Controlling Process Temperature
October 13, 2000
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Controlling process temperature ensures
product uniformity and integrity. Temperature control systems and
chillers are used where tight temperature control of the process is
critical. Processes requiring heating and chilling can combine a
circulating water temperature control system and a portable chiller to
provide single- or multiple-zone control.
Circulating Water Temperature Control
Hydrotherm is designed to provide accurate process temperature control in a 2 ft2 footprint. Standard features include 9 kW heating capacity; 3/4 hp motor; 25 gal/min and up to 40 psi pumping capacity; microprocessor-based controller; and 250°F (121°C) maximum operating temperature. Stainless steel, hydroformed pump is designed to ensure less thinning of material. From Mokon Div., Protective Closures Co. Inc., the temperature control system employs nonferrous construction and has indicating lights for need of operator, suction and discharge gauge.Space-Saving Chiller Package
Offered in cooling capacities from 810 to 5,045 W, the Merlin Series from Neslab Instruments Inc. provides cooling in a space-saving package. Features include an easy-view fluid reservoir, reservoir drain for quick fluid changes, and integrated fluid pressure reducer/flow controller. Several user interface features are available, including high and low temperature safeties, audible alarm, computer control and stability to I0.1°C.Temperature Control System
Tri-Temp from Advantage Engineering Inc. can provide up to three independent process water temperatures from 30 to 250°F (0 to 121°C). The portable system has a single chilled water circuit and two heating circuits. The chilled water circuit uses an internal water reservoir. Cooling circuits are available with 1.5 to 40 tons of chilled water capacity and with 0.75 to 5 hp pumps. Heating circuits are available with heaters from 4.5 to 36 kW and with pumps from 0.5 to 7.5 hp.Chiller Has Communication Protocol
Kodiak recirculating chiller from Lytron contains an ozone-friendly refrigeration system with hot gas bypass. Its RS232 communication protocol allows for remote monitoring and chiller control. OEMs can collect chiller data on a system's host computer and review it remotely to analyze operating trends, troubleshoot or diagnose difficulties. The communication protocol sends and controls chiller parameters. It is available with cooling capacities of 600, 1,100, 2,200 and 4,500 W and with a variety of electrical, pump and controller options.Rack-Mount Chiller
RK-19 replaces tap water usage in water-cooled equipment. From Tek-Temp Instruments Inc., the chiller provides 2,500 BTU/hr (733 W) of cooling. The air-cooled model utilizes a CFC-free, ozone-protective refrigeration system with hot gas bypass to maintain stability to I0.1°C over the coolant temperature control range of 41 to 95°F (5 to 35°C). Microprocessor-based controller provides simultaneous display of process temperature and setpoint. To facilitate computer control and datalogging, the unit can be equipped with an RS485 communications interface.Small Footprint Chiller
Chiller's Cool Command microprocessor-controlled refrigeration technology provides energy efficiency and improved compressor life. Chiller from PolyScience offers temperature ranges from 5 to 176°F (-15 to 80°C) and up to 10,000 BTUs. A choice of pumps is available to satisfy a range of applications.Temperature Application Heater/Chiller
Model PWG-060K-BE27CBC from Affinity Inc. has 1 kW of cooling capacity at a setpoint of -40°F (-40°C) and a heating capacity of 2 kW. Process coolant temperature range is -40 to 248°F (-40 to 120°C). System has hard-plumbed stainless steel coolant loop, sealed stainless steel reservoir with sealed top, and magnetically driven sealless pump for specialty heat transfer fluids. The unit is operated with a non-ozone-depleting HFC refrigerant and is CE marked. Standard features include a digital controller; interlock for flow, temperature and coolant supply level; and coolant pressure gauge.Hot Oil Control Unit
Thermal VAC negative-pressure temperature control unit provides continuous production even under demanding conditions. From Budzar Industries Inc., the controller has a maximum temperature of 400°F (204°C) and is available in heater sizes up to 24 kW and oil-flow rates to 30 gal/min. A low pressure centrifugal pump delivers oil to the process, and an onboard vacuum pump draws oil through the process under negative pressure. If a leak develops, air is sucked in instead of hot oil being forced out, allowing the process to continue running under negative pressure until an opportune stopping point arises.
