Reacting kettle
Reacting kettle is the main equipment for polymerization and impregnation, as picture 2-4 shows, and it is mainly composed of  kettle body, stirrer, heat exchanger and driving device. During the production, the materials are poured into the kettle from the upper part, being mixed by the stirrer quickly and begin to react. If the materials need to be heated, add heating steam into the jacket; If the materials need to be cooled down, add cold water or cryogen into the jacket. As the reaction is finished ,the materials will be released from the bottom part of the kettle.
Picture2-4   

kettle-type reactor

1. Stirrer; 2-Kettle body ;3-Coil pipe;4-Half pipe-coiled jacket;5-Stirring shaft;6-Manhole; 7-Shaft seal;8-driving device
2. Kettle body

Generally the kettle body is cylinder shape, and the proportion of its height and diameter is between 1~3.The kettle body is welded from steel panel, and it has a stainless steel lining so as to avoid the corrosive materials used in the EPS resin production process. The manhole,  hand hole , joint pipe (except the material discharge pipe) and other devices are all installed on the top cover of the reactor .

1. Stirrer

The stirrer can reinforce the reactor’s roles to transmit materials and heat, make the units dispersed equably and turn into small oil drops suspending above inside the kettle. The method used in the EPS resin production’s polymerization process is suspension polymerization , so usually we use the paddle stirrer, the stir speed of which is 20~80r/min; If the stirring is too fast ,it will cause turbulence phenomenon, and the particles tend to joint and agglomerate accompanying with powder particle phenomenon. So reacting kettles and dispersion systems of different capacity should use different stirrer.

1. Heat exchanger

During the EPS resin production process, different temperature should be set as the constant temperature in different periods, the reacting kettle should be heated and cooled to control the temperature.

Auxiliary equipments
1.Buffer slot
Buffer slot (Intermediate slot) can also be called pickling slot or washing slot. During the reacting process, HCL is often added to dissolve the impurities such as CaCO3 and TCP , which are the water insoluble inorganic salts. Usually, the buffer slot is normal pressure vessel, demands low in manufacturing ,but it should be equipped with stirring device.
2.Centrifugal dehydrator
During the styrene polymerization process, the proportion between the liquid and the solid should be 1:2. The centrifugal dehydrator is often used to remove the moisture and the impurities which are dissolved in water. The main part of the centrifugal dehydrator is a fast-rotating drum, the drum is installed on the horizontal or vertical axis. Small holes are drilled on the rotating drum’s wall, and its surface is covered with metal net and filter cloth. Suspending liquid is added into the drum by automatic valve, and then rotating with the fast-rotating drum, at last, being released through the filter cloth hole under the centrifugal force.   
3.Whirlwind dryer
There still will be some moisture left on the surface of the EPS resin which has been dehydrated by the centrifugal dehydrator. So as to ensure the drying effect of the resin, we need to use dryer to dry the resin. The common dryers are: Tray dryer, whirlwind air current dryer, fluidized bed dryer, etc.
Picture2-5 Horizontal automatic centrifugal dehydrator

1. Rotating drum ; 2-filter layer ; 3-Scraper;4-Shaft

Picture2-6  Whirlwind dryer

1.  Hot blast stove; 2-taper pipe; 3-Screw feeder;4-whirlwind separator; 5-Screw discharger; 6-Whirlwind de-duster;7-Intrduced draft fan;

Air current drying is a continuous efficient drying method to fluidize solid. The air current blows into the dryer with the materials in the tangential direction, forming screw movement along the inner wall. The materials disperse equably and rotate in the air current ,which strengthen the drying process.
Besides, we have other auxiliary equipments such as sieving machine, coating machine, packaging machine, etc.