1. Water-glass self-hardening sand casting process
Water glass is a kind of sodium silicate true solution and silica colloidal particles composed of multi-phase dispersion of aqueous solution. Its advantages are low cost and wide range of resources, easy to operate without pollution, flexible application, energy saving, casting quality scrap less. But the water glass sand has some inherent disadvantages, the most important of which are: the use of traditional CO2 hardening process, the water glass itself bond strength failed to get full play, the amount of water glass added high (generally up to 7% ~ 8%), resulting in the pouring of the core of the collapse of poor, castings very difficult to clear sand. In addition, the water glass old sand release rate is low, the old sand is difficult to regenerate reuse, strong alkaline water glass waste sand emissions, serious pollution of the environment. Modified water glass sand process, especially ester hardening modified water glass sand process is widely promoted and used, especially cast steel parts, such as rolling stock, heavy machinery, pump valves and other industries, in the production of thin-walled, box-shaped and other vulnerable to thermal cracking of cast steel parts, with high quality, low cost, good production environment, and can be expected to achieve no waste sand wastewater discharge, etc., is an intensive green clean casting process.
2. Composition of water glass self-hardening sand recycling equipment
2.1 Vibrating sand drop crushing regenerating conveying and dust removal machine
2.2Ductless dust removal device
2.3Intelligent de-filming rate adjustable bucket wheel regenerator
2.4Double tank pneumatic sending device
2.5Sand purifier
This short flow sand processing system for the recycling of old water glass sand developed for the steel casting industry breaks the traditional concept and adopts the new idea of hitting the box while it is still hot. The newly developed vibrating sand crushing and regeneration dust removal and conveying machine, bucket wheel rubbing regenerator and other new process equipment through the subsequent medium temperature thermal regeneration, in order to completely solve the water glass old sand regeneration problems, and make the water glass old sand regeneration Na2O residual rate of less than 0.5%, can be reused as new sand. The system adopts the wet regeneration technology of wet soaking and scrubbing in hot water + chemical reagents to remove the film immediately after hitting the box while it is hot, which solves the problems of large water consumption and low Na2O removal rate of wet regeneration of water-glass sand casting waste sand, reaching only 100kg of water consumption per ton of sand and reducing the Na2O residue from 0.5% to 0.1% by hot dry method.
3. The mainframe of the system adopts advanced short flow technology, bucket wheel rubbing technology, sintered plate cartridge energy-saving filtration technology and intelligent concept, the main breakthrough and innovation points are as follows.
3.1 Vibrating sand falling crushing regeneration dust removal and conveying short process technology Combining sand falling, crushing, regeneration, dust removal, sorting and conveying in one, solving the problems of many interfaces of traditional equipment, large maintenance, large floor space and low efficiency, especially the rate of water glass old sand falling crushing and de-filming while hot is increased from 20% to about 25%.
3.2 Mechanical method bucket wheel rubbing regeneration technology The old sand is driven by the high speed rotating bucket wheel rubbing hammer to rub and collide with each other, and the key technology of regenerating while hot after the short flow of sand crushing can increase the efficiency of film removal by 5%.
3.3 Intelligent control technology A variety of online detection and digital control means to achieve simulation, to ensure the systematization, engineering, intelligence and safety of the foundry old sand short process regeneration technology.
3.4 Process technology and characteristics
3.41 The old sand or sand box with castings first enters the vibrating falling sand crushing and regeneration dust removal all-in-one machine, after the castings or sand box is lifted out by the lifting device, the remaining old sand pieces start to vibrate and crush, the waste iron pieces and core bones are discharged periodically at the end of the all-in-one machine, and the sand particles less than 1mm which are initially regenerated by crushing enter the intelligent de-filming rate adjustable bucket wheel regenerator. Then after feedback from the online scorch reduction detector it is sent through the double tank sending device to the sand purifier with pneumatic impact, air separation, cooling and magnetic separation functions and then sent to the sand hopper or self-hardening sand mixer for use.
3.42 The sand drop crusher regenerator dust collector in one set has the functions of sand drop, crushing, regenerating and dust collector. Multiple individual dust collectors are connected to the dust collector hood without pipes, with good sealing performance and low power consumption.
3.43 The productivity of one set can be from 5 to 30t/h, and the productivity of two parallel sets can be from 30 to 60t/h, which can be flexibly selected.
3.44 A recycled sand discretionary online monitor is connected in parallel to the bucket wheel regenerator discharge, in order to adjust the bucket wheel roller speed or adjust the height of the sand discharge door through frequency conversion technology, and change the sand rubbing pressure through the amount of sand in the rubbing bin to change to a moderate de-filming rate. The intelligent bucket wheel regenerator with adjustable film removal rate allows the number of bucket wheel rollers (3 to 8 rollers) to be selected according to the amount of sand and the process, in order to meet the maximum productivity requirements. The bucket wheel disc uses a wear-resistant dredge bucket wheel to achieve sand regeneration by squeezing and rubbing between the sand particles. The bucket wheel regenerator bucket wheel negotiation grinding hammer blade form adopts the dredging bucket type, forming a collision between sand and sand in the dredging bucket, which belongs to soft regeneration, because the sand and sand collision, the impact probability is 3 to 4 times higher than hammer blade type, which greatly improves the regeneration effect, and reduces the direct impact between sand and bucket, prevents the bucket wheel from wearing, and increases the life of the dredging bucket by 3 to 4 times.
3.45 Double tank pneumatic sending tank works alternately, single set can achieve 10～30t/h continuous conveying volume, with high temperature resistance.
3.5 Range of applications
The short process regeneration system for old foundry sand is an integrated intelligent short process sand regeneration device, which can also be flexibly applied to other self-hardening sand foundry workshops. We know that in other foundry workshops such as furan resin self-hardening sand sand drop section often uses the old sand regeneration line includes vibrating sand drop machine as well as tape conveyor, magnetic separator, bucket elevator, vibrating crusher, vibrating conveyor and dust removal system and many other equipment, sand regeneration equipment combination is huge and the production line is complex. The production and installation of each piece of equipment is generally completed separately before forming the production line with non-standard steel structures and electrical control pipelines and dust removal pipelines. Nowadays, the intensive energy-saving intelligent short process high-efficiency regeneration system has a simple and reasonable structure, is lighter in weight and occupies less space, and is suitable for all kinds of foundries to crush and regenerate old sand from hard sand and send dust removal for wind, magnetic and cooling processes. It is a kind of intelligent old sand regeneration combination device, which provides a modular design for the regeneration of old sand in self-hardening sand foundry workshops.
Qingdao Sanzhuji Equipment Manufacturing Co., Ltd. specializes in the production of Green Sand Molding Line,Self-hardening sand molding line,foundry machines,Sand molding machine,Sand casting equipment,sand mixer,GS high efficiency rotary mixer,Resin sand mixer,no-bake resin sand mixer,Jolt squeeze molding machine/Jolt-squeezing moulding machines,Multi- Piston Moulding Machine/Hydraulic multi-piston moulding machine,sand casting molding machine,sand reclamation equipment，foundry molding machine,flaskless moulding machine,shot blasting machine,dust collector,according to the amount of old sand recovered Carry out plan customization, and provide sand reclamation equipment installation, commissioning, and training. Welcome guests to visit the factory.
