by ▲ Click the card above to pay attention to the Prefabricated Building Network Introduction With the in-depth development of China’s efforts to promote prefabricated buildings, the development and innovation of precast concrete technology and products has become a hot spot of building technology innovation in recent years.
Precast concrete components are the basic components for the development of prefabricated buildings.
Assembling integral wall, slab, beam, column, stair and other supporting components has become the main product of building industrialization.
In this case, various quality problems of precast concrete are also emerging, which are puzzling the construction and use process.
In the whole concrete project, concrete curing is a sub project that takes the longest time and has the greatest impact on concrete quality.
The service life of assembled buildings is determined by the quality of precast concrete slabs, which puts forward higher requirements for the maintenance of precast concrete slabs.
The following is an example of how the combination scheme of intelligent maintenance system can meet the flexible production and maintenance needs of the prefabrication factory, and how to prevent and solve problems in the production of prefabricated concrete PC components and how to deal with them.
Project overview Tianjin Hejia Metalworking Construction Industrialization Co., Ltd.
(hereinafter referred to as Hejia Metalworking) has invested 360 million yuan in Ninghe Industrial Base, covering an area of 160 mu.
Hejia Metalworking is committed to promoting the industrialization of prefabricated buildings and the industrialization of prefabricated buildings.
The industrial products of buildings mainly include: prefabricated laminated panels, prefabricated stairs, exterior wall panels, interior wall panels, partitions, balconies, etc.
There are two production lines of prefabricated components in Xindi, Hebei, one is the composite production line and the other is the composite production line.
Each production line has 2 face-to-face warm air curing kilns, a total of 4 curing kilns, and more than 140 fixed mold tables.
If the production scale of concrete precast slab is large and the traditional steam boiler is used for curing, the cost and the later maintenance cost will be a large expenditure; Secondly, the boiler is a special equipment that needs to be declared, inspected annually, and a boiler room needs to be built.
If the boiler room is far away from the workshop producing concrete precast slabs, the steam will lose some heat during the transmission process, causing energy waste, and is often limited by the existing space and power distribution, the utilization rate of equipment is not high; Finally, in the production process, if the operator cannot accurately control the curing temperature, humidity and the rate of rise/fall of the concrete precast slab, the quality of the product is difficult to be guaranteed.
Therefore, through the introduction of the flexible combination maintenance scheme of the equipment of Germany Curetec Gult ConCure warm air heating curing kiln system and NDG low-pressure steam generator with advanced technology in the concrete curing industry, to achieve the engineering purpose, control the quality problems such as cracks in the production process of components, improve the strength of concrete components, and flexibly adapt to the intermittent and continuous curing needs to save energy costs, And accelerate the construction period.
Figure 1 Specific Maintenance Scheme and Principle Engineering Scheme for Entering Hejia Metalworking Factory Project 1 – Heating and Curing of Four Precast PC Component Curing Kilns: Customized German Curetec Gult ConCure Heating Equipment WE250B Figure 2 Design Diagram of ConCure Heating System Curing Kiln Figure 3 Precast Component Heating and Curing Kiln (Field Installation Diagram) The main content of this equipment includes a 250 kW/h heating heater device – heating generator.
The air heater used is a vertical air pipe heat exchanger with forced circulation, which can quickly and effectively separate high-quality hot air.
This is the basic configuration of the heating system.
The CureTecConCure air heater is set to heat and circulate the air in the curing room.
The indoor air is sucked in through the return pipe, heated in the air heater, and transmitted back again through the circulation pipe and the branch pipe of the room.
The air circulation and air distribution at different levels ensure a very uniform temperature distribution throughout the room.
The heating medium can be oil, gas, hot water, steam, electricity or solar energy.
ConCure heating system can also provide a variety of performance specifications, ranging from 40kW/h to 1200kW/h.
All ConCure heating systems are designed according to customer requirements, with different arrangements for piping systems (design, materials) and heaters of different sizes to provide the highest efficiency and performance.
The standard pipe structure is a standard galvanized air duct plus thermal insulation material.
All ConCure heating systems have the advantages of long service life, low maintenance cost and economical operation.
The structure of the heater generator is shown below.
Fig.
4 Structural diagram of the air heater generator shows that the main body of the air heater generator is connected in series with the heat exchanger through the upper part and the fan through the lower part.
The whole heat exchanger is made of stainless steel.
Fig.
5 Warm air heating system generator physical picture Warm air curing kiln curing principle: concrete needs heat and moisture to hydrate perfectly.
The cement mix proportion of concrete prefabricated components already contains a lot of water, so we only need to add heat to the curing process.
Through ConCure, a system was designed to heat and circulate the air in the kiln without increasing moisture.
Because of the high moisture content, we just need to ensure that the temperature and circulation are correct.
The warm air enters from the higher pipe of the curing kiln, and the air is heated by the air burner, and rises evenly to different heights of the room through the ConCure heating system.
The curing process of external concrete products is an exothermic process, and the heat released can also ensure that the temperature in the kiln will not decrease, which can reduce the supplement of heat sources inside and outside the whole curing system, thus saving energy for operation.
The humidity contained in the wet poured component itself is stable without loss in the sealed kiln, so as to maintain the constant temperature and humidity in the curing kiln and realize ecological maintenance..
