U.S. patent application number 14/430481 was filed with the patent office on 2015-10-29 for wall ring for an axial fan.
This patent application is currently assigned to ebm-papst Mulfingen GmbH & Co. KG. The applicant listed for this patent is EBM-PAPST MULFINGEN GMBH & CO. KG. Invention is credited to JORG GUNTHER, JOCHEN HAFNER, THOMAS HELI, PETER RIEGLER.
Application Number | 20150308455 14/430481 |
Document ID | / |
Family ID | 49212766 |
Filed Date | 2015-10-29 |
United States Patent
Application |
20150308455 |
Kind Code |
A1 |
HELI; THOMAS ; et
al. |
October 29, 2015 |
WALL RING FOR AN AXIAL FAN
Abstract
The present invention relates to a wall ring for receiving in
particular an axial fan, comprising an annular body with a flow
inlet opening and a flow outlet opening and a central longitudinal
axis X-X as well as an annular wall extending between both
openings. The annular wall has a cavity which is enclosed by an
outer wall and an inner wall, in which an electrical heating
element may be secured at least over a partial area of the
periphery of the annular wall. The annular body consists of at
least two partial bodies which are formed by a division of the
annular body in a separating plane that extends perpendicular to
its longitudinal axis and are detachably connected to one
another.
Inventors: |
HELI; THOMAS; (LANGENBURG,
DE) ; RIEGLER; PETER; (BOXBERG, DE) ; GUNTHER;
JORG; (DORZBACH, DE) ; HAFNER; JOCHEN;
(BLAUFELDEN, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EBM-PAPST MULFINGEN GMBH & CO. KG |
Mulfingen |
|
DE |
|
|
Assignee: |
ebm-papst Mulfingen GmbH & Co.
KG
Mulfingen
DE
|
Family ID: |
49212766 |
Appl. No.: |
14/430481 |
Filed: |
September 16, 2013 |
PCT Filed: |
September 16, 2013 |
PCT NO: |
PCT/EP2013/069145 |
371 Date: |
June 17, 2015 |
Current U.S.
Class: |
415/177 |
Current CPC
Class: |
F04D 29/522 20130101;
F04D 29/584 20130101; F04D 19/002 20130101 |
International
Class: |
F04D 29/58 20060101
F04D029/58; F04D 29/52 20060101 F04D029/52; F04D 19/00 20060101
F04D019/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 8, 2012 |
DE |
10 2012 109 546.9 |
Claims
1. A wall ring for receiving, in particular, an axial fan,
comprising an annular body with a flow inlet opening and a flow
outlet opening and having a central longitudinal axis, as well as
with a ring wall running between the two openings, characterized in
that the ring wall has a hollow space which is enclosed by an outer
wall and an inner wall, and in which an electric heating element
can be attached at least over part of the circumference of the ring
wall, and in that the annular body consists of at least two partial
bodies that are formed by dividing the annular body along a
separation plane running perpendicular to its longitudinal axis and
that are removably joined to each other.
2. The wall ring according to claim 1, characterized in that the
outer wall sections and the inner wall sections of the two partial
bodies have complementary stepped profiles at their abutting ends,
so that there is overlapping in the area of the stepped
profiles.
3. The wall ring according to claim 2, characterized in that the
outer wall sections of the partial bodies are of different lengths
from each other and the inner wall sections of the partial bodies
are of different lengths from each other.
4. The wall ring according to one of claims 1, characterized in
that the inner wall 12, which has a convex curvature, is configured
as a flow profile.
5. The wall ring according to one of claims 1, characterized in
that the outer wall is a flat wall profile running parallel to the
longitudinal axis X-X.
6. The wall ring according to one of claims 1, characterized in
that, in the transition area between the outer wall sections and
the associated inner wall sections, on at least one of the partial
bodies, advantageously on both of the partial bodies, there are
fastening journals that run axially parallel to the longitudinal
axis, that are arranged along the circumference, and that, together
with the opposite inner wall section, enclose a gap whose width is
greater than or equal to the thickness of the heating element that
is to be used, especially a tape-like heating element.
7. The wall ring according to claim 6, characterized in that, when
the fastening journals of the two partial bodies are in the
installed state, they are arranged along the circumference so as to
be offset relative to each other, and their length is greater than
the width of an installed tape-like heating element.
8. The wall ring according to one of claim 1, characterized in that
the two partial bodies are removably joined to each other by means
of several screws that are arranged along the circumference and
that run axially in the direction of the longitudinal axis.
9. The wall ring according to one of claims 1, characterized in
that the annular body is made of plastic.
10. The wall ring according to one of claims 1, characterized in
that the flow inlet opening is covered by a protective wire
grill.
11. The wall ring according to claim 10, characterized in that the
protective wire grill has radially running struts whose radially
inner ends are joined to a motor mount and whose radially outer
ends are joined to the associated partial body.
12. The wall ring according to claim 11, characterized in that a
covering cap for the electric motor is removably attached in the
center of the protective grill.
13. The wall ring according to one of claim 1, characterized in
that a circumferential mounting flange that protrudes radially is
shaped onto one of the partial bodies, especially onto the partial
body that encompasses the inlet opening.
14. The wall ring according to claim 13, characterized in that
fastening tabs are shaped onto the mounting flange.
15. The wall ring according to one of claim 1, characterized in
that the connection line runs along the protective grill, enters
the partial body and exits the partial body in the axial direction
through drilled holes.
Description
[0001] The present invention relates to a wall ring for receiving,
in particular, axial fans, comprising an annular body having a
central longitudinal axis, with a flow inlet opening and a flow
outlet opening as well as with a ring wall running between the two
openings.
[0002] Axial fans are used, among other things, for applications at
very low temperatures. Here, there is a risk that ice will form and
thus that the fan wheel blade will freeze onto the wall ring.
Typical applications in which this risk exists include heat pumps,
evaporators in cold-storage rooms and the like. In order to prevent
such a freezing from occurring, it is a known procedure to install
a heating element in the form of an electric resistance heater on
the wall ring and to use it as a heater. A drawback here is the
great amount of energy that has to be supplied in order to heat the
wall ring all the way through so as to prevent ice formation on the
inside of the wall ring or else to melt off any ice that might have
formed there. Here, a high heat release to the surroundings takes
place and the heat that enters into the cold-storage room in this
manner has to be subsequently removed once again from the
cold-storage room. As a result, such a wall ring heater is not
energy-efficient.
[0003] The present invention is based on the objective of avoiding
the above-mentioned disadvantages and reducing the formation of ice
on the inside of the wall ring.
[0004] According to the invention, this is achieved in that the
ring wall has a hollow space which is enclosed by an outer wall and
an inner wall, and in which an electric heating element can be
attached at least over part of the circumference of the ring wall,
and in that the annular body of the wall ring consists of at least
two partial bodies that are formed by dividing the annular body
along a separation plane running perpendicular to the longitudinal
axis and that are removably joined to each other.
[0005] The wall ring according to the invention is made of plastic
so that, already due to the inner hollow space and the double wall
as well as due to the material used (plastic) for the wall ring
according to the invention, ice formation on the inside of the wall
ring is reduced without the use of a heating element since the air
space in the interior as well as the outer wall provide insulation
vis-a-vis the environment. In addition, the configuration according
to the invention makes it possible to install heating tape in the
hollow space formed between the outer wall and the inner wall,
whereby the heating tape is in contact with the inner wall of the
ring wall. Advantageously, the hollow space formed between the
outer wall and the inner wall is dimensioned in such a way that its
volume is at least twice as large as the volume of the
advantageously used heating tape that serves as an electric
resistance heater. In this manner, an optimal insulation effect
towards the outside is achieved. Since the wall ring according to
the invention is configured in two partial bodies that are inserted
into each other in the axial direction, that is to say, in the
direction of the longitudinal axis, and then joined to each other,
especially screwed together, it is easy to retrofit the wall ring
according to the invention with a heating element.
[0006] Additional advantageous embodiments of the invention are
contained in the subordinate claims and are explained in greater
detail with reference to the embodiment shown in the accompanying
drawings. The following is shown:
[0007] FIG. 1 a perspective view of a wall ring according to the
invention, with an installed axial fan in the direction of its
inlet opening,
[0008] FIG. 2 an exploded view of the wall ring according to the
invention as shown in FIG. 1,
[0009] FIG. 3 a section along the sectional line III-III in FIG.
1,
[0010] FIG. 4 a perspective view of the wall ring according to the
invention as shown in FIG. 1, in the direction of its outflow
opening, when its partial body is not in the installed state.
[0011] In FIGS. 1 to 4, the same parts or functionally equivalent
parts are always designated with the same reference numerals. Even
if certain features of the wall ring according to the invention or
of its components that have been described and/or that can be
derived from the drawings are only described in conjunction with
one embodiment, the features are nevertheless also essential
according to the invention, irrespective of said embodiment, either
as an individual feature or else in combination with other features
of the embodiment, and are construed as belonging to the
invention.
[0012] As shown in the figures, a wall ring according to the
invention consists of an annular body 1 having a central
longitudinal axis X-X, with a flow inlet opening 2 and with a flow
outlet opening 3. The annular body 1 according to the invention has
a ring wall 4 that is situated between the two openings 2, 3 and
that has a circular cross section that is perpendicular relative to
the central axis X-X. In the embodiment shown, there is an axial
fan 6 inside the wall ring according to the invention. This axial
fan 6 consists of an electric motor 7, which is arranged centrally
in the central longitudinal axis X-X and to which an impeller 8
with fan blades 9 is connected.
[0013] According to the invention, the ring wall 4 consists of an
outer wall 11 and an inner wall 12 that enclose a hollow space 13
between them.
[0014] As can be seen especially in FIGS. 2 and 3, the annular body
1 according to the invention is subdivided by means of a division
perpendicular to the central longitudinal axis X-X into two partial
bodies 14, 16, namely, a partial body 14 that encompasses the flow
outlet opening 2, and a partial body 16 that encompasses the flow
outlet opening 3. Since the division is perpendicular to the
longitudinal axis X-X, these two partial bodies 14, 16 can be
axially joined together and axially moved apart from each other.
The annular body 1 according to the invention is made of plastic.
Owing to the configuration of the hollow space in the ring wall 4
and owing to the use of plastic as the material, the annular body 1
already has a thermally insulating effect since, on the one hand,
condensation and frost occur on a plastic surface to a lesser
degree than on a metal surface and, on the other hand, the hollow
space 13 has a thermally insulating effect.
[0015] As can be seen especially in FIG. 3, the outer wall 11 and
the inner wall 12 of the two partial bodies 14, 16 have
complementary stepped profiles 22, 23 on their outer wall sections
17, 18 as well as on their inner wall sections 19, 21 at their
abutting ends, so that there is overlapping in the area of the
stepped profiles 22, 23. In this manner, a seal is created between
the outer wall sections 17, 18 and the inner wall sections 19, 21
in the area of their abutting ends, and a mutual positional
fixation is likewise created. The outer wall sections 17, 18 and
the inner wall sections 19, 21 of the partial bodies 14, 16 are
each of different lengths so that the outer wall sections 17, 18
have different lengths and the inner wall sections 19, 21 likewise
have different lengths, namely, in such a way that a longer outer
wall section 17 is opposite from a shorter inner wall section 19,
while the shorter outer wall section 18 is opposite from a longer
inner wall section 21. As can be seen especially in FIG. 3, it is
advantageous according to the invention for the inner wall 12 to
have a convex curvature, so that a flow profile is created, whereby
in the apex of the curvature, a very small rise in the curvature is
formed at both sides of the apex. The outer wall 11 is
advantageously made as a flat wall profile running parallel to the
longitudinal axis X-X. As can also be seen from FIGS. 2, 3 and 4,
it can be provided according to the invention that, inside the
hollow space 13, there is an electric heating element 24 that, in
the embodiment shown here, is configured as a heating tape, whereby
it is advantageously an electric resistance heating element. The
electric heating element 24 is arranged in such a way that it is in
contact with the inside of the inner wall 12 facing the hollow
space 13.
[0016] Advantageously, in the transition area between the outer
wall section 17 and the inner wall section 19, and especially
between the outer wall section 18 and the inner wall section 21,
that is to say, at least on one of the partial bodies 14, 16,
advantageously on both of the partial bodies 14, 16, there are
fastening journals 26 that run axially parallel to the longitudinal
axis X-X, that are arranged along the circumference, and that,
together with the appertaining inner wall section 19, enclose a gap
whose width is greater than or equal to the thickness of the
heating element 24 that is to be used. Here, when the two partial
bodies 14, 16 are in the installed state, their fastening journals
26 are arranged along the circumference so as to be offset relative
to each other, and their length is advantageously greater than the
width of the especially tape-like heating element 24. In order for
the tape-like heating element 24 to be installed, it is slipped
under the fastening journals 26 which then affix them axially and
circumferentially. For this purpose, it is particularly
advantageous for the fastening journals 26 to overlap the heating
element 24 on both sides on its lengthwise edges that run
circumferentially.
[0017] The two partial bodies 14, 16 are advantageously removably
joined to each other by means of several screws 27 that are
arranged along the circumference and that run axially in the
direction of the longitudinal axis X-X. Moreover, it is
advantageous according to the invention for a circumferential
mounting flange 28 to be shaped onto one of the partial bodies 14,
16, in the present embodiment onto the partial body 14 that
encompasses the inlet opening 2. This mounting flange 28 is formed
by an edge web projecting radially relative to the longitudinal
axis X-X. On this mounting flange 28, there are preferably four
fastening tabs 29 that are uniformly distributed on the
circumference and that have holes through which the corresponding
fastening elements can be inserted. The electric motor 7 is held by
means of a preferably flat protective wire grill 31, especially
made of metal, whereby the protective wire grill 31 is attached by
means of struts 32 to the partial body 14 on the circumference of
the flow inlet opening 2.
[0018] In the embodiment shown, a rectangular housing 33 is shaped
onto the annular body 1 between two fastening tabs 29, and said
housing 33 is made up of two housing sections 34, 35, whereby the
one housing section 34 is shaped onto the partial body 14 while the
other housing section 35 is shaped onto the partial body 16.
[0019] The housing 33 has a side wall section that runs parallel to
a tangent on the flow inlet opening 2 or on the flow outlet opening
3 and that is joined to the appertaining partial bodies 14, 16 via
wall sections that run perpendicular to the side wall section. On
the one hand, the electric connection line 37 of the electric motor
7 passes through the housing 33 from the partial body 14 or from
the housing section 34 to the outside, namely, via drilled holes in
the partial body 16 or in the housing section 35, preferably
parallel to the longitudinal axis X-X that first runs along the
protective grill 31, and on the other hand, the housing 33 serves
to establish the contact of the electric heating element 24 to an
electric power line 38 that is inserted into the housing 33
parallel to the longitudinal axis X-X. The housing 33 is closed by
means of screw elements that are screwed in from the back, that is
to say, from the side where the flow outlet opening 3 is located.
The screwing in of the fastening screws 27 takes place in the same
manner.
[0020] According to the invention, it can also be advantageous if a
covering cap 39 in the center of the protective grill 31 is
attached to the electric motor 7 through an opening in the
protective grill 31, said covering cap 39 serving as protection
against splashing water during a cleaning procedure. In particular,
this cover 39 is preferably removably attached by means of a
latched connection.
[0021] The two-part wall ring according to the invention, which is
made of plastic and which has an integrated hollow chamber, reduces
the tendency to ice formation in fans that are installed in cooling
equipment and evaporators, it also reduces the heat input into the
heat exchanger, and ice formation is prevented by means of the
heating element 24, which can also be installed subsequently. The
metal protective grill 31 which, according to the invention, is not
curved, that is to say, it is flat, can also be easily cleaned
mechanically if ice formation occurs.
[0022] The invention is not limited to the embodiments shown and
described, but rather, it encompasses all embodiments that have the
same effect as set forth in the invention. Moreover, the invention
is not yet limited to the feature combinations defined in the
claims, but rather, it can also be defined by any other desired
combination of certain features among all of the individual
features altogether disclosed. This means that fundamentally
speaking, practically any individual feature of the independent
claims can be left out or replaced by at least one individual
feature disclosed in another place in the application.
Consequently, the claims are only to be understood as an initial
attempt at formulating an invention.
LIST OF REFERENCE NUMERALS
[0023] 1 annular body [0024] 2 flow inlet opening [0025] 3 flow
outlet opening [0026] 4 ring wall [0027] 6 axial fan [0028] 7
electric motor [0029] 8 impeller [0030] 9 fan blade [0031] 11 outer
wall [0032] 12 inner wall [0033] 13 hollow space [0034] 14 partial
body [0035] 16 partial body [0036] 17 outer wall section [0037] 18
outer wall section [0038] 19 inner wall section [0039] 21 inner
wall section [0040] 22 stepped profile [0041] 23 stepped profile
[0042] 24 heating element [0043] 25 fastening journal [0044] 27
fastening screws [0045] 28 mounting flange [0046] 29 fastening tab
[0047] 31 protective wire grill [0048] 32 strut [0049] 33 housing
[0050] 34 housing section [0051] 35 housing section [0052] 37
electric connection line [0053] 38 power line [0054] 39 covering
cap [0055] X-X central longitudinal axis
* * * * *