Integrated Turnover and Demoulding Production Process and Equipment for Precast Concrete Pipe and Manhole, by Suzhou Kexing Concrete and Cement Products Equipment Co., Ltd.

Based on the defects of current forming process of precast concrete manhole, the project puts forward an innovative production process featured high-frequency vibration, vertical turnover and integral demoulding. Furthermore, a complete set of equipment is developed, which can be used to produce round or rectangle precast concrete manhole with or without base and precast concrete pipe. The project has been authorized 3 national invention patents and 4 national utility model patents. 

The main innovations of the project are as follows.

I. Technological innovations:

---The high frequency vibration mode compacts the concrete in the mould and can achieve immediate demoulding.

---The precast concrete is bottom up during the vibration forming process, which effectively overcome the defect of poor flowability of concrete.

---The precast concrete is turned degrees along with the outside and inside moulds, which is  conducive to stable the whole structure and prevents the collapse of concrete during demoulding.

--- The product is free of steaming curing, which is beneficial to energy conservation.

II. Equipment innovations:

---The whole set of equipment is composed of a concrete feeder, a 180 degree flipping and lifting mechanism, a working hydraulic station, an electronically controlled frequency conversion combination, a structural support frame and a built-in vibration unit with high integration and automation.

--- The whole set of equipment can be installed in the pit for fixed production, or be placed in the ground or outdoor mobile mode.

---In addition to produce precast concrete manhole, the equipment can be applied to the production of other municipal precast concrete products. For example, after adding the high frequency vibration unit and roller compacting device, it can be used to produce drainage pipes with 3000 mm diameter.

After two years of application of this production technology and equipment, it has been used in more than 10 production enterprises of concrete products. The products are widely used in the construction of drainage, sewage, electricity, telecommunication and other construction projects, which have obtained good application performance and have achieved remarkable economic and social benefits. The production technology and equipment have been pioneered in China and promote technology level in this field.