Drying and gas or vapor contact with solids – Apparatus – Rotary drums or receptacles
Reexamination Certificate
2002-08-12
2003-09-16
Esquivel, Denise L. (Department: 3749)
Drying and gas or vapor contact with solids
Apparatus
Rotary drums or receptacles
C034S138000, C034S139000
Reexamination Certificate
active
06618958
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a laundry dryer, and more particularly, to a laundry dryer and a rear plate for a drum thereof enabling to apply a rear plate of a drum to an electric laundry dryer and a gas type laundry dryer in common.
2. Discussion of the Background Art
Generally, a laundry dryer is installed separately from a washer so as to dry wet laundry automatically after completion of washing.
An example of such a laundry dryer is schematically illustrated in
FIG. 1
, and a background art laundry dryer is explained by referring to
FIG. 1
as follows.
Referring to
FIG. 1
, an opening
1
a
is formed at a front of a case
1
so as to put in or remove laundry, and the opening is closed or opened by a door
2
.
A drum
30
in which inputted laundry is dried is rotatively installed inside the case
1
, and a driving motor
4
generating a turning force is installed at a lower part of the drum
30
. A pulley
5
and a belt
6
are connected between the driving motor
4
and drum
30
so as to transfer turning power to the drum
30
.
The drum
30
includes a cylindrical drum body
31
of which both sides are open, a front plate
33
coupled with a front portion of the drum body
31
and having a laundry input opening
33
b
at a central portion, and a rear plate
35
coupled with a rear portion of the drum body
31
.
An inlet hole
35
a
is formed at the rear plate
35
of the drum
30
, and an inlet duct
10
guiding external air inside the drum
30
is coupled with the inlet hole
35
a
. A heater
8
is installed at an entrance of the inlet duct
10
so as to heat the air introduced through an air intake lb of the case
1
into hot and dry air.
An outlet hole
33
a
is formed at the front plate
33
, and an outlet duct
9
guiding air discharged from the drum
30
to the outside is coupled with the outlet hole
33
a
. A blow fan
7
driven by the driving motor
4
is installed inside the outlet duct
9
so as to make the air in the drum
30
flow forcibly.
Numerals ‘C’ and ‘F’ in
FIG. 1
indicate a laundry and a filter, respectively.
Operation of the laundry dryer according to the background art is carried out as follows.
A user opens the door
2
, puts wet laundry C and the like inside the drum
30
through the opening
1
a
, and then pushes a start button to actuate the driving motor
4
so that the driving motor
4
rotates to generate a turning force. The turning force of the driving motor
4
is then transferred to the drum
30
through the pulley
5
and belt
6
so as to rotate the body
31
of the drum
30
. Hence, the laundry C inside the drum
30
is mixed.
Simultaneously, the blow fan
7
is actuated to rotate so as to make the external air flow into the drum
30
through the inlet duct
10
and inlet hole
35
a
. In this case, the suctioned air is heated by the heater
8
and changed into a very dry and hot air having very low humidity. The drum is supplied with the dry and hot air to dry the laundry C inside the drum
30
.
Moreover, the dry air inside the drum
30
comes into contact with the wet laundry to remove the humidity from the laundry, and then is discharged outside the case
1
through the outlet duct
9
. In this case, the filter F removes pile, waste thread, and the like from the discharge air.
Drying performance of such a laundry dryer depends mostly on the active contact between the wet laundry C and the dry air flowing inside the drum
30
. Various study and research teaches that a factor having the biggest influence on a flow of the dry air passing through the drum
30
is the position and shape of the inlet hole
35
a
formed at the rear plate
35
.
The position of the inlet hole
35
a
formed at the rear plate
35
according to the background art and a structure of the inlet duct
10
connected to the inlet hole
35
are explained by referring to FIG.
2
and
FIG. 3
as follows.
Referring to
FIG. 2
, the rear plate
35
has a disk shape, and the inlet hole
35
a
is formed at a left upper position of the rear plate
35
.
Referring to
FIG. 3
, the inlet duct
10
is constructed with a pair of plates
11
and
12
assembled with each other so as to form a path for the dry air. An entrance
11
c
is formed at a lower portion of the inlet duct
10
to make hot air flow in by being coupled with the heater
8
, and a plurality of duct holes
11
a
are formed at an upper portion of the inlet duct
10
to correspond to the inlet hole
35
a
of the rear plate
35
.
A total open area of the duct holes
11
a
is generally formed to cover about 40% of the open area of the inlet hole
35
A.
When the inlet hole
35
a
is formed at the upper position of the rear plate
35
, as shown in
FIG. 4
, the air drawn inside the drum
30
tends to flow in a direction having a least airflow resistance and the wet laundry tends to be distributed at a lower part of the drum. Hence, the air drawn inside the drum
30
flows as having a speed component preponderating toward about 45° upper side for the rotating axis of the drum
30
.
Accordingly, the hot and dry air drawn inside the drum
30
fails to be contacted with the wet laundry C actively so as to be discharged through the outlet duct
9
. Thus, the laundry drying time increases and energy efficiency decreases.
The inlet hole
35
a
in the laundry dryer according to the background art is positioned at the upper portion of the rear plate
35
, thereby becoming disadvantageous with regard to drying performance.
In spite of such disadvantages, the reason why the inlet hole
35
a
is designed to be located at the upper portion of the rear plate
35
is as follows.
Generally, laundry dryers are divided into an electrical laundry dryer and a gas type laundry dryer in accordance with the form of using the heater
8
. The electrical laundry dryer includes an electric hot wire for heating air, while the gas type laundry dryer includes a nozzle jetting a gas so that the air is heated in a manner that the jetted gas reacts with suctioned air for combustion.
Specifically, the gas type laundry dryer should secure at least a predetermined length of the inlet duct
10
for the characteristics of combustion. If the sufficient length of the inlet duct
10
fails to be secured, a flame reaches the inside of the drum
30
so as to cause damage on the laundry C or set it on fire.
For the above safety reasons, the gas type laundry dryer, as shown in
FIG. 4
, should form the inlet hole
35
A at the upper portion of the rear plate
35
. Yet, the electrical laundry dryer does not need the long combustion section like the gas type, so therefore the length of the inlet duct
10
can be shortened and the inlet hole
35
a
is installed at the lower portion of the rear plate
35
. Hence, the electrical laundry dryer enables to improve the drying performance.
As mentioned through
FIG. 1
to
FIG. 4
, when the positions of the inlet holes
35
a
of the electrical and gas type laundry dryers are set up at the upper portions of the rear plates
35
, the same rear plate shown in
FIG. 2
can be used regardless of the species of the laundry dryers. Besides, the inlet ducts
10
having different shapes in part are used only case by case. Namely, the inlet duct
10
can be used for both the electrical and gas type laundry dryers. Nevertheless, a vent
11
b
(as a plurality of air paths), as shown in
FIG. 3
, is added to the inlet duct
10
to dilute the burnt air.
When the inlet hole
35
a
is formed equivalently at the upper portion of the rear plate
35
, the inlet duct
10
manufactured differently in accordance with the electrical or gas type can be assembled with the same rear plate
35
by the same assembly process so as to reduce a product cost of the laundry dryer. As such, it is impossible to increase the drying performance of the electrical laundry dryer any more.
On the contrary, if the position of the inlet hole
35
a
is adjusted to fit the characteristics of the electrical or gas type laundry dryer, the product cost of the laundry dryer increases.
Namely, if the inlet hole
Hong Sang-Wook
Myung Hwan-Joo
Song Sung-Bae
Yoon Sang-Heon
Esquivel Denise L.
LG Electronics Inc.
Ragonese Andrea M.
LandOfFree
Laundry dryer and rear plate for drum thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Laundry dryer and rear plate for drum thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Laundry dryer and rear plate for drum thereof will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3037254