Thermocompressors: Engineered For Efficiency
Thermocompressors: Engineered For Efficiency
Thermocompressors: Engineered For Efficiency
As the mixed flow enters the diffuser section, the diffuser flow area gradually
increases to allow the velocity of the mixed flow to be reduced. As the velocity Diffuser
is reduced, the steam pressure increases. At the end of the diffuser, the
discharge steam pressure is higher than the lower-pressure suction flow
entering the thermocompressor.
Discharge
Features Benefits
u Computational fluid dynamics used to model flow u Entrainment efficiency improvements up to 25%
characteristics compared to conventional designs
u Nozzle and mixing chamber are sized based on u Minimise high-pressure motive steam use
specific operating conditions
u Low-cost upgrade to latest jet compressor
u Retrofit existing installations without piping technology
modifications
u Wider operating range
u Optimised thermocompressor geometry
u Increased energy efficiency
2,00 1000
1,94 923
1,88 846
1,83 769
1,77 692
1,71 615
1,65 538
1,60 462
1,54 385
1,48 308
1,42 231
1,37
154
1,31 Pressure [bar]
1,25 Cut Plot 1: contours 77 Velocity [m/s]
0 Cut Plot 1: contours
As the motive jet accelerates the suction flow, a low pressure The motive flow is accelerated at the nozzle and a high
region is created at the entrance to the mixing chamber. As velocity jet is created. The jet transfers momentum to the
the flow moves along the mixing chamber, pressure rises. At suction flow and accelerates it as the two flows mix.
the diffuser, velocity decreases and pressure rises.
High-efficiency thermocompressors
In addition to retro-fitting existing steam jet compressors, Standard High-Efficiency
Unit Unit
Kadant also provides high-efficiency thermocompressors for
Booster and recirculating
improved energy utilisation. Based on extensive product ✓ ✓
applications
development, modeling, testing, and field applications,
Retrofit existing installations ✓ ✓
Kadant’s high-efficiency thermocompressor offers entrainment
ratio improvements of up to 25% over conventional steam Match thermocompressor to
✓ ✓
syphons
jet compressors.
Maximise entrainment ratio ✓
Using advanced computer analysis techniques to model the
intricacies of flow dynamics within the thermocompressor, Minimise motive steam use ✓
Kadant custom-engineers its high-efficiency thermocompressor
CFD flow analysis ✓
to optimise the nozzle position, nozzle shape, and mixing
chamber entrance geometry and length. This increases the Improve system control ✓
dynamic head entering the diffuser and allows for more
pressure recovery. The result is less motive steam consumption, Increase electrical generation ✓
higher energy efficiency, and a wider operating range.
Dimensions shown are for standard design. High-efficiency thermocompressors are custom-engineered and
dimensions provided above are for reference only. Dimensions are subject to change without notice.
*Other / special connections possible upon request. C (Discharge outlet)
Thermocompressor Sizing
The following charts can be used to estimate the size of a Calculate the motive and discharge (total) steam flow rates
thermocompressor. The size is based on the motive, suction, from the Entrainment ratio R:
and discharge steam pressures and the required steam flow. Motive steam flow rate = Mm = Ms / R = (9.000 / 1,5) =
The following parameters are used for these estimates: 6.000 kg/hr
P = Atmospheric pressure (absolute) = 1 bar (typical)
Pm = Motive steam pressure (absolute) = gauge pressure + Discharge (total) steam flow rate = Md = Mm + Ms = 6.000 +
atmospheric pressure 9.000 = 15.000 kg/hr
Ps = Suction steam pressure (absolute) = gauge pressure +
atmospheric pressure Determine the size of the thermocompressor using the
Pd = Discharge steam pressure (absolute) = gauge pressure Discharge (total) steam flow rate and the Discharge steam
+ atmospheric pressure pressure and the Sizing Table underneath:
Mm = Motive steam flow rate For this example, the thermocompressor size = 12"
Ms = Suction steam flow rate
Md = Discharge (total) steam flow rate = Mm + Ms Note: Consult Kadant Johnson for optimum sizing and
E = Expansion ratio = Pm / Ps (should be over 1,4) thermocompressor performance curves.
C = Compression ratio = Pd / Ps (normally less than 1,8)*
R = Entrainment ratio = Ms / Mm ( * ) For higher compression ratios, please contact Kadant
Johnson.
Sizing Example Thermocompressor Entrainment
Operating Parameters: 8,0
Pm = Motive steam pressure = 5,9 barg + 1 bar = 6,9 bar E = Pm / Ps = 20
7,0 E = Pm / Ps = 10
R = Entrainment Ratio = Ms / Mm
1,0
Use these ratios and the sizing graph underneath to
0,0
determine entrainment ratio R: 1,0 1,1 1,2 1,3 1,4 1,5 1,6 1,7 1,8
R = Entrainment ratio = 1,5 C = Compression Ratio = Pd / Ps