WO2004109003A1

WO2004109003A1 - Drying system with waste heat recovery apparatus

Info

Publication number: WO2004109003A1
Application number: PCT/KR2004/001389
Authority: WO
Inventors: Nyeon-Mook Choi
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-06-10
Filing date: 2004-06-10
Publication date: 2004-12-16
Anticipated expiration: 2005-12-10
Also published as: KR200326329Y1

Abstract

The present invention relates to a drying system in which a waste heat recovery apparatus provided with a pipe type heat exchanger is disposed between a plurality of chambers of a first dryer and an exhaust fan connected to the chambers. Introduced ambient air is preheated with heat retained by gas exhausted from the first dryer by means of the waste recovery apparatus and the preheated air is then supplied to the first dryer or a second dryer. Thus, an excellent saving effect can be reliably obtained in view of time and thermal energy efficiency due to reduction in drying time and fuel consumption. Since the present invention employs the pipe type heat exchanger, accumulated condensed-contaminants can be easily removed by an automatic cleaning device contrary to other plate-shaped or curved heat exchangers, thereby minimizing degradation of its performance. Further, since the removal of the contaminants can be automatically executed, use convenience can be achieved and it is easy to manage, maintain and repair the heat exchanger without a need for disassembling the heat exchanger to clean the heat exchanger.

Description

DRYING SYSTEM WITH WASTE HEAT RECOVERY APPARATUS

Technical field The present invention relates to a drying system employing a waste heat recovery apparatus, and more particularly, to a drying system provided with a waste heat recovery apparatus, wherein ambient cool air is preheated through an operation of a pipe type heat exchanger using heat retained by exhausted gas from a first dryer and the preheated air is then supplied to the first dryer or a second dryer to recover and circulate waste gas, whereby an excellent saving effect can be reliably obtained in view of time and thermal energy efficiency.

Background Art

Generally, when textile fabrics are processed, a drying process is required. Such a drying process is performed by using a conventional drying system shown in Fig. 5. In the dryer 10' provided with a plurality of drying chambers such as ovens, processing materials, i.e. textile fabrics, are introduced into the dryer and pass through the plurality of drying chambers, the introduced materials are dried by high-temperature air, and the dried materials are discharged from the dryer. At this time, the high-temperature air which has been used in the drying process is contaminated and forcibly exhausted to the exterior of the dryer 10' by an exhaust fan 20' connected to the drying chambers, while fresh air is continuously supplied to the dryer 10'. The contaminated gas is forcibly exhausted at a temperature of about 110 to 220 ^°C, wherein the exhausted gas has heat of 80 to 95% of input heat required for performing the drying process. Meanwhile, a waste gas re-treatment apparatus for recovering waste gas and recycling the recovered waste gas was issued to the present inventor as Korean Patent No. 30094 on May 15, 2002.

In this waste gas re-treatment apparatus, the exhausted high-temperature air is heat-exchanged with supplied cool air through a first waste heat-recovery unit. A temperature control unit is provided for removing a condensate generated when the hot air and the cool air are encountered with each other. Further, a second waste heat-recovery unit is provided for controlling the temperature control unit.

However, the conventional waste gas re-treatment apparatus has a disadvantage in that since the plurality of heat exchangers are used, the structure of the apparatus is complicated, and the air is condensed in an inlet and an outlet of a processing chamber due to temperature difference between the hot interior of the processing chamber and cool external air so that a condensate generated by the condensation comes into contact with a cleaning solution, resulting in poor processing.

Disclosure of Invention

Accordingly, the present invention is conceived to solve the aforementioned problems. An object of the present invention is to provide a drying system, wherein introduced ambient air is preheated with heat retained by gas exhausted from a first dryer by means of a waste recovery apparatus having a pipe type heat exchanger and the preheated air is then supplied to the first dryer or a second dryer, so that an excellent saving effect can be reliably obtained in view of time and thermal energy efficiency due to reduction in drying time and fuel consumption, contaminants can be easily removed, and degradation of a heat recovery efficiency can be prevented, thereby eventually reducing production costs of processing materials. In order to achieve the above object, the present invention has a structure in which a waste heat recovery apparatus provided with a pipe type heat exchanger is disposed between a plurality of chambers constituting a dryer and an exhaust fan connected to the chambers. That is, the present invention provides a drying system including a first dryer having a plurality of drying chambers, and an exhaust fan connected to the drying chambers for forcibly exhausting high-temperature contaminated gas, which has been generated after drying of introduced materials through application of heat thereto, from the drying chambers, wherein a waste heat recovery apparatus provided with a pipe type heat exchanger is further disposed between the first dryer and the exhaust fan.

As described above, since the present invention employs the pipe type heat exchanger, accumulated condensed-contaminants can be easily removed by an automatic cleaning device contrary to other plate-shaped or curved heat exchangers, thereby minimizing degradation of its performance. Further, since the removal of the contaminants can be automatically executed, use convenience can be achieved and it is easy to manage, maintain and repair the heat exchanger due to the absence of a need for disassembling the heat exchanger to clean the heat exchanger.

According to the present invention, the waste heat recovery apparatus may comprise a housing having an inlet port and an outlet port through which the high- temperature exhausted gas from the first dryer is introduced and the exhausted gas is discharged, respectively, at front and rear ends thereof and a penetration hole through which cool air is introduced from and discharged to the ambient at both lateral sides thereof; the pipe type heat exchanger accommodated across the penetration hole within the housing; and a filtering means for removing foreign substances contained in the air introduced into the pipe type heat exchanger.

The filtering means may comprise a first filter disposed between the inlet port and the pipe type heat exchanger for removing solid substances from the exhausted gas; a second filter disposed between the pipe type heat exchanger and the outlet port for removing condensed mist of the gas which is heat-exchanged with the cool air; an air filter provided at the penetration hole through which the ambient air is introduced; and a cleaning device for cleaning the interiors of the pipes in the pipe type heat exchanger. The cleaning device may comprise a hollow cross bar having a plurality of nozzles; a linear-movement guide means for vertically moving the cross bar; and a motor for driving the linear-movement guide means.

Brief Description of Drawings Fig. la is a view schematically showing the configuration of a drying system according to the present invention.

Fig. 2 is a side view of a waste heat recovery apparatus employed in the present invention.

Fig. 3 is a plan view of Fig. 2. Fig. 4 is an explanatory view illustrating an operation principle of the waste heat recovery apparatus.

Fig. 5 is a diagram schematically showing a conventional waste heat recovery apparatus.

1 : Pipe type heat exchanger 2: First filter

3: Second filter 4: Cleaning device

5 : Air filter 6: Inlet port 7: Outlet port 8: Penetration hole

9: Housing 10: First dryer

20: Exhaust fan 30: Waste heat recovery apparatus

40: Air supplying fan 50: Bypass damper

60: Second dryer

Best Mode for Carrying out the Invention

Hereinafter, the present invention will be described in detail with reference to accompanying drawings.

Fig. la is a view schematically showing the configuration of a drying system according to the present invention. As shown in Fig. 1, the drying system of the present invention comprises a first dryer 10 having a plurality of drying chambers; and an exhaust fan 20 connected to the drying chambers for forcibly exhausting high-temperature contaminated gas, which is generated after drying of introduced materials through application of heat thereto, from the drying chambers. In addition, a waste heat recovery apparatus 30 provided with a pipe type heat exchanger 1 is disposed between the first dryer

10 and the exhaust fan 20. The drying system of the present invention further comprises an air supplying fan 40 for supplying the first dryer 10 or a second dryer 60 with preheated air flowing from the waste heat recovery apparatus 30, and a bypass damper 50 acting as a switch for enabling the preheated air to be selectively supplied to the first dryer 10 or second dryer 60. Figs. 2 and 3 are a side view and a plan view of the waste heat recovery apparatus employed in the present invention, respectively. The waste heat recovery apparatus 30 comprises a housing 9 having an inlet port 6 and an outlet port 7 through which high- temperature exhausted gas from the first dryer 10 is introduced and the exhausted gas is discharged, respectively, at front and rear ends thereof, and a penetration hole 8 through which cool air is introduced from and discharged to the ambient at both lateral sides thereof; the pipe type heat exchanger 1 disposed across the penetration hole 8 within the housing 9 and having a plurality of pipes stacked in the form of a matrix for preheating the cool air passing across sides of the pipes using heat retained by the exhausted gas flowing through the pipes; a first filter 2 disposed between the inlet port 6 and the pipe type heat exchanger 1 for removing any solid substances which may be entrained by the contaminated gas and introduced into the housing; a second filter 3 disposed between the pipe type heat exchanger 1 and the outlet port 7 for removing condensed mist of the gas which is heat-exchanged with the cool air; and an air filter 5 provided at the penetration hole 8 through which the ambient air is introduced.

Further, the waste heat recovery apparatus 30 may be provided with a cleaning device 4 that is positioned upstream of the pipe type heat exchanger 1 and injects a cleaning solution under high pressure for removing contaminants deposited on the interior of the pipe type heat exchanger 1. The cleaning device 4 comprises a hollow cross bar having a feed nut and a plurality of nozzles, a linear-movement guide means threadably engaged with the feed nut to vertically move the cross bar, and a motor for driving the linear-movement guide means. The cleaning solution is injected from the nozzles mounted to the cross bar which has moved to a certain level by the linear-movement guide means, so that the cleaning solution cleans the interiors of the pipes arranged in one horizontal row. Here, the means for vertically moving the horizontal stand is not limited to the feed nut and the linear-movement guide means threadably engaged with the feed nut, but may comprise, for example, a linearly moving bearing, or a chain and a sprocket.

The operation of the drying system with the waste heat recovery apparatus according to the present constructed as above will be described. As described above, in the plurality of drying chambers of the first dryer 10, introduced processing materials are dried through application of heat thereto and then discharged from the drying chambers. The high-temperature contaminated gas created in the drying chambers is forcibly discharged toward the waste heat recovery apparatus 30 by the exhaust fan 20 connected to the drying chambers, so that the high-temperature contaminated gas is sent to the inlet port 6 of the waste heat recovery apparatus 30. At this time, the high-temperature contaminated gas passes through the first filter 2 so that solid substances contained in the gas are filtered out and removed.

Then, as shown in the explanatory view of Fig. 4, while the exhausted gas that has passed through the inlet port 6 and the first filter 2 passes through the pipes stacked in the form of the matrix in the pipe type heat exchanger 1 and proceeds to the outlet port 7, the exhausted gas preheats the cool air that is introduced into the housing 9 of the waste recovery apparatus 30 through the penetration hole 8 and the air filter 5 and then passes across sides of the pipes.

Here, since each of the stacked pipes in the pipe type heat exchanger 1 is formed to take the shape of a cylindrical hollow pipe, the residual contaminants which have not been filtered out after passing through the first filter 2 can hardly adhere to inner surfaces of the pipes, whereby it is easy to clean the interiors of the pipes.

Further, in the pipe type heat exchanger 1, air can be more smoothly introduced since a flow resistance between the pipes and air passing across the pipes is reduced. Next, while the gas which has passed through the pipe type heat exchanger 1 and has been heat-exchanged with external cool air passes through the second filter 3, condensed mist of the gas is removed, and the gas is exhausted from the waste heat recovery apparatus 30 through the outlet 7 and then discharged toward the exterior of the system by the exhaust fan 20. Meanwhile, the high-temperature air preheated in the waste heat recovery apparatus 30 can be supplied to the first dryer 10 or second dryer 60 by the exhaust fan 40, and a flow path of the preheated air can be changed by the bypass damper 50 so that the preheated air can be selectively supplied to the first dryer 10 or second dryer 60.

After the drying process is completed in such a manner, a cleaning process is performed to clean the interior of the heat exchanger. The cleaning process is more easily performed due to the tubular pipes.

It will be apparent to those skilled in the art that the present invention is not limited to the embodiment described above and illustrated in the accompanying drawings but can be variously modified and changed within the technical spirit and scope of the present invention. For example, the number, positions, orientations and the like of parts employed in the present invention can be changed according to its application.

Industrial Applicability According to the present invention described above, introduced ambient air is preheated with heat retained by gas exhausted from the first dryer by means of the waste recovery apparatus and the preheated hot air is then supplied to the first dryer or second dryer, so that an excellent saving effect can be reliably obtained in view of time and thermal energy efficiency due to reduction in drying time and fuel consumption, thereby eventually reducing production costs of processing materials.

Further, since the condensed contaminants is automatically and easily removed by using the pipe type heat exchanger, the present invention is an advantage in that an initial condition of the drying system can be maintained even though the system has been used for a long time, thereby obtaining the energy saving effect. Moreover, since foreign substances are filtered out through the filters provided in the housing, it is possible to prevent the foreign substances from being introduced into the interiors of the drying chambers. Thus, a clean environment can be maintained within the drying chambers and the drying quality of products can be enhanced. Since the cleaning device for cleaning the pipes in the pipe type heat exchanger is provided, a use environment can be maintained in a hygienic state.

Furthermore, since the cleaning device is provided in the heat exchanger, there is no need for disassembling the heat exchanger to remove the contaminants deposited on the heat exchanger. Thus, it is easy to manage, maintain and repair the heat exchanger.

In addition, since the tubular pipes are used in the heat exchanger, the residual contaminants contained in the exhaust gas can hardly adhere on inner surfaces of the pipes, so that it is easier to clean and manage the pipes. Since a flow resistance between the pipes and air flowing across the heat exchanger is reduced, the amount of air to be introduced into the drying chambers is increased.

Claims

1. A drying system including a first dryer having a plurality of drying chambers, and an exhaust fan connected to the drying chambers for forcibly exhausting high-temperature contaminated gas from the drying chambers, the gas being generated after drying of introduced materials through application of heat thereto, wherein: a waste heat recovery apparatus provided with a pipe type heat exchanger is disposed between the first dryer and the exhaust fan.

2. The drying system as claimed in claim 1, wherein the waste heat recovery apparatus comprises: a housing having an inlet port and an outlet port through which the high- temperature exhausted gas from the first dryer is introduced and the exhausted gas is discharged, respectively, and a penetration hole through which cool air is introduced from and discharged to the ambient; the pipe type heat exchanger disposed across the penetration hole within the housing to preheat the cool air passing across sides of the pipes using heat retained by the exhausted gas flowing through the pipes; and a filtering means for removing foreign substances contained in the air introduced into the pipe type heat exchanger.

3. The drying system as claimed in claim 2, wherein the filtering means comprises: a first filter disposed between the inlet port and the pipe type heat exchanger for removing solid substances which may be entrained by the exhausted gas and introduced into the housing; a second filter disposed between the pipe type heat exchanger and the outlet port for removing condensed mist of the gas which is heat-exchanged with the cool air; an air filter provided at the penetration hole through which the ambient air is introduced; and a cleaning device for cleaning the interiors of the pipes in the pipe type heat exchanger.

4. The drying system as claimed in claim 3, wherein the cleaning device comprises: a hollow cross bar having a feed nut and a plurality of nozzles; a linear-movement guide means threadably engaged with the feed nut to vertically move the cross bar; and a motor for rotatably driving the linear-movement guide means.

5. The drying system as claimed in claim 1, further comprising an air supplying fan for supplying the first dryer or a second dryer with the preheated air flowing from the waste heat recovery apparatus, and a bypass damper for enabling selection of a flow path of the preheated air.