JB/T 4311.7-1991 Indirect resistance furnace SX series practical box type resistance furnace
Some standard content:
Mechanical Industry Standard of the People's Republic of China
Indirect Resistance Furnace
SX Series Experimental Box Resistance Furnace
Subject Content and Scope of Application
JB4311.7—91
Replaces 4311.7—87
This standard specifies the requirements for SX series experimental box resistance furnace products (hereinafter referred to as box furnaces), including varieties and specifications, technical performance, and ordering and supply, etc. This standard applies to natural atmosphere and protective atmosphere experimental box resistance furnaces. Reference standards
GB10067.1
GB10067.4
GB10066.1
GB10066.4
ZBK60001
JB/Z146
3'Terms
Basic technical requirements for electric heating equipment Part 1 General part Basic technical requirements for electric heating equipment Part 4 Test methods for indirect resistance furnace electric heating equipment Part 1 General part Test methods for electric heating equipment Part 4: Safety of indirect resistance furnace electric heating equipment Part 1 General part Method for compiling product models for electric heating equipment
Painting process for electrical products
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 size referred to in this standard is the nominal size of the furnace. The "width" in the furnace size is the width of the furnace mouth, the "length" is the clearance distance between the inside of the furnace mouth and the rear wall of the furnace, and the "height" is the height of the furnace mouth, ignoring the arched part above the furnace mouth. Protective atmosphere
The atmosphere in the box furnace is used to protect the charge to avoid or reduce oxidation and decarburization during heating (see Article 9.1). 4 Product classification
4.1 Varieties and specifications
4.1.1 Box furnaces are divided into multiple varieties according to the furnace atmosphere and the maximum operating temperature, as shown in Table 1. Table 1
(SX13)
Approved by the Ministry of Machinery and Electronics Industry on June 28, 1991
Natural atmosphere
Maximum working temperature
Implemented on July 1, 1992
JB4311.7-91
Continued Table 1
Protective atmosphere
Maximum working temperature
Note: The brackets outside the variety code in Tables 1 to 6 indicate that the variety is a reserved variety. Other maximum working temperature values are allowed in the enterprise product standards. In this case, the number in the variety code (maximum working temperature divided by 100, without decimals) should be changed accordingly.
4.1.2 Each variety of box furnace is divided into multiple specifications according to the size of the working area. The dimensions of the working area (width × length × height) shall comply with the following provisions: Minimum specification: 60mm × 120mm × 40mm
Other specifications: Width and height increase by 40mm to 300mm and 200mm respectively, length increases by 40mm to 200mm first, and then increases by 80mm to 600mm.
The position of the working area in the furnace shall be indicated on the attached drawing in the box furnace product manual. 4.1.3 Each box furnace manufacturer may choose from the varieties and specifications specified in Articles 4.1.1 and 4.1.2, and formulate its own box furnace enterprise product standards accordingly.
4.2 Model
The model of the box furnace shall be compiled in accordance with ZBK60001, and the technical level code shall be determined in accordance with Article 7.3 of this standard. 4.3 Main parameters
In the enterprise product standards, the following items should be listed for each model of box-type 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 box-type furnace); working temperature, °C;
Furnace chamber size, mm,
Working area size, mm wwW.bzxz.Net
Furnace Temperature average, ℃;
Furnace temperature stability, ℃;
Empty furnace loss, kW,
Empty furnace heating time, min,
Applicable atmosphere and gas (or liquid) consumption, Nm\/h (or kg/h) (applicable to sXQ box furnace); m.
Weight, kg,
Overall dimensions, mm,
When the box furnace is powered by a voltage regulator or transformer, the working voltage should be listed separately. 5
Technical requirements
General requirements
Box furnaces 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. 48
5.2: Supplementary requirements for design and manufacture
5.2.1 Overall design
JB.4311.7—91
The box-type furnace is mainly composed of the furnace body and the controller, which can be combined into one. The furnace body is generally table-top. When a bracket for placing the furnace body is required, it can be proposed in accordance with Article 9.2. The SXQ box-type furnace should be an airtight structure used to work under the required protective atmosphere (see Article 9.1). 5.2.2 Furnace shell
The furnace shell should be made of steel plate and properly reinforced. All welds should be reliably welded to form a rigid structure. The furnace panel where the furnace mouth is located should be made of materials with small thermal deformation, and the furnace surface structure should be able to avoid warping. The furnace shell of the SXQ box-type furnace without a furnace tank should be welded into an airtight whole, and pipe joints for the inlet and outlet of protective gas should be set at appropriate positions on the furnace shell.
Except for furnace shells made of stainless steel or surface-treated steel plates, their outer surfaces shall be sprayed with heat-resistant protective paint, and the paint accuracy shall not be lower than the sub-grade in JB/Z146.
5.2.3 Furnace lining
The material and structure of the furnace lining shall meet the performance requirements for box-type furnaces (see Article 5.3). The lining of a Class C furnace shall be made of refractory fiber except for the bearing and collision-prone parts. The service life of the lining shall be no less than 3 years for ordinary refractory lining box-type furnaces; and no less than 1.5 years for refractory fiber lining box-type furnaces. However, for box-type furnaces whose linings need to be replaced at the same time as the heating elements, the service life shall not be less than the heating elements. 5.2.4 Heating elements
For SX-type box-type furnaces with a maximum operating temperature not exceeding 1200°C, the heating elements are generally made of electric heating alloys; for those above 1200°C, silicon carbide, molybdenum disilicide or materials with the same or better comprehensive properties shall be used. When selecting the heating element materials for SXQ box furnace, the effect of atmosphere on the materials should be considered.
For furnaces using non-metallic heating elements such as silicon carbide, multi-tap transformers or other voltage regulating devices should be equipped, and the heating elements should be guaranteed to work normally throughout the service life. The service life of the heating element is limited to the input power at the rated power supply voltage or the maximum working voltage being less than 15% of the rated power, and should comply with the provisions of Table 2.
Product code
SX10, SXQ10
SX12, SXQ12
(SX13), SX14, SXQ14
SX16, SXQ16
Service life of heating elements》
5.2.5 Furnace door
The furnace door is generally operated by manpower, and the opening and closing of the furnace door should be light and flexible, and should be equipped with appropriate balancing weights when necessary. When a power operating mechanism is required, it can be proposed in accordance with Article 9.2. The furnace door should have the same good fire resistance and heat insulation performance as the furnace lining, and have reliable sealing facilities to ensure reliable sealing of the furnace. The width of the overlap between the furnace door and the furnace mouth should not be less than 20mm. When it is required to set an observation hole on the furnace door, it can be proposed in accordance with Article 9.2. 5.2.6 Exhaust pipe
Box-type furnaces using reducing gas in the furnace should be equipped with exhaust pipes. The flame height on the exhaust pipe should be adjustable. 5.2.7 Measurement, control and recording
JB4311.7-91
The measurement, control and recording of box-type furnaces shall comply with the provisions of Article 5.2.7 of GB10067.4 except Articles 5.2.7.7 and 5.2.7.10 and the following supplementary provisions.
Class C furnaces should be equipped with digital display program temperature control instruments with a resolution of not less than 1°C and microprocessors. The digital display should be clearly legible, and the instrument should be equipped with an external socket for connecting a recorder or printer. When required (see Article 9.2), the box furnace should be equipped with an over-temperature controller or over-temperature fuse. The over-temperature control circuit should be an independent circuit. The controller should be able to select the over-temperature control point. When the furnace temperature reaches the over-temperature control point, the controller should operate to cut off the heating power of the box furnace and make the control system sound an alarm. Unless manually started, the furnace will remain in the power-off state. The accuracy of the over-temperature controller should not be less than Class 1.
5.2.8 Grounding
The grounding of the box furnace shall comply with the requirements of Article 10.4 of GB5959.1, and the grounding screw of its grounding terminal shall not be less than M6.5.3 Performance requirements
The performance of the box 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 box furnace shall be within the range listed in Table 3. Table 3
SX10, SXQ10
SX12, SXQ12
(SX13)
SX14, SXQ14
SX16, SXQ16
Working temperature
7501000
950~1200
11501300
11501400
1350~1600
Within the working temperature range, the box furnace shall meet the requirements of furnace temperature uniformity and furnace temperature stability in Articles 5.3.2 and 5.3.3. 5.3.2 Furnace temperature uniformity
The furnace temperature uniformity of box-type furnaces shall not exceed the range specified in Table 4. Table
SX10, SXQ10, SX12, SXQ12
(SX13), SX14, SXQ14
SX16, SXQ16
Uniformity
The maximum operating temperature of the box-type furnaces is different from that listed in Article 4.1.1, and their furnace temperature uniformity shall be assessed according to the similar varieties. Furnace temperature stability
The furnace temperature stability of a box-type furnace shall not exceed the following specified range: Grade A furnace
±10 ℃
Grade B furnace
Grade C furnace
±4℃
± 1℃
5.3.4·Surface temperature rise
When a box-type 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 100℃; the surface temperature rise of the 50℃ of the operating handle shall not exceed 30℃.
5.3.5 Empty furnace heating time
JB4311.7—91
Unless otherwise required (see Article 9.2), the empty furnace heating time of a box-type furnace shall comply with the provisions of Table 5. Table 5
SX10, SXQ10
SX12, SXQ12
(SX13)
SX14, SXQ14
SX16, SXQ16
5.3.6 Rated power and empty furnace loss
Working area volume
Empty furnace heating time
The rated power of the box-type furnace should take into account factors such as furnace size, empty furnace heating time and maximum working temperature, which should be specified in the enterprise product standards. The empty furnace loss of the box-type furnace should be specified in the enterprise product standards, and its ratio to the rated power should comply with the provisions of Table 6. Table 6
SX10, SXQ10
SX12, SXQ12
(SX13), SX14, SXQ14
SX16, SXQ16
5.4 Requirements for complete sets
Empty furnace loss/rated power
5.4.1 The complete set supply scope of box-type furnace specified by the supplier shall be listed in the enterprise product standards, generally including the following items: box-type furnace body,
b. Controller:
Temperature instrument:
Thermocouple:
Compensation wire:
f. Spare parts;
9. Product Manual, including necessary drawings. JB4311.7-91
The specific contents of the above items shall be listed in the enterprise product standards, including model, specification and quantity. If the purchaser has different requirements for the 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 SXQ type furnace): d. Protective gas generator and (or) its accessories (applicable to SXQ type furnace). 6 Test method
The test of box-type furnace shall be carried out in accordance with the corresponding provisions of GB10066.1 and GB10066.4 and the following supplementary provisions. 6.1 Measurement of furnace temperature uniformity and furnace temperature stability The test temperature is stipulated as follows:
For box-type furnaces with a maximum operating temperature not exceeding 1200℃, the test temperatures are the minimum operating temperature and the maximum operating temperature respectively. For box-type furnaces with a maximum operating temperature exceeding 1200℃, the test temperature is 1200℃. The test of SXQ box furnace is carried out under the condition that the furnace is in natural atmosphere. The arrangement of temperature measurement points for the temperature uniformity measurement of box furnace shall comply with the provisions of Article 6.13.3.2 of GB10066.4. 6.2 Exhaust pipe ignition test
This standard applies to SXQ box furnace. The test is carried out after the cold commissioning. With the furnace door closed, the reducing gas is introduced into the furnace. The gas escaping from the exhaust pipe is ignited. The flame height should be adjustable. 6.3 Measurement of surface temperature rise
The position of the measurement point is stipulated as follows:
The measurement point should be at any point on the outer surface of the furnace shell, furnace door, operating handle, etc., except 75mm from the edge of the metal heating element and thermocouple lead-out hole and the center of the furnace lining penetration fastener, 90mm from the edge of the furnace door and observation hole, and the surface where the non-metallic heating element lead-out hole is located and the upper surface of the furnace door.
The surface thermometer with a measurement accuracy of not less than Class 5 shall be used for measurement, and glass thermometer shall not be used. 7 Inspection rules and classification of grades
The inspection and classification of box-type furnaces shall be carried out in accordance with Chapter 7 of GB10067.1 and the following articles. 7.1 The factory inspection items of box-type furnaces are as follows: a. General inspection;
b. Safety inspection;
Detection of furnace size and working area size;c.
Inspection of furnace lining quality;
Inspection of manufacturing quality of heating elements;
Measurement of cold DC resistance of metal heating elements;f.
Inspection of short circuit of heating elements to furnace shell;
Measurement of insulation resistance (applicable to box-type furnaces for baking before leaving the factory); calibration of temperature instruments;
Cold inspection of operation or movement of motion mechanism (i.e. furnace door mechanism);k.
Inspection of interlock alarm system;
JB4311.7—91
Inspection of gas circuit system (applicable to SXQ type furnace), inspection of accessories, including inspection of model, specification and factory qualification certificate;mi
Scope of supply, including inspection of completeness of factory technical documents;n.
Packing inspection.
7.2 The type inspection items of box-type furnaces are as follows: a.
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;
Leakage detection of furnace shell (applicable to SXQ box-type furnace); j.
Inspection after hot test.
7.3 The technical classification of box-type furnaces shall be as specified in Table 7. Box-type furnaces of various technical levels shall fully meet the requirements listed in the table and other provisions of this standard.
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 5.2.7 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. The national-level superior products of box-type furnaces should meet the requirements of Class C above in terms of technology. Marking, packaging, transportation and storage
The marking, packaging, transportation and storage of box-type furnaces should comply with the provisions of Chapter 8 of GB10067.1. 8.1
The following items shall be marked on the nameplate of the box-type furnace: 8.2
Product model and name
Power supply voltage, Vs
Power supply frequency, Hz;
Number of phases;
Rated power, kW;
Connection of heating elements (applicable to three-phase box-type furnaces); Working temperature, ℃;
Working area dimensions, mm;
Weight, kg;
Product number,
Can complete sets of equipment be provided in accordance with the requirements of Articles 5.4.1 and 5.4.2
k. Date of manufacture,
JB4311.791
1. Name of manufacturer (country name shall be indicated for export products). When the box-type furnace is equipped with a voltage regulator or transformer, the working voltage shall be listed separately. 9 Ordering and Supply
9.1 The ordering and supply of box-type furnaces shall comply with the provisions of Chapter 9 of GB10067.1. For SXQ box-type furnaces, the type of atmosphere used (exothermic, endothermic, ammonia decomposition, nitrogen, dripping, etc.) shall be stated in the ordering documents. 9.2 If the purchaser has the following special requirements, they may 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 GB10067.1); b.
Different requirements for use environment (see Article 5.1.2 of GB10067.1); c.
Additional requirements for safety and environmental protection (see Article 5.1.5.1 of GB10067.1); special requirements for packaging (see Article 8.2.5 of GB10067.1); different requirements for power supply (see Article 5.2.2 of GB10067.4); different requirements for temperature instrument type, etc. (see Article 5.2.7.3 of GB10067.4) Requirement to provide a bracket for placing box furnace (see Article 5.2.1); requirement to provide a power operating mechanism for furnace door (see Article 5.2.5); requirement to install a power supply in the furnace Observation hole is set on the door (see Article 5.2.5); Over-temperature controller or over-temperature fuse is required (see Article 5.2.7); 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); Digital display program temperature control instrument with microprocessor is required (see Article 5.4.2a), Temperature recorder is required (see Article 5.4.2b); Furnace pot is required for SXQ box furnace (see Article 5.4.2c); Protective gas generator and (or) its accessories are required for SXQ box furnace (see Article 5.4.2d) P.
The supplier shall try its best to meet the special requirements of the buyer, but the special requirements that can be selected by the buyer shall be determined by the supplier according to their own conditions with reference to this standard. Some of them can be listed in the enterprise product standards, and the other parts shall be agreed upon by the supplier and the buyer when ordering. Additional Notes:
This standard was proposed and managed by the National Technical Committee for Standardization of Industrial Electric Heating Equipment. This standard was 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. 54
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