High Pressure Gas Conditioners

Bemco HPG, High Pressure Gas Conditioners are similar to the PTS Portable Temperature Conditioners except they are designed for continuous operation at up to two atmospheres (29.4 psia) of pressure.

This higher base operating pressure doubles the gas density per cfm of circulating air or gaseous nitrogen allowing the use of smaller connecting tubes while also increasing thermal capability. Besides operating at a higher base pressure, HPG Conditioners are equipped with high pressure blowers capable of delivering full rated flow at a loop pressure drop of up to 10 inches of water.

HPG Conditioners are available to circulate gaseous nitrogen or air. Direct nitrogen injection systems are always nitrogen circulating systems. All HPG systems include a high pressure blower mounted in a high pressure scroll discharging through an appropriately sized duct or tubing connection. Air or nitrogen is returned to the conditioner through a second, matched duct or tubing connection. Wide temperature range tubing or flexible metal tubing is always used with these systems due to the higher operating pressures involved.

The high pressure blower is driven by an externally mounted motor with dual ball bearing races, through a Bemco high pressure and low temperature shaft seal connected by a large diameter extended stainless steel shaft. Like the PTS systems, HPG motor speed and total system gas flow can be adjusted to match load conditions using a variable speed solid state drive. A minimum flow is required to prevent heater burnout.

Fast-response, open type, or sheath heaters, depending on the system temperature range, raise temperature as required.

No asbestos is used in construction. Outer cases and machinery enclosures are fabricated from cold rolled steel finished in Bemco Blue. All electrical wiring meets the United States National Electric Code. UL and CSA approved components are used where possible.

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Instrumentation

Each HPG Conditioner includes a microprocessor based, programmable 1/4-DIN, solid state 256-step ramping controller with a 4-line LCD interface display and a large red LED display. An RS232 and RS485 interface is standard. The protocol is Modbus™. LabVIEW™ drivers are available.

Temperature control is + or - 1 C (+ or - 1.8 F) guaranteed, + or - 0.15 C (+ or - 0.25 F) typical.

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LN2 Cooling

For those systems that include liquid nitrogen cooling, either a direct nitrogen injection system, or a liquid nitrogen heat exchanger is supplied.

Liquid nitrogen systems include dual liquid solenoids, one for proportional control and one to act as an interlock to prevent run away in the event of a solenoid failure. A liquid line strainer and a relief valve are also included.

When an air to LN2 heat exchanger system is selected, a liquid nitrogen level control system is provided. The level control system prevents fluid blow-through in the event that the heat exchanger system is calling for more cooling but is already full of liquid nitrogen due to previous demand. For HPG systems associated with a Thermal Shroud or Baseplate, gaseous nitrogen (GN2) is always used as the circulating medium.

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Mechanical Cooling

Mechanically refrigerated systems are selected when operating cost versus first cost is a primary consideration. Mechanically refrigerated systems can be optionally furnished with liquid nitrogen boost cooling to allow operation down to -180 C. In some cases, special provisions must be made to isolate the refrigeration system from this cold temperature.

When a mechanically refrigerated system is specified, a proportionally controlled cascade, two compressor, refrigeration system for -70 C ultimate temperature systems, or a single stage, one compressor refrigeration system for -35 C ultimate temperature systems is provided. These systems utilize modern environmentally friendly refrigerants to cool the circulating air or gas. The refrigeration system includes automatic hot gas bypass and suction cooling unloading. Cascade systems also feature Bemco’s exclusive, high performance coaxial cascade heat exchanger.

All systems have thermal and current sensors on each compressor as well as numerous safety and reliability protection systems for dependable operation. Standard systems all have water cooled condensing. Air cooled condensing is optionally available.

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Matching Thermal Shrouds

Gas circuited Bemcoil thermal shrouds matched to the selected HPG Conditioner are offered, either as part of a Bemco Space Simulator or Thermal Vacuum System, or independently for installation in a competitor's product or in an existing piece of equipment.

Bemcoil, is a proprietary Bemco stainless steel shroud material proven in high vacuum service for over 50 years. This material is available in both single and double embossed versions. It is made from 18 gauge roll welded stainless steel with welded edges.

Because each panel is made to order, circuiting can be optimized to match both the fluid in the shroud and the shape of the enclosing space. Starting with shrouds as small as 12 inches in diameter, Bemcoil is available for installation in systems as large as 50 feet in diameter. You can review our Space Simulator and Thermal Vacuum system products by clicking here or you can see more information on Bemcoil by clicking here.

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Mechanical Options

• A set of two appropriately sized insulated hoses or metal tubes with connectors at both ends. Standard duct length is 8 feet each.
• Refrigeration gauges (two per compressor) mounted in the refrigeration package.

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Optional Instruments

• 24 hour or 7 day, digital indicating, self chart printing, circular recorders for temperature.
• Single-pen or multi-pen strip chart recorders.
• Programmable logic control sequencing of test processes. Bemco recommends Allen Bradley (ABB) PLC’s and software.
• Gas flow volume or mass flow, display or control instruments.
• Set of two, one high and one low, microprocessor-based, FM Approved temperature safety controls.
• A low flow safety control with an audible and visual alarm system.
• Touch screen HMI’s (human machine interfaces).
• RS232, RS485, and Ethernet communication interfaces.
• Engraved or silk screened graphic control panels.

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Available Literature Includes:

Bemco PTS and HPG Series, Portable Temperature Servo Conditioners and High Pressure Gas Servo Conditioners. PTS Servos provide a closed loop flow of controlled temperature air or gas and HPG High Pressure Gas Servos provide a flow of temperature controlled high pressure gas. HPG gas conditioners are commonly used with Space Simulator thermal shrouds. Maximum standard temperature range is -185 C to +150 C. Higher temperatures are available on request. Sixteen standard PTS and twelve standard HPG models are available. Gas distribution panels are also discussed. Document is 8 pages, 676 KB download.

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The systems described above are our Standard Models. We make custom equipment to your specifications.  If you have any questions, need assistance in preparing a specification, or have a technical problem you want help with, we are ready.  Our quotations and advice are free.