Double-Stack Firing Process

I. Process Description
Double-stack firing represents a modern, two-stage production process in which drying and firing are conducted separately.
This method follows European brick plant standards, ensuring stable quality and product diversification.

1. Typical process flow:
Clay preparation → Extrusion forming → Cutting → Automatic stacking onto drying car → Tunnel dryer → Secondary stacking onto kiln car → Tunnel kiln firing → Cooling → Packaging

2. Equipment Configuration
This process requires:
• Forming system: Vacuum extruder + automatic cutting and stacking line
• Drying system: Single-layer tunnel dryer (through-type or circulation-type)
• Firing system: Dedicated tunnel kiln
• Handling system: Robotic manipulators or automatic stacking machines
• Control system: Centralized PLC automation and temperature-pressure regulation

3. Product Range
Double-stack firing enables production of:
• High-strength hollow blocks
• Thin-wall facing bricks
• Thermal-insulating perforated blocks
• Decorative sintered bricks with color control
The product quality meets or exceeds EN and ISO standards.

4. Process Advantages
• Wide product range and high precision.
• Energy-efficient operation: optimized drying and firing balance reduces overall fuel consumption by 10–15%.
• Stable quality: independent drying ensures consistent moisture control.
• High automation level: less labor required.
• Suitable for export-grade or high-end construction products.

5. Limitations
(1) Higher initial investment (about 1.5× to 2× that of single-stack).
(2) Longer construction and equipment commissioning period.
(3) Requires higher management and technical capability.

II. Economic and Technical Comparison

III. Summary and Recommendations
1. Single-Stack Firing is suitable for regions where:
(1) Local clay quality is stable;
(2) Market demand focuses on common construction bricks;
(3) Investors aim for low investment and quick returns.
2. Double-Stack Firing is recommended for:
(1) Enterprises pursuing premium brick quality, product variety, and export capability;
(2) Projects seeking long-term, sustainable development aligned with European energy-saving standards.
Both systems have their merits — Single-stack firing emphasizes cost-efficiency and simplicity, while double-stack firing focuses on technological advancement and product excellence.

● Company profile

Xi'an Brictec engineering Co., Ltd. (abbreviation: Xi'an Brictec) was founded in 2011. It employs senior Italian engineers to work with domestic experts, creating a strong technical team by combing the European and Chinese technologies. The company is devoted to provide clients multiple professional brick making solutions, including building structure bricks, decorative bricks,wall cladding bricks, paver and dry press bricks, etc.

Business Scope

(1) Design and engineering
Xi’an Brictec offers process design and engineering service for clients to have a fully automated modern bricks and tile factory, including chamber drying, tunnel drying, rapid drying and tunnel kiln and other process design and technical consultation, among which the dryer and kiln constructing and engineering is the utmost importance in our general contracting program. This part is the key to achieve production targets by using key technologies in the project.

(2) Machinery manufacturing and supply
Xi’an Brictec Machinery Equipment Manufacturing Co., Ltd. introduces the latest European brick machinery technology for smooth production domestically. In 2018, Xi’an Brictec built cooperation relationship with Shandong Mine Machinery Cosmec Materials Machinery Co, Ltd, jointly R &D and manufacturing automation equipment for brick making.
1.Cutting machine, setting machine, automatic unloading and packing machine and automatic packaging machine;
2.Ferry car, cone blower, stepping machine, pulling machine, kiln car and other kiln automation equipment;
3.Gas burning system (natural gas/liquefied petroleum gas / coal gas), liquid burning system (heavy oil/waste tire oil), solid fuel burning system (pulverized coal, petroleum coke, rice husk, palm kernel husk, coconut husk, cottonseed husk, etc.)

(3) Installation, maintenance and production guarantee service
Xi’an Brictec provides production, commissioning and maintenance services to brick making factories, helping clients to make bricks easily.

● Project reference from Xi’an Brictec

1.Shaoxing Lvzhan environmental protection technology Co., Ltd

Xi’an Brictec designed this Lvzhan project in 2023. The project has annual output of 300,000㎡ of sintered bricks and prefabricated brick wall by using local solid waste such as chemical contaminated soil, construction residue, printing and dyeing sludge as the main raw materials, etc. so as to make high quality sintered bricks making, and 60%-70% of electricity needed for production line is from the photovoltaic power generation on the factory roof. Xi’an Brictec provides whole package service from the preliminary planning and design of the project to the supply of core equipment in the later stage. Single layer tunnel dryer process is adopted with natural gas burning system for tunnel kiln (7 meters inner width). Xi’an Brictec has delivered a very satisfactory EPC project to our client, and also set a new benchmark for the solid waste recycle and utilization in the industry.

2.Najmadin project in Iraq

This project was jointly designed and implemented by Xi’an Brictec and China National Building Materials Co., Ltd. in 2023, with a daily output of 750 tons of sintered bricks. It is located in Sulaimani Province, Kurdish region of Iraq, and the raw material is shale. Xi’an Brictec has participated in project planning, design, construction and commissioning. Single layer tunnel dryer process is adopted, and Heavy oil/liquefied petroleum gas dual fuel serve as the fuel for dryer and tunnel kiln (9 meters cross-section) . In this project, Xi’an Brictec competes with European production line on the same platform and wins honor for the country. So far the project has been put into production, expecting to meet the production target in May 2024.

3.Antique Bricks Project for Yan'an Green Building Material Recycling Industrial Zone

The project was designed and implemented by Xi’an Brictec as a whole in 2022, mainly to produce antique bricks, facing bricks and paver, etc.. The raw material is high-quality shale and purple sand soil, and the fuel is natural gas. The entire production line combines two shaping methods (extruding and pressing), and uses chamber dryer for drying and tunnel kiln for burning, and integrates three shuttle kilns for antique bricks production. Xi’an Brictec was fully engaged and offer excellent package service in the project in the preliminary process design, dryer construction and core equipment supply and production commissioning. This automatic degree applied in this project is the highest domestically, also meets the advanced international level.

4.Guangdong Baolihua Electric Power Co. Ltd. brick making project with high content fly ash as raw material

Xi’an Brictec designed the whole project and led multiple raw material batching experiments, and finally got the result of 65% fly ash content being the perfect ratio to produce qualified sintered bricks. And because of this project, Xi’an Brictec has obtained the invention patent for making bricks with high content fly ash added.

5.ECO CERMICS project in Bangladesh
This is an EPC project by Xi’an Brictec. Single-layer tunnel drying process is adopted with two 4.8-meter tunnel kilns in use. Bongianni soft plastic extruder from Italy, roller and pulverized coal burner invented by Xi’an Brictec are also applied in this project. Invested by GPH, the 3rd largest cement enterprise in Bangladesh, the production line has the characteristics of highest automation and largest production scale. The factory roof is laid with solar photovoltaic, offering 60% power generation for production line.

6.Uzbekistan Project

The project is for the high-grade brick making production, ranking top three in Uzbekistan. It has two production lines and Xi’an Brictec is responsible for the whole set of cutting, loading & unloading automation system and the natural gas burning system. Client thinks highly of Xi’an Brictec and compliments it as the most reliable partner, offering the easier natural gas burning system with lower energy consumption than European burning system. With the assistance of Xi 'an Brictec, the client uses tire pyrolysis oil to make bricks in its Phase II project, producing high quality bricks under low cost.
Xi 'an Brictec will continue to make breakthrough in every aspects, continuously providing all various tailor-made brick making solutions for our valuable clients!

● Business region

Over 30 countries and regions including China, Russia, Kosovo, Kazakhstan, Uzbekistan, Tajikistan, Vietnam, Malaysia, Iraq, India, Bangladesh, South Africa, Zimbabwe, Peru, Colombia...
In addition, the company has local offices and after-sales service centers in countries such as Iraq, Kazakhstan, Bangladesh, Uzbekistan, Zimbabwe and other.
Adhering to company’s culture and spirit “ Struggle-oriented and customer-centered”, Xi’an Brictec is here to help you make bricks easily!