Green Sand Molding Line sand recycling equipment 3.0

Three-stage tower series process layout
Due to the application of the high-efficiency and high-reliability double-row bucket elevator, the foundry sand processing department has produced a technical breakthrough in the process layout of a tower layout. Not only saves a lot of inefficiency levels The conveying belt conveyor simplifies the process equipment, and can be directly connected with the technology. The overall layout is compact and the production line process flow is more reasonable. The three-stage tower series process layout has been successfully applied to the molding production lines of various small and medium-sized and medium-sized foundry factories with high efficiency in modern casting production lines. The three-stage tower series process layout can meet the casting production lines supporting the sand processing department of various vertical and horizontal, boxed and boxless molding lines.

1.1 Features of the first tower (used sand processing unit) The first tower is set as an important pretreatment process unit for obtaining high-quality molding sand.
1.11 The high-temperature hot used sand discharged from the shakeout department (sand rolling or vibrating shakeout machine) first passes through the belt conveyor, and is subjected to the first automatic temperature measurement and spray humidification. Hang magnets after climbing out of the pit Selected and the belt conveyor head wheel two-way strong magnetic separation, and then lifted by the double row bucket elevator to the first tower to enter the large-scale fine crushing and screening. After magnetic separation and screening, the stiff beans and iron debris flow into the scrap iron bucket (trolley) for regular cleaning, which ensures the cleanliness of the working environment."

1.12 The middle of the first tower is a uniform storage hopper with a metering material level meter to control the uniform flow of hot used sand in the material conveying process, so that the far-infrared sensor on the belt feeder can detect the temperature of the used sand synchronously. The temperature changes, and the humidification of the hot old sand is regulated in an accurate proportion. The humidified old sand is evenly stirred by the blade sand loosening machine, which improves the rapid cooling of the hot old sand and reduces the influence of the damp and hot old sand on the vibration boiling cooling orifice plate.

1.13 The wet and hot old sand after being evenly humidified enters the vibrating boiling cooling device at the bottom of a tower. Under the action of the high-speed air flow under the boiling orifice plate of fish scales, the hot old sand is formed into fluidized boiling heat exchange, and the hot old sand is quickly taken away. The humidified water and a large amount of latent heat of vaporization in the sand make the temperature of the used sand be controlled below the ambient temperature +15C, and the water content is controlled at 1.5%~2.5%. Thereby, the recycling performance of old sand and the performance of molding sand can be improved, and casting defects can be reduced.

1.14 Temperature measurement and humidification setting of one tower: Usually, the sand processing department conducts temperature measurement and humidification treatment in a dedicated hot used sand cooling equipment. In order to avoid excessive water addition in the process, affect the evaporation and cooling effect of water, and avoid the phenomenon of wet mass, sand beans and logistics sticking. The tower layout adopts a two-stage automatic temperature measurement and humidification system to control the unstable factors of the hot used sand conveying flow, and can fully diffuse the cooling vaporization heat to achieve the cooling effect of the used sand reuse.

1.15 Setting of new sand supplementary addition: The amount of new sand supplementary addition should be proportional to the number of sand molds for molding and falling sand, and the addition point is set on the first belt conveyor after the falling sand (or adding it on the cooling line of the casting mold, with appropriate control). After the new sand is pretreated in advance, the mixing uniformity of the molding sand can be improved.

1.2 Characteristics of the second tower (parallel used sand mixing unit) The second tower is a parallel used sand mixing unit, which is composed of 3~4 used sand intermediate storage buckets for the amount of circulating sand above 4h. The old sand hopper has a large reserve setting, so that the turnover pouring times per working day is small, and the performance and stability of the old sand are good.

1.21 The use of multiple old sand intermediate hoppers in parallel, monitored and controlled by a material level meter, feeds sequentially from the upper part in the order of time periods, and simultaneously discharges from multiple feeders from the lower part. Mixing the used sand for multiple periods of time within 4 hours is beneficial to minimize the fluctuation of the composition and performance of the used sand such as effective clay and pulverized coal content, moisture, temperature, etc., and control the performance of the molding sand to be easy to stabilize, thereby effectively reducing the rate of waste and defective products.

1.22 Taking 2~3h of each used sand reserve as an example, 2~3 ductile iron used sand storage buckets and 2~3 gray iron used sand storage buckets store two kinds of used sand respectively, a total of 4~6 used sand middle fight. Coal when preparing ductile iron sand The amount of powder added is 0.3%~0.5% more than the molding sand of gray iron pieces, and the amount of pulverized coal in the old sand of ductile iron pieces in the parallel storage bucket is 0.8%~1% higher than that of the old sand of gray iron pieces. It has obvious effect on reducing subcutaneous air bubbles and pinhole defects of ductile iron parts and reducing scrap rate. It is especially suitable for the foundry of large-scale commodity parts, which adopts a molding line and a sand treatment line to produce ductile iron parts or gray iron parts in turn.

1.23 Features of the third tower (mixing unit for batching and molding sand) The third tower is a mixing processing unit for batching and molding sand, and is a weighing, batching, and mixing department with a sand mixer as the core. Three microcomputer batching scales with different ranges are set on the sand mixer to weigh and batch old sand, clay, pulverized coal and water, and the dust collection of the dust removal system is weighed with the molding sand (to ensure the smoothness of the casting, the toughness and fluidity of the molding sand, proper air permeability and recycling of active ingredients in dust collection).

1.24 In order to adapt to the production of high-grade and complex castings, a starch (dextrin) batching hopper and feeder are set up. The microcomputer batching scale is suspended and installed with a pull-type sensor with an accuracy of 2/10,000, so that the dynamic weighing is accurate. It can cooperate with the online detector of moisture and compaction rate to replenish moisture at any time to meet the requirements of batching and mixing process.

1.25 The sand mixer is equipped with a rubber hopper and a large disc feeder with non-stick and non-shedding materials. When the disc surface rotates, the arc-shaped scraper with low inner and outer high will send out the molding sand at a constant speed. The bottom of the disc feeder and the front of the scraper are lined with engineering plastic plates, which are non-stick and have low friction coefficient. The high-strength wet-viscous molding sand has low resistance when it is output, and will not be hardened by extrusion, so it is important to maintain the uniformity and fluidity of the molding sand mixed by the sand mixer.

1.3 The 3-disc sand storage capacity of the disc feeder can ensure the rapid discharge of the sand mixer within 30s, shorten the auxiliary time of the process, and meet the material storage when the moulding machine fails, and the material level of the 3-disc storage sand hopper on the moulding machine The interlocking control system can supply the molding sand with good fluidity and formability to the high-speed molding machine at any time.

1.31 Horizontal series process layout characteristics (three-stage tower) Horizontal series process layout, suitable for vertical Configuration of parting extrusion molding lines. The old sand drop point and the molding sand use point of this production line are respectively at both ends of the molding line. The material conveying process is long, and it is easy to arrange the old sand treatment, sand mixing and molding sand transportation in a horizontal series in stages. At the same time, due to the long and narrow floor area, it can be segmented in parallel. The dust removal system is matched and arranged. The resistance of the dust removal pipeline system is small, and the dust removal effect is good. The required fan generally does not need to be equipped with a high-pressure fan, and the pipeline is not easy to condense, and the maintenance and cleaning are convenient. It is also beneficial for dust collection and reuse.

1.32 The dust removal system is arranged in parallel on the side of the sand treatment system, and a screw conveyor or a pneumatic conveying device is set up accordingly to uniformly recycle the dust collected under the dust collector into the old sand treatment system. The arrangement of the dust collector installed in the parallel old sand intermediate bucket, in front of the elevator and on the belt conveyor can make the dust collected under the dust collector directly recycled and distributed to the old sand intermediate bucket, so as to reduce the intermediate handling of dust and facilitate dust collection and discharge. secondary pollution of the process".

1.33 The dust recovery and the dust collection hopper and screw feeder set on the sand mixer are quantified in the form of small batching scales, which are necessary for the modern casting technology. Modern high-speed high-pressure molding machine The molding specific pressure is high, and the moisture and mud content of the molding sand are low. Most of the dust collection and ingredients must be recycled to ensure the necessary fluidity, compaction rate and smooth surface of the casting sand.

1.34 Cooperate with the use of high-performance sand mixer, and then strengthen the screening with a fine sieve with a mesh size of 5~8mm, and control the content of used sand, sand peas and sand beans in the molding sand from 10% to below 8%. It can be reduced from 2% to 3% to 0.8% to 1.1%, and at the same time, the rejection rate of castings is reduced by 2% to 3%.

1.35 The batching and mixing system of the third tower is arranged close to the main machine of the molding line to reduce the phenomenon of water loss and unstable performance during the conveying process of molding sand.

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.