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Plate Heat Exchanger
Plate heat exchanger is assembled by heat transfer plates,Plate heat exchanger is assemb-
led by heat transfer plates, sealing gaskets, frame plates, fastening bolts and etc. ( As figure
)Heat transfer plates and sealing gaskets as the main parts plays the important functions for
PHE Properties quality of performance.
There are four corners on the plate. When equipment is tigh tened by fastening bolts, the pla-
tes give each other the supporting points at regular intervals to form cold and hot media cha-
nnels.
Generally, PHE design is pressure of 0.6, 0.8, 1.0, 1.2 and 1.6Mpa, it can be reached to 2.0,
2.5 MPa and temperature lower than 150° if special technology adopted. When performance
of steam or condensed conditions, PHE should be equi- pped with attemperator to protect
heat transfer plates and sealing gaskets.
Generally, materials of heat transfer plate are material of sus304,sus316,sus 316L and etc.
Sealing gaskets are material of butyronitrile rubber and EPDM rubber. Other materials, if
required, according to customer's requirements and actual conditions.
The characteristics of PHE is an advanced equipment with great thermal efficiency, compact
structure, heat transfer loss to the minim, fewer space occupied, flexible, easy to open and
clean, applied range wide and long service period. PHEs are widely used in project of petro-
chemicals, power plant, metallurgicals, food, pharmacy, district heating and etc. PHE can be
divided into type of Symmetrical Passage Channel(BR) and unsymmetrical passage channel
( BB ) , single-flow process ( Nozzles on the same side ) multi-flow process. ( Noz- zles on
both sides)
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BB TYPE of PHE
Generally ,sectional area of intervals are the same, i, e, type of BR, but in actual performance, the flow rate of the two media are
not equal to , difference of flow rate may be generated if single-flow process adopted, thus influencing heat transfer efficiency.
Heat transfer plate of BB type is pressed by unequal sectional area of waveform. After combination, wide and narrow passage
channels are generated with ratio of 2:1. During the performance, larger flow rate flows in narrow passage channel. Under the
conditions of single-flow process, flow velocities of two media are similar or equal to, thus improving heat transfer efficiency.
The characteristics as follows:
1、 Nozzle D. of BB type is unequal to, big corner communicates with wide passage interval channel to flow larger flow rate of
fluid, small corner communicated with narrow interval channel to flow small flow rate of fluid.
2、BB type of PHE adopts structure of diagonal flow,dead zone between intervals to the minimum,thus improving heat transfer
efficiency.
3、Connective nozzles of BB type are on the same, thus marking it convenience for installation, commissioning and mainten-
ance.
4、Under the conditions of unequal treatment value of cold fluid, asymmetry type of PHE can reduce calculated area and inve-
stment.
For the conditions of district heating, primary flow rate generally is 1/2 of seconda- ry side, so BB type of PHE is applicable for
district heating.
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