Laboratory furnace heating method used

1, the heating
⑴ direct heating: Suitable for high temperature decomposable in solution or pure liquid, usually placed in containers filled with liquids, asbestos online with a gas lamp (or experimental furnace) heating.
⑵ heated on a water bath: For above 100 ℃ decomposition or combustion of volatile solution or pure liquid.
⑶ heated on the sand bath: General requirements at 100 ~ 400 ℃ heat evenly between those suitably heated sand bath.
2, evaporated
And heating the liquid, like, according to the thermal stability of the liquid, respectively by direct heating, water bath heating and a sand bath heated to evaporate. In order to accelerate the evaporation rate, in addition to an appropriate increase in temperature, the need to expand the evaporation area. Evaporation pan evaporation container used. During evaporation, the evaporation of the liquid remaining in plate should not exceed the total capacity of 2/3.

Furnace safe operating procedures

The use of high-temperature furnace heating current to the furnace heating elements or heating medium, and thus the workpiece or industrial furnace for heating materials. Industry resistance furnace divided into two categories, periodic furnace operation and continuous operation furnace, tube furnace is a high-temperature furnace, a unique feature has a simple structure, temperature uniformity, easy to control, heating quality is good, no smoke, no noise, etc., but with higher fees. Use high-temperature tube furnace furnace should strictly follow safe operating procedures to do, to ensure the safety of personnel and to avoid the furnace, the workpiece damage.
First, before work processes
1, check the furnace is clean, clean up debris to ensure the furnace clean.
2, check the furnace wall, floor furnace for cracks and other damage.
3, the resistance wire and thermocouple leads to the installation of fastening rods, check the meter is normal.
4, check the resistance furnace door switch is flexible.
5, to ensure that the normal, they began to put the workpiece.
Second, the work flow
1, put the workpiece to ensure that power is off.
2, gently so as not smashed heating elements, furnace floor, etc.;
3, put a wet piece is strictly prohibited, furnace heating of the workpiece and the heating element should be kept 50-70mm distance; workpiece should be placed neatly, not stacked too high in order to avoid damage the thermowell
4, the work examine the various instrumentation and, if abnormal, timely maintenance.
5, high-temperature furnace at 700 ℃ or more, are not allowed to open the door to cool down or baked, so as to avoid quench furnace shortened lifespan.
Third, the work process.
1, cut off the power supply
2, gently work, make sure not to damage the furnace and the workpiece.
3, replace furnace, according to the above procedure is repeated.
4, clear theory within the debris to ensure clean.
5, pay attention to routine maintenance work.

The RCW series of mesh belt heat treatment furnace

RCW series mesh belt heat treatment furnace:
The RCW series mesh belt heat treatment furnace with a high degree of automation, easy to adjust the parameters, low labor intensity, do not pollute the environment, energy conservation, etc., can be widely used in light machinery, textile machinery, weapons industry, mechanical and electrical industrial mass production The heat treatment of small and medium-sized workpieces.
Furnace shell is welded by steel plate and steel lining Light clay and aluminum silicate refractory fiber as a heat insulation material.
RCW series mesh belt heat treatment furnace lining structure:
RCW series mesh belt heat treatment furnace, furnace the backing insulation layer bulk density 0.8 high insulation bricks, insulation layer on both sides full aluminum silicate fibers, furnace shell surface pad with a layer of asbestos board (low temperature thermal conductivity minimum); lid insulation fiber acupuncture blanket module, with a special method of anchoring the lid on a steel plate (commonly known as the ceiling structure). This structure has good insulation effect, low energy storage, heat loss, good thermal shock resistance, easy maintenance and many other advantages. Greatly improve the life of the lining. The parameters of the furnace air furnace loss power, the temperature rise of the furnace wall, the furnace temperature uniformity better than national standards.
RCW series mesh belt heat treatment furnace temperature control instrumentation:
RCW Series mesh belt heat treatment furnace heating temperature control using the Japanese island of Yan / Island power (Shima) smart temperature. The instrument configuration module of self-tuning PID operation and standards can effectively prevent the temperature overshoot the same time, the instrument can function selection, configuration and parameter setting and digital display of set and actual values. Main heating SCR series of modular three-phase thyristor power controller, the use of continuous on-off control, it is not a traditional electrical on-off continuously and automatically adjust the heating power, but according to the temperature control requirements. High-power high precision temperature control, no noise, no interference in the internal grid.
RCW series mesh belt heat treatment furnace uses:
RCW Series mesh belt heat treatment furnace is mainly used for medium heat hardening, the thin layer carburizing and carbonitriding and subsequent tempering. Widely used in mass production of small and medium-sized parts, such as solid pieces, chains, bearings, small weapons, hardware tools, elastic components, sewing machines, bicycles, car and motorcycle, agricultural machinery parts quenching or thin smooth protective atmosphere carburizing and carbonitriding. According to the different kinds of steel, can be water, oil or molten salt quenching tank quenching agent.

Vacuum hot pressing furnace use Common Faults and exclusion method

High vacuum pumping on but does not leak (mean value of the vacuum table for a long time does not move)
Possible causes:
1. High vacuum gauge tube aging
 2. Diffusion pump oil aging
Solution: Replace the vacuum gauge; replacement diffusion pump oil.
But not on the low vacuum pumping does not leak (mean value of the vacuum table for a long time does not move)
Possible causes:
1 low vacuum current regulatory work incorrectly.
2. Mechanical pump oil aging
Solution: Adjust vacuum gauge tube current; replacement of mechanical pump oil.
Thermocouple automatic access failure, warning lights alarm
Possible causes:
1. Inner and outer limit failure.
2. Out of the motor does not turn.
Solution: Adjust or replace the external stopper; tests whether the motor has been broken, such as the replacement of the same type of motor bad. (Note) within the furnace limit should be observed before heating indicator light should be lit.
After a period of time the temperature does not rise up
Possible causes: heater resistance value becomes larger.
Solution: According to instructions to transfer large instrument output power; serious aging can only be replaced with a new heater
Incase control panel lights are on and the police overcurrent
Possible causes: heater shorted
Solution: Open the lid heater observe whether there is a short circuit, troubleshooting.
Over-temperature alarm and alarm lights on
Possible causes:
1. Over-temperature furnace
2. Instrument is set incorrectly
Solution: Press the manual reset over-temperature alarm parameters
Without water is lit and the alarm
Possible causes:
1. Valve did not open
2. Water pressure is too low
Solution: Open the valve; increase water pressure.

High temperature laboratory furnace lining thickness detection technology

High-temperature furnace lining life directly affects the overall life of the high-temperature furnace, today mainly talk about how to detect corrosion of furnace lining, describes several practical ways.
1, the resistance method
The lining is embedded in the resistive element, and lining the inner surface of the front of the sensor alignment, through a lead connected to the measurement system, the resistance value of the resistance element related to its length, as the resistance element and lining synchronization loss, resistance changes, the use of appropriate measurement meter element output measured electric signal line can be measured remaining thickness of the lining.
2, the capacitance method
Capacitance method and electrical resistance similar to the lining sensor is embedded coaxial circular capacitor, the capacitance value corresponding to its length relationship can be determined by measuring the capacitance value of the thickness of the furnace masonry.
3, heat detection
According to thermodynamics, temperature, thermal conductivity and thickness of the furnace wall of the heat intensity, the furnace lining, thermal conductivity is fixed, the temperature and heat flux intensity furnace wall thickness can be obtained.
Heat lining temperature sensor installed in the lower part, by cooling the hearth wall water temperature, heat flux intensity is calculated, and then the temperature inside the brick lining with galvanic the measured temperature value, calculated baked wall thickness.
4, the stress wave method
Stress wave signal has a high sensitivity to structural defect, when the stress wave propagation in a medium, in case of holes, cracks and other discontinuities in the interface occurs reflection, refraction, scattering, and mode conversion, the use of stress wave characteristics cooling can determine the thickness of the wall material.
Future trends in the lining thickness measurement is a combination of different methods. Furnaces, blast furnace body, the furnace can be long waist galvanic method or resistance method; Hearth Bottom parts can heat detection method or model extrapolation;-line monitoring, we can use the stress wave method.

Muffle furnace, box-type resistance furnace installation and use

Muffle furnace in China generic name for the following: furnace, resistance furnace, Burnout Furnaces, muffle furnace. Muffle furnace is a common heating equipment based on appearance and shape can be divided into box-type furnace tube furnace crucible furnace. Divided by nationality of domestic and imported muffle muffle furnace. Distinguished by the heating elements are: electric stove Sima Fu furnace, muffle furnace silicon carbide, silicon molybdenum rod muffle furnace; according to the rated temperature to distinguish generally divided into: 900 degrees series muffle furnace, muffle furnace 1000 degrees, 1200 degrees muffle furnace at 1300 degrees muffle furnace, muffle furnace 1600 degrees, 1700 degrees muffle furnace. Press the controller to distinguish between the following categories: pointer table, ordinary digital display table, PID regulation control table, the program control table; distinguished by insulation material: ordinary firebrick and ceramic fiber two kinds.Muffle furnace cycle mode of operation for the laboratory, industrial and mining enterprises, scientific research units for elemental analysis and general small steel hardening, annealing, tempering heat treatment, heating, high temperature muffle furnace can be made of metal, ceramic sintering, dissolution , analysis, high-temperature heating.Muffle furnace installation and use:1, after opening the package, check the muffle furnace is intact, accessories are complete. General muffle furnace does not require special installation, just flat on the ground or indoor flat shelf. Controller should avoid vibration, placement and should not be too close to the furnace, to prevent overheating and causing internal components can not work properly.2, a thermocouple inserted into the furnace 20-50mm, the gap between the hole and the thermocouple asbestos rope packing. Connect the thermocouple to the control is best to use compensation wire (or insulated steel core wire), pay attention to the positive and negative, not reversed.3, in the power cord into the power switch at the need to install in order to control the power. To ensure safe operation, the controller must be grounded furnace.4, prior to use, the thermometer indicator adjusted to 0:00, in the use of wires and cold junction compensation compensation, should the mechanical zero adjustment to the cold junction compensator reference temperature point, do not use compensation wire, then the mechanical zero adjusted to zero-scale bits, but the indicated temperature measurement points and the thermocouple cold junction temperature.5, after confirmation by checking wiring, cover the controller enclosure. The temperature indicator setting pointer adjustment to the desired operating temperature, then connect the power. Turn the power switch, then the green light on the temperature indicating instrument both light, relay start working, electric powered, ie a current meter display. As the internal temperature furnace, the temperature is gradually increased indicating instrument pointer, this phenomenon indicates that the system is working properly. Furnace heating, constant temperature, respectively, the temperature indicator of traffic lights, the green light indicates warming, red light means constant temperature.Maintenance and precautions:1, when the first use of a muffle furnace again after disabling or long-term use, the oven must be carried out. The oven temperature 200 ℃ time should be four hours. 200 ℃ to 600 ℃ four hours. When used, the furnace temperature shall not exceed the maximum rated temperature, to avoid burning heating element. Prohibit the furnace infusion of liquid and soluble in a variety of metals, Burnout oven below the maximum temperature of preferably below 50 ℃ work, then furnace wire has a longer life.2, muffle furnace and the controller must not exceed 85% relative humidity, no conductive dust, explosive or corrosive gases in the workplace. Where the grease is attached to a metal material being heated, the volatile gas will affect a large number of heating element surface and etching, so that destruction and shortened life span. Therefore, the heating should be timely prevention and well sealed containers or suitable openings to be eliminated.3, muffle furnace controller should be limited to the ambient temperature 0-40 ℃ range.4, according to the technical requirements, regular and frequent checks furnace, the controller of the wiring connection is good, whether the indicator pointer moves stuck stranded phenomenon, and because electricity meter calibration potentiometer magnets, demagnetization, up wire, shrapnel fatigue, balance error increases caused damage situation.5, thermocouples do not suddenly pull out at high temperatures to prevent the jacket burst.6, and keep the furnace clean, timely removal of the furnace oxide and the like things.

 

Box furnace slagging furnace main reason

Ash slagging itself, mainly with ash softening temperature, ash composition of various compounds (sulfur, iron content of large, low ash melting point), in which the atmosphere of ash (ash in a reducing atmosphere than low melting point, the oxidizing atmosphere) and other factors.
 Box furnace slagging external factors:1, the combustion space gas shortage;2, the fuel and air mixture is not sufficient;3, the flame deflection;4, the boiler overload operation;5, the furnace exit gas temperature increased (the lower chamber of air leakage, excessive amount of air, with the wind properly, coal and so will the flame is too rough on the move, exit gas temperature rise);6, box furnace boiler design capacity of the furnace volume heat intensity election too big. Power plant boilers, turbines, electrical, water treatment and other industries and technological exchanges thermoelectric specific analysis: You plant using low-quality bituminous coal, but look at your burner arrangement (not used classification with the wind), so I think you burning coal Although it is inferior bituminous coal, heat certainly is not high, but the ash content does not it (you did not specify ash content). Then cause the furnace slagging serious cause I speculated that it might still run to adjust the problem!Generally prevent the top box-type furnace slagging adjustment principles are: to maintain a low velocity air flow and a secondary air descending from top to bottom with the wind principles to control the burning rate, reduce the flame center position. I mention this statement and your method of adjusting the opposite; another one if it is caused by the back wall of flame center top side slagging, that both sides should try to tune the amount of wind or wind speed to be effective (which transfer large side of the air flow, depending on the inscribed circle is tangent or tangential).Cold ash hopper at the lower slagging analysis there are two possibilities: First, under the care of coal particles secondary air suction enough; if it is for this reason that it is appropriate to increase the lower secondary air, which prevents cold ash bucket Results residue, but not as you said to tone the back wall of the lower part of the hopper slagging severe cold, and opened the back wall of the lowermost two share a large secondary air), I think the key thing is to analyze the tangential way, then Press the airflow direction to reduce the back wall of the adjacent angles lower secondary upstream wind speed, while increasing the back wall an angle appropriate under secondary air; two are mixed under the direction of the back wall of the secondary air velocity is too large, causing the downstream (after wall side) a secondary air jet separation, the lower the position of the local coal combustion. The adjustment method should also be reduced back wall of an adjacent angles under the upstream secondary wind speed.