Plants for regenerating foundry sand are provided having a combustion chamber, which has at least one inlet for introducing sand to be regenerated into the combustion chamber, nozzles for feeding combustible gas into the combustion chamber, nozzles for injecting air so as to maintain a heated fluidized bed of sand in the combustion chamber, a cooling chamber for cooling sand coming from the combustion chamber, the cooling chamber having nozzles for blowing air in order to maintain a fluidized bed of sand in the cooling chamber, refrigerating pipes arranged above the air nozzles, a communicating duct which connects the combustion chamber with the cooling chamber, the communicating duct including a vertical or inclined lower end portion which is at least partially surrounded by or adjacent to a plurality of the refrigerating pipes in the cooling chamber, and wherein the lower end portion has a bottom outlet arranged at a lower level with respect to at least one of the refrigerating pipes.

A process of recovering clean sand and active clay from sand or dust from a foundry is disclosed.

A return sand cooling system, including: a sand moisture and temperature measuring instrument measuring the moisture content and temperature of the return sand; a control device determines an appropriate water addition amount, which is an amount of water to be added to the return sand; a water-sprinkling cooling device adds water of the appropriate water addition amount to the return sand and cools the return sand by the latent heat of vaporization of water to obtain the cooled return sand; an air introducing device that introduces air into the water-sprinkling cooling device; and an introduced air temperature and humidity measuring instrument measures the temperature and humidity of introduced air to be introduced into the water-sprinkling cooling device; the control device determining the appropriate water addition amount on the basis of the moisture content and temperature of the return sand, and the temperature and humidity of the introduced air.

A return sand cooling system, including: a sand moisture and temperature measuring instrument measuring the moisture content and temperature of the return sand; a control device determines an appropriate water addition amount, which is an amount of water to be added to the return sand; a water-sprinkling cooling device adds water of the appropriate water addition amount to the return sand and cools the return sand by the latent heat of vaporization of water to obtain the cooled return sand; an air introducing device that introduces air into the water-sprinkling cooling device; and an introduced air temperature and humidity measuring instrument measures the temperature and humidity of introduced air to be introduced into the water-sprinkling cooling device; the control device determining the appropriate water addition amount on the basis of the moisture content and temperature of the return sand, and the temperature and humidity of the introduced air.

A 3D printer creates a ceramic casting shell of high accuracy. Casting molten metal into this shell creates an accurate metal object. The ceramic shell is formed from a paste made from a low hardness ceramic, dried by freeze drying. To overcome the shear thinning behaviour of ceramic pastes a positive displacement pump is in close proximity to the nozzle.

A 3D printer creates a ceramic casting shell of high accuracy. Casting molten metal into this shell creates an accurate metal object. The ceramic shell is formed from a paste made from a low hardness ceramic, dried by freeze drying. To overcome the shear thinning behaviour of ceramic pastes a positive displacement pump is in close proximity to the nozzle.

A mixing and adjusting method for foundry sand includes calculating a total supplied water amount until a compactability (CB) value of mixed sand becomes larger than a lower limit value of a target CB value range, determining the total supplied water amount as a predetermined amount of water associated with an electric resistance of the foundry sand, and determining a ratio of a variation in the CB value corresponding to an additionally supplied water amount from the additionally supplied water amount during an additional water pouring and the CB value of the mixed sand.

A mixing and adjusting method for foundry sand includes calculating a total supplied water amount until a compactability (CB) value of mixed sand becomes larger than a lower limit value of a target CB value range, determining the total supplied water amount as a predetermined amount of water associated with an electric resistance of the foundry sand, and determining a ratio of a variation in the CB value corresponding to an additionally supplied water amount from the additionally supplied water amount during an additional water pouring and the CB value of the mixed sand.

The present invention concerns a casting sand cooler comprising a sand chamber having an air inlet optionally with a fan for the feed of air into the sand chamber and an air outlet optionally with a fan for sucking air out of the sand chamber. To provide an improved casting sand cooler in which the sand discharge during the cooling operation by way of the air outlet is markedly reduced, it is proposed according to the invention that a dynamic wind sifter which is rotatable about an axis and which is so arranged that substantially the complete air flow leaving the sand chamber through the air outlet is passed through the dynamic wind sifter.

The present invention concerns a casting sand cooler comprising a sand chamber having an air inlet optionally with a fan for the feed of air into the sand chamber and an air outlet optionally with a fan for sucking air out of the sand chamber. To provide an improved casting sand cooler in which the sand discharge during the cooling operation by way of the air outlet is markedly reduced, it is proposed according to the invention that a dynamic wind sifter which is rotatable about an axis and which is so arranged that substantially the complete air flow leaving the sand chamber through the air outlet is passed through the dynamic wind sifter.