Improved efficiency deaerator

Abstract

Deaerator device for liquids which comprises: a hollow outer tubular body (1), which extends from an upstream end (4) to a downstream end (6) around an axis (A-A); an inlet conduit (3), which enters the outer tubular body (1); an outlet conduit (5), which departs from the outer tubular body (1) from a position downstream of said inlet conduit (3); a vent (9) arranged on the upstream end (4) of the outer tubular body (1), an inner tubular body (2), which is arranged inside the outer tubular body (1) and is joined to the vent (9) so as to allow the outflow of the air present in the inner tubular body (2) through said vent ( 9 ), the outer tubular body (1) delimiting, together with said inner tubular body (2), at least in a first reduction length (LI), a passage cross-section (S), which is reduced when proceeding downstream in a longitudinal direction.

Description

[0001] "IMPROVED EFFICIENCY DEAERATOR"

[0002] ★★★★★★★

[0003] FIELD OF THE INVENTION

[0004] The present invention relates to an improved efficiency deaerator and a deaerating method according to the preamble of the main claims.

[0005] Deaerators are used in a number of industrial processes in which the air contained in a fluid, usually water, needs to be removed or reduced.

[0006] This is important in heat pumps, for example, as the air contained in water worsens heat exchange.

[0007] KNOWN PRIOR ART

[0008] In the state of the art, there are metal mesh or wire mesh deaerators, in which the water flow collides directly with the metal mesh or wire mesh to achieve the dissociation of air from water.

[0009] In other deaerators, instead, the centrifugal effect is used, which causes the fluid to move in a vortex pattern.

[0010] Typically, deaeration treatment cannot completely remove air from water, but it does reduce the content thereof.

[0011] A deaerator comprises an inlet through which water, from which air has to be removed, enters and two outlets, one for air and one for treated water.

[0012] Sometimes, a deaerator device is combined with a sludge separator, thus forming a single device that performs both functions: separating and removing air from water and removing sludge and other impurities .

[0013] The action of the sludge separator is normally carried out downstream of the deaerator, also by means of a mechanical filter and a permanent magnet whose task is to attract and remove ferrous particles from the fluid .

[0014] A deaerator-sludge separator device therefore comprises a deaerator upstream and a sludge separator downstream . This device has thus an inlet conduit and three outlets : a first outlet for air, a second outlet for water from which air and solid impurities have been removed, and a third outlet to remove the resulting sludge .

[0015] One problem with existing deaerators is that their ef ficiency is not very high, so air is not totally removed but a certain amount of air still remains in the water even after the deaeration process , so the degree of deaeration of water, i . e . the percentage of air which is removed from water, is often unsatis factory .

[0016] In addition, some currently produced deaerators have signi ficant pressure drop due to the direct impact of the fluid with the metal mesh or wire mesh .

[0017] Therefore , it is an obj ect of the present invention to make a deaerator that allows to overcome the drawbacks mentioned, speci fically, an obj ect is to make an improved ef ficiency deaerator that allows a greater amount of air to be removed from the fluid, and speci fically from water, compared to existing deaerators , thus achieving a higher degree of deaeration .

[0018] It is a second obj ect to obtain a deaerator which, with the same ef ficiency, achieves a lower pressure drop compared to existing deaerators or, with the same pressure drop, achieves a higher degree of deaeration .

[0019] SUMMARY OF THE INVENTION

[0020] Said obj ects are achieved by a deaerator whose inventive features are highlighted by the claims .

[0021] SHORT DESCRIPTION OF THE DRAWINGS

[0022] The invention will be better understood from the following speci fication, provided purely for illustration purposes only, thus not limiting, of a preferred embodiment depicted in the attached drawings in which :

[0023] Fig . 1 shows a perspective view of a deaerator according to the invention;

[0024] Fig . 2 shows a longitudinal section of a preferred embodiment of the deaerator in which the inlet conduit , which would not be visible in that section, has also been depicted;

[0025] Fig . 3 shows a top view of the preferred embodiment of the deaerator ; Fig . 4 shows a cross-section B-B of the deaerator ;

[0026] Fig . 5 shows a longitudinal section view of a deaerator-sludge separator in which the inlet conduit , which would not be visible in that section, has also been depicted .

[0027] DESCRIPTIONN OF A PREFERRED EMBODIMENT OF THE INVENTION

[0028] The invention concerns the deaerator only, to which a sludge separator is sometimes also j oined, to perform both functions .

[0029] In reference to Figures 1 to 4 , it can be seen that the deaerator device for liquids according to the invention comprises : a hollow outer tubular body 1 , which extends from an upstream end 4 to a downstream end 6 around an A-A axis ; an inlet conduit 3 , which enters the outer tubular body 1 at a region close to the upstream end 4 , with a direction that has at least one component which lies on a plane transverse to the A-A axis ; an outlet conduit 5 , which departs from the outer tubular body 1 , from a position downstream of said inlet conduit 3 , at a region close to the downstream end 6 ; a vent 9 arranged on the upstream end 4 of the outer tubular body 1 at the A-A axis ; an inner tubular body 2 , which is arranged at least partially inside the outer tubular body 1 , between the upstream end 4 and the downstream end 6 , said inner tubular body having on its side surface one or more holes 7 adapted to allow the passage of air, and being j oined to the vent 9 , so as to allow the outflow of the air present in the inner tubular body 2 through the vent 9 .

[0030] The vent 9 may be a vent conduit that departs from the upstream end 4 of the outer tubular body 1 , as a prolongation of the inner tubular body 2 , as in Fig . 2 , or a simple vent hole arranged on the upstream end 4 of the outer tubular body 1 .

[0031] Preferably, the outlet conduit 5 departs tangentially from the outer tubular body 2 .

[0032] The outer tubular body 1 and the inner tubular body 2 are usually coaxial .

[0033] The inner tubular body 2 departs from the upstream end 4 and ends at one end at the vent 9 and ends at the other end with a downstream opening 23 , which is open and is located inside the outer tubular body 2 , so as it can receive rising air bubbles , it being located near the A-A axis and downstream of the inner tubular body 2 .

[0034] The device has a reduction length L comprising a first reduction length LI and a second reduction length L2 .

[0035] The outer tubular body 1 delimits or helps to delimit therein, at least in said first reduction length LI and / or in said second reduction length L2 , a passage cross-section S which is reduced when proceeding downstream in a longitudinal direction, i . e . from the upstream end 4 to the downstream end 6 .

[0036] In the first reduction length LI , the outer tubular body 1 and the inner tubular body 2 together delimit the passage cross-section S , which is reduced when proceeding downstream in a longitudinal direction .

[0037] In the second reduction length L2 , the outer tubular body 1 alone delimits a passage crosssection S , which is reduced when proceeding downstream in a longitudinal direction .

[0038] At the upstream end 4 of the outer tubular body 1 , the cross-section portion between the outer tubular body 1 and the inner tubular body 2 is closed, for example by a cover 16 , which, however, allows the outflow of the vent 9 .

[0039] Preferably, the inlet conduit 3 enters the outer tubular body 1 tangentially, as seen in Fig . 3 , from a direction that lies on a transverse plane and thus normal to the A-A axis , so as to more ef ficiently impart to the flowing-in liquid a vortex or rotary motion, to which a downstream motion is naturally added .

[0040] In Fig . 2 it can be seen that the direction in which the inlet conduit 3 enters the outer tubular body 1 lies on a transverse plane , i . e . on a plane which transversely intersects the A-A axis of the outer tubular body 1 .

[0041] It is , however, possible for the inlet conduit 3 to enter the outer tubular body 1 with a direction that not only has a transverse component , but also a component arranged in a longitudinal direction .

[0042] The deaerator device is normally mounted vertically, thus with the A-A axis of the outer tubular body 1 arranged vertically .

[0043] It was surprisingly found that , by placing a hori zontal row of holes 7 on the inner tubular body 2 , close to the upstream end 4 , air evacuation is improved .

[0044] Said holes 7 are thus preferably arranged at the intersection between the inner tubular body 2 and an ideal plane transverse to the A-A axis , said plane preferably being at a distance of less than or equal to 20 mm from the upstream end 4 .

[0045] Air evacuation is further improved i f said holes 7 have a diameter between 1 and 2 mm .

[0046] In the first reduction length LI , both said outer tubular body 1 and said inner tubular body 2 comprise a f rustoconical-shaped length, the f rustoconical-shaped length of the inner tubular body 2 being arranged inside the f rustoconical- shaped length of the outer tubular body 1 .

[0047] In the first reduction length LI , the f rustoconical shapes of said inner tubular body 2 and of said outer tubular body 1 are inverted with respect to each other, the cross-section of the outer tubular body 1 becoming narrowed and the crosssection of the inner tubular body 2 becoming widened when proceeding downstream in a longitudinal direction .

[0048] The f rustoconical shapes of the outer tubular element 1 and the inner tubular element 2 are coaxial in said first reduction length LI of the deaerator and are inverted with respect to each other, thus resulting in the passage cross-section S being narrowed between the two f rustoconical shapes , when proceeding downstream in a longitudinal direction .

[0049] It was also surprisingly found that the deaeration ef fect is particularly ef ficient when the cone of the outer tubular element forms an angle a, between a cross-section and the side surface , between 84 ° and 88 ° , preferably 86 ° .

[0050] This means that , in a longitudinal section of the f rustoconical shape of the outer tubular body 1 , the acute angle a between the trace of a crosssection and the trace of the side surface of the outer tubular body 1 is between 84 ° and 88 ° , preferably 86 ° .

[0051] As regard to the f rustoconical shaped inner tubular body 2 , in a longitudinal section of the f rustoconical shape of the inner tubular body 2 , the acute angle 0 between the trace of a cross-section and the trace of the side surface of the inner tubular body 2 is between 84 ° and 88 ° , preferably 86 ° .

[0052] As can be seen in Fig . 2 , an inlet filter 8 can be arranged inside the inlet conduit 3 to prevent pebbles , algae and other large impurities from entering the deaerator . Alternatively, an additional mechanical filter could be installed .

[0053] In the first reduction length LI , the outer tubular body 2 comprises a first f rustoconical element which is narrowed when proceeding downstream .

[0054] In a second reduction length L2 , the outer tubular body 2 comprises a second f rustoconical element which is narrowed when proceeding downstream, with an acute angle y defined as the angle formed in a longitudinal section between the trace of a cross-section and the trace of the side surface of the inner tubular body 2 .

[0055] Said angle y is larger than the angle a, and is between 85 ° and 89 ° , preferably the angle y is equal to 87 ° .

[0056] The outer tubular body 1 of the deaerator device also comprises , at its ending part , downstream of the reduction length L, a cylindrical length 20 ending with the downstream end 6 .

[0057] In the cylindrical length 20 , at the A-A axis , a pin 21 is arranged which supports a disk trap 22 arranged transversely to the A-A axis .

[0058] The purpose of the disk trap 22 is to prevent any air bubbles that are dissociated from the water and close to the A-A axis from being dragged by the water into the outlet conduit 5 .

[0059] In reference to Fig . 5 , in which a deaerator j oined to a sludge separator is depicted, it can be seen that the device also comprises a sludge outlet conduit 10 at the ending or downstream part of the sludge separator, to allow the outflow of sludge and impurities extracted from water .

[0060] The outer tubular body 1 of the deaerator-sludge separator device also comprises , at its ending part , a cylindrical shaped length that departs from the end of the reduction length L when proceeding downstream . One or more cylindrical shaped magnets 11 are contained in it and, between the magnet and the inner surface of the outer tubular body 1 , a mechanical filter 12 and a cleaning comb 13 which is adapted to rotate by swiping on the surface of the magnet .

[0061] The cleaning comb 13 is connected to a lever 14 which allows it to be rotated by causing it to swipe on the magnet 11 .

[0062] The cylindrical shaped length of the outer tubular body 1 , in which the magnet 11 , the mechanical filter 12 and the cleaning comb 13 are arranged, acts as sludge separator and consists of standard elements already known in the relevant art .

[0063] In the upper part of the deaerator, at the vent conduit 9 , there is a float 15 , which rises when the air that has been separated from the water needs to flow out .

[0064] The deaerator comprises a cover 16 with a knob 17 at the upstream end of the outer tubular body 1 .

[0065] The cover 16 is adapted to manually rotate about the A-A axis by gripping the knob 17 .

[0066] Rotating the cover 16 allows the inlet conduit 3 to be closed, in order to stop the water flow and carry out maintenance .

[0067] By rotating the cover 16 in the opposite direction, the inlet conduit 3 can be opened again and water inflow into the device can be allowed .

[0068] The cover 16 , being able to rotate , thus also acts as a valve adapted to intercept the fluid coming from the inlet conduit 3 .

[0069] The fluid from which air has to be removed is normally water used in various types of systems , such as for example heat exchangers used in heat pumps , so reference will be made to water in the following, even though what stated can also apply to other fluids , such as oil .

[0070] In operation, the device is mounted vertically, as in Fig . 1 , 2 or 5 , and connected to a pipe the water from which the air has to be removed comes from .

[0071] Water thus comes from the inlet conduit 3 , and large si ze impurities , such as cobbles , algae or pieces of wood, are retained by the inlet filter 8 .

[0072] Water then enters the gap formed between the outer tubular body 1 and the inner tubular body 2 .

[0073] Given the tangential arrangement of the inlet conduit 3 , as highlighted in Fig . 3 , water follows a rotary or vortex path around the common A-A axis of the outer tubular body 1 and the inner tubular body 2 , while moving downstream from the inlet conduit 3 to the outlet conduit 5 .

[0074] The motion of water is thus substantially similar to a helix in which, however, in the reduction length L, the distance from the A-A axis is progressively reduced when proceeding from the inlet conduit 3 to the outlet conduit 5 .

[0075] Thanks to the cross-section area S of the gap progressively decreasing downstream in a longitudinal direction, a motion in a radial direction, which brings the fluid closer to the A-A axis , is added to the vortex motion of the fluid .

[0076] This promotes the separation of air from water, more ef ficiently than currently known deaerators .

[0077] Due to centri fugal ef fect , with the vortex motion, the air, which is lighter than water, tends to move towards the A-A axis .

[0078] Part of the air dissociated from the water passes through the holes 7 of the inner tubular body 2 and flows out of the vent 9 .

[0079] The remaining part of air flows along the walls of the inner tubular body 2 , then enters the same through its downstream opening 23 and, thanks to the Venturi ef fect , flows out of the vent 9 .

[0080] The inlet to the vent 9 is thus arranged on the top 4 of the outer tubular body 1 and preferably at the A-A axis .

[0081] It is possible that the sludge separator, which comprises the permanent magnet 11 and the mechanical filter 12 , is arranged downstream of the deaerator .

[0082] In this case , the water from which air has been removed still proceeds in a vortex motion towards the outlet conduit 5 by passing through the mechanical filter 12 , which is finer than the inlet filter 8 . Ferromagnetic particles are attracted to the surface of the magnet 11 .

[0083] Particles adhering to the magnet 11 are occasionally scraped of f by the cleaning comb 13 and descend towards the sludge outlet conduit 10 .

[0084] The sludge that is retained by the mechanical filter 12 also descends towards the sludge outlet conduit 10 from which it outflows together with the particles removed from the surface of the magnet 11 .

[0085] The deaerator-sludge separator device thus allows deaeration to be obtained in a first step and sludge removal in a second step, whereas particles of larger diameter do not enter the device and are retained by the inlet filter 8 .

[0086] The deaeration ef fect is particularly ef fective due to the combination of the vortex motion and the passage cross-section S being narrowed between the outer tubular body 1 and the inner tubular body 2 .

[0087] The coaxial and opposing f rustoconical shape of the two tubular bodies in the first reduction length LI allows for greater ef fectiveness compared to known deaerators .

[0088] A speci fic deaeration ef ficiency was noted when the outer tubular surface 1 is f rustoconical and is narrowed with an angle a equal to 86 ° .

[0089] Similarly, it has been noted that a better ef fect is achieved i f the inner tubular surface 2 is f rustoconical and is narrowed with an angle 0 equal to 86 ° .

[0090] A further deaerating ef fect is achieved in the second reduction length L2 in which the inner tubular body is absent , but the passage cross-section S is narrowed when proceeding downstream in a longitudinal direction .

[0091] The speci fic shape of the deaerator gives the fluid a movement comprising a tangential component of rotation about the A-A axis ; a longitudinal downstream component with direction parallel to the A-A axis ; and a radial direction component of moving closer to the A-A axis , causing the separation of air from the fluid with greater ef ficiency than known deaerators .

[0092] The present invention therefore also aims to protect a method of deaerating a fluid, comprising the following steps : a ) a fluid is obtained and is fed into a tubular body with an upstream end 4 , a downstream end 6 and with an A-A axis b ) a movement is imparted to the fluid, which comprises a tangential component of rotation about the A-A axis , a longitudinal component with a direction parallel to the A-A axis and a component in a radial direction moving closer to the A-A axis , thus causing the air to separate from the fluid; c ) the air, which is separated from the fluid, is intercepted; d) a fluid with a smaller amount of air is obtained .

[0093] Thanks to the fact that the deaerator according to the invention forces the flowing-in fluid to move with a rotary motion about the A-A axis , combined with a motion in a longitudinal downstream direction and a radial motion moving closer to the A-A axis , causing the fluid to pass through a passage crosssection S which, in the first reduction length LI and the second reduction length L2 is progressively reduced when proceeding downstream, the deaerator achieves a particular ef fectiveness in dissociating and removing from water the air initially contained in it .

[0094] Speci fically, in the first reduction length LI , the passage cross-section S is delimited by the inner tubular body 2 and the outer tubular body 1 , whereas in the second reduction length L2 the passage crosssection S is delimited by the outer tubular body 1 only .

[0095] It is of course possible to provide that the passage cross-section S between the two tubular bodies is narrowed when proceeding from upstream to downstream, without the two tubular bodies having a f rustoconical shape , or even having a curved and not straight A-A axis .

[0096] For example , it is possible that the inner tubular body 2 has a cylindrical shape and only the outer tubular body has a f rustoconical shape , which is narrowed when proceeding downstream in the first reduction length LI .

[0097] Or that the outer tubular body 1 has a cylindrical shape and that the inner tubular body 2 has a f rustoconical shape that opens up when proceeding downstream in a longitudinal direction .

[0098] It is also possible that the two f rustoconical shapes of the inner tubular body 2 and the outer tubular body 1 are equally oriented and not inverted with respect to each other .

[0099] For example , it is possible that the f rustoconical shape of the outer tubular body 1 is narrowed more quickly than that of the inner tubular body 2 when proceeding downstream, so that the passage cross-section S between the two tubular bodies is reduced when proceeding downstream .

[0100] In a non-pref erred embodiment , the deaerator may not have the inner tubular body 2 and thus comprise the second reduction length L2 without there being a first reduction length LI .

[0101] An advantageous feature of the invention is that , for the same pressure drop, the degree of deaeration is greater and, for the same degree of deaeration, the pressure drop is lower than known deaerators .

[0102] It is also possible , however, that the deaerator according to the invention has both a lower pressure drop and a better deaeration than known deaerators .

Claims

CLAIMS1. Deaerator device for liquids which comprises : a hollow outer tubular body (1) , which extends from an upstream end (4) to a downstream end (6) around an axis (A-A) ; an inlet conduit (3) , which enters the outer tubular body (1) ; an outlet conduit (5) , which departs from the outer tubular body (1) from a position downstream of said inlet conduit (3) ; a vent (9) arranged on the upstream end (4) of the outer tubular body (1) , an inner tubular body (2) , which is arranged inside the outer tubular body (1) and is joined to the vent (9) so as to allow the outflow of the air present in the inner tubular body (2) through said vent ( 9 ) , characterised in that the outer tubular body(1) delimits, together with said outer tubular body(2) , in at least one first reduction length (LI) , a passage cross section (S) which is reduced when proceeding downstream in a longitudinal direction.

2. Device according to the preceding claim, characterised in that said vent (9) is arranged at the axis (A-A) .

3. Device according to one or more of the preceding claims, characterised in that said innertubular body (2) comprises on its surface one or more holes (7) adapted to allow the passage of air, said holes (7) preferably being arranged at the intersection between the inner tubular body (2) and an ideal plane transverse to the axis (A-A) , said plane preferably being at a distance of less than or equal to 20 mm from the upstream end (4) .

4. Device according to the preceding claim, characterised in that said holes (7) have a diameter between 1 mm and 2 mm.

5. Device according to one or more of the preceding claims, characterised in that said inlet conduit (3) tangentially enters the outer tubular body (1) from a direction having at least one component which lies on a plane transverse to the axis (A-A) and which preferably lies on said plane transverse to the axis (A-A) , in a manner adapted to impart a vortex motion to the flowing-in liquid.

6. Device according to one or more of the preceding claims, characterised in that said inner tubular body (2) is coaxial to said outer tubular body ( 1 ) .

7. Device according to one or more of the preceding claims, characterised in that said outer tubular body (1) comprises at least one f rustoconical-shaped length.

8. Device according to one or more of the preceding claims, characterised in that said innertubular body (2) comprises a f rustoconical-shaped length .

9. Device according to claims 7 and 8, characterised in that the f rustoconical shape of said inner tubular body (2) is inverted with respect to the f rustoconical shape of said outer tubular body (1) , the cross section of the outer tubular body (1) being narrowed and the section of the inner tubular body (2) being widened when proceeding in the first reduction length (LI) downstream in a longitudinal direction.

10. Device according to one or more of claims7 to 9, characterised in that in a longitudinal section of the f rustoconical shape of the outer tubular body (1) , the acute angle a between the trace of a cross section of the outer tubular body (1) and the trace of the side surface is between 84° and 88°, preferably 86°.

11. Device according to one or more of claims8 to 10, characterised in that in a longitudinal length of the f rustoconical shape of the inner tubular body (2) , the acute angle 0 between the trace of a cross section of the inner tubular body (2) and the trace of the side surface is between 84° and 88°, preferably 86°.

12. Method of deaerating a fluid, comprising the following steps: a) a fluid is obtained and fed into a tubularbody with an upstream end ( 4 ) , a downstream end ( 6 ) and an axis (A-A) characterised in that b ) a movement is imparted to the fluid, which comprises a tangential component of rotation about the axis (A-A) , a longitudinal component with a direction parallel to the axis (A-A) and a component in the radial direction moving closer to the axis (A-A) , thus causing the air to separate from the fluid; c ) the air, which is separated from the fluid, is intercepted; d) a fluid with a smaller amount of air is obtained .

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