JPH0243038Y2 - - Google Patents
Info
- Publication number
- JPH0243038Y2 JPH0243038Y2 JP1982027212U JP2721282U JPH0243038Y2 JP H0243038 Y2 JPH0243038 Y2 JP H0243038Y2 JP 1982027212 U JP1982027212 U JP 1982027212U JP 2721282 U JP2721282 U JP 2721282U JP H0243038 Y2 JPH0243038 Y2 JP H0243038Y2
- Authority
- JP
- Japan
- Prior art keywords
- furnace
- furnace chamber
- core tube
- firing
- inlet side
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000010304 firing Methods 0.000 claims description 23
- 238000010438 heat treatment Methods 0.000 claims description 20
- 238000005192 partition Methods 0.000 claims description 8
- 239000000758 substrate Substances 0.000 claims description 3
- 238000000034 method Methods 0.000 description 11
- 230000008569 process Effects 0.000 description 7
- 239000007789 gas Substances 0.000 description 4
- 239000005416 organic matter Substances 0.000 description 4
- 230000005855 radiation Effects 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 230000008674 spewing Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Tunnel Furnaces (AREA)
- Furnace Details (AREA)
- Manufacturing Of Printed Wiring (AREA)
Description
【考案の詳細な説明】
本考案は連続厚膜焼成炉の改良に関する。厚膜
集積回路の製造においては、アルミナ等の基板上
に所要の回答パターンを印刷したのち、これをレ
ベリング及び乾燥し次いで焼成する工程がとられ
る。この厚膜回路の焼成を行う手段として最近で
は近赤外線を利用した赤外線加熱方式が採用され
ているが、本方式は焼成時間の短縮という点では
メリツトはあるものの、この方式で予熱・バーン
アウトおよび本焼成の全工程を行つた場合には、
複数の赤外線ランプによる熱放射という特性から
波長のフラツキなどにより温度分布が炉内各部で
一様となりにくく、ことに一定のキープ時間（た
とえば10分）のあいだきわめて高い温度精度（た
とえば±1.5〜２℃以内）の再現を必要とする本
焼成工程においてペースト内金属成分の酸化、還
元および融合反応を安定して行い得ず、そのため
特に抵抗体印刷ペーストを焼成した場合に回路特
性に大きなバラツキが生じ、歩留りを悪下させる
という欠点があつた。[Detailed Description of the Invention] The present invention relates to an improvement of a continuous thick film firing furnace. In the production of thick film integrated circuits, the process of printing a desired response pattern on a substrate such as alumina, leveling and drying, and then firing the printed pattern is performed. Recently, an infrared heating method using near-infrared rays has been adopted as a means of firing this thick film circuit, but although this method has the advantage of shortening the firing time, it is difficult to prevent preheating, burnout, etc. If the entire process of main firing is carried out,
Due to the characteristics of heat radiation from multiple infrared lamps, it is difficult for the temperature distribution to be uniform in each part of the furnace due to fluctuations in wavelength, etc., and in particular, extremely high temperature accuracy (for example, ±1.5 to 2 During the main firing process, which requires reproduction of temperatures (within 30°F (°C) However, it had the disadvantage of decreasing yield.
本考案は上記した従来の厚膜焼成炉の不具合を
解消し、焼成時間を短縮できるうえに安定した高
い温度精度を再現でき、品質の良好な抵抗体焼成
を行うことができる連続式厚膜焼成炉を提供しよ
うとするもので、その特徴とするところは同一炉
内で赤外線直接放射により予熱・バーンアウトを
行い、続いて抵抗加熱による間接加熱で一定のキ
ープ時間のあいだ本焼成を行うようにしたことに
ある。 The present invention solves the problems of the conventional thick film firing furnace described above, shortens the firing time, and reproduces stable and high temperature accuracy.The continuous thick film firing furnace is capable of firing high-quality resistors. It is intended to provide a furnace, and its feature is that in the same furnace, preheating and burnout are performed using direct infrared radiation, followed by indirect heating using resistance heating for the main firing for a certain holding time. It's what I did.
すなわち本考案は、基板上に厚膜ペーストを印
刷した被処理物をコンベアベルトで移送させつつ
焼成する横型連続炉において、トンネル状炉体内
に入口側の炉室と残部炉室とを区画する仕切壁を
設け、残部炉室に入口側の炉室に到らぬように炉
芯管を内挿するとともに、炉芯管と入口側の炉室
を貫いてコンベアベルトを移動自在に配し、前記
入口側の炉室に被処理物を直接加熱してバーンア
ウトを行う赤外線ヒータを配設し、炉芯管外周に
本焼成用の抵抗発熱体を配したことを特徴とする
ものである。 In other words, the present invention is a horizontal continuous furnace in which a workpiece printed with a thick film paste on a substrate is fired while being transported by a conveyor belt. A wall is provided, a furnace core tube is inserted into the remaining furnace chamber so as not to reach the furnace chamber on the entrance side, and a conveyor belt is movably arranged to pass through the furnace core tube and the furnace chamber on the entrance side. The furnace chamber on the entrance side is equipped with an infrared heater that directly heats the workpiece to perform burnout, and a resistance heating element for main firing is arranged around the outer periphery of the furnace core tube.
以下本考案の実施例を添付図面に基いて説明す
る。 Embodiments of the present invention will be described below with reference to the accompanying drawings.
第１図ないし第３図において、１はセラミツク
などの耐火材で構成されたトンネル状の炉体であ
り、この炉体１には入口からたとえば炉長の約1/
３〜1/5の位置に相当する部位に内方へ張出す仕切
り壁２が設けられ、この仕切り壁２により入口側
の炉室３と後側の長大な炉室４とが区画形成され
ている。 In Figures 1 to 3, 1 is a tunnel-shaped furnace body made of a refractory material such as ceramic, and the furnace body 1 is entered from the entrance to about 1/1/2 of the furnace length.
A partition wall 2 extending inward is provided at a position corresponding to 3 to 1/5, and this partition wall 2 defines a furnace chamber 3 on the entrance side and a long furnace chamber 4 on the rear side. There is.
５，５′は前記入口側の炉室内に所定間隔で配
設された赤外線ヒータであり、アルゴンなどの不
活性ガスを充填した石英シーズの如きにタングス
テンフイラメント類を納めたランプ等により構成
され、フイラメントに加える電圧により波長を直
接制御せしめるようになつている。 Infrared heaters 5 and 5' are arranged at predetermined intervals in the furnace chamber on the inlet side, and are composed of lamps containing tungsten filaments such as quartz seeds filled with an inert gas such as argon. The wavelength can now be directly controlled by applying a voltage to the filament.
６は後側の長大な炉室４の全長にわたり挿設さ
れた炉芯管であり、石英もしくは耐熱鋼により構
成され、その先端部６１をもつて前記仕切り壁２
に嵌合保持され、中間部はセキ８，８により間隔
的に支承されている。そして炉芯管６の外周域の
炉室内壁には抵抗発熱体７が配設され、測定用熱
電対９により給電力をコントロールするようにな
つている。 A furnace core tube 6 is inserted over the entire length of the large rear furnace chamber 4, and is made of quartz or heat-resistant steel.
The intermediate portion is supported by the shafts 8, 8 at intervals. A resistance heating element 7 is disposed on the inner wall of the furnace chamber in the outer peripheral area of the furnace core tube 6, and the power supply is controlled by a measuring thermocouple 9.
１０はベルトコンベアであり、炉体前後のプー
リ１１，１１′に懸回され、駆動装置１２により
所定速度で印刷基板Ｗを搬送するようになつてお
り、入口側の炉室３には炉床から炉芯管とほぼ同
レベルの高さでベルト受け１３が設けられてい
る。 Reference numeral 10 denotes a belt conveyor, which is suspended by pulleys 11 and 11' at the front and rear of the furnace body, and is adapted to convey the printed circuit board W at a predetermined speed by a drive device 12. A belt support 13 is provided at approximately the same height as the furnace core tube.
１４は炉芯管６の後端に連接された冷却筒であ
り、水冷ジヤケツトにより２重筒として構成され
ている。１５は入口筒であり乾燥清浄空気の導入
部１６と強制排気部１７が設けられている。 A cooling cylinder 14 is connected to the rear end of the furnace core tube 6, and is configured as a double cylinder with a water cooling jacket. Reference numeral 15 denotes an inlet cylinder, which is provided with an introduction part 16 for dry clean air and a forced exhaust part 17.
本考案は上記のような構成からなるので、基板
に抵抗ペーストなどを印刷した印刷基板Ｗを焼成
するにあたつては、予め赤外線ヒータ５，５′に
昇温及びバーンアウト用の所定電圧を設定すると
共に、抵抗発熱体７にフアイアリング用キープ温
度に対応する電力を設定し、各ガス導入部にクリ
ーンエアもしくはN2ガスを供給する。 Since the present invention has the above-mentioned configuration, when firing the printed circuit board W on which a resistive paste or the like is printed, a predetermined voltage for temperature increase and burnout is applied to the infrared heaters 5 and 5' in advance. At the same time, power corresponding to the firing keep temperature is set for the resistance heating element 7, and clean air or N2 gas is supplied to each gas introduction section.
このような条件で次に駆動装置１２によりコン
ベアベルト１０を移動させつつ、このコンベアベ
ルト１０に印刷基板Ｗを栽置すれば、印刷基板Ｗ
は入口筒１５から大きなボリユームの入口側炉室
３に装入される。この入口側炉室３には赤外線発
熱ヒータ５，５′が配設されており、各赤外線発
熱ヒータ５，５′から設定電圧に対応する波長で
赤外線エネルギが直接放射され、これが印刷基板
Ｗのペーストに急速に浸透する。これによりペー
ストは急加熱されペースト内有機物が蒸発しクリ
ーンエアによりバーンアウトされる。このように
赤外線加熱で予焼成とバーンアウトを行うため、
抵抗加熱方式にくらべて同工程に要する時間がき
わめて短かくなり、また赤外線放熱の特性から抵
抗加熱方式で急加熱した場合のようなペーストの
表面膜の剥れや有機物の噴出しなどの不具合が生
じない。 Under these conditions, if the printed circuit board W is placed on the conveyor belt 10 while moving the conveyor belt 10 by the drive device 12, the printed circuit board W
is charged from the inlet cylinder 15 into the large volume inlet side furnace chamber 3. Infrared heaters 5 and 5' are disposed in the inlet furnace chamber 3, and infrared energy is directly radiated from each infrared heater 5 and 5' at a wavelength corresponding to the set voltage. Penetrates the paste quickly. As a result, the paste is rapidly heated, organic matter in the paste evaporates, and is burnt out by clean air. In this way, infrared heating is used to perform pre-firing and burnout.
The time required for the same process is extremely short compared to the resistance heating method, and due to the characteristics of infrared heat radiation, there are no problems such as peeling of the surface film of the paste or spewing out of organic matter, which can occur when rapidly heating with the resistance heating method. Does not occur.
上記のように入口側炉室３で急加熱されること
により印刷基板Ｗは本焼成温度に到るが、この印
刷基板Ｗはベルトコンベア１０により引続いて炉
芯管６に装入されそのまま移送されながら炉芯管
６の外周の抵抗発熱体７により一定時間のあいだ
加熱される。この場合、炉室４が入口側の炉室３
と仕切壁２により区画され、入口側炉室３の赤外
線放射エネルギによる外乱がほとんどないこと、
抵抗発熱体７による間接加熱であるため炉芯管内
全体が一様な温度分布となりいわゆるコールドポ
イントが生じないこと、温度制御が容易で赤外線
放射の場合のような電圧の変化に伴う波長のフラ
ツキという不安定要素がないこと、炉芯管６と入
口側炉室３との断面積差によりクリーンガスが入
口側方向へときれいに流れることなどにより、印
刷基板Ｗに高い温度精度と雰囲気を与えることが
できる。したがつて印刷ペーストの還元、酸化お
よび合金反応がきわめて安定した状態で進行し、
こうして焼成を終えた印刷基板Ｗは炉体１から送
出されることにより徐冷され、冷却部１４におい
て降温冷却されることにより特性のバラツキの少
ない目的IC製品となる。 As mentioned above, the printed circuit board W reaches the main firing temperature by being rapidly heated in the inlet furnace chamber 3, but this printed circuit board W is subsequently charged into the furnace core tube 6 by the belt conveyor 10 and transferred as it is. While heating, the furnace core tube 6 is heated for a certain period of time by the resistance heating element 7 on its outer periphery. In this case, the furnace chamber 4 is the furnace chamber 3 on the inlet side.
and partition wall 2, and there is almost no disturbance due to infrared radiant energy of inlet side furnace chamber 3;
Because indirect heating is performed by the resistance heating element 7, the temperature distribution throughout the furnace core tube is uniform, so that so-called cold points do not occur, and temperature control is easy and there is no fluctuation in wavelength due to voltage changes as in the case of infrared radiation. The absence of unstable elements and the difference in cross-sectional area between the furnace core tube 6 and the inlet-side furnace chamber 3 allow the clean gas to flow cleanly toward the inlet side, making it possible to provide the printed circuit board W with high temperature accuracy and atmosphere. can. Therefore, the reduction, oxidation and alloying reactions of the printing paste proceed in an extremely stable manner,
The printed circuit board W that has been fired in this way is sent out from the furnace body 1 and is slowly cooled, and then cooled down in the cooling section 14 to become a target IC product with less variation in characteristics.
以上説明した本考案によるときには、トンネル
状炉体１内に入口側の炉室３と残部炉室４とを区
画する仕切壁２を設け、残部炉室４に入口側の炉
室３に到らぬように炉芯管６を内挿するととも
に、炉芯管６と入口側の炉室３を貫いてコンベア
ベルト１０を移動自在に配す一方、入口側の炉室
３に被処理物を直接加熱してバーンアウトを行う
赤外線ヒータ５，５′を配設し、芯管６外周に本
焼成用の抵抗発熱体７を配したので、入口側の炉
室３において印刷基板に赤外線ヒータ５，５′か
ら電磁波が直接照射されてペーストが急速加熱さ
れ、それにより有機物が蒸発、バーンアウトさ
れ、るため、処理時間が極めて短く、かつペース
トの表面の割れや有機物の噴出が生じない。 According to the present invention described above, a partition wall 2 is provided in the tunnel-like furnace body 1 to partition the furnace chamber 3 on the entrance side and the remaining furnace chamber 4, and the remaining furnace chamber 4 is connected to the furnace chamber 3 on the entrance side. At the same time, a conveyor belt 10 is movably arranged passing through the furnace core tube 6 and the furnace chamber 3 on the inlet side, and the material to be processed is directly inserted into the furnace chamber 3 on the inlet side. Infrared heaters 5, 5' for heating and burnout are provided, and a resistance heating element 7 for main firing is provided around the outer periphery of core tube 6. The paste is rapidly heated by direct irradiation of electromagnetic waves from 5', thereby evaporating and burning out the organic matter, so the processing time is extremely short and no cracking on the surface of the paste or spouting of organic matter occurs.
しかも、続く焼成工程が抵抗加熱で行われ、温
度分布が一様で、電圧の変化による波長のフラツ
キすなわち電磁波のムラという不安定さがなく、
かつ、この抵抗加熱を行う残部炉室４が入口側の
炉室３と仕切壁２で区画されているため、炉室４
に赤外線による外乱がほとんどなく、さらに入口
側の炉室３と炉芯管６との断面積差によりクリー
ンガスが印刷基板と向流するように入口側に流れ
る。そのため、焼成工程が極めて高い温度精度条
件と雰囲気条件で行われ、前段のバーンアウト処
理とあいまち、回路特性のバラツキの少ない良質
の厚膜ICを歩留り良く量産することができると
いうすぐれた効果が得られる。 What's more, the subsequent firing process is performed by resistance heating, so the temperature distribution is uniform, and there is no instability caused by fluctuations in wavelength due to voltage changes, that is, unevenness in electromagnetic waves.
Moreover, since the remaining furnace chamber 4 in which this resistance heating is performed is divided by the furnace chamber 3 on the inlet side and the partition wall 2, the furnace chamber 4
There is almost no disturbance due to infrared rays, and furthermore, due to the difference in cross-sectional area between the furnace chamber 3 and the furnace core tube 6 on the inlet side, clean gas flows toward the inlet side in a countercurrent manner to the printed circuit board. Therefore, the firing process is performed under extremely high temperature accuracy and atmospheric conditions, which, in combination with the burnout process in the previous stage, has the excellent effect of mass-producing high-quality thick-film ICs with less variation in circuit characteristics at a high yield. It will be done.
第１図は本考案に係る連続厚膜焼成炉の一実施
例を示す縦断側面図、第２図は第１図における予
熱・バーンアウトゾーンの拡大断面図、第３図は
第１図における本焼成ゾーンの拡大断面図であ
る。
１……炉体、２……仕切壁、３……入口側炉
室、４……残余炉室、５，５′……赤外線ヒータ、
６……炉芯管、７……抵抗発熱体、１０……コン
ベアベルト。
Fig. 1 is a vertical sectional side view showing an embodiment of the continuous thick film firing furnace according to the present invention, Fig. 2 is an enlarged sectional view of the preheating/burnout zone in Fig. 1, and Fig. 3 is the book in Fig. FIG. 3 is an enlarged cross-sectional view of the firing zone. 1...Furnace body, 2...Partition wall, 3...Inlet side furnace chamber, 4...Remaining furnace chamber, 5, 5'...Infrared heater,
6...furnace core tube, 7...resistance heating element, 10...conveyor belt.
Claims (1)
ンベアベルトで移送させつつ焼成する横型連続炉
において、トンネル状炉体１内に入口側の炉室３
と残部炉室４とを区画する仕切壁２を設け、残部
炉室４に入口側の炉室３に到らぬように炉芯管６
を内挿するとともに、炉芯管６と入口側の炉室３
を貫いてコンベアベルト１０を移動自在に配し、
前記入口側の炉室３に被処理物を直接加熱してバ
ーンアウトを行う赤外線ヒータ５，５′を配設し、
炉芯管６外周に本焼成用の抵抗発熱体７を配した
ことを特徴とする連続厚膜焼成炉。 In a horizontal continuous furnace in which a workpiece having a thick film paste printed on a substrate is fired while being transported by a conveyor belt, a furnace chamber 3 on the entrance side is provided in a tunnel-shaped furnace body 1.
A partition wall 2 is provided to separate the remaining furnace chamber 4 from the remaining furnace chamber 4, and a furnace core tube 6 is provided in the remaining furnace chamber 4 so as not to reach the furnace chamber 3 on the inlet side.
At the same time, insert the furnace core tube 6 and the furnace chamber 3 on the inlet side.
A conveyor belt 10 is movably arranged through the
Infrared heaters 5 and 5' are arranged in the furnace chamber 3 on the inlet side to directly heat the workpiece to burn out,
A continuous thick film firing furnace characterized in that a resistance heating element 7 for main firing is arranged around the outer periphery of a furnace core tube 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2721282U JPS58131662U (en) | 1982-03-01 | 1982-03-01 | Continuous thick film firing furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2721282U JPS58131662U (en) | 1982-03-01 | 1982-03-01 | Continuous thick film firing furnace |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58131662U JPS58131662U (en) | 1983-09-05 |
| JPH0243038Y2 true JPH0243038Y2 (en) | 1990-11-15 |
Family
ID=30039129
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2721282U Granted JPS58131662U (en) | 1982-03-01 | 1982-03-01 | Continuous thick film firing furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58131662U (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6247185A (en) * | 1985-08-27 | 1987-02-28 | 富士通株式会社 | Drying of thick film circuit part |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5442283U (en) * | 1977-08-31 | 1979-03-22 |
-
1982
- 1982-03-01 JP JP2721282U patent/JPS58131662U/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5442283U (en) * | 1977-08-31 | 1979-03-22 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58131662U (en) | 1983-09-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH0442113B2 (en) | ||
| JPH07509102A (en) | Apparatus and method for soldering components onto plates | |
| JPS5825860A (en) | Method and device for heating of casting | |
| JPH0243038Y2 (en) | ||
| GB1520770A (en) | Method and apparatus for preheating metal | |
| JPH0826760A (en) | Method for bending and tempering of sheet glass | |
| US3542349A (en) | Radiation-type heating furnace with atmosphere regulation | |
| JPH02204935A (en) | Method and device for manufacturing fluorescent lamp | |
| JPH0132762Y2 (en) | ||
| US3471135A (en) | Tunnel kiln for firing ceramics | |
| JP2003292154A (en) | Heat-treating apparatus for thick-film printed circuit board, and carrier roller | |
| CA2159569C (en) | Apparatus and method for continuous processing of granular materials using microwaves | |
| JPS54154376A (en) | Jig for detecting internal temperature of horizontal type heat treatment furnace | |
| US5876198A (en) | Sequential step belt furnace with individual concentric heating elements | |
| US2925260A (en) | Furnace | |
| US4719333A (en) | Firing of ceramic ware | |
| JPH074839A (en) | Apparatus for drying metal plate for printing | |
| JPH01131887A (en) | Resistor with axial connector and device for drying other electronic element | |
| FR2369228A1 (en) | Variable length furnace for firing ceramics - in a single layer having removable segments of preheating and cooling regions | |
| EP0237334A3 (en) | Process and apparatus for the firing of ceramic products | |
| US3142884A (en) | Method and apparatus for controlling the cooling zone of a tunnel kiln | |
| US1917924A (en) | Ceramic ware treating method and apparatus | |
| JPH04268187A (en) | Continuous burning furnace | |
| JPH0240476Y2 (en) | ||
| Astsaturov et al. | An Investigation of Heat Exchange in the Jet Heating of Billets |