3.8　Automatic Control

3.8.1　Pusher type furnace shall be set with instrument control system；walking beam furnace shall be set with basic automatic control system（L1）made up by sequential control and instrument control.

3.8.2　The walking beam furnace's equipment movement sequence control shall be in accordance with the paragraph 1 of article 3.3.6.

For the walking beam furnace which is applied with cantilevered rolls for side charging，length measuring and positioning device should be installed before charging；variable frequency speed adjusting shall be adopted for rolls in furnace.

3.8.3　Instrument control system of the furnace whose fuel is gas or oil（large sized），should be basic automatic control level at least，its control and detection contents should comply with the following rules:

1　The main thermal control items shall include the following contents:

1）Auto control of the furnace temperature of heating section；

2）Auto proportion adjustment of the air and fuel of heating section；

3）Auto control of furnace pressure；

4）Pressure adjustment of the main hot air pipe；

5）Preheater protection control；

6）Oil temperature adjusting or viscosity adjusting for the large size furnace whose fuel is oil；

7）Surge control for combustion fan，namely，fan damper control.

2　Main thermal detection items shall include the following contents:

1）Hourly air and fuel flow rate of each zone（indication，logging）；

2）Accumulated fuel flow rate of furnace；

3）Temperature and pressure parameters of air，fuel and fume；

4）Low pressure signals of air and fuel and automatic disconnection；the low pressure signals and auto automatic disconnection device shall operate reliably in case of sudden power failure；

5）Measuring instruments as to flow rate，temperature and pressure shall be provided based on technological requirements for cooling water，compressed air，steam and other power medium.

3.8.4　Cameras can be installed on the charging end and discharging end furnace wall or other places on the furnace according to the furnace type and technological requirements.

3.8.5　The furnace whose fuel is gas or oil shall be set up with an instrument room.Operations such as furnace conditions display，set data modification，production data and report printing etc.can be done by computer.