Vacuum atmosphere furnace maintenance required

Environmental testing equipment variety, but the most widely used environmental test equipment for the heat, cold, heat vacuum atmosphere furnace. Hot and cold impact testing machine, for example, to talk about the vacuum atmosphere furnace construction and some of the common faults and troubleshooting.
Some vacuum atmosphere furnace and troubleshooting common faults:
1 in the high-temperature tests, such as temperature changes reach the test temperature value, you can check the electrical system, each troubleshooting. Such as the temperature rose very slowly, we must view the air circulation system, look at the wind circulation damper is open properly, otherwise, check the air circulation motor is functioning properly. Such as temperature overshoot badly then you need to set the parameters of PID tuning. If the temperature rise directly, over temperature protection, then the controller failures, to be replaced control instrument.
(2) during the operation of the test equipment suddenly fails, control instruments corresponding fault appears on the display prompts and a voice alarm. The operator can control the operation of the device using the troubleshooting chapter quickly check out which category failure, you can ask professionals quick troubleshooting to ensure that the test correctly. Other environmental test equipment in use there will be other phenomena, it should be specific phenomenon, specific analysis and troubleshooting.
3 reach the test temperature indicator, then you have to observe the temperature changes, the temperature drop is very slow, the temperature to a certain value, or the temperature tends to increase, the former is necessary to check the laboratory vacuum furnace to make low-temperature test whether the studio before drying, so the studio remain dry and then do the test sample into the working chamber test, the working chamber of the test sample is placed too much, so that indoor air can not fully cycle, the exclusion of the above reasons , it is necessary to consider whether the failure of the refrigeration system, and so we must ask the manufacturer's maintenance professionals.

 

Through type muffle furnace, gas carburizing furnace heat treatment work safety rules

1. Blast furnace gas pipes should be checked to open the valve sealing and gas pipeline pressure is not less than the specified value.2. Air furnace test putter agencies, institutions and rod lifting mechanism work.3. Release of the compression spring to a predetermined size range.4. Regulate the water level in the water seal, seal exhaust combustion tube through the open valve, close the valve through the seal.5. The feed side of the oven door closed, turn on the discharge side of the door look, when kerosene spray mist flow direction normal form and then close the door.6. The feed chamber burner lit.7. Exhaust valve seal shall be discharged by the barrier.8. First, the intermittent production carburizing furnace tank.9. Parts placement, parts and not less than 5 mm distance between the parts; Part bottom edge does not exceed the specified length and height.10. To quickly switch the feed and discharge gate door, but the speed of push-pull rod to be stable.11. Parts should be located in a pre-cooling chamber is below the thermocouple.12. Furnace filled with 24 chassis only allowed to continue feeding must first pull push.13. When we shutdown the furnace zone down to the same temperature, and then began to naturally cool.14. Equipment cleaning:(A) in the continuous production carburizing furnace tank cleaned once a week, intermittent production furnace tank cleaning should be carried out immediately after shutdown,(2) tank cleaning oven temperature is 850 ~ 870 ℃ when the chassis all out;(3) a nozzle with compressed air blown from the feed end of the furnace, the valve opening was not too much, blowing must move around, to prevent local overheating;(4) In the carburizing gas burner with kerosene before cleaning.15. Chassis or fixture should return after quenching chilling room to remove oil.16. Found that the exhaust pipe blockage (sudden increase in pressure inside the furnace) should be cleaned up immediately. First open the exhaust valve seal barrier, and then close the valve exhaust pipe through the water seal. Cleared should hit the exhaust pipe valve seal the opening, and then close the barrier seal exhaust valves.17. Note:(A) combustion conditions and constant attention to districts gas pressure;(2) Open the door can not stand them, to prevent the flame jet burns;(3) Note whether the combustion burner into sections and wedge the door with torches check for leaks;(4) found in the work burner flame goes out, you should immediately turn off the gas valve, close the air valve;(5) working parts from falling or wedge the door switch not working, you should stop feeding, remove the parts.

 

Tube furnace fire accident occurred when oil disposal measures

1, the first self-adjusting valve from the gas bypass valve at the gas cut off, lower the fire, when off the gas slowly to prevent tempering explosion.
2, a heat exchanger from the rich oil-rich oil outlet valve is closed into a tube furnace at the oil-rich, to prevent leakage of oil-rich continue to make fire intensified. De-oil rich in benzene column close the valve at the inlet tube furnace oil-rich tubular pipes, the pipe and other pipe furnace off.
3, surrounded by oil spillages with sand to prevent the spread of fire.
4, if the fire is not possible to place the furnace fire steam, the muffle furnace steam valve to open hearth fire put out the fire.
5, from the door of the joints foam firehouse with fire hoses connected to the foam bubbles firehouse. Tube furnace with foam fire on parts of the fire.
6, the most critical to control the outflow of gas and oil-rich, to prevent the fire intensified.

 

What laboratory furnace masonry carried

Laboratory furnace, furnace masonry and methods of the basic sequence of what? Laboratory furnace method of wet masonry masonry and dry assemble two kinds: Wet puzzle parts: the Ministry of flames melted the side walls and arch roof space, flue, chimney and furnace insulation bricks, masonry used in the wet mud bricks used should be based on refractory clay material prepared accordingly.
① laboratory furnace bottom masonry, including the passage at the end. Qi Hao large brick insulation brick and kaolin after the masonry wall at the inside and outside to relax 30-50mm leveling. Multilayer structure underground masonry elevation negative deviation must be controlled, the bottom of the total thickness tolerances generally-3mm. In the bottom layer of kaolin large brick laying above chrome ramming as a sealing layer to prevent liquid penetration to the corrosion resistance of glass poor clay layer.
② In the bottom steel structure on the basis of acceptance, according to the baseline and experimental furnace construction furnace, furnace centerline release related to feeding port, front and rear bubbling and forming pathway of Taiwan brushed drain board centerline.
③ lifting column. Interim measures to stabilize the column, and then install the ballast ballast according to design requirements angles, columns and ballast ballast angle must be close to the same time determined the exact elevation.
④ masonry wall, including the passage wall. The bottom brick masonry wall must ensure that the level of degree, or to the bottom of the tile area for processing until it reaches the requirements. Multi-wall brick building, the first in the field after the operation to make sure the furnace size, non-timber hewn side facing brick hearth. Masonry joints to be staggered corner pressure, strictly maintain verticality.
⑤ masonry parapet, the front wall, back wall and channel flame space. Masonry parapet bracket should be carefully examined, pallets and bearers installed after passing. Masonry brick and chest wall hooks have taken measures to prevent the dumping of the kiln.
⑥ big arch masonry. Production arch tires, do carry through gantry sedimentation test and check the corresponding size, the big arch masonry to the center from both sides simultaneously, and requires continuous operation, try to control! * + Complete. Large arch insulation layer construction after the end of the kiln to be baked.
⑦ laboratory furnace masonry flue, chimney. Kiln debris must be cleared, and with a vacuum cleaner after masonry. Laboratory furnace, furnace flue and chimney masonry, but also compatible with the metal heat exchanger, access paths masonry chimney must be completed before other masonry.

Oven proper use instructions

The use of oven
1. Use of environmental requirements:
a) Temperature: 5 ~ 40 ℃
b) Relative humidity: ≤ 85% RH
c) Power supply voltage: AC220V ± 10% 50Hz
d) four weeks without a strong vibration and corrosive gases affect
2 vacuum debugging:
a) The box door and tighten the door handle in place, closed discharge valve (the rubber stopper holes with the holes on the release valve twisted partial 90 °), open the vacuum valve (by the counterclockwise rotation 90 °), the first time you use the vacuum valve switch may be tight, be forced to rotate.
b) Using random accessories vacuum connection tube (inner diameter: Φ16mm thickness: 10mm) vacuum drying oven exhaust pipe (diameter: Φ16mm) and a vacuum pump (2XZ-2 type, the inlet diameter Φ16mm) connected securely (6090 and 6210 already connected). Vacuum pump connected to the power and began pumping seriously empty table indicates values ??reached-0.1Mpa, the first closure of the vacuum pump valve closed after power to prevent vacuum pump oil to flow back into the studio, this time in a vacuum chamber.
3 oven vacuum box debugging:
In the vacuum, after debugging, can be manipulated as follows:
a) Turn the vacuum chamber, and the Power LED should light. Power On Self Test temperature controller, PV display the working chamber measuring temperature, SV display is factory set temperature. Temperature control device on the AT and HEAT and other lights should be lit, heated instrument to enter the working state.
b) to modify the set temperature oven
1 Click temperature controller function key (SET); PV display SP characters, the available key head button to set the temperature changes.
(2) After modification, press the SET button, PV display ST characters, set the timer time.
 If you do not use the timer function, you can still let ST = 0
3 Press the SET button, the screen display studio temperature PV, SV screen displays the new set temperature. AT AND HEAT instrument lights, then re-enter the meter heated working condition.
c) When operating the indoor temperature close to the set temperature, HEAT lamp light suddenly flickered, which means that the heating stage to enter the PID regulator, the instrument is sometimes measured temperature exceeds the set temperature, sometimes below the set temperature is normal. When measuring the temperature close to or equal to the set temperature, and then after the studio until 1 ~ 2h enter a constant temperature, goods enter the drying stage.
d) the desired temperature is low, the second setting mode can be used, such as the required operating temperature 70 ℃, the first time to set 60 ℃, and other temperature overshoot began to fall, and then the second set 70 ℃ , so that the temperature can be reduced or even Du do overshoot, as soon as possible to enter a constant temperature.
e) when the goods drying is complete, turn the power off, if accelerated cooling, then open the bleeder valve so that the vacuum is 0, for 5 minutes or so call box door.
(4) If the working chamber of dry matter humidity, water vapor generated will affect the performance of the vacuum pump is recommended between the oven and the vacuum pump, string into a "Dry / filter."
5 If the drying process of the article, you need to add nitrogen and other inert gases, should be specified in the contract, was equipped with an inlet valve.
(Note: 1. If the pump properly and meet the technical requirements, can not vacuum, then open the door to use the product in the annex to wrench the door button on the box screwed to the inside circle to close short, re-close the door. 2 This vacuum oven can not be used as an electric oven, because the studio is not in a vacuum state, measuring the actual temperature and the working chamber temperature error great)

Industrial furnace with ceramic fiber products Features

1, the installation process, the lifting of blanket folded after bundling will have an enormous stress, crowding each other sealed without leaving any gaps.
2 ceramic blanket high-dimensional elastic deformation of the furnace shell can make to reduce construction costs. Meanwhile, the different components inside the furnace can make different changes due to heat generated by the gap.
3, due to light weight, low heat capacity (only for light and light resistant refractory lining of 1/10), can significantly reduce the furnace energy consumption in the operation control.
4, elastic fiber blanket can withstand mechanical force.
5, with the ability to resist any thermal shock.
6, the lining of the body without drying and curing, lining construction is completed ready for use.
7, chemical stability. In addition to phosphoric acid, hydrofluoric acid and alkali, the other acids, alkali, water, oil, steam, not being eroded.

Tool heat treatment process operating skills

The majority of the heat treatment process cycle operation is a collective operation. Therefore, heat treatment processing technology boundaries are not clear, such as a number of parts quenching may be completed by the two shifts, quenching and tempering often consists of two service completion, coupled with the uneven quality of workers, small enough to improve management practices, production The process often appears quality problems. Problems, analyze problems, to find out why, is not only time-consuming, laborious, and sometimes can not find the real reason.
1 carburized gear low hardness
Record 800 (capsule) the infusion Unicase gas carburizing furnace nitride carburized gear claim after carburizing surface hardness 58 ~ 63HRC, when the sampling parts of the surface hardness of 52 to 56HRC. Carburizing, quenching; quenching heating or cooling problem, and sometimes difficult to conclude. Emergency batch of gear production tasks, the author has been detected gear to take three tied with wire, re-heated in a salt bath furnace, quenching in an oil bath, about 30 ~ 40 minutes after the last detected quenching hardness 63 ~ 65HRC . Hardening group of gear pump Jian hardness, all qualified. This way to cut the Gordian knot, although not necessarily able to identify the real cause of the problem, but to solve the urgent needs of the production.
2 bar quenching cracks
There are a number of 14mm x 240mm 40Cr the pensions materials by quenching and tempering is buried, after about a week (when used) was discovered almost all the crack, the crack shape the longitudinal single crack, the majority of crack through both ends of the bar surface. Judge quenching cracks crack the duty operator has failed to honor it. Check the job log, can only be found in the the batch bar for the second class quenching, three shifts tempering, parts and materials, quenching temperature and the cooling medium and process parameters are not recorded. I take a bar with 45 steel joints with heated in a salt bath furnace, and then quenching in salt water, after cooling about 20 ~ 30 minutes, the bar cracking, and the shape of the crack and the crack shape. In the face of the facts, the operator admitted mistakenly batch bar as 45 steel quenched.
Box-type resistance furnace annealing uneven hardness
The process route: annealing → band saw cutting → the roughing → quenched → fine cars → grinding → nitride. Band saw cutting, often find a bar on the uneven hardness, the local high hardness, low efficiency of the cutting blade wear quickly. After analysis, the front bar length due to the installed furnace or bar. The box-type resistance furnace mouth neither heating resistance wire, heat loss, so for the average box-type resistance furnace, furnace installed parts from the furnace inside the mouth 200 to 300mm, in order to ensure uniform heating temperature of the furnace parts.
 4 cast iron quenching should be controlled micro-alloying elements
Thermal conductivity of cast iron. Poor, ships oil cold quenching. The matrix of the cast iron and steel, is also composed of pearlite and ferrite. Cast iron with high carbon content, the increase in carbon content can increase hardenability, but after all, do not increase. Therefore, to improve hardenability of cast iron: they rely on micro-alloying elements in cast iron control good content of alloying elements, in order to ensure the quality of heat treatment and quenching.