Multi channel tube furnaceWith the advantage of multi-channel parallel processing, it is widely used in material synthesis, sample annealing and other scenarios. The core of its working condition adaptation lies in achieving "inter channel collaboration" and "parameter sample characteristic matching". The following are key usage techniques.
1、 Channel configuration adaptation: balancing parallel and differentiated requirements
For samples of the same batch and characteristics, a "symmetrical and uniform distribution" configuration is adopted to evenly place the samples in the center area of each channel, ensuring that the heating element load of each channel is balanced and the temperature deviation is controlled within ± 2 ℃; If processing samples with different characteristics (such as different heating rate requirements), enable the "independent temperature control mode" and set the target temperature, heating rate, and insulation time for each channel through the touch screen. At the same time, cross distribute high-energy consumption channels and low-energy consumption channels to avoid local circuit overload.
The selection of channel diameter should match the sample size. For small-sized samples (such as powder crucibles with a diameter of less than 5mm), a small diameter channel with a diameter of 20-30mm should be selected to reduce redundant space in the furnace cavity and improve heating efficiency; For large-sized samples (such as pipes with a diameter of 50mm), use channels with a diameter of 60-80mm to ensure smooth loading and even heating of the samples. In addition, channels of the same experimental type can share the same gas path system, and channels with different gas requirements (such as inert atmosphere and reducing atmosphere) need to be independently configured with gas paths to prevent cross contamination.
2、 Accurate adaptation of temperature and heating rate
Adapt the heating rate based on the thermal stability of the sample: ceramic materials and other high-temperature resistant samples can be rapidly heated at 10-20 ℃/min to shorten the experimental period; Heat sensitive samples such as polymer materials and nano powders should be heated slowly at 2-5 ℃/min to avoid sample decomposition or agglomeration. For the demand of multi-channel stepped heating, multiple temperature rise curves can be preset through the program temperature control function, such as "room temperature -200 ℃ (5 ℃/min) - insulation 30min-800 ℃ (10 ℃/min) - insulation 2h", and each channel can be executed synchronously or independently.
High temperature conditions (above 800 ℃) require preheating of the furnace body 30 minutes in advance. After the overall temperature of the furnace chamber stabilizes, the sample can be placed to reduce the impact of temperature fluctuations on the experimental results; Low temperature conditions (below 200 ℃) can activate the "local heating mode", which only activates the heating elements in the area where the sample is located, reducing energy consumption.
3、 Adaptation skills for atmosphere and pressure conditions
When conducting experiments in an oxidizing atmosphere (such as air), ensure that the ventilation openings of the furnace are unobstructed and promptly release the gases produced by sample oxidation; The inert atmosphere (such as nitrogen and argon) experiment requires first replacing the atmosphere in each channel at a rate of 5-10L/min. After 3 replacements, the oxygen content should be detected to be ≤ 0.1%, and then the temperature should be increased to prevent sample oxidation. Explosion proof type should be selected for reducing atmosphere (such as hydrogen) experimentsMulti channel tube furnaceThe gas system is equipped with a leak detector to ensure a leakage rate of ≤ 1 × 10 ⁻⁹ Pa · m ³/s.
During the atmospheric pressure experiment, keep the sealing gaskets at both ends of the furnace tube intact to prevent atmosphere leakage; Negative pressure experiment (vacuum degree ≤ -0.095MPa) requires the use of vacuum resistant sealing components, and vacuum pumping should be carried out in stages before heating (first pumping to -0.05MPa and holding for 10 minutes, then pumping to the target vacuum degree); Positive pressure experiments (pressure ≤ 0.1MPa) require the installation of a safety valve, with a set upper pressure limit of 1.2 times the working pressure to avoid the risk of overpressure.
4、 Adaptation and optimization for special working conditions
For long-term continuous operation conditions (exceeding 24 hours), models with automatic temperature compensation function should be selected, and temperature compensation thresholds should be set (such as automatic temperature compensation when the deviation is ≥ 5 ℃). At the same time, the heating wire temperature of each channel should be regularly checked to avoid local overheating; Intermittent operation conditions can enable the "standby insulation mode", maintaining the furnace temperature at 100-200 ℃ during experimental intervals to reduce energy consumption and time for the next heating up.
When there are significant differences in multi-channel samples, energy consumption can be optimized through "weight allocation" to prioritize temperature accuracy in the channels where key samples are located, and parameter fluctuation ranges can be appropriately relaxed for auxiliary sample channels; Paired with furnace temperature monitoring software, real-time collection of temperature and atmosphere data from various channels, adjustment of operating parameters through data analysis, and improvement of adaptation accuracy.