Process thermostat for energy-saving professional temperature control in the working range of -90 up to 200 °C
LAUDA process thermostats of the Kryoheater Selecta (KHS) series ensure high-performance temperature control at high energy efficiency and reliability. The compact device construction provides a long service life and maintenance friendliness.
Corresponding to the lowest working temperature, two-stage compressors (up to -60 °C) and/or cascade cooling systems (up to -90 °C) are used. The condenser is cooled by means of cooling water. The cooling capacity is controlled continuously and precisely by injection control. A step switch ensures energy-saving and low-wear partial load operation using an automatic compressor system. By means of the electric heating, Kryoheater Selecta can cover an operating temperature of up to 200 °C.
- Test stands
- Distillation plants
- Temperature stress test for environmental simulation
Download a PDF of our Kryoheater brochure:
LAUDA Kryoheater Selecta Brochure (1.9 MB)
Working temperature min.
Working temperature max.
Powerful pump (flow rate 85 L/min max. pressure 5.5 bar max.) – high volume flow even in case of pressure loss
Magnetic coupling – no sealing problems at the pump shaft as it is hydraulically sealed
Integrated frequency conversion – highly precise user-specific speed control (40 to 100 percent)
Pressure limitation – protection of the consumer against excess pressure
Nitrogen overlay of the expansion vessel – no condensation of the air humidity
Pressure-resistant expansion vessel made of stainless steel – no odours; no evaporation and no oxidation of the heat transfer liquid; enables larger operating temperature range of the heat transfer liquids
Automatic on/off of the second refrigeration step for KHS 2190 W (cascade cooling up to -90 °C) – up to 50 percent energy conservation in applications over -20 °C
Protection class IP 54 – safe, reliable and long-term use in production environments
Robust construction using steel frames – protection of the control against all environmental influences, such as dust, dirt, liquids and touch
Industrial control cabinet – simple maintenance and service by ideal accessibility to all components
PLC control (programmable logic controller) – extensive data exchange with process control systems
7″ touch panel – intuitive operation
Detailed display of parameters – quick analysis of process data
Visualisation of alarm and error messages – identification of disturbance variables
Use of a refrigerant with low global warming potential (GWP* < 2,500) – fulfills the European F Gas Directive No. 517/2014
Low amount of refrigerant
The Kryoheater Selecta series consists of the two systems KHS 3560 W and KHS 2190 W, which are used in chemical and pharmaceutical production as well as for the simulation of environmental conditions in test stands of the automobile and aerospace industries.
Advantages ensured by nitrogen overlay
A nitrogen overlay permits the insulation of the heat transfer liquid from atmospheric oxygen in pressureless operation. This prevents an oxidation at high temperatures. Thus the life of the heat transfer liquid is extended drastically on the one hand and in addition the maximum operating temperature permitted is increased. In addition, the overlay prevents the condensation of air humidity at low temperatures. The Kryoheater Selecta process thermostats have been designed for pressurised operation. By a pressurized operation with nitrogen the advantages mentioned above are reached, and in addition the boiling points of the heat transfer liquids and thus the maximum permissible operating temperatures are increased.
- Lemo sockets for external temperature control
- USB interface to read out data and for information transmission for diagnosis or configuration
- A freely selectable analog or digital interface
Simple and intuitively designed user interface:
- Visualisation of heating and cooling circle, warning messages and failures
- Clear overview of the parameters – directly recognizable on the piping schematic
PLC (programmable logic controller) fitted in an industrial switch cabinet
- Comfortable and extensive interlinking with other IT systems
- High process transparency ensured by large information density in the control system
- Long-time compatible, vibration-resistant, maintenance-free and scalable
- Extremely high reliability
- Remote maintenance and remote diagnosis (update of parameter sets or software online possible)
|Technical features||KHS 3560 W||KHS 2190 W|
|Select to compare:|
|Working temperature min. °C||-60||-90||Working temperature max. °C||200||200||Bath volume min. L||15.0||15.0||Cooling output at 20 °C kW||35.00||21.00||Temperature stability ±K||0.50||0.50||Heater power max. kW||18.0||18.0||Pump pressure max. bar||5.5||5.5||Pump flow max. L/min||85||85||Cat. No. 400 V; 3/PE; 50 Hz||LWP 556||LWP 557||Cat. No. 440-480 V; 3/PE; 60 Hz||LWP 656||LWP 657||Cat. No. 400 V; 3/PE; 50 Hz & 440–480 V; 3/PE; 60 Hz||LWP 756||LWP 757|
Heat transfer liquids
|Unit||Kryo 65||Kryo 70||Kryo 90|
|Cat. No.||10 L||LZB 218||LZB 227||LZB 228|
|Cat. No.||20 L||LZB 318||LZB 327||LZB 328|
Cooling water tube EPDM
|Cat. No.||Description||di (mm)||da (mm)||Pressure range||Temp. range (°C)|
|RKJ 033||Fiber-reinforced||25||34 max.||10 bar||-40…100|
|Stainless steel tube clip|
|EZS 016||External ∅; 1″||25–40|
Metal hoses with cold insulation
|Cat. No.||Description||di (mm)||da (mm)||Length (cm)||Temp. range (°C)|
|LZM 094||M38X 100S||25||78||100||-100…350|
|LZM 095||M38X 200S||25||78||200||-100…350|
|LZM 096||M38X 300S||25||78||300||-100…350|
|EOF 539||With 1″ internal thread||Brass|
|EOF 540||With hose nozzle 1″, attachable with counter nut||Brass|
|EDF 222||Flat graphite gasket||DN25-PN40 DIN 2690|
|HKA 198||Flange adapter||M38 x 1,5 A to DIN 2633/DN25|
|LWZ 936||Remote maintenance by modem|
|EZ 214||Machine foot in steel with height adjustment|
|LWZ 942*||Additional expansion vessel, filling volume 50 L|
*Installation of an optional expansion vessel causes an enlargement of the housing height from 1,650 to 2,350 mm.
Cooling process of a 250 L reactor between 20 and -50 °C
- High efficiency for every temperature setpoint value by using precisely harmonised refrigerants and frequency-controlled compressors. In case of KHS 2190 W, the two frequency-controlled compressors are automatically run in single or two stage operation depending on load and temperature.
- Transport of the heat transfer liquid with the required pressure by means of the 2.2 kW magnetically coupled and frequency controlled pump in the external consumer, such as a reactor.
- Limitation of the outlet temperature; programmable temperature ramps as well as Delta T limitations to take minimum and maximum temperature loads of reactors into consideration.
- Link to the process control system by various interface options enabled by the standard Siemens PLC control