Changzhou Fondarc Green-Sand Foundry Machine Co., Ltd.

Function:
RTM variable speed sand mixer is developed and put into market by France Fondarc in 1990s. This machine has the advantages of high reliability, good mixed sand quality, high efficiency, and low operation cost. It is very suitable to match with upscale automatic molding lines.

Working principle:
The sand mixing principle of RTM mixer is different with other rotor type or rotary bottom plate type mixers. The basic principle of RTM mixer is: use the driving method of planetary rotor structure; different number of rotors (3-4 rotors) will be equipped according the mixer size and capacity.

As the cooling system starts, its control system first measures the temperature and moisture of return sand to determine rough water quantity accordingly. After return sand entering the cooler, it moves three-dimensionally in “∞” shape at horizontal and vertical directions driven by the blender and wind force. Meanwhile, the water dosing system sprays the determined quantity of water uniformly to the return sand. Water evaporates and carries a lot of heat. The evaporated hot air is exhausted into dust collecting system from the upper part of the cooler. During the stirring and cooling, the temperature and moisture measuring system continuously monitors the temperature and moisture variation of return sand. At the same time, the current of mixing motor is continuously monitored to adjust the position of discharging door so as to keep the sand quantity inside cooler stable. The output sand temperature and moisture is also measured and back fed to water dosing system to adjust water quantity. Thus, output sand temperature is controlled within 40℃ (or ambient temperature +10℃) and moisture is accurately controlled to 2.2±0.2%.

RTC measures the real time compactibility and green compression strength of molding sand during the mixing process. After comparing with set value and calculation, it adjusts and controls automatically the filling quantity of water and bentonite to realize real time control of molding sand quality. At the same time, RTC will record automatically related process data and equipment fault diagnosis for long term so as to provide process staff with correct information for process analysis and also provide maintenance staff with equipment operation status record and fault diagnostic report.