzles (5), which receive the compressed air introduced in the said manifold (3) and the liquid suctioned by the electrical pump (2) and eject a mixed liquid-air jet.
2) Machine as claimed in above claim, characterised in that the body (1) is composed of the said diffuser (6), an upper annular flange (7) with vaulted profile section and a lower annular flange (8) that closes a gap (11) positioned under the diffuser (6), communicating with the internal space of the upper flange (7) through a series of holes (6b) drilled on the diffuser (6) in spaced position with respect to the radial pattern of channels (6a); it being provided that the upper flange (7) is equipped with nozzles (7a) on which the compressed air manifold (3) is inserted.
3) Machine as claimed in above claims, characterised in that each nozzle (5) is supported by a corresponding nozzle-holder nozzle (4) fitted on the external wall of the diffuser (6), provided with holes (6c) to put in communication the said gap (11) with the internal space of the nozzle-holder nozzle (4).
4) Machine as claimed in above claim, characterised in that each nozzle- holder nozzle (4) contains two additional nozzles and, specifically, the air nozzle (12) and the liquid nozzle (13), both being coaxial with the longitudinal axis of the radial nozzle (5), with opposite profile, meaning that the air nozzle (12) is divergent and contains the liquid nozzle (13), which is convergent; it being provided that a slot (12a) is obtained in the lower part of the air nozzle (12) and is used to transfer the compressed air from the holes 6c) into the nozzle-holder nozzle (4) inside the air nozzle (12).
5) Machine as claimed in the above claim, characterised in that each nozzle (5) is crossed by a central jet of pressurised liquid (L), surrounded by an annular jet of compressed air (A), which both accelerate as they move towards the exit, whose cross-section is practically identical to the choked exit of the liquid nozzle (13), in such a way an area with high turbulence is formed in the final section (5a) of the nozzle (5), favouring the incorporation of a very high number of micro air bubbles in the liquid jet (L).
6) Machine as claimed in above claim, characterised in that the liquid reaches the inside of the liquid nozzle (13) with a radial translation and rotation motion, thus moving along helicoidal trajectories (E).
7) Machine as claimed in any of the above claims, characterised in that it is provided with support feet (9) fitted under the lower flange (8).
PCT/IT2006/000868 2005-12-27 2006-12-22 Ventilation machine for active mud purification plants WO2007074492A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP06832370A EP1969233A1 (en) 2005-12-27 2006-12-22 Ventilation machine for active mud purification plants

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITMC2005A000142 2005-12-27
IT000142A ITMC20050142A1 (en) 2005-12-27 2005-12-27 VENTILATION MACHINE FOR WASTEWATER TREATMENT PLANTS.

Publications (1)

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WO2007074492A1 true WO2007074492A1 (en) 2007-07-05

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ID=37951821

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IT2006/000868 WO2007074492A1 (en) 2005-12-27 2006-12-22 Ventilation machine for active mud purification plants

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Country Link
EP (1) EP1969233A1 (en)
IT (1) ITMC20050142A1 (en)
WO (1) WO2007074492A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102588331A (en) * 2011-01-17 2012-07-18 江苏海狮泵业制造有限公司 Fixed reversely bent impeller for vertical type self-priming pump

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH559576A5 (en) * 1973-12-04 1975-03-14 Mueller Hans Maennedorf
DE2559236A1 (en) * 1975-12-30 1977-07-14 Poepel Franz Prof Dr Ing Habil Liquid aeration device - using double-suction impeller on vertical shaft with specified leading parameters
EP0294736A1 (en) * 1987-06-11 1988-12-14 Outokumpu Oy Aerator for industrial and domestic wastewaters
WO1997013071A1 (en) * 1995-10-06 1997-04-10 Ray Robert B Aeration system
DE19539121A1 (en) * 1995-10-20 1997-04-24 Paul Esser Gas-liquid mixing process and device for aeration of waste water

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH559576A5 (en) * 1973-12-04 1975-03-14 Mueller Hans Maennedorf
DE2559236A1 (en) * 1975-12-30 1977-07-14 Poepel Franz Prof Dr Ing Habil Liquid aeration device - using double-suction impeller on vertical shaft with specified leading parameters
EP0294736A1 (en) * 1987-06-11 1988-12-14 Outokumpu Oy Aerator for industrial and domestic wastewaters
WO1997013071A1 (en) * 1995-10-06 1997-04-10 Ray Robert B Aeration system
DE19539121A1 (en) * 1995-10-20 1997-04-24 Paul Esser Gas-liquid mixing process and device for aeration of waste water

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102588331A (en) * 2011-01-17 2012-07-18 江苏海狮泵业制造有限公司 Fixed reversely bent impeller for vertical type self-priming pump

Also Published As

Publication number Publication date
ITMC20050142A1 (en) 2007-06-28
EP1969233A1 (en) 2008-09-17

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