Regenerative Thermal Oxidizer (RTO) for Printing industry
Learn how regenerative thermal oxidizers (RTOs) can significantly reduce VOC emissions and improve air quality in the printing industry. Learn about our efficient, cost-effective, and environmentally friendly RTO solutions tailored for your printing business.
Characteristics of Waste Gas in the Printing Industry
Exhaust gas characteristics
- Large air volume: The exhaust gas generated during the printing process usually has a large air volume, especially when using large ovens and continuous production lines.
- Low concentration: Although the total amount of exhaust gas is large, the concentration of harmful substances in it is relatively low. This requires special technology and equipment to ensure efficient purification when treating these exhaust gases.
Exhaust Gas Concentration:400mg/m³~5000mg/m³
Emission Limit Values:NMHC≤50mg/m³
Organized waste gas:
Printing oven: During the printing process, the ink needs to be dried in a high-temperature oven. A large amount of VOCs will be released during this process.
Laminating machine oven: The adhesives and solvents used in the laminating process will also volatilize at high temperatures to produce waste gas.
Unorganized waste gas:
Printing workshop: Various operations in the printing workshop, such as ink mixing, cleaning equipment, etc., will produce unorganized waste gas.
Ink mixing room: During the ink mixing process, the mixing of ink and solvent will produce a large amount of VOCs.
Waste Gas Components
- Ethyl Acetate (EtOAc): Commonly used as a solvent with high volatility.
- n-Propyl Acetate (n-PAc): Another commonly used solvent, often used in inks and coatings.
- Methyl Ethyl Ketone (MEK): Widely used in inks and cleaners, with high volatility and toxicity.
- Isopropyl Alcohol (IPA): A common solvent used for cleaning and diluting inks.
- Ethanol (EtOH): Used in a variety of inks and cleaners, with low toxicity and high volatility.
- Propylene Glycol Methyl Ether Acetate (PMA): Used as a high-performance solvent, commonly found in high-end inks and coatings.
Recommended RTO System Solutions
Unorganized Capture + Zeolite Wheel Concentration + Organized Air Reduction + Concentration Increase + Rotary RTO + Waste Heat Recovery
Printing Plant VOCs Treatment & Waste Heat Recovery System Diagram
Standard Planning & Design Scheme for VOCs Waste Gas Treatment In Flexible Packaging Printing Workshop
Key Links in VOCs Waste Gas Treatment in Gravure Printing Enterprises
Unorganized Waste Gas Control & Capture Technology
Schematic diagram of unorganized waste gas emission points of printing presses
Solution: Remodel the structure of the return air device.
For equipment with a decent oven structure but a poor return air passage, increase the back exhaust to increase the return air volume
Ideas for controlling unorganized waste gas
- Ensure that the air volume of the air supply system is ≤ the unorganized exhaust volume (to ensure a slight negative pressure in the workshop);
- Ensure that the air supply volume of the air conditioner at the operating end of the printing machine is ≤ the unorganized exhaust volume of a single device (to ensure a slight negative pressure in the printing equipment)
- Make unorganized partitions for each printing machine and make magnetic leather curtains between color groups;
- Set up unorganized top exhaust and side exhaust to capture unorganized waste gas at the oven outlet and the oven joint
Wind Reduction, Concentration, Energy Saving
The “box-type internal circulation” LEL parallel air reduction and concentration heating device is a hot air heating device for flexible packaging printing machines. Its excellent air reduction and concentration concept can significantly reduce the total exhaust volume of the equipment and increase the exhaust gas concentration while ensuring that the drying capacity does not decrease. While saving heating energy consumption, it can be perfectly linked with the rear-end rotary valve RTO equipment to solve the company’s VOCs emission control problem.
The main technical features of the “box-type internal circulation” LEL parallel air reduction and concentration device are:
- All hot air components are centrally arranged in an insulation box, and the thickness of the box insulation layer is 50mm; the return air circulation channel is built-in to reduce the heat dissipation consumption of the pipeline;
- The secondary return air is internally circulated and the short-path circulation greatly reduces the pipeline wind resistance;
- The dual fans actively intake and exhaust air, variable frequency speed regulation, and the air reduction and concentration ratio can be linearly adjusted;
- Large-diameter exhaust and exhaust air to reduce the pollution of unorganized exhaust gas in the workshop;
- Patented technology, each color group is independently paralleled to reduce air and increase concentration, and there is no disturbance between the colors;
Processing method:
1. The color group circulation fan and the color group exhaust air valve actuator are linked to each other;
2. The printing press main exhaust fan and the traction roller operation signal are linked to each other;
3. The main exhaust fan and the main exhaust air valve actuator are linked to each other;
4. The negative pressure sensor detects the negative pressure value to control the main exhaust fan frequency, thereby ensuring the stability of the pipeline negative pressure.
Zeolite Molecular Sieve Rotor
Zeolite Molecular Sieve Rotor
- Air volume: 10000m³/h—200000m³/h
- Exhaust gas temperature: <40℃
- Exhaust gas concentration: <1000mg/m³
- Concentration ratio: 5-30
Special Wheel for Printing Industry
- Most of the waste gas adsorbents in the printing industry have a molecular size between 3.2Å and 5.5Å;
- Select the appropriate “cage” according to the specific composition and proportion of the user;
- The waste gas components will vary depending on the process, and zeolite powder with a wide range of adaptability needs to be selected;
- Our Zeolite Wheel takes into account the changing process of customers.
Rotary valve RTO VS lift valve RTO
(Take 300,000 Nm³/h as an example)
Performance parameters | Rotary valve RTO | RTO lift valve |
Processing air volume | 300,000 Nm³/h | 300,000 Nm³/h |
Reversing valve structure | Rotary valve | Lift valve/butterfly valve |
Number of reversing valves | 3 | 27 |
Frequency of reversing valve switching impact | Continuous operation without impact | 6.48 million times/year |
Number of heat storage beds | 36 beds | 9 beds |
Cross-sectional area of single heat storage chamber | 20,000 Nm³/h | 75,000 Nm³/h |
Filling weight of single-chamber heat storage ceramic | 3㎡ | 14㎡ |
Number of burners (pieces) | 3,300 kg | 15,600kg |
Occupancy (length * width) | 3 | 5 |
Single-chamber processing air volume | 26m×8m | 48m×5m |
Waste Gas Heat Energy Utilization
Recovering heat from excess water
Recovering heat from waste oil
Low pressure steam waste heat recovery
Hot air waste heat recovery
Customization Process of Our RTO Solutions for Printing Industry
1. Initial consultation and demand analysis
- Initial communication: Initial communication with you via phone, email or online form to understand your basic needs and project background.
- Demand collection: Learn in detail about your production scale, exhaust gas characteristics (such as air volume, concentration, composition), existing exhaust gas treatment facilities, environmental protection regulations and other information.
- On-site inspection appointment: Arrange a professional team to conduct an on-site inspection based on the results of the initial communication.
2. On-site inspection and evaluation
- On-site inspection: Send experienced engineers and technicians to your factory for a detailed inspection, including: Production line layout, Exhaust gas emission points, Existing exhaust gas treatment equipment
Energy usage - Data collection: Collect key data such as exhaust gas flow, temperature, pressure, VOCs concentration, etc.
- Environmental assessment: Evaluate the working environment and safety conditions on site to ensure the feasibility of the design plan.
3. Scheme design and optimization
- Preliminary scheme design: Based on the results of on-site inspection and data collection, design a preliminary RTO system scheme, including: Unorganized capture system, Zeolite rotor concentration system, Organized air reduction and concentration system, Rotary RTO system, Waste heat recovery system
- Technical discussion: Have in-depth discussions with your technical team to ensure that the scheme meets your production needs and process requirements.
- Scheme optimization: Optimize the preliminary scheme based on the discussion results to ensure optimal performance and economic benefits.
4. Quotation and contract signing
- Cost estimation: Provide a detailed cost estimate, including all costs such as equipment procurement, installation, commissioning, and training.
- Quotation: Submit a formal quotation to clarify the various costs and service contents.
- Contract negotiation: Conduct contract negotiations with you to determine the final project scope, price, delivery time, payment method, etc.
- Contract signing: After the two parties reach an agreement, sign a formal contract to clarify the rights and obligations of both parties.
5. Equipment manufacturing and installation
- Equipment manufacturing: Equipment manufacturing is carried out in our factory according to the design plan, and quality and progress are strictly controlled.
- Quality inspection: Conduct a comprehensive quality inspection on the manufactured equipment to ensure compliance with standards and specifications.
- Transportation and installation: The equipment will be delivered to your factory and installed by a professional team. The installation process will be strictly carried out in accordance with the construction drawings and safety specifications.
- On-site commissioning: After the installation is completed, the system will be commissioned to ensure that all parts work in coordination and achieve the expected results.
6. Training and technical support
- Operation training: Provide comprehensive operation training for your operators, including equipment startup, operation, maintenance and troubleshooting.
- Maintenance training: Provide regular maintenance and maintenance training to ensure long-term and stable operation of the equipment.
- Technical documentation: Provide detailed technical manuals and operation guides for your team to refer to.
- Technical support: Provide long-term technical support services to answer your questions and solve possible problems.
7. Acceptance and after-sales service
- System acceptance: Conduct the final acceptance of the system with your team to ensure that all functions and performance indicators meet the contract requirements.
- After-sales service: Provide comprehensive after-sales service, including regular inspections, fault repairs, spare parts supply, etc.
- Continuous improvement: Based on your feedback and actual operation, continuously optimize and improve the system to ensure optimal performance.
Current Status of the Printing Industry
The global printing industry is a huge market involving a variety of products such as books, magazines, packaging materials, labels, etc. With the rise of e-commerce and digital media, although the demand for traditional printing has declined, the demand for packaging printing and other professional printing fields is still growing. The development of digitalization and automation technology has greatly improved printing efficiency and quality. Advanced printing equipment and processes make the production process more efficient and flexible. More and more printing companies have begun to pay attention to sustainable development and adopt environmentally friendly materials and technologies to reduce the impact on the environment.
Environmental Challenges Facing the Printing Industry
Regulatory pressure: Governments and international organizations are increasingly stringent in their requirements for environmental protection, and the printing industry is facing increasing compliance pressure. For example, the EU’s REACH regulations and the US’s Clean Air Act have put forward specific requirements for emission standards.
Public awareness: Consumers are paying more and more attention to environmental protection, and they are more inclined to choose companies that take environmental protection measures. This forces printing companies to not only comply with regulations, but also actively improve their environmental image.
Cost pressure: Although environmental protection technologies are constantly improving, implementing these technologies often requires higher initial investments. For small and medium-sized enterprises, how to find a balance between cost control and environmental protection investment is a challenge.