U.S. patent application number 12/798532 was filed with the patent office on 2010-10-21 for heat exchanger.
Invention is credited to Yoshiyasu Fujiwara.
Application Number | 20100263845 12/798532 |
Document ID | / |
Family ID | 42341403 |
Filed Date | 2010-10-21 |
United States Patent
Application |
20100263845 |
Kind Code |
A1 |
Fujiwara; Yoshiyasu |
October 21, 2010 |
Heat exchanger
Abstract
A heat exchanger is provided in which steam locking is prevent
and which allows steam condensate generated in heat transfer tubes
to quickly flow down into a condensate outlet chamber. The heat
exchanger includes a shell (1) in which a plurality of heat
transfer tubes (5) are disposed. The shell (1) has an inlet (2) for
fluid to be heated through which fluid to be heated flows in and an
outlet (3) for heated fluid through which heated fluid flows out.
The heat transfer tubes (5) are penetratingly fixed, at their ends,
to a tube plate (7). The tube plate (7) has an end face covered by
partition chamber cases (8) and (9) provided with a top steam inlet
(10) through which steam flows in and a bottom condensate outlet
(11) through which condensate flows out. The tube plate (7) and the
partition chamber cases (8) and (9) form, between them, a partition
chamber having a partition plate (14) partitioning the partition
chamber into a steam inlet chamber (12) having the steam inlet (10)
and a condensate outlet chamber (13) having the condensate outlet
(11). The partition plate (14) has an opening (15) through which
the steam inlet chamber (12) and the condensate outlet chamber (13)
are communicated with each other, and a steam trap (16) for
draining steam condensate from the steam inlet chamber (12) into
the condensate outlet chamber (13) is connected to the opening (15)
of the partition plate (14).
Inventors: |
Fujiwara; Yoshiyasu;
(Hyogo-ken, JP) |
Correspondence
Address: |
KENYON & KENYON LLP
ONE BROADWAY
NEW YORK
NY
10004
US
|
Family ID: |
42341403 |
Appl. No.: |
12/798532 |
Filed: |
April 5, 2010 |
Current U.S.
Class: |
165/157 |
Current CPC
Class: |
F28D 7/06 20130101; F28B
1/02 20130101; F28B 9/08 20130101 |
Class at
Publication: |
165/157 |
International
Class: |
F28D 21/00 20060101
F28D021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 15, 2009 |
JP |
2009-99386 |
Claims
1. A heat exchanger including a shell in which a plurality of heat
transfer tubes are disposed, the shell having an inlet for fluid to
be heated through which fluid to be heated flows in and an outlet
for heated fluid through which heated fluid flows out, the heat
transfer tubes being penetratingly fixed at their ends to a tube
plate, the tube plate having an end face covered by a partition
chamber case provided, in an upper part thereof, with a steam inlet
through which steam flows in and, in a lower part thereof, with a
condensate outlet through which condensate flows out, the tube
plate and the partition chamber case forming, between them, a
partition chamber having a partition plate partitioning the
partition chamber into a steam inlet chamber having the steam inlet
and a condensate outlet chamber having the condensate outlet,
wherein the partition plate has an opening through which the steam
inlet chamber and the condensate outlet chamber are communicated
with each other and wherein a steam trap for draining steam
condensate from the steam inlet chamber into the condensate outlet
chamber is connected to the opening of the partition plate.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a heat exchanger for
exchanging heat between steam flowing as a heating fluid through
plural heat transfer tubes installed in the shell of the heat
exchanger and a fluid to be heated flowing outside the heat
transfer tubes in the shell.
BACKGROUND OF THE INVENTION
[0002] A known heat exchanger is described in JP-A No. H05-34084.
The heat exchanger has a shell which is provided with an inlet for
fluid to be heated and an outlet for heated fluid and which
includes plural heat transfer tubes installed therein. In the
shell, the heat transfer tubes are, at their ends, penetratingly
fixed to a tube plate. The tube plate has an outer face covered by
a partition chamber case having, in an upper part thereof, a steam
inlet through which steam flows in and, in a lower part thereof, a
condensate outlet through which condensate flows out. Thus, a
partition chamber is formed between the tube plate and the
partition chamber case. The partition chamber is partitioned by a
partition plate into a steam inlet chamber having the steam inlet
and a condensate outlet chamber having the condensate outlet.
Though not described in JP-A No. H05-34084, the partition plate has
a weep hole to allow steam condensate to flow down from the steam
inlet chamber into the condensate outlet chamber.
SUMMARY OF THE INVENTION
[0003] The known heat exchanger described above has a problem that,
when the amount of steam condensate in the steam inlet chamber is
small, steam leaks into the condensate outlet chamber via the weep
hole thereby causing steam locking to prevent the steam condensate
generated in the heat transfer tubes from flowing down into the
condensate outlet chamber.
[0004] It is an object of the present invention to provide a heat
exchanger which can prevent steam locking and allow condensate
generated in heat transfer tubes to flow down quickly into a
condensate outlet chamber.
[0005] To achieve the above object, the present invention provides
a heat exchanger including a shell in which a plurality of heat
transfer tubes are disposed. The shell has an inlet for fluid to be
heated through which fluid to be heated flows in and an outlet for
heated fluid through which heated fluid flows out. The heat
transfer tubes are penetratingly fixed at their ends to a tube
plate. The tube plate has an end face covered by a partition
chamber case provided, in an upper part thereof, with a steam inlet
through which steam flows in and, in a lower part thereof, with a
condensate outlet through which condensate flows out. The tube
plate and the partition chamber case form, between them, a
partition chamber having a partition plate partitioning the
partition chamber into a steam inlet chamber having the steam inlet
and a condensate outlet chamber having the condensate outlet. The
partition plate has an opening through which the steam inlet
chamber and the condensate outlet chamber are communicated with
each other, and a steam trap for draining steam condensate from the
steam inlet chamber into the condensate outlet chamber is connected
to the opening of the partition plate.
[0006] According to the present invention, a partition plate is
provided with an opening through which a steam inlet chamber and a
condensate outlet chamber are communication with each other, and a
steam trap for draining steam condensate from the steam inlet
chamber into the condensate outlet chamber is connected to the
opening of the partition plate, so that, when steam condensate
flows from the steam inlet chamber into the steam trap, the steam
trap opens its valve to allow the steam condensate to be discharged
into the condensate outlet chamber and so that, when steam flows
from the steam inlet chamber into the steam trap, the steam trap
closes its valve to prevent the steam from leaking out into the
condensate outlet chamber. Thus, steam locking is prevented, and
the steam condensate generated in heat transfer tubes is allowed to
quickly flow down into the condensate outlet chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a sectional view of a kettle-type reboiler
representing an embodiment of a heat exchanger according to the
present invention.
[0008] FIG. 2 is a section view of the steam trap shown in FIG.
1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0009] An embodiment of the present invention will be described
below with reference to FIGS. 1 and 2. An approximately cylindrical
shell 1 is provided: in a lower right part thereof as seen in FIG.
1, with an inlet 2 for fluid to be heated through which fluid to be
heated flows in; in an upper middle part thereof as seen in FIG. 1,
with an outlet 3 for heated/vaporized fluid through which
heated/vaporized fluid flows out; and, in a lower left part thereof
as seen in FIG. 1, with a blow port 4 through which
heated/nonvaporized fluid flows out. Plural heat transfer tubes 5
are installed in the shell 1 to extend along the longitudinal
direction of the shell 1. The heat transfer tubes 5 are U-shaped,
being curved in front of a weir 6. The ends opposite to the curved
portion of the heat transfer tubes 5 are penetratingly fixed to a
circular tube plate 7. The outer face of the tube plate 7 is
covered by partition chamber cases 8 and 9. The partition chamber
case 8 is provided, in an upper middle part thereof as seen in FIG.
1, with a steam inlet 10 through which steam flows in and, in a
lower middle part thereof as seen in FIG. 1, with a condensate
outlet 11 through which condensate flows out. The tube plate 7 and
the partition chamber cases 8 and 9 thus form a partition chamber
which is divided by a flat partition plate 14 into a steam inlet
chamber 12 having the steam inlet 10 and a condensate outlet
chamber 13 having the condensate outlet 11.
[0010] The partition plate 14 has an opening 15 through which the
steam inlet chamber 12 and the condensate outlet chamber 13 are
communicated with each other. A steam trap 16 for draining steam
condensate from the steam inlet chamber 12 into the condensate
outlet chamber 13 is fixedly welded to the partition plate 14 such
that the steam trap 16 is connected to the opening 15. Reference
numeral 17 in FIG. 1 represents plural baffle plates partitioning
the interior of the shell 1, across the longitudinal direction of
the shell 1, so as to regulate the flow of fluid to be heated.
Steam coming in the steam inlet chamber 12 through the steam inlet
10 is distributed to the heat transfer tubes 5 via the tube plate 7
and, while flowing through the heat transfer tubes 5, exchanges
heat with the fluid to be heated flowing, after coming in the shell
1 through the inlet 2 for fluid to be heated, outside the heat
transfer tubes 5. The steam condensate generated, as a result of
heat exchange, in the heat transfer tubes 5 flows down into the
condensate outlet chamber 13 to then flow out through the
condensate outlet 11. The fluid heated through heat exchange and
vaporized outside the heat transfer tubes 5 in the shell 1 flows
out through the outlet 3 for heated/vaporized fluid. The fluid
heated through heat exchange without being vaporized outside the
heat transfer tubes 5 in the shell 1 flows over the weir 6 and then
flows out through the blow port 4. The steam condensate is drained
from the steam inlet chamber 12 via the steam trap 16 into the
condensate outlet chamber 13 to then flow out through the
condensate outlet 11.
[0011] Even though the steam trap 16 connected to the opening 15 of
the partition plate 14 is a free-float steam trap as shown in FIG.
2, the present invention allows it to be of any other type, for
example, a lever float type, bucket type, bimetal type,
expansion/contraction type, or disc type. Referring to FIG. 2, the
free float steam trap 16 has a casing including a body 21 and a
cover 22 bolted to the body 21. A valve chamber 23 is formed in the
casing. The body 21 has, in an upper part thereof, an inlet 24 and,
in a lower part thereof, an outlet passage 25 and an outlet 26. The
inlet 24 is communicated with an upper part of the valve chamber
23. The inlet 24 is also communicated with the opening 15 of the
partition plate 14. A valve seat 29 having a valve orifice 27 is
screwed to a portion, making up a lower side wall of the valve
chamber 23, of the cover 22. The valve orifice 27 faces diagonally
downward. The cover 22 has an outlet passage 30. A lower part of
the valve chamber 23 is communicated with the outlet 26 via the
valve orifice 27 and the outlet passages 30 and 25.
[0012] In the valve chamber 23, a hollow spherical float 31 for
opening and closing the valve orifice 27 is disposed in a free
state. A fork-shaped float seat 32 against which the float 31 abuts
when positioned to close the valve orifice 27 is disposed below the
float 31. A bimetal 33 is disposed as a temperature-responsive
member in the valve chamber 23. The bimetal 33 has an approximately
U-shaped section and is fixed, at an end thereof, to the cover 22
with a screw 34. When subjected to a high temperature, the bimetal
33 is deformed to squeeze its sectional U-shape, so that it does
not interfere with the float 31. When subjected to a low
temperature, the bimetal 33 is deformed to widen its sectional
U-shape, so that it pushes the float 31 rightward, as seen in FIG.
2, to open the valve orifice 27. A cap-shaped filter 35 for
capturing foreign matter is fixed to the body 21 with a screw 36
such that the filter 35 is positioned upstream of the float 31 in
the valve chamber 23.
[0013] In the steam trap 16, when the temperature in the valve
chamber 23 is low, the bimetal 33 is deformed to widen its
sectional U-shape, thereby pushing the float 31 away and opening
the valve orifice 27. This causes the low-temperature air and
condensate flowing into the valve chamber 23 to be discharged
through the valve orifice 27 and the outlet 26 into the condensate
outlet chamber 13. When the low-temperature air and condensate is
discharged from the valve chamber 23 and the temperature of
condensate flowing into the valve chamber 23 rises, the bimetal 33
is deformed to squeeze its sectional U-shape not to interfere with
the float 31. When condensate flows into the valve chamber 23
causing the float 31 to be floated up and the valve orifice 27 to
be opened, the condensate is discharged through the valve orifice
27 and the outlet 26 into the condensate outlet chamber 13. When
steam flows into the valve chamber 23 causing the float 31 to
descend and the valve orifice 27 to be closed, the steam is
prevented from leaking out. In this way, steam locking is
prevented, and the condensate generated in the heat transfer tubes
5 is allowed to quickly flow down into the condensate outlet
chamber 13.
[0014] The heat exchanger according to the present invention can be
applied to, for example, kettle-type reboilers, feed-water heaters,
evaporators, and air-conditioners.
* * * * *