The patented circular wind flow pattern of the Uni-DRAW® provides excellent wind distribution throughout the effective work zone without the need for movable baffles. Wind from the rear-mounted high capacity recirculating fan moves out along the walls to the front of the furnace. The wind then travels back through the work zone to the fan inlet. Fast heating and excellent uniformity of +/-10°F during the soak period results.

Built to Surface’s exacting standards of ruggedness and reliability, the Uni-DRAW is designed for decades of useful life with minimal maintenance and adjustment. The furnace casing is manufactured with gas-tight welded heavy steel plate supported by structural steel shapes. The insulation package is balanced to be energy efficient, allow rapid temperature changes and ease of maintenance. Surface’s proprietary soft-seal door design also helps promote rapid heating, low heat losses and excellent temperature uniformity. This batch furnace may be loaded with simply a fork truck or an advanced automated charging system. Multiple furnace hearth designs are available to support light or heavy workloads and enable automation. Work zone sizes and hearth capacities are the same as the Allcase batch integral quench furnace.

Standard Uni-DRAW temper furnaces are available with maximum temperatures of 900 and 1400°F. Surface offers four different heating systems for the Uni-DRAW. Electric elements, gas-fired radiant tubes or Surface’s proprietary Ported Tube^TM direct-fired burner system are rear wall mounted and spaced around the load envelope for even heating. Our base model offers an economical side mounted tangentially fired package burner system.

Nitrogen Uni-DRAW Temper Furnace

Nitrogen atmosphere may be added to electrically heated and radiant tube models to reduce oxidation and work discoloration. Purge and process nitrogen flow may be automatically set in the furnace controller. Each Nitrogen Uni-DRAW has an external cooling package to rapidly reduce load temperature to a prevent discoloration when the door opens and air enters the furnace at the end of the cycle. Radiant tube furnaces have the added benefit of plunge cooling to add to the cooling rate of the furnace.

The Nitrogen Uni-DRAW uses the same patented windflow as the Uni-DRAW. It also comes in the same standard sizes, load capacities and temperature ratings as the Uni-DRAW.

PM / Uni-DRAW Temper Furnace

The P/M Uni-DRAW is designed specifically to temper or draw powder metal parts after oil quenching.  Due to the porosity of the powder metal parts, oil is retained from quenching. This oil is released in the form of smoke during the temper cycle. The P/M Uni-DRAW is designed to capture and remove much of the smoke generated.

The furnace is direct-fired. Smoke from the burners and the parts is released through a stack opening at the top of the furnace through customer provided ductwork to an electrostatic precipitator specifically designed and sized for the furnace. The electrostatic precipitator’s controls are integrated and interlocked with the furnace control system. Within the electrostatic precipitator, smoke is converted to oil for collection and disposal, reducing the visible effluent from the stack.

The furnace design uses a unique “inside/out” construction, consisting of an internal steel casing with external fiber insulation and a light gauge sheet metal covering. This design provides rugged construction and protects the insulation from oil impregnation and contamination. The internal steel casing may be easily cleaned of any residual oils.

The P/M Uni-DRAW uses the same patented windflow as the Uni-DRAW. It also comes in the same standard sizes and load capacities of the Uni-DRAW. Maximum temperature rating for the P/M Uni-DRAW is 800°F and temperature uniformity is +/-10°F during the soak

A Uni-DRAW can be designed to stand alone or be part of a new or existing furnace line. Surface provides a wide range of companion equipment, advanced controls and support services for single source responsibility. This allows you piece of mind that your installation will run smoothly, and your equipment will be taken care of for the long term.

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