Suggestions on the transformation and upgrading of sand recycling system

1. In the casting production, compared with the modeling, core making, cleaning, and melting steps, the sand treatment process has its universality and particularity. The following characteristics should be fully considered in the process of technological transformation:
1.1 The process equipment is complex, with a wide range of varieties, non-standard equipment, and strong steel structure.
The process equipment for foundry sand processing is generally divided into: process equipment, conveying equipment, auxiliary equipment, dust removal equipment, etc., roughly totaling twelve categories. There are many equipment parameters and specifications. The existing casting equipment has been preliminarily implemented serialization, generalization and standardized design and manufacturing, which makes the structure, performance and supporting facilities more reasonable and perfect. Non-standard and complex steel structures require a lot of design work and on-site construction and installation work. Moreover, the stage of installation, commissioning, and trial production is also an important and complicated task.
The unstable quality of molding sand is one of the important reasons for casting waste. Choose a reasonable configuration process and improve the supporting process equipment to ensure the quality and technical indicators of the foundry sand. Therefore, it is necessary to strictly manage the production process and strengthen inspection and control methods.

1.2 The material handling capacity is large, the dust source is large, the noise is large, and the working conditions are poor.
In the process of sand treatment, the process, transportation and storage of various materials is basically a cyclic operation of an operating system. The transportation volume of modeling materials in a sand processing step, such as new sand, old sand, molding sand, clay, coal powder, and auxiliary materials, often accounts for about 50% of the total transportation volume of the entire foundry shop. Moreover, the conveyed powder materials and granular bulk materials are mainly, and the dust is overflowing. Cause environmental pollution in the work area. Therefore, it is necessary to realize the mechanization of sand handling and transportation and environmental protection.

1.3 The sand processing program system should adopt mechanization and automation to realize the operation.
Although the sand treatment process is more complicated, each process can be connected with each other through mechanized conveying equipment. It constitutes a circulatory system of mechanized procedures. With the development of modern industrial technology, the application of various equipment and new technologies has improved the automatic control and operation of the foundry production sand processing process. For example, the analog screen control display of the sand processing system, the Internet technology application of casting production, and the automatic weighing of sensors can all reflect the operating status of various equipment in real time. Conducive to the timely adjustment, control and management of the operator.

1.4 The layout and design of the sand processing program system is heavy and the civil structure is complicated.
When the foundry is building new sand processing steps or technically renovating, due to the mechanical equipment, conveying equipment and ventilation and dust removal equipment selected by the process requirements, the pit, overhead, suspension and platform are generally used to make reasonable installation and layout. Make the degree of sand processing mechanization obtain the best running performance. However, this brings a lot of work to the process design. Including: equipment process layout design, steel structure design, electrical control system design, civil engineering foundation design, ventilation and dust removal pipeline design, etc. (the design process must be carried out in accordance with relevant standards and technical specifications). The process is more complicated and is a systematic project.

2. Renovation design principles
Combine local transformation and overall transformation. Appropriate process adjustments and equipment updates should be made to the foundry and surrounding environment to change the existing dirty, messy, poor, and severely polluted conditions, improve the level of mechanization and automation, and reduce the labor intensity of workers.

2.1 Basic principles
According to the requirements of the access system of the foundry industry, carry out upgrading and transformation; according to the characteristics of foundry production, according to the design specifications and factory workshop design principles, carry out comprehensive workshop process design and scientific and reasonable layout; adopt automated production lines to improve production efficiency and reduce labor Intensity; ensure that the flue gas emission in the production process of the workshop meets the standard, improve working conditions, and become a green and environmentally-friendly foundry enterprise with the international advanced level. For the purpose of meeting environmental protection standards, improving mechanization, automation and production efficiency, reducing labor intensity of workers, ensuring the quality of castings, reducing pollution, and saving energy are the design principles.

2.11 It is necessary to adopt advanced molding lines as the basis, supporting new processes, new technologies, and new equipment, and strengthen process management, and improve quality control methods and testing levels.

2.12 The nature of casting production should choose the mass continuous production system, the production method adopts the parallel work system, and the production organization adopts the organizational form of department (section) and team.

2.13 The foundry workshop is considered to be composed of five major engineering departments for melting, molding, sand processing, cleaning and dust removal systems, and is equipped with auxiliary departments such as rapid analysis in front of the furnace, molding sand laboratory, and raw material storage.

2.14 In order to ensure product quality requirements and reduce labor intensity of workers, advanced production methods and key job equipment should be adopted. When selecting equipment and formulating plans, both the advancement, applicability and reliability of process equipment are considered, and the economic rationality of cost performance is also considered.

2.15 The production process and logistics operations are both considered to be completed with mechanized equipment.

2.2 Renovation design and layout

2.21 Consider setting up a joint foundry workshop (including melting and pouring, modeling, sand treatment and falling sand cleaning department), core making room, cleaning and processing workshop, surface treatment and finished product warehouse, raw and auxiliary material warehouse, etc.

2.22 According to the design principles of the foundry workshop, according to the requirements of ventilation and lighting and improving the environment. Design according to the layout requirements of modeling, pouring and sand processing equipment. and adjust the layout according to the characteristics, specific conditions and needs of casting production.

2.23 The production process of castings includes modeling, core making, smelting and pouring, sand treatment, and cleaning.

2.24 The workshop is relatively independent, followed by the raw material warehouse, the moulding and pouring workshop, the sand processing workshop and the cleaning workshop.

2.25 Factory structure, generally can adopt steel structure factory building with ventilation roof and daylighting skylight. The span and height of the workshop meet the requirements of equipment layout and utilization to improve the ventilation and lighting of the workshop. The length of the workshop will be adjusted according to the process requirements.

2.26 Ventilation and dust removal system, for cupolas that easily generate dust sources and flue gas, melting pouring and sand treatment, falling sand cleaning, and trench air supply and exhaust, try to set up a sealed cover to seal it.

3. Main process and equipment selection principles

3.1 In the clay sand green casting, the performance of the sand has a significant impact on the quality of the casting and the casting reject rate. Especially when a high-productivity molding line and a high-productivity sand mixer with a large batch and short mixing cycle are used, once the molding sand performance is out of control, a large amount of waste will be produced in a short time. In order to produce high-quality molding sand with stable performance, the sand processing department must be equipped with advanced molding sand preparation equipment that is compatible with the production scale and modeling method, and must also be equipped with advanced molding sand performance testing and control equipment that is compatible with it. .

3.2 Layout: The sand processing department adopts a multi-layer tower structure layout to simplify logistics, save energy and control floor space.

3.3 Main equipment and basic parameters: High-efficiency rotor sand mixer and supporting weighing, water adding and online sand performance detection controller are adopted, and the other equipment can be matched with the best. The sand processing department can be equipped with a full set of control systems, using PLC+PC centralized control, and the control room is equipped with an analog screen.

3.4 Performance testing and Internet: A quick analysis before the furnace and a molding sand laboratory are set up separately to test the material and the performance of the molding sand. The production site management adopts the Internet system control mode for real-time monitoring.

4. Comprehensive utilization and disposal of waste

4.1 The main wastes of the foundry workshop mainly include: waste sand, waste slag, and productive dust generated by the dust removal system. These wastes are first collected in the workshop, and then recycled and reused. Protective measures should be taken during transportation to prevent secondary pollution.

4.2 Energy-saving measures: The foundry is a large energy-consuming consumer, when the energy-saving effect is fully considered. New processes, new equipment, and new technologies should be used as much as possible to improve the quality of castings, reduce waste and increase product life, so as to reduce the energy consumed by excess waste products and achieve indirect energy saving effects.

4.3 Use the cooling water of the cooling system for recycling, not only considering saving water resources, but also saving energy.

4.4 The smelting recycle material adopts purification treatment, thereby reducing the energy consumption of the smelting process.

4.5 There are many mechanized transportation equipment in the foundry workshop, many pits and platforms, and there are unsafe factors. At the same time, there are many sources of dust and noise, which seriously affect the physical and mental health of workers. Active precautions should be considered.

5. Protective measures that should be paid attention to

5.1 Fire and explosion safety

5.11 Lay refractory bricks in the pit in front of the cupola; consider drainage measures in the pit to ensure that the pit is dry, and take rain and waterproof measures around and above the furnace to avoid explosion.

5.12 Fire hydrants are installed in the workshop, and various types of portable fire extinguishers are equipped to reduce the fire hazard in the workshop.

5.2 Prevent mechanical damage

5.21 The operating equipment is equipped with an interlocking control system, an emergency stop button, and a safety door for maintenance. The production line shall comply with all safety measures required by the national safety evaluation standards.

5.22 All moving parts are colored with eye-catching colors. An alarm bell is installed for the equipment for transporting molten iron.

5.23 All mechanical transmission parts in the workshop are equipped with protective covers.

5.24 The arrangement of the safety distance of each equipment meets the safety requirements.

5.25 Consider safety doors and evacuation passages in the workshop to facilitate evacuation in the event of a fire in the workshop.

5.26 The cupola has power failure, leakage prevention and water shutdown alarms. The water can not be stopped when the power is suddenly cut off during normal operation. The water can only be stopped when the furnace temperature drops to room temperature after the furnace is shut down.

5.27 Set up necessary guards, covers, etc. in the shot blasting area to prevent the shots from splashing and hurting people.

5.3 Safety protection

5.31 The entrance of the pit and the steel structure platform should be equipped with protective nets and protective railings. For live equipment and mobile equipment, there should be obvious safety signs and reliable zero connection protection. and it complies with the relevant standard JB5545-91 "Technical Conditions for Safety Protection of Foundry Machinery".

5.32 Consider proper lighting in the trench, and consider ground communication wind according to the actual situation.

5.33 The melting and pouring work area belongs to high temperature, radiant heat and smoke and dust hazardous work places, including other harmful smoke and dust work areas, the hood-type exhaust and dust removal system should be used to strengthen ventilation. Operators should be equipped with labor protection masks, radiation protection glasses, gloves, and wear labor insurance clothes, shoes, etc.

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.