JP5990104B2 - Equipment for drying objects - Google Patents

Description

The present invention is an apparatus for drying an object, particularly a vehicle body,
a) a drying tunnel located in an insulated housing;
b) a plurality of tunnel sections each having at least one gas outlet and at least one gas inlet;
c) A heating unit is associated with each tunnel section, the heating unit being fed with gas from the at least one gas outlet and capable of forming a hot primary gas stream therein. ,
d) The primary gas stream can be introduced into a circulating gas heat exchanger of the heating unit, in which the circulating gas can be heated by the primary gas stream, It relates to a device that can be fed again into the tunnel section in the circuit by at least one gas inlet.

  Such dryers known commercially are used in particular for drying freshly painted car bodies, but also for drying other objects. This type of dryer is heated as follows. That is, gas (in other objects) is taken from a tunnel section that is shorter than the total length of the drying tunnel. Then, the gas is heated in a heating unit using a heat exchanger and supplied again to the corresponding tunnel section in the circulation path. When drying a freshly painted car body, the gas removed from the tunnel section contains primarily a solvent, which is released during the drying process. In addition, coating elements released during the car body drying process are also included in the gas. However, from the viewpoint of simplifying the description, only the gas containing the solvent or the exhaust will be described below.

  However, the exhaust containing the solvent is processed in a separate system, separate from the heating circuit. For this purpose, the exhaust containing the solvent to be treated is taken off at the central gas outlet of the drying tunnel and fed to a thermal or regenerative post-combustion process. In this step, the solvent is burned out. If required, the heat exchanger is placed downstream of the post-combustion unit. Here, in the heat exchanger, the outside air is heated by the generated combustion gas. This hot ambient air is then fed into the drying tunnel and consequently heated as well.

  However, the pipeline for leading the exhaust gas containing the solvent to the post-combustion process becomes very long. Since these pipelines require complex insulation, the resulting costs associated with the system as a whole are relatively high.

  Loss of energy also occurs because the hot, pure combustion gases are released through the exhaust pipe into a substantially unused environment (apart from the use of these combustion gases in the outdoor air heat exchanger) , Will become relatively large.

  The object of the present invention is therefore to provide a device of the type described above with a particularly improved energy balance.

In an apparatus of the type described above, this object is achieved by the following configuration. That is,
e) The heating unit has a distribution device, by which the gas flowing out from the tunnel section is divided into a circulating air flow and an exhaust flow,
f) The heating unit has a thermal post-combustion device, exhaust is supplied to the thermal post-combustion device, and a hot primary gas stream is formed by the thermal post-combustion device.

  Therefore, according to the present invention, the post-combustion step and the gas treatment step including the solvent thereby are incorporated in the heating unit, and only a part of the gas taken out from the tunnel section is transferred to the tunnel section as a circulating gas. It will be returned and supplied. At least a portion of the hot combustion gas forms a hot primary gas stream that is utilized to heat the circulating gas. As a result, the energy contained in the combustion gas is effectively used to heat the dryer.

  It is therefore possible to dispense with an external post-combustion step, which was a conventional method in commercially known systems. Thereby, on the one hand, the structural costs can be reduced and on the other hand the dryer structure can be made simpler. Thus, in addition to making the dryer space requirements smaller, the loss of heat can also be reduced.

  It has been found that it is practically preferable when the post-combustion device is a gas burner.

  Here, regarding the gas balance in the dryer, it is particularly preferred if the gas burner is operable without receiving a secondary gas supply. In this case, the hot primary gas stream consists only of hot combustion gas, and therefore the combustion gas will be fully and effectively used to heat the circulating gas.

  It is particularly preferred when the gas burner is a surface combustion burner. A surface combustion burner provides good combustion performance and does not require an exposed supply of gas.

  The heating unit has an exhaust heat exchanger, and exhaust is introduced into the exhaust heat exchanger, where the exhaust is heated by the hot primary gas before reaching the post-combustion device. The exhaust can be preheated before combustion. Thereby, the energy required for the burner for heating the gas containing the solvent from the initial temperature when it reaches the burner to the combustion temperature can be reduced.

  The amount of hot primary gas supplied to the exhaust heat exchanger is preferably adjusted by the first control flap. This makes it possible to adjust the degree to which the exhaust is heated in advance.

  If required, the first control flap is placed in the bypass line, through which hot primary gas is directed through the exhaust heat exchanger.

  When hot primary gas that has passed through the exhaust heat exchanger is supplied to the circulating gas heat exchanger, the hot combustion gas is utilized twice, which can be particularly effective. The combustion gas functions on the one hand to preheat the exhaust and on the other hand functions to heat the circulating gas.

  If the temperature of the hot primary gas leaving the exhaust heat exchanger is not sufficient to heat the circulating gas to the desired temperature, the hot primary gas is fed from the bypass line section to the circulating gas heat exchanger And it is advantageous if the section is arranged downstream of the first control flap. This makes it possible to supply the primary gas that has not yet been cooled (or only slightly) to the circulating gas heat exchanger.

  If the section of the bypass line is located between the first control flap and the second control flap, the position of the first control flap and the proportion of the primary gas flow that has passed through the exhaust heat exchanger The amount of primary gas for the circulating gas heat exchanger can be controlled by the second control flap without having to be changed.

  When the heating unit has an outside air heat exchanger, a high temperature primary gas is introduced into the outside air heat exchanger, and the outside air is heated by the high temperature primary gas in the outside air heat exchanger, the primary gas Alternatively, it can be further used to heat the outside air required for heating the dryer.

  When the heating unit has an outside air heat exchanger, and the high temperature primary gas that has passed through the exhaust heat exchanger and the circulating gas heat exchanger is introduced into the outside air heat exchanger, the primary gas is used three times. It becomes possible to do. As a modification, the high temperature primary gas supplied to the outside air heat exchanger may pass through only the outside air heat exchanger or only the circulating gas heat exchanger in advance.

  In order to be able to heat the outside air in a controlled manner, the outside air heat exchanger is supplied with hot primary gas from a section of the bypass line, which section is located downstream of the second control flap. In this case, it is advantageous.

  Hot outside air is supplied to an entrance gate region disposed at the entrance of the drying tunnel and / or an exit gate region disposed at the exit of the drying tunnel, from which hot outside air flows into the drying tunnel. To do.

FIG. 2 is a schematic layout diagram of a dryer with a drying tunnel having a plurality of tunnel sections, with a heating unit associated with each case. It is the figure which expanded the heating unit shown in FIG.

  Exemplary embodiments of the present invention are described in detail below with reference to the drawings.

  In FIG. 1, reference numeral 10 denotes a dryer as a whole, and the dryer 10 includes an insulated housing 12 in which a drying tunnel 14 is disposed. The drying tunnel 14 comprises a plurality of tunnel sections 16.1, 16.2,. n.

  The dryer 10 can be used in the basic concept of drying any type of object, but in particular is used to dry a freshly painted car body.

  The vehicle body is installed on a conveyor system (not shown), and is put into the dryer 10 from one end of the dryer 10. The vehicle body first reaches the entrance gate 18 and enters the drying tunnel 14 from there. The car body has tunnel sections 16.1, 16.2,. After passing through n, it finally exits the dryer 10 through the exit gate 20 in a dry state.

  Tunnel sections 16.1, 16.2,. Each of n includes a gas outlet 22 and a gas inlet 24.

  Furthermore, each heating unit 26 has a tunnel section 16.1, 16.2,. associated with each of n. Only the heating units 26 of the tunnel sections 16.1 and 16.2 are shown in FIG.

  Each tunnel section 16.1, 16.2,. n is heated by the heating unit 26, and via the respective gas inlets 24 in the circulation path, the corresponding tunnel sections 16.1, 16.2,. n can be re-fed. The re-supplied gas is guided onto the vehicle body to be dried through a nozzle (not shown).

  Thus, the tunnel sections 16.1, 16.2,. It is possible to maintain different temperatures in n, which is most preferred for the case-by-case drying process.

  The operating mode and configuration of the heating unit 26 will be described below with reference to the heating unit 26 associated with the tunnel section 16.1. The other heating units 26 are also configured according to this, and function in the same manner.

  When drying the vehicle body located in the tunnel section 16.1, the solvent is released into other substances, so that the atmosphere in the tunnel section 16.1 has a gas containing the solvent.

  The heating unit 26 has a vent 28 which is arranged in a line 30 connected to the gas outlet 22 of the tunnel section 16.1. Thereby, the gas containing a solvent can be taken out from the tunnel section 16.1. The gas containing the solvent is typically at a temperature in the range of about 140 ° C to about 220 ° C.

  The temperatures indicated in the following description relate to the drying process and the gas balance that normally occurs immediately when drying a car body coated by electrophoretic dip coating. Here, depending on the type of coating used, upward and downward fluctuations can occur.

  It should be inferred below that the gas containing the solvent in the tunnel section 16.1 is about 200 ° C.

  The line 30 extends downstream into the distribution device 32, and the distribution device 32 divides the extracted gas into an exhaust flow and a circulating air flow.

  The exhaust stream flows from the distributor 32 further through the line 34 into the heat exchanger chain 36 of the exhaust heat exchanger 38. From there, the exhaust stream flows into the combustion chamber 40 of the thermal afterburner 42 having a gas burner 44. This exhaust flow is illustrated by two arrows 46 and 48. In the exemplary embodiment described herein, the burner used as gas burner 44 is operable without receiving a secondary gas supply. In practice, surface combustion burners are known per se, but have proven effective in this application. However, it is also possible to use a fan burner that needs to supply gas in a known manner for operation.

  In the thermal post-combustion device 40, the solvent in the exhaust substantially burns while the hot combustion gas of about 700 ° C. is being generated as the primary gas. These hot combustion gases are guided by the supply line 50 to the exhaust heat exchanger 38. In the exhaust heat exchanger 38, the hot combustion gases heat the exhaust containing the solvent flowing in the heat exchanger chain 36 to a temperature of about 400 ° C. At this temperature, the exhaust containing the solvent flows into the combustion chamber 40 of the thermal post-combustion device 42.

  On the other hand, the high-temperature combustion gas is originally about 700 ° C., is cooled in the exhaust heat exchanger 38, and flows out of the exhaust heat exchanger 38 through the first intermediate line 52 at a temperature of about 450 ° C. .

  The combustion gas is guided into the circulating gas heat exchanger 54 by the intermediate line 52. The circulating gas is supplied by the distributor 32 to the circulating gas heat exchanger 54 via the line 56 and flows in the heat exchanger chain 56 of the circulating gas heat exchanger 54. The circulating gas flowing from the distributor 32 at a temperature of about 200 ° C. is heated to about 220 ° C. by the combustion gas, while the combustion gas is cooled to a temperature of about 450 ° C. to about 350 ° C.

  The hot circulating gas is at about 200 ° C. and flows from the heat exchanger chain 56 of the circulating gas heat exchanger 54 to a return line 58 leading to the gas inlet 24 of the tunnel section 16.1. From there, the gas returns to the car body to be dried.

  The hot combustion gas is about 350 ° C. at this stage and flows through the heating unit 26. The combustion gas flows from the circulating gas heat exchanger 54 into the outside air heat exchanger 62 through the intermediate line 60. In the outside air heat exchanger 62, the heat exchanger chain 64 is supplied with outside air through the outside air line 66 by the vent holes 68. The hot combustion gas flowing in the outside air heat exchanger 62 heats the outside air to about 200 ° C. in the heat exchanger chain 64, while the combustion gas is cooled to about 80 ° C.

  The high temperature outside air flows out from the outside air heat exchanger 62 through a line 70 connected to the inlet gate 18, and from there, the outside air flows into the drying tunnel 14. Each line 70 of the heating unit 26 that is placed in close proximity to the outlet gate 20 leads to the outlet gate 20 in a considerable manner. Thereby, high temperature outside air can flow into the drying tunnel 14 from there.

  The combustion gas cooled to about 80 ° C. is guided to the exhaust vent hole 76 through the capacitor separator 74 via the supply line 72. In this way, pure combustion gas reaches the external environment.

  In the heating unit 26, the supply line 50 in the exhaust heat exchanger 38 communicates with the supply line 72 in the outside air heat exchanger 62 through a bypass line 78. The bypass line 78 has four bypass sections 78a, 78b, 78c, and 78d. The bypass line 78 includes a first control flap 80 disposed between the first bypass section 78a and the second bypass section 78b, and a second bypass section 78b and a third bypass section 78c. A second control flap 82 disposed therebetween and a third control flap 84 disposed between the third bypass section 78c and the fourth bypass section 78d are provided.

  The second bypass section 78 b communicates with the intermediate line 52 between the exhaust heat exchanger 38 and the circulating gas heat exchanger 54 via a line 86.

  The third bypass section 78 c communicates with the intermediate line 60 between the exhaust heat exchanger 38 and the circulating gas heat exchanger 54 via a line 88.

  The process and temperature described above is achieved when the first control flap 80 is fully closed. It should additionally be inferred that the second control flap 82 and the third control flap 84 are also completely closed.

  In this case, all the high-temperature combustion gas flows out of the combustion chamber 40 and is led into the exhaust heat exchanger 38. Thus, the exhaust is preheated to about 400 ° C. in the exhaust heat exchanger 38, so that a relatively small gas is used to heat the preheated exhaust to 700 ° C. combustion temperature. The energy for the burner 44 is required.

  However, since all the combustion gas is cooled in the exhaust heat exchanger 38, the remaining energy of the combustion gas heats the 200 ° C. circulating gas to 220 ° C. in the circulating gas heat exchanger 54. Only it will be enough energy. However, if the circulating gas heat exchanger requires more energy, the first control flap 80 will open based on either its configuration and the purpose of making the circulating gas a higher final temperature. May be.

  Thus, a portion of the hot combustion gas, which is about 700 ° C., is channeled from the combustion chamber into the first intermediate line 52 via the first two bypass sections 78a and 78b and line 86. In the first intermediate line 52, these combustion gases are mixed with the combustion gas that has arrived from the exhaust heat exchanger 38. The resulting combustion gas stream is at a higher temperature than the combustion gas that has arrived from the exhaust heat exchanger 38. Therefore, more energy is supplied to the circulating gas heat exchanger 54 to heat the circulating gas.

  The proportion of the combustion gas flowing into the intermediate line 52 via the bypass line 78 and the energy supplied to the circulating gas heat exchanger 54 as a result of the mixing of the two gas streams thereby is determined by the first control flap 80. Can be controlled by the opening angle.

  Then, if the first control flap 80 is open, the exhaust in the exhaust heat exchanger 38 will no longer be preheated to the same extent as if the first control flap 80 was closed. . Accordingly, the power of the gas burner 44 needs to be increased to achieve the combustion temperature in the gas chamber 40, resulting in an increase in the consumption of combustion gas for the gas burner 44.

  In a corresponding manner, by additionally opening the second control flap 82 in the bypass line 78, hot combustion gas flows from the combustion chamber 40 into the intermediate line 60 where it flows from the circulating gas heat exchanger 54. It is guaranteed to heat the incoming combustion gas stream.

  Then, the combustion gas flows into the outside heat exchanger 62 at a higher temperature than when the control flap 82 is closed.

  The proportion of the combustion gas flowing into the intermediate line 60 via the bypass line 78 and the energy supplied to the outside heat exchanger 62 as a result of the mixing of the two gas streams is thereby determined by the second control flap 82. It can be controlled by the opening angle (or in conjunction with the opening angle of the first control flap 80). As a matter of course, the opening angle of the second control flap 82 similarly affects the ratio of the combustion gas flowing in the bypass line 78. Here, the combustion gas flowing in the bypass line 78 reaches the first intermediate line 52 and then affects the temperature of the combustion gas flow that is then guided to the circulating gas heat exchanger 54.

  By opening the third control flap 84, a part of the combustion gas flowing in the bypass section 78c can be guided to the supply line 72 through the outside heat exchanger 62. As a result, the temperature of the combustion gas flow finally reaching the outside air heat exchanger 62 is higher than that in the case where the third control flap 84 is closed and the first and second control flaps 80 and 82 are opened. May be set again to a lower temperature.

  Overall, a bypass line 78 having three control flaps 80, 82, and 84 changes and sets the energy supplied to the circulating gas heat exchanger 54 and the outside air heat exchanger 62 in the form of hot combustion gases. Can be used.

  In a variation, a control flap may be provided on one or both of lines 86 and 88. In this case, it passes through the exhaust gas heat exchanger 38 and the circulation gas heat exchanger 54 and passes through all of the three heat exchangers 38, 54, and 62, or the bypass passage of the combustion gas flowing into the outside air heat exchanger 62. Thus, a bypass passage for the combustion gas flowing into the supply line 72 is additionally possible.

  Each heating chamber 26 therefore contributes both to the treatment of the exhaust containing the solvent and to the heating of the dryer. Many of the contaminants that are trapped in the exhaust are converted to useful energy in the heating chamber 26. Furthermore, there is no need to supply additional air to the burner. This is because hot exhaust is directly utilized for gas combustion and primary gas flow.

  Furthermore, it is possible to incorporate and improve the above-described heating chamber 26 in existing dryers that are known from the prior art and that realize external post-combustion of the exhaust.

Claims (8)

a) a drying tunnel (14) disposed in an insulated housing (12);
b) a plurality of tunnel sections (16.1, 16.2,..., 16.n) each having at least one gas outlet (22) and at least one gas inlet (24); Prepared,
c) A heating unit (26) is associated with each of the tunnel sections (16.1, 16.2,..., 16.n), the heating unit (26) being connected to the tunnel section (16.1). , 16.2, ..., 16.n) can be supplied with gas from the at least one gas outlet (22) and can form a hot primary gas stream therein,
d) The high temperature primary gas can be introduced into the circulating gas heat exchanger (54) of the heating unit (26), and in the circulating gas heat exchanger (54), the circulating gas is the high temperature 1 Can be heated by a secondary gas, and the circulating gas is recirculated to the tunnel sections (16.1, 16.2,..., 16.n) in the circulation path by the at least one gas inlet (24). A device for drying an object, in particular a car body, which can be supplied,
e) The heating unit (26) has a distributor (32), and the gas flowing out of the tunnel sections (16.1, 16.2, ..., 16.n) by the distributor (32). Is split into a circulating airflow and an exhaust airflow,
f) The heating unit (26) has a thermal post-combustion device (42), the exhaust can be supplied to the thermal post-combustion device (42), and the thermal post-combustion device (42). 42) can form the hot primary gas stream,
The heating unit (26) has an exhaust heat exchanger (38), and the exhaust is introduced into the exhaust heat exchanger (38). In the exhaust heat exchanger (38), the exhaust is Before reaching the post-combustion device (42), it is heated by the hot primary gas,
The amount of hot primary gas supplied to the exhaust heat exchanger (38) is adjusted by a first control flap (80),
The first control flap (80) is disposed in the bypass line (78), and the hot primary gas bypasses the exhaust heat exchanger (38) via the bypass line (78). led to,
The circulating gas heat exchanger (54) is supplied with hot primary gas that has passed through the exhaust heat exchanger (38),
The circulating gas heat exchanger (54) is fed with hot primary gas from a section (78b) of the bypass line (78), which is downstream of the first control flap (80). Placed in
A device, characterized in that the section (78b) of the bypass line (78) is arranged between the first control flap (80) and the second control flap (82) .   The device according to claim 1, characterized in that the post-combustion device (42) is a gas burner.   3. A device according to claim 2, characterized in that the gas burner (42) is operable without receiving a supply of secondary gas.   4. A device according to claim 3, characterized in that the gas burner (42) is a surface combustion burner. The heating unit (26) has an outside air heat exchanger (62), and a high temperature primary gas is introduced into the outside air heat exchanger (62). In the outside air heat exchanger (62), outside air is , characterized in that it is heated by the hot primary gas a device according to any one of claims 1-4. The heating unit (26) includes an outside air heat exchanger (62), and at least the exhaust heat exchanger (38) and the circulating gas heat exchanger (54) are included in the outside air heat exchanger (62). primary gas hot passing through one is characterized in that it is introduced, according to any one of claims 1 to 4. a) a drying tunnel (14) disposed in an insulated housing (12);
b) a plurality of tunnel sections (16.1, 16.2,..., 16.n) each having at least one gas outlet (22) and at least one gas inlet (24); Prepared,
c) A heating unit (26) is associated with each of the tunnel sections (16.1, 16.2,..., 16.n), the heating unit (26) being connected to the tunnel section (16.1). , 16.2, ..., 16.n) can be supplied with gas from the at least one gas outlet (22) and can form a hot primary gas stream therein,
d) The high temperature primary gas can be introduced into the circulating gas heat exchanger (54) of the heating unit (26), and in the circulating gas heat exchanger (54), the circulating gas is the high temperature 1 Can be heated by a secondary gas, and the circulating gas is recirculated to the tunnel sections (16.1, 16.2,..., 16.n) in the circulation path by the at least one gas inlet (24). A device for drying an object, in particular a car body, which can be supplied,
e) The heating unit (26) has a distributor (32), and the gas flowing out of the tunnel sections (16.1, 16.2, ..., 16.n) by the distributor (32). Is split into a circulating airflow and an exhaust airflow,
f) The heating unit (26) has a thermal post-combustion device (42), the exhaust can be supplied to the thermal post-combustion device (42), and the thermal post-combustion device (42). 42) can form the hot primary gas stream,
The heating unit (26) has an exhaust heat exchanger (38), and the exhaust is introduced into the exhaust heat exchanger (38). In the exhaust heat exchanger (38), the exhaust is Before reaching the post-combustion device (42), it is heated by the hot primary gas,
The amount of hot primary gas supplied to the exhaust heat exchanger (38) is adjusted by a first control flap (80),
The first control flap (80) is disposed in the bypass line (78), and the hot primary gas bypasses the exhaust heat exchanger (38) via the bypass line (78). Led to
The heating unit (26) includes an outside air heat exchanger (62), and at least the exhaust heat exchanger (38) and the circulating gas heat exchanger (54) are included in the outside air heat exchanger (62). The hot primary gas that passed through one side was introduced,
A section (78b) of the bypass line (78) is disposed between the first control flap (80) and a second control flap (82);
The outdoor air heat exchanger (62) is supplied with hot primary gas from a section (78c) of the bypass line (78), which is downstream of the second control flap (82). you being arranged, equipment. High temperature outside air is supplied to at least one of an inlet gate region (18) disposed at the inlet of the drying tunnel (14) and an outlet gate region (20) disposed at the outlet of the drying tunnel (14). The apparatus according to claim 7 , wherein the high temperature outside air flows into the drying tunnel from the gate region.

Images