JPH035836Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an improvement of an indirect heating type hot air circulation furnace used for drying workpieces, etc.

2. Description of the Related Art This type of furnace has conventionally been constructed as shown in FIG. In this figure, the numbers 1, 2, 3
is a working furnace installed along the path of the workpiece (not shown), and the workpiece is dried while traveling in the direction of the arrow. Hot air is used for this drying, and a hot air circulation path 4 for circulating the hot air;
5 and 6 are provided in each of the working furnaces 1, 2, and 3.
Reference numerals 7, 8, and 9 are fans for circulating hot air.

Further, each of the hot air circulation paths 4, 5, and 6 is provided with a heat medium circulation path 10, 11, and 12, respectively, and each heat medium circulation path 10, 11, and 12 is provided with a burner 13, which is a heat medium heating section. 14, 15 and combustion furnace 16, 17, 1
8 is provided. Fans 19, 20, and 21 are also provided for circulating the heat medium. Note that numerals 22, 23, and 24 are exhaust gas dampers.

Each of the above hot air circulation paths 4, 5, 6 and each heat medium circulation path 1
Heat exchangers 25, 26, and 27 are provided at predetermined points of contact with the wind turbines 0, 11, and 12 to provide heat from combustion gas, which is a heat medium, to the wind.

When the fuel from the burners 13, 14, 15 is burned in the combustion furnaces 16, 17, 18, the combustion gas is transferred to each heat medium circulation path 10, 11, 12 by the action of the fans 19, 20, 21. At the same time, air flows in the direction of the arrow in the hot air circulation paths 4, 5, and 6 by fans 7, 8, and 9, while the heat exchangers 25, 26, and 27 generate heat. It receives heat from the medium and becomes hot air, which blows into each work furnace 1, 2,
Go through 3. The hot air hits the workpieces in the work furnaces 1, 2, and 3 and performs operations such as drying.

Further, in FIG. 2, reference numerals 28, 29, and 30 are ducts for collecting the atmospheric gas in the working furnaces 1, 2, and 3 and guiding it to the deodorizing device 31. code 32,3
3 and 34 are dampers provided in each duct 28, 29, and 30. The deodorizing device 31 includes a combustion chamber 35 for the atmospheric gas, and a deodorizing burner 3 for feeding fuel and fresh air into the combustion chamber 35 for combustion.
6. Reference numeral 37 is a fan, and the gas coming from the ducts 28, 29, 30 is forced into the combustion chamber 35 by this fan 37.
Further, reference numeral 38 is a heat exchanger, and the duct 2
Gases from 8, 29, and 30 are preheated here and then sent to a combustion chamber 35 by a fan 37.

However, when baking and drying of paint etc. is carried out in each work furnace 1, 2, 3, HC components, tar, etc. are generated in the furnace, and some of the atmospheric gas containing these is transferred to the duct 28. , 29, and 30, the gas reaches the deodorizing device 31, where harmful components contained in the gas are burned and removed. The gas that has undergone such treatment is discharged out of the apparatus from the exhaust duct 39 in an odorless state, and this dilutes the HC components in the working furnace and prevents them from concentrating.

FIG. 3 shows another conventional example. Although this figure shows a single working furnace 1 portion extracted for convenience of drawing, a direct combustion deodorizing furnace 40 is provided for each of the working furnaces 1, 2, and 3, unlike the conventional example described above. This deodorizing furnace 40 includes a collection duct 41 for taking out a part of the atmospheric gas therein from the working furnace 1, and a fan 42, a burner 43, the deodorizing furnace 40, and a heat exchanger 44 are arranged along the flow direction of the collection duct 41. It is what it is.

Therefore, the atmospheric gas inside the working furnace 1 is
2 is drawn into the collection duct 41,
It is ejected from the burner 43 into the deodorizing furnace 40 together with the fuel. In the furnace, harmful components in the atmospheric gas are burned and removed by flame and high temperature atmosphere (usually 700° C. or higher) and are discharged from the exhaust gas duct 47. Note that fresh outside air corresponding to the amount of atmospheric gas discharged from the inside of the working furnace 1 is supplied into the working furnace from the conduit 45 via the heat exchanger 46.

Problems to be solved by the invention However, in the case of the former type of conventional circulation furnace, a deodorizing device 31 must be installed separately from the combustion system, which occupies a large space and has a very high initial cost. Become. Furthermore, there is a problem in that running costs for deodorizing treatment are required separately.

In addition, in the case of the latter, each work furnace 1, 2,
The disadvantage is that a deodorizing furnace 40 etc. must be provided for every 3.

Means for Solving the Problems In order to solve the above problems, the present invention includes a heat medium circulation path having a heat medium heating section at a predetermined location, and a plurality of hot air circulation paths each having a working furnace at a predetermined location. In the indirect heating type hot air circulation furnace, in which a heat exchanger for the wind to receive heat from the heating medium is provided at a predetermined contact point of both circulation paths, the heating medium heating section of the heating medium circulation path is provided at one location. The heating medium is liquid, and the heating medium circulation path is formed between the heating medium heating section and each heat exchanger, and the heating medium circulation path is formed between the heating medium heating section and the combustion section of the heating medium heating section. A configuration is adopted in which a collection path is provided that communicates between the combustion chambers and guides the atmospheric gas within the working furnace to the combustion section.

Function A liquid is used as the heating medium in the heating medium circuit, rather than a gas. Moreover, there is only one heating section.
For this reason, the heat medium circulation path and its surroundings have been downsized,
The space it occupies is also getting smaller.

Atmospheric gas generated in the furnace during operation of the furnace reaches the combustion section of the heat medium heating section through a collection path. Here, harmful components in the atmospheric gas are burned, and the atmospheric gas is discharged in an odorless state. Furthermore, this prevents concentration of HC components and the like within the working furnace.

Embodiment FIG. 1 shows an embodiment of the present invention. In these figures, parts having the same configuration as in FIGS. 2 and 3 are given the same reference numerals.

As shown in FIG. 1, the heat medium heating section 48 has one
Only certain locations are provided. Furthermore, the heat medium used is not gas, but oil, which is a liquid. The heat medium heating section 48 is a boiler, and the boiler includes a burner 4.
9, an exhaust duct 50 etc. are attached.

The heat medium heating section 48 and each heat medium circulation path 4, 5, 6
Heat medium circulation paths 54, 55, 56 are formed in parallel between the heat exchangers 51, 52, 53,
Control valves 57, 58, 59 such as solenoid valves are provided on each outward path.
is installed. In addition, a pump 60 is installed at a specified location.
is installed. These control valves 57, 58,
59 are all controlled by a control section (not shown), and the control section is equipped with a timer, etc., and when starting up the work furnaces 1, 2, and 3, the workpieces located on the upstream side of the workpiece flow are controlled by a control section (not shown). It is configured to sequentially open the control valves 58 and 59 downstream from the control valve 57 corresponding to the furnace 1 over time. The time T from the opening operation of one control valve to the opening operation of the next valve almost coincides with the start-up time of one working furnace.

Thus, when starting up the working furnaces 1, 2, and 3, the boiler, which is the heating medium heating section 48, is operated to heat the heating medium. This heating medium, oil, has a specific heat of
424 (Kcal/m ³ , ℃), which is approximately 1,400 times the 0.30 (Kcal/m ³ ℃) of air, which is a conventional heating medium. , the pump 60 is much smaller than conventional pumps. In addition, the heat exchangers 51, 52, and 53 are also gas-liquid type compared to the conventional gas-gas type, and the heat transfer rate (Kcal/ ^m3・h・℃) is approximately twice as large as the conventional size. About half of that can be used.

Next, based on the signal from the control section, the control valve 5
9 is opened and the heat medium reaches the heat exchanger 51, while the air generated by the operation of the fan 7 circulates in the hot air circulation path 4 and receives heat in the heat exchanger 51 to heat the inside of the working furnace 1. The time T during which only the control valve 57 is open corresponds to the start-up time of the working furnace 1, and the capacity of the burner 49 to shorten this T as much as possible is:
If the load of the working furnace 1 during standard operation during this period is Q, it is set to, for example, 2Q. When the temperature inside the working furnace 1 rises to a predetermined level, it is detected by a detector (not shown) in the control section, and the next control valve 58 is opened.

As a result, the capacity of the burner 49 is adjusted as 2Q+Q=3Q so that 2Q of heat is added to the adjacent work furnace 2 on the downstream side, and the furnace 2 is also
During this time, more heat is generated and the rise time is shortened. After time T has elapsed, the next control valve 59 is opened.

As a result, the capacity of the burner 49 is increased to 2Q+ so that 2Q of heat is added to the work furnace 3 further downstream.
Adjustment is made such that Q+Q=4Q, and the furnace 3 is also heated more during time T to shorten the rise time. After time T passes, the capacity of burner 49 becomes
The work furnace 3 is adjusted to 3Q, and the work furnace 3 is brought into a standard operating state with a load of 3Q, and the workpieces are started to be carried into the furnaces 1, 2, and 3.

Reference numerals 61 and 62 in FIG. 1 indicate the working furnaces 1 and 3.
This is a duct that communicates between the burner 49 and the burner 49 which is the combustion section of the heat medium heating section 48. This duct 61,6
Reference numeral 2 denotes an atmospheric gas collector for guiding the atmospheric gas in the working furnaces 1 and 3 to the burner 49. A fan 63 for collecting atmospheric gas is provided in the middle.

Therefore, the atmospheric gas is sent to the burner 49, mixed with combustion gas, and burned in the heat medium heating section 48. As a result, HC components and the like in the atmospheric gas are burned and removed, and the atmospheric gas becomes odorless and harmless and is discharged to the outside world from the exhaust duct 50. In addition, this prevents harmful components from increasing in concentration within each of the working furnaces 1, 2, and 3.

Further, reference numeral 64 is a fresh air supply duct, and a heat exchanger 6 installed in the exhaust duct 50
5 to the working furnace 2.

As a result, the same amount of atmospheric gas discharged from each work furnace 1, 2, and 3 is transferred to the work furnaces 1, 2, and 3.
3, thereby promoting the deodorization and detoxification of the inside of each working furnace 1, 2, and 3. Note that the duct 61 and the duct 62 may also be connected to the work furnace 2.

Effects of the invention Since the present invention has the above-described configuration and operation, the heating medium heating section 48, the heating medium circulation paths 54, 55, 5
6 The heat exchangers 51, 52, 53, etc. can be downsized, and the overall configuration of the indirect heating hot air circulation furnace can be simplified, occupying space, and fixed losses of equipment such as heat loss can be reduced. It is possible. Since the combustion section of the heat medium heating section 48 is used as the deodorizing device, the deodorizing device 31 is provided separately from the conventional combustion system, and each work furnace 1, 2,
Compared to the method of providing every third section, the space occupied can be further reduced. Furthermore, since it can be made smaller in this way, it is also possible to reduce the energy required for heating and deodorizing.

[Brief explanation of drawings]

Fig. 1 is a block circuit diagram of an indirect heating type hot air circulation furnace according to the present invention, Fig. 2 is a block circuit diagram of a conventional example, and Fig. 3 is a block circuit diagram of a part of another conventional example. It is a diagram. 1, 2, 3... Working furnace, 48... Heat medium heating section,
49... Burner, 54, 55, 56... Heat medium circulation path, 61, 62... Collection path.

Claims (1)

[Scope of utility model registration request] a heating medium circulation path having a heating medium heating section at a predetermined location;
An indirect heating hot air circulation system comprising a plurality of hot air circulation paths each having a working furnace at a predetermined location, and a heat exchanger for the air to receive heat from the heating medium at a predetermined contact point between the two circulation paths. In the furnace, the heat medium heating section of the heat medium circulation path is provided at only one location, the heat medium is in liquid form, and the heat medium circulation path is formed between the heat medium heating section and each of the heat exchangers. , an indirect heating type hot air circulation characterized in that a collection path is further provided that connects a predetermined working furnace and a combustion section of the heat medium heating section and guides atmospheric gas in the working furnace to the combustion section. Furnace.