KR101210957B1

KR101210957B1 - Controlling method of regenerative hot air dryer

Info

Publication number: KR101210957B1
Application number: KR1020100104810A
Authority: KR
Inventors: 권순목
Original assignee: (주)상원기계
Priority date: 2010-10-26
Filing date: 2010-10-26
Publication date: 2012-12-12
Also published as: KR20120043482A

Abstract

Disclosed is a control method of a regenerative hot air dryer that optimally controls the operation of a hot air dryer to reduce exhaust volume of a drying furnace, thereby minimizing heat loss, thereby reducing fuel consumption and maintaining a clean state of a combustion furnace (dry furnace).
The control method of the regenerative hot air dryer disclosed includes a drying furnace heat-up process for driving the regenerative combustion machine to heat up the drying furnace to a predetermined temperature; A drying product heat up process for heating up the dried product fed into the drying furnace in which the heat up is performed until the drying set temperature is reached; The drying control process removes volatile organic compounds by heating the dry matter while maintaining the drying set temperature by adjusting the output of the VOC blower fan and the hot air circulation blower fan, and the opening amount of the manual exhaust damper and the automatic mixing mixing damper. Include.

Description

Control method of regenerative hot air dryer {Controlling method of regenerative hot air dryer}

The present invention relates to a control method of a regenerative hot air dryer, and more particularly, to optimally control the operation of the hot air dryer so that the exhaust gas volume is reduced by drying, thereby reducing fuel consumption and minimizing heat loss, and thus a state of a combustion furnace (dry furnace). It relates to a control method of a regenerative hot air dryer to keep it clean at all times.

In general, a drying apparatus is used for various processes such as painting, bonding, and printing. Such a drying apparatus has a structure having a hot air feeder, a heat exchanger, and the like, which supplies heated air into a drying chamber (dry furnace) in general, and allows a paint-coated or adhesive-coated dry matter, a printed dry matter, etc. Heat through and dry.

At this time, a volatile organic compound (VOC) is generated, and regenerative thermal oxide (RTO) is used as a means for burning and removing the volatile organic compound. The heat storage combustor (RTO) has a structure in which the harmful gas introduced therein is preheated through an internal heat storage layer and then burned at a high temperature of 800 ° C. or higher using a burner in a combustion chamber, and is then purged at a high purity of about 98% or more and then evacuated.

However, such a general drying apparatus, the heat storage burner (RTO) and the hot air generator are installed separately, operated separately, and installed outside the line, and the exhaust gas is discharged at a temperature higher than the hot air temperature of the drying furnace because it is disposed of. . Therefore, there was a problem that the total installation cost and installation space of the drying apparatus takes more than necessary. Specifically, as the RTO and the hot air generator are separately provided, the heat dissipation area of the treatment device and the duct is increased, so that the heat dissipation is increased, and the area required for the facility is also increased. Control system for controlling the burner is also doubled. In addition, since the heat of VOC itself cannot be recovered and reused, it is discharged to the atmosphere as it is. Therefore, the energy use efficiency is very low and the operation cost of the device is excessive.

In order to solve this problem, a conventionally proposed one is disclosed in Korean Patent Laid-Open Publication No. 10-2009-0037286 (published on April 15, 2009) (name of the invention: an eco-friendly drying apparatus having a regenerative burner combined with a hot air generator). .

Such a conventional drying apparatus, by using a heat storage combustion apparatus (RTO) to purify the harmful gases generated during the drying process of the dry matter such as paints, prints, adhesives, etc., which generate volatile organic compounds during drying, and discharge them from the heat storage combustion equipment. By recovering the heat of the purified air to be re-supplied to the drying chamber to save energy, while maintaining the harmful gas concentration in the drying furnace far below the LEL standard, the exhaust volume is reduced compared to the general furnace has the advantage of high energy efficiency.

However, such a conventional drying apparatus can reduce the displacement compared to a general furnace, but the energy efficiency is increased to a certain degree, but there is a disadvantage that it is impossible to stably minimize the displacement because there is no drying apparatus control algorithm to minimize the displacement.

Accordingly, the present invention has been proposed to solve all the problems occurring in the conventional drying apparatus as described above,

The problem to be solved by the present invention is to provide a control method of the heat storage type hot air dryer to optimally control the operation of the hot air dryer to reduce the exhaust volume by drying, to reduce fuel consumption by minimizing heat loss.

Another problem to be solved by the present invention is to provide a control method of a regenerative hot air dryer which keeps the state of a combustion furnace (drying furnace) clean at all times.

"Control method of a heat storage type hot air dryer" according to the present invention for solving the above problems,

A drying furnace heat-up process of heating the drying furnace to a predetermined temperature by driving a regenerative combustion machine;

A drying product heat up process for heating up the dried product fed into the drying furnace in which the heat up is performed until the drying set temperature is reached;

Controlling the output of VOC blower fan and hot air circulating blower fan and opening amount of manual exhaust damper and automatic mixing mixing damper to control the exhaust volume to maintain drying set temperature and remove volatile organic compounds. Characterized in that.

In addition, the "control method of the regenerative hot air dryer" according to the present invention,

When the operation stop is requested, the operation of lowering the combustion chamber temperature of the heat storage combustor to a predetermined temperature or less, and further operating the rotor for a predetermined time, characterized in that it further comprises an operation stop process for stopping the operation of the heat storage burner.

The drying furnace heat-up process,

Adjusting the VOC blower fan output to 30% with the door closed by drying and operating the regenerative combustor;

After the operation of the heat accumulator, the fan output fan fan output is adjusted to 100%, the opening amount of the manual exhaust damper is adjusted to 5%, the opening amount of the automatic mixing damper is adjusted to 100%, and the burner is ignited. ;

Heating the temperature of the combustion chamber to the heat storage combustor setting temperature while controlling the burner until the combustion chamber temperature TC1 of the heat storage combustor reaches a preset heat storage combustor set temperature;

When the temperature of the combustion chamber reaches the regenerative combustion temperature, the output of the VOC blower fan is adjusted to 0%, the opening amount of the manual exhaust damper is adjusted to 5%, and then the output of the hot air circulation blower fan is adjusted to 0%. Closing the automatic mixing damper.

The dry matter heat up process,

The output of the hot air circulating blower fan is controlled by adjusting the opening amount of the manual exhaust damper to 5%, the VOC blower fan output to 100%, and the opening amount of the automatic mixing damper by PID control while the building is loaded in the drying furnace. Injecting hot air into the drying furnace by adjusting to 100%;

Detecting the temperature of the drying furnace, and maintaining the step until the detected temperature of the drying furnace reaches a preset drying set temperature to reach the drying set temperature.

The drying control process,

Adjust the opening of the manual exhaust damper to 5%, adjust the output of the VOC blower fan to 50%, PID control the automatic mixing damper, and control the output of the hot air circulation blower fan to 100% to dry the temperature of the drying furnace. Maintaining at a set temperature for a first set time;

After the first set time, the opening amount of the manual exhaust damper is maintained at 5%, the output of the VOC blower fan is adjusted to 30%, PID control of the automatic mixing damper, and the output of the hot air circulation blower fan is 100%. Maintaining the temperature of the drying furnace at a drying set temperature for a second predetermined time while controlling;

When drying is finished and the door is opened by drying, adjust the opening amount of the manual exhaust damper to 5%, adjust the output of the VOC blower fan to 0%, close the automatic mixing damper and set the output of the hot air circulation blower fan to 0%. It characterized in that it comprises a step of controlling.

The stop operation process,

Adjusting the opening amount of the manual exhaust damper to 5%, adjusting the output of the VOC blower fan to 50%, closing the automatic mixing damper, turning off the hot air circulation blower fan, and then turning off the burner;

Detecting the temperature of the combustion chamber after the burner-off, and when the detected combustion chamber temperature drops to the off temperature of the VOC blower fan, turning off the VOC blower fan, driving the rotor for 15 minutes, and ending the operation of the rotor. Characterized in that it comprises a.

According to the present invention, by optimally controlling the operation of the hot air dryer to reduce the exhaust volume of the drying, there is an advantage that can reduce the fuel consumption by minimizing the heat loss.

In addition, according to the present invention, there is an advantage that the state of the combustion furnace (drying furnace) can always be kept clean.

1 is a schematic configuration diagram of a regenerative hot air dryer to which the present invention is applied.
Figure 2 is a flow chart showing a control method of a heat storage hot air dryer according to the present invention.
3 is a detailed flowchart of a driving stop process of FIG. 2;
4 is a temperature control timing diagram of an intermittent drying furnace to which the present invention is applied.
5 is a temperature control timing diagram of a continuous drying furnace to which the present invention is applied.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

1 is a schematic configuration diagram of a heat storage type hot air dryer to which the present invention is applied, and a drying furnace 10 into which a dry matter is input, and a heat storage combustion apparatus (RTO) 20 connected to an upper or lower portion of the drying furnace 10. And a hot air circulation blower (HSF) 30 for transmitting the hot air generated in the heat storage combustor 20 to the drying furnace 10, a VOC blower 40, and a passive exhaust damper (EDP) 50.

In addition, although not shown in Figure 1, the regenerative hot air dryer is essentially provided with a control device for controlling the overall operation of the regenerative hot air dryer, the control method according to the present invention is a program in the memory provided inside the control device Stored.

Drying furnace 10 is provided with a temperature sensor for detecting the drying furnace temperature (TC2), the hot air circulation blower 30 is provided with a hot air circulation blower fan, the VOC blower 40 is provided with a VOC blower fan.

In addition, the heat storage combustor 20 is provided with a combustion fan for injection of combustion air, a temperature sensor for detecting the combustion chamber temperature TC1, an automatic mixing damper MDP, a burner, and the like.

1 shows only one drying furnace, and the present invention is not limited to a regenerative hot air dryer having only one drying furnace, and the same applies to a continuous hot air dryer in which a plurality of drying furnaces are connected. Therefore, in the present invention, only a control process for one drying furnace will be described for convenience of description.

The dried or printed dry matter, to which the paint is coated or the adhesive is applied to the drying furnace 10, passes from the inlet side of the drying furnace to the outlet side.

At the same time, the harmful gas introduced from the drying furnace 10 through the supply part of the rotor of the heat storage combustor 20 is burned by the burner of the combustion chamber through the heat storage layer of the heat storage combustor 20, and is purified by the clean air, and the purified clean air. Is discharged to the outside through the discharge portion of the rotor.

Through this process, the volatile organic compound (VOC) of the dry matter is removed. For this purpose, the control of the regenerative hot air dryer should be efficient, and FIG. 2 shows the flow of the control method of the regenerative hot air dryer according to the present invention. .

As shown in the drawing, the control method of the regenerative hot air dryer according to the present invention includes a drying furnace heat-up process (S100) for driving a regenerative combustion heater to heat up the drying furnace to a predetermined temperature; A dry matter heat-up process (S200) for heating up the dry matter inputted to the drying furnace in which the heat-up has been made until a dry set temperature is reached; Drying control process to heat the dry matter and remove volatile organic compounds by controlling the exhaust volume by adjusting the output of the VOC blower fan and the hot air circulating blower fan and the opening amount of the manual exhaust damper and the automatic mixing mixing damper (S300) And when the operation stop is requested to perform the operation of lowering the combustion chamber temperature of the heat storage combustor to a predetermined temperature or less, and further operating the rotor for a predetermined time and includes an operation stop process (S400) to stop the operation of the heat storage combustor.

Wherein the drying furnace heat-up process (S100), the step of adjusting the VOC blower fan output to 30% in the state in which the drying furnace door is closed, and operating the heat storage combustor (S101 ~ S107); Adjusting the hot air circulation blower fan output to 100% after the operation of the regenerative combustion burner, adjusting the opening amount of the manual exhaust damper to 5%, adjusting the opening amount of the automatic mixing damper to 100%, and then burning the burner ( S109 to S115); Heating the temperature of the combustion chamber to the heat storage combustor setting temperature while controlling the burner until the combustion chamber temperature TC1 of the heat storage combustor reaches a preset heat storage combustor set temperature (S117 to S119); When the temperature of the combustion chamber reaches the regenerative combustion temperature, the output of the VOC blower fan is adjusted to 0%, the opening amount of the manual exhaust damper is adjusted to 5%, and then the output of the hot air circulation blower fan is adjusted to 0%. The step of closing the automatic mixing damper (S121 ~ S123).

In addition, the building heat-up process (S200), by adjusting the opening amount of the passive exhaust damper to 5%, the VOC blower fan output to 100%, the opening amount of the automatic mixing damper in the state that the dry matter is inserted into the drying furnace Controlling hot water circulation fan by controlling the PID control to 100% to inject hot air into the drying furnace (S201 to S203); Detecting the temperature of the drying furnace, and maintaining the step until the detected drying furnace temperature reaches a preset drying set temperature to reach the drying set temperature (S205 to S207). do.

In addition, the drying control process (S300), to adjust the opening amount of the manual exhaust damper to 5%, to adjust the output of the VOC blower fan to 50%, PID control the automatic mixing damper, the output of the hot air circulation blower fan Maintaining the temperature of the drying furnace at a drying set temperature for a first predetermined time while controlling the temperature to 100% (S301 to S303); After the first set time, the opening amount of the manual exhaust damper is maintained at 5%, the output of the VOC blower fan is adjusted to 30%, PID control of the automatic mixing damper, and the output of the hot air circulation blower fan is 100%. Maintaining the temperature of the drying furnace at a drying set temperature for a second predetermined time while controlling (S305 to S307); When drying is finished and the door is opened by drying, adjust the opening amount of the manual exhaust damper to 5%, adjust the output of the VOC blower fan to 0%, close the automatic mixing damper and set the output of the hot air circulation blower fan to 0%. Control step (S309 ~ S311).

In addition, the operation stop process (S400), as shown in Figure 3, to adjust the opening amount of the manual exhaust damper to 5%, adjust the output of the VOC blower fan to 50%, close the automatic mixing damper and hot air circulation Turning off the blower fan and then turning off the burners (S401 to S403); Detecting the temperature of the combustion chamber after the burner-off, and when the detected combustion chamber temperature drops to the off temperature of the VOC blower fan, turning off the VOC blower fan, driving the rotor for 15 minutes, and ending the operation of the rotor. (S405 to S409).

In the control method of the regenerative hot air dryer according to the present invention made as described above, first, a process (S100) of heating up the drying furnace 10 is performed.

Here, the process of heat-up the drying furnace, in the state in which the door of the drying furnace is closed, as in step S101, to operate the rotor (ROTOR) as in step S103, and then in the VOC blower 40 as in step S105 The regenerative combustion (RTO) 20 is operated as in step S107 with the output of the VOC blower fan adjusted to 30%.

With the regenerative combustion engine (RTO) in operation, the output of the hot air circulation blower fan provided in the hot air circulation blower 30 is adjusted to 100% as in step S109, and the manual exhaust damper (EDP) is 5% in step S111. Only open and in step S113 the automatic mixing damper (MDP) is opened to 100%, and in step S115 the burner provided in the heat storage combustor 20 is ignited.

Here, the% of the VOC blower fan's output 30%, the hot air circulating blower fan's output 100%, the manual exhaust damper 5%, and the automatic mixing damper 100% means the control amount controlled by each device, and 0 to 100 for each device. The control amount (%) for% is stored in the internal memory of the control device, and based on this control amount, the control device individually controls the corresponding device to control the amount of opening, closing, and fan speed (output). . The control amount for each device is preferably calculated in advance through experiments and stored in the internal memory. For example, the passive exhaust damper 5% means the amount of opening of the passive exhaust damper corresponding to 5%, assuming 100% when the manual exhaust damper is fully opened.

After the burner is ignited, the combustion chamber temperature TC1 of the heat storage combustor is detected as in step S117, and the combustion chamber temperature TC1 thus detected is set to a preset temperature of the heat storage combustor which is preset for heating up. For example, it is checked whether the temperature reaches 820 ° C. (S119).

As a result of this check, when the combustion chamber temperature TC1 reaches the set temperature of the heat storage combustor preset for heat-up by drying, the process moves to step S121 to turn off the burner, otherwise the combustion chamber temperature TC1 is changed to the drying furnace. If the set temperature of the heat storage burner which has been preset for the heat up has not been reached, the process moves to the above-described step S115 to maintain the burner's ignition state and perform the following steps.

If the combustion chamber temperature reaches the set temperature of the heat storage combustor and the burner is turned off, the flow goes to step S123 to set the opening amount of the manual exhaust damper to 5%, close the automatic mixing damper completely, and close the VOC blower. The output of the equipped VOC blower fan is set to 0%, the output of the hot air circulation blower fan is adjusted to 0%, thereby ending the heat up process by drying.

After the heat-up process is completed by drying, the process of heat-up the dried material is performed in the next process (S200).

That is, in the building heat-up process (S200), as in step S201, the door of the drying furnace 10 is opened, the dry material is input, the door is closed to the drying furnace, and the door is moved to S203 to the next step to open the manual exhaust damper. , Adjust the output of the VOC blower fan to 100%, adjust the automatic mixing damper to proportional integral derivative (PID), and adjust the output of the hot air circulation blower fan to 100%. Hot air is applied to dry.

When drying starts, the temperature TC2 of the drying furnace is detected as in step S205. In step S207, it is checked whether the detected temperature TC2 of the drying furnace and the preset drying set temperature are reached. As a result of this check, when the temperature of the drying furnace does not reach the preset drying set temperature, it heats up the drying furnace by maintaining the current state.In contrast, when the temperature of the drying furnace reaches the preset drying set temperature, it heats up the drying furnace. It is determined that this is completed, and the heat-up process is terminated by drying.

When the heat up process is completed by drying, the drying control process (S300) is performed as the following process. The drying control process (S300) performs drying while controlling the temperature of the drying furnace and removes volatile organic compounds.

In more detail, when the temperature TC2 of the drying furnace reaches the drying set temperature in step S301, the opening amount of the manual exhaust damper is adjusted to 5%, and the output of the VOC blower fan is adjusted to 50%, By controlling the proportional integral derivative (PID) control of the automatic mixing damper, the output of the hot air circulating blower fan is adjusted to 100% to dry the dry matter.

In the state of drying the dried material in the above-described process, it is checked in step S303 whether the above-described first drying time has elapsed, and the above-mentioned drying process has not passed the first predetermined time. In this case, the current drying process is maintained. Otherwise, when the above drying process has elapsed a first predetermined time, the process moves to step S305 to control drying.

That is, the opening amount of the manual exhaust damper is adjusted to 5%, the output of the VOC blower fan is adjusted to 30%, the automatic mixing damper is controlled to the proportional integral derivative (PID), and the output of the hot air circulating blower fan is 100%. By adjusting the drying.

In the state of drying the dried material in the above-described process, it is checked in step S307 whether the above-described drying process has elapsed the second preset time, and the above drying process does not elapse the second preset time. In this case, the current drying process is maintained. Otherwise, when the above drying process has elapsed a second preset time, the process moves to step S309 to terminate drying.

After that, go to step S311 to adjust the opening amount of the manual exhaust damper to 5%, adjust the output of the VOC blower fan to 0%, close the automatic mixing damper, and set the output of the hot air circulation blower fan to 0%. Will be adjusted.

Here, the first and second set times are preferably set appropriately by experiments, and FIGS. 4 and 5 are timing diagrams for a drying control process.

When the drying of the dry material is completed through this process, the operation stop process (S400) is performed as the following process. In this case, the operation stop process S400 is performed in the same manner even when the operation stop is manually performed by the administrator.

In operation S400, as illustrated in FIG. 3, after adjusting the opening amount of the manual exhaust damper to 5% in step S401, adjusting the output of the VOC blower fan to 50%, closing the automatic mixing damper, Turn off the hot air circulation blower fan.

Thereafter, the burner is turned off in step S403, and it is checked in step S405 whether the combustion chamber temperature TC1 falls below a preset fan off temperature (400 ° C.) to turn off the VOC blower fan and the combustion fan. As a result of this check, if the combustion chamber temperature is higher than the fan off temperature, the current state is maintained. Otherwise, if the combustion chamber temperature is lower than the fan off temperature, the flow moves to step S407 to turn off the VOC blower fan and turn off the combustion fan.

Thereafter, the process moves to step S409 and the rotor is operated for 15 minutes, and then the rotor is stopped, thereby terminating the driving stop process.

According to the present invention, since the operation of the hot air dryer can be optimally controlled to reduce the exhaust volume of the drying furnace, fuel consumption can be reduced by minimizing heat loss, and the combustion furnace (drying furnace) can always be kept clean. Will be.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents. Of course, such modifications are within the scope of the claims.

10... Drying furnace
20 ..... Regenerative Combustion (RTO)
30 ... Hot air circulation blower
40 ... VOC Blower
50... Manual exhaust damper

Claims

In the control method of the regenerative hot air dryer,
A drying furnace heat-up process of heating the drying furnace to a predetermined temperature by driving a regenerative combustion machine;
A drying product heat up process for heating up the dried product fed into the drying furnace in which the heat up is performed until the drying set temperature is reached;
By controlling the output of the VOC blower fan and hot air circulation blower fan and the opening amount of the manual exhaust damper and the automatic mixing mixing damper, the drying control process is performed to heat the dry matter and remove volatile organic compounds while maintaining the drying set temperature. Control method of a regenerative hot air dryer, characterized in that it comprises.

The method according to claim 1,
When the operation stop is requested, the operation of lowering the combustion chamber temperature of the heat storage combustor to a predetermined temperature or less, and further operating the rotor for a predetermined time after the operation of the heat storage dryer, characterized in that further comprising an operation stop process for stopping the operation of the heat storage combustor. Control method.

The method of claim 1, wherein the drying furnace heat-up process,
Adjusting the VOC blower fan output to 30% with the door closed by drying and operating the regenerative combustor;
After the operation of the heat accumulator, the fan output fan fan output is adjusted to 100%, the opening amount of the manual exhaust damper is adjusted to 5%, the opening amount of the automatic mixing damper is adjusted to 100%, and the burner is ignited. ;
Heating the temperature of the combustion chamber to the heat storage combustor setting temperature while controlling the burner until the combustion chamber temperature TC1 of the heat storage combustor reaches a preset heat storage combustor set temperature;
When the temperature of the combustion chamber reaches the regenerative combustion temperature, the output of the VOC blower fan is adjusted to 0%, the opening amount of the manual exhaust damper is adjusted to 5%, and then the output of the hot air circulation blower fan is adjusted to 0%. The control method of the heat storage type hot air dryer, comprising the step of closing the automatic mixing damper.

The method of claim 1, wherein the building heat up process,
The output of the hot air circulating blower fan is controlled by adjusting the opening amount of the manual exhaust damper to 5%, the VOC blower fan output to 100%, and the opening amount of the automatic mixing damper by PID control while the building is loaded in the drying furnace. Injecting hot air into the drying furnace by adjusting to 100%;
Detecting the temperature of the drying furnace, and maintaining the step until the detected temperature of the drying furnace reaches a preset drying set temperature to reach the drying set temperature. Control method of regenerative hot air dryer.

The method of claim 1, wherein the drying control process,
Adjust the opening of the manual exhaust damper to 5%, adjust the output of the VOC blower fan to 50%, PID control the automatic mixing damper, and control the output of the hot air circulation blower fan to 100% to dry the temperature of the drying furnace. Maintaining at a set temperature for a first set time;
After the first set time, the opening amount of the manual exhaust damper is maintained at 5%, the output of the VOC blower fan is adjusted to 30%, PID control of the automatic mixing damper, and the output of the hot air circulation blower fan is 100%. Maintaining the temperature of the drying furnace at a drying set temperature for a second predetermined time while controlling;
When drying is finished and the door is opened by drying, adjust the opening amount of the manual exhaust damper to 5%, adjust the output of the VOC blower fan to 0%, close the automatic mixing damper and set the output of the hot air circulation blower fan to 0%. Control method of a heat storage hot air dryer, characterized in that it comprises the step of controlling.

The method of claim 2, wherein the driving stop process,
Adjusting the opening amount of the manual exhaust damper to 5%, adjusting the output of the VOC blower fan to 50%, closing the automatic mixing damper, turning off the hot air circulation blower fan, and then turning off the burner;
Detecting the temperature of the combustion chamber after the burner-off, and when the detected combustion chamber temperature drops to the off temperature of the VOC blower fan, turning off the VOC blower fan, driving the rotor for 15 minutes, and ending the operation of the rotor. Control method of a regenerative hot air dryer, comprising a.