JB/T 4311.8-1991 Indirect resistance furnace SK series experimental tube resistance furnace
Some standard content:
Mechanical Industry Standard of the People's Republic of China
JB/T4311.8-1991
Indirect Resistance Furnace
SK Series Experimental Tubular Resistance Furnace
Published on 1991-06-28
Implementation by the Ministry of Machinery and Electronics Industry of the People's Republic of China on 1992-07-01
Mechanical Industry Standard of the People's Republic of China
Indirect Resistance Furnace
SK Series Experimental Tubular Resistance Furnace
JB/T4311.8-1991
Replaces JB4311.8-1987
This standard specifies the requirements for SK series experimental tubular resistance furnace products (hereinafter referred to as tubular furnaces), including varieties and specifications, technical performance, and ordering and supply. This standard applies to natural atmosphere experimental tubular resistance furnaces. 2www.bzxz.net
Cited Standards
GB10067.1
GB10067.4
GB10066.1
GB10066.4
ZBK60001
JB/Z146
Basic Technical Requirements for Electric Heating Equipment
Basic Technical Requirements for Electric Heating Equipment
Part I
General Part
Part IV
Part Part I
Test methods for electric heating equipment
Test methods for electric heating equipment
Part IV
Safety of electric heating equipmentPart I
Product model compilation method for electric heating equipment
Painting process for electrical products
Indirect resistance furnace
General part
Indirect resistance furnace
General part
Except for the following supplementary provisions, the rest shall be in accordance with the provisions of Chapter 3 of GB10066.4. 3.1 Furnace size
The furnace cavity size referred to in this standard is the nominal size of the furnace. The furnace length is the axial range of the heating elements arranged in the furnace specified in the design of the tubular furnace and indicated on the drawing, and the diameter is the inner diameter of the furnace tube. 3.2 Working area size
The size of the space for placing the charge in the furnace tube specified in the design of the tubular furnace and indicated on the drawing, where the working area diameter is the inner diameter of the furnace tube. 4 Product Classification
4.1 Varieties and Specifications
Tube furnaces are divided into several varieties according to their structure and maximum operating temperature, as shown in Table 1. Table 1
(SK13)
Approved by the Ministry of Machinery and Electronics Industry on June 28, 1991
Ordinary type
Rotary type
Maximum operating temperature
Implemented on July 1, 1992
(SKS13)
JB/T4311.8-1991
Continued Table 1
Open type
Double-tube type
Three-tube type
Four-tube type
Note: The variety codes in Tables 1 to 5 are enclosed in brackets, indicating that the variety is a reserved variety. Maximum operating temperature
Other maximum operating temperature values are allowed in enterprise product standards. At this time, the number in the product code (maximum working temperature divided by 100 without decimals) should be changed accordingly.
4.1.2 Tube furnaces of various types are divided into multiple specifications according to the size of the working area. The size of the working area should meet the following requirements: a. The minimum length of the working area is 50mm, and it increases by 10mm between 50 and 100mm, and increases by 25mm after 100mm. However, for open furnaces, the minimum length of the working area is 15mm, and it increases by 10mm between 15 and 95mm, and increases by 25mm after 95mm.
The inner diameter of the furnace tube is 20, 30, 40, 50, 60, 80 and 100mm. b.
The working area should be located in the middle of the tube furnace. 4.1.3 Each tube furnace manufacturer can choose from the varieties and specifications specified in Articles 4.1.1 and 4.1.2, and formulate their own enterprise product standards for tube furnaces accordingly.
4.2 Model
The model of the tube furnace shall be compiled according to ZBK60001, and the technical level code shall be determined according to Article 7.3 of this standard. Main parameters
In the enterprise product standard, the following items shall be listed for each model of the tube furnace; a,
Power supply voltage, V
Power supply frequency, Hz;
Number of phases,
Rated power, kW,
Connection method of heating element (applicable to three-phase tube furnace); working temperature, ℃
Bowel size, mm;
Working area size, um
Furnace temperature uniformity (applicable to tube furnaces using metal heating elements), CFurnace temperature stability,,
Surface temperature rise, K,
Empty furnace loss, kW,
m. Empty furnace heating time, min;
Weight, kg,
o, overall dimensions, mm.
JB/T4311.8-1991
When the tube furnace is powered by a voltage regulator or transformer, the working voltage should be listed separately. 5 Technical requirements
1 General requirements
The tube furnace should comply with the provisions of Chapter 5 of GB10067.4. When there are differences with the provisions of this standard, this standard shall prevail. 5,2 Supplementary requirements for design and manufacturing
5.2.1 Overall design
The tube or furnace is mainly composed of the furnace body and the controller, which can be combined into one body. If necessary, a bracket should be set. For rotary furnaces, the rotation angle in both directions from the horizontal position should reach 90°, and the positioning must be firm. For open furnaces, the movable closing part shall have good insulation and sealing performance to reduce heat loss, and shall be equipped with a locking device; the opening angle after opening shall not be less than 90°, and it shall be able to stably maintain the open position. The design of multi-tube furnaces shall keep the temperature of the corresponding parts of each tube as consistent as possible. 5.2.2 Furnace shell and support
The furnace shell shall be made of steel plate and properly reinforced. All welds shall be reliably welded to form a rigid structure. The support of the rotary furnace shall be able to stably support the furnace body, and its two supporting points shall be concentric and equal in height so that the furnace body can rotate flexibly. In addition to the furnace shell made of stainless steel or surface-treated steel plate, its outer surface shall be sprayed with heat-resistant protective paint, and the paint accuracy shall not be lower than the dish grade in JB/Z146.
5,2.3 Furnace lining
The material and structure of the furnace lining shall meet the performance requirements for tube furnaces (see Article 5.3). The lining of the C-class furnace shall be made of refractory fiber except for the furnace tube.
The service life of the furnace lining shall be no less than 3 years for ordinary refractory lining tube furnaces and no less than 1.5 years for refractory fiber lining tube furnaces. However, for tube furnaces whose linings need to be replaced at the same time as the heating elements, the service life of the lining shall not be less than the service life of the heating elements. 5.2.4 Heating elements
For tube furnaces with a maximum operating temperature not exceeding 1200℃, the heating elements are generally made of electric heating alloys; for those above 1200℃, silicon carbide, molybdenum disilicide or materials with the same or better comprehensive properties are used. Furnaces using non-metallic heating elements such as silicon carbide should be equipped with multi-tap transformers or other voltage regulating devices, and the heating elements should be guaranteed to work normally throughout the service life. The service life of the heating element is limited to when its input power at the rated power supply voltage or the maximum operating voltage is less than 15% of the rated power, and shall comply with the provisions of Table 2.
SKK9, SK10, SKH10, SKS10, SKT10, SKF10. SK12, SKH12, SKS12, SKT12, SKF12, (SK13), (SKS13), SK14, SKS14, SKT14, SKF14. 5.2.5 Furnace door or furnace plug
Service life》
The furnace door or furnace plug shall have the same good fire resistance and heat insulation performance as the furnace village, and shall ensure that the furnace chamber or furnace tube is reliably sealed when it is closed or inserted.
JB/T 4311.81991
5.2.8 Measurement, control and record
The measurement, control and record of the tube furnace shall comply with the provisions of Article 5.2.7 of GB10067.4 except Article 5,2.7.7 and Article 5,2.7.10 and the following supplementary provisions.
Class C furnaces shall be equipped with digital display program temperature control instruments with a resolution of not less than 1°C and equipped with microprocessors. The digital display shall be clearly legible. The instrument shall be equipped with an external socket for connecting a recorder or printer. When required (see Section 9.2), the tube furnace shall be equipped with an over-temperature controller or over-temperature fuse. The over-temperature control circuit shall be an independent circuit. The controller shall be able to select the over-temperature control point. When the furnace temperature reaches the over-temperature control point, the controller shall operate to cut off the heating power supply of the tube furnace and cause the control system to sound an audible alarm. Unless manually started, the furnace will remain in the power-off state. The accuracy of the over-temperature controller shall not be less than Class 1.
5.2.7 Grounding
The grounding of the tube furnace shall comply with the requirements of Article 10.4 of GB5959.1, and the grounding screw of its grounding terminal shall be no less than M6.5.3 Performance requirements
The performance of the tube furnace shall comply with the requirements of Article 5.3 and the following articles of GB10067.4. 5.3.1 Working temperature
Unless otherwise specified (see Article 4.1.1), the working temperature of the tube furnace shall be within the range listed in Table 3. Table 3
SK10, SKH10, SKS10, SKT10, SKF10SK12, SKH12, SKS12, SKT12, SKF12(SK13), (SKS13)
SK14, SKS14, SKT14, SKF14
Working temperature
750~900
750~1000
950~1200
1150~1300
1150~1400
Within the working temperature range, the tube furnace shall meet the requirements of furnace temperature uniformity and furnace temperature stability in Articles 5.3.2 and 5.3.3. 5.8.2 Furnace temperature uniformity
The furnace temperature uniformity of a tube furnace shall not exceed the range specified below, but this requirement does not apply to tube furnaces using non-metallic heating elements. Grade A furnace
±8℃
Grade B furnace
Grade C furnace
±5℃
±2℃
The maximum operating temperature of a tube furnace different from that listed in Article 4.1.1 shall be assessed according to the closest type. 5.3.3 Furnace temperature stability
The furnace temperature stability of a tube furnace shall not exceed the following specified range: Grade A furnace
±10℃
Grade B furnace
Grade C furnace
±4℃
5.8.4 Surface temperature rise
When a tube furnace is in a thermally stable state at the highest operating temperature, the surface temperature rise of its furnace shell and furnace door shall not exceed 100K, and the surface temperature rise of the operating handle shall not exceed 30K.
5.8.5 Empty furnace heating time
Unless otherwise required (see Article 9, 2), the empty furnace heating time of ordinary, rotary and open furnaces shall comply with the provisions of Table 4; the empty furnace heating time of double-tube 4
JB/T 4311.81991
furnaces, three-tube furnaces and four-tube furnaces shall be specified in the enterprise product standards. Table 4
Product code
(SK13)
Working area
5.3.6 Rated power and empty furnace loss
Empty furnace heating time
The rated power of the tube furnace should take into account factors such as furnace size, empty furnace heating time and maximum working temperature, and be specified in the enterprise product standards.
The empty furnace loss of the tube furnace should be specified in the enterprise product standards. The ratio of the empty furnace loss to the rated power of some varieties of tube furnaces should comply with the provisions of Table 5. Table 5
(SK13)
5.4 Complete set requirements
Area area
Empty furnace loss/rated power
5.4.1 The complete set supply scope of the tube furnace specified by the supplier should be listed in the enterprise product standards, generally including the following items: a. Tube furnace body,
b. Controller;
Temperature instrument;
Thermocouple;
Compensation wire:
Spare parts:
JB/T4311.8-1991
Product manual, including necessary drawings. 9.
The specific contents of the above items should be listed in the enterprise product standards, including models, specifications and quantities. If the purchaser has different requirements for the supply items specified by the supplier, it can be proposed in accordance with Article 9.2. 5.4.2 When the following accessories or devices are required; they can be proposed in accordance with Article 9.2. The necessary technical requirements shall be agreed upon by the supply and demand parties. a. Digital display program temperature control instrument with microprocessor; b. Temperature recorder;
c. Furnace tank (applicable to tubular furnaces with protective atmosphere or other special requirements). 6 Test method
The test of the tube furnace shall be carried out in accordance with the corresponding provisions of GB10066.1 and GB10066.4 and the following supplementary provisions. Measurement of furnace temperature uniformity and furnace temperature stability 6.1
The test temperature is stipulated as follows:
For a tube furnace with a maximum working temperature not exceeding 1200°C, the test temperature is its minimum working temperature and maximum working temperature respectively. For a tube furnace with a maximum working temperature exceeding 1200°C, the test temperature is 1200°C. The temperature measuring points are respectively set on the axis of the furnace tube, two of which are located at the intersection of the two end surfaces of the working area and the axis, and the other temperature measuring points are evenly distributed in between. The spacing between the temperature measuring points shall not be greater than 100mm, and the total number of temperature measuring points shall not be less than 3 points. 6.2 Measurement of surface temperature rise
The position of the measuring point is stipulated as follows:
The measuring point shall be at any point on the outer surface of the furnace shell, furnace door, operating handle, etc., except within the range of 75mm from the edge of the lead-out hole of the metal heating element and the thermocouple, 90mm from the edge of the lead-out hole of the non-metallic heating element, and 10mm from the opening seam (applicable to open-type furnaces), as well as the surface of the round furnace end plate and the upper surface of the square furnace tube. The surface thermometer with a measurement accuracy of not less than Class 5 shall be used for measurement, and the glass thermometer shall not be used. Inspection rules and classification
The inspection and classification of tubular furnaces shall be carried out in accordance with Chapter 7 and the following articles of GB100671. The factory inspection items of tubular furnaces are stipulated as follows:7.1
a. General inspection;
safety inspection;
detection of furnace size and working area size; inspection of furnace village quality;
inspection of manufacturing quality of heating elements,
measurement of cold DC resistance of metal heating elements; inspection of short circuit of heating elements to furnace shell;
measurement of insulation resistance (applicable to tubular furnaces for baking before leaving the factory); calibration of temperature instruments;
cold inspection of movement mechanism operation or action; inspection of interlock alarm system;
inspection of accessories, including inspection of model, specification and factory qualification certificates; m.
scope of supply, including inspection of completeness of factory technical documents; n.
packaging inspection.
7,2 The type inspection items of tube furnaces are as follows: a.
JB/T 4311.8—1991
All factory inspection items (under type inspection conditions), circuit test:
Measurement of empty furnace heating time;
Measurement of rated power,
Measurement of maximum working temperature;
Measurement of empty furnace loss,
Measurement of furnace temperature uniformity,
Measurement of furnace temperature stability;
Measurement of surface temperature rise;
Inspection after hot test;
, the technical classification of tube furnaces shall be as specified in Table 6. Tube furnaces of various technical levels shall fully meet the requirements listed in the table and other provisions of 7.3
of this standard.
Technical grade
Temperature instrument
According to the requirements of Article 5.2.3
According to the requirements of Article 5.2.7.3 of GB10067.4 and Article 5.2.6 of this standardAccording to the requirements of Articles 5.3.2, 5.3.3 and 5.3.5, it can provide complete sets of equipment according to the requirements of Article 5.4.1. National-level superior products of tubular furnaces should meet the requirements of the above C-level in terms of technology. 7.4
Marking, packaging, transportation and storage
The marking, packaging, transportation and storage of tubular furnaces should comply with the provisions of Chapter 8 of GB10067.1. The following items should be marked on the nameplate of the tube furnace: a.
Product model and name;
Power supply voltage, V,
Power supply frequency, Hz)
Number of phases,
Rated power, kW;
Heating element connection method (applicable to three-phase tube furnace); working temperature, ℃;
Working area size, mm,
Weight, kgs
Product number,
Manufacture date;
Manufacturer name (the country name should be indicated for export products). When the tube furnace is equipped with a voltage regulator or transformer, the working voltage should be listed separately. 9
Ordering and supply
Can provide complete sets of equipment according to the requirements of Articles 5.4.1 and 5.4.2
JB/T4311.81991
The ordering and supply of tube furnaces should be in accordance with the provisions of Chapter 9 of GB10067.1. 9.1
9.2 When the purchaser has the following special requirements, they can make them to the supplier. a. Different requirements for unit system, power supply voltage, power supply frequency, etc. (see Article 5.1.1.1 of GB100671); b. Different requirements for the use environment (see Articles 5.1, 2 of GB10067.1); c.
Additional requirements for safety and environmental protection (see Articles 5.1.5. of GB10067.1).1), special requirements for packaging (see GB10067.1 Articles 8, 2, and 5); different requirements for power supply (see GB10067.4 Article 5.2.2); different requirements for temperature instrument types, etc. (see GB10067.4 Article 5.2.7.3); requirement to provide over-temperature controller or over-temperature fuse (see Article 5.2.6); different requirements for empty furnace heating time (see Article 5, 3.5); different requirements for the supply items specified by the supplier (see Article 5, 4.1); requirement to provide digital display program temperature control instrument with microprocessor (see Article 5.4.2 a); requirement to provide temperature recorder (see Article 5.4.2 b); k.
requirement to provide furnace tank (see Article 5.4.2 c). The supplier should try its best to meet the special requirements of the buyer. However, the special requirements items that the buyer can actually choose are determined by the supplier according to their own conditions with reference to this standard. Part of it can be listed in the enterprise product standards, and the other parts are agreed upon by the supply and demand parties when ordering. Add a note:
This standard is proposed and managed by the National Technical Committee for Standardization of Industrial Electric Heating Equipment. This standard is drafted by Xi'an Electric Furnace Research Institute and Shanghai Experimental Electric Furnace Factory. The main drafters of this standard are Ge Huashan, Zhang Wanchun and Kou Jun. 8
People's Republic of China!
Mechanical Industry Standard
Indirect Resistance Furnace
SK Series Experimental Tubular Resistance Furnace
JB/T 4311.81991
Published by the Mechanical Science Research Institute
Printed by the Mechanical Science Research Institute
(No. 2 Shouti South Road, Beijing
Postal Code 100044)
Print Sheet X/X
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