Dry screw vacuum pumps COBRA NC 0070-050 A COBRA NC 050 A Description Busch COBRA NC A series vacuum pumps feature our unique one-piece, fixed-pitch, screw profile rotors. Ideal for harsh applications in the chemical and pharmaceutical industries, COBRA pumps are also well suited for any application requiring oil-free compression along with high suction capacity at low operating pressure. All pumps have a single-stage, dry-running, non-contacting design, are water-cooled standard (air-cooled optional) and are directdriven by explosion proof motors. For applications requiring higher pumping speeds and/or lower end pressures, combination booster/ pump systems are available. Quiet running, COBRA pumps are easy to install and maintain, are suitable for variable speed operations and feature an overall low cost of ownership. Features Single-stage design One-piece screw casting 00% dry compression Non-contacting internal components Protective coating on internal components Low vibration and noise Levels Small footprint Suitable for variable speed control Standard Equipment NEMA C-face motor, explosion proof Class I, Groups C&D, Division, Service factor.5 Purge regulator for discharge end seals Cooling water flow control system (for direct-cooled models) Cooling water temperature switch and gauge Exhaust gas temperature switch Stainless steel exhaust silencer Exhaust check valve Stainless steel inlet flange Pump stand Fully assembled and tested
Dry screw vacuum pumps Operating Principle 8 8 5 0 4 9 7 6 5 3 Inlet Exhaust 3 Water Jacket 4 Screw 5 Oil 6 Gas Path 7 Timing Gears 8 Bearings 9 Shaft Seals 0 Oil Seal Operating Principle Two counter rotating, noncontacting screw shaped rotors rotate inside of a common cylinder. As the screws rotate, a volume of gas is trapped at the inlet of the vacuum pump, and the gas is conveyed towards the vacuum pump discharge. Due to non-contacting screws, no lubricant is required in the pumping chamber. Lubricants for the bearings and gears are sealed from the pumping chamber by shaft seals. Cooling is achieved by either a direct (once-through) water cooling system or by an integral coolant recirculating system, utilizing an internal liquid pump and a fan cooled radiator. Applications Chemical Pharmaceutical Solar Metallurgy Vacuum packaging Food processing Plastics Renewables Laboratory Accessories Inlet filters Liquid separators Knock-out pots High volume bag filters Control valves Gauges Switches and transmitters Motor starters Variable speed drives Gear oils Vacuum receivers
Technical Data Pumping Speed vs. Inlet Pressure Pumping Speed (ACFM) 00 NC050 A 50 NC060 A 00 50 NC0070 A 0 0.0 0. 0 00 000 Inlet Pressure (Torr) Technical Data NC 0070 NC 060 NC 050 Nominal pumping speed* ACFM 50 5 80 Ultimate pressure Torr.075.075.075 Motor size HP 5 7.5 5 Motor rotational speed RPM 3600 3600 3600 Sound rating** db(a) 75 8 8 Approx. oil capacity Qts. Average water usage rate GPM Approximate weight Lbs. 850 000 00 *Performance based on ambient conditions of 4.7 PSIA and 70 o F, and have a tolerance of + /- 0%. ** DIN EN ISO 5
Cooling Systems Direct Cooling System Radiator Cooling System The water in the cooling jacket of this system is maintained at a constant temperature through the continuous exchange of cooling water entering and leaving the pump water jacket. A manually operated needle valve and water outlet temperature gauge are installed on the system to allow for precise water flow adjustment in order to achieve an optimal pump operating temperature. An optional radiator cooled system is available for applications where a water supply is not available. This system uses a magnetically driven water pump to continuously circulate the coolant mixture through the cooling jacket and heat exchanger. The heat exchanger uses a shaft mounted cooling fan to remove heat and maintain an optimal operating temperature of the cooling system.
(direct-cooled) 8 / 4" N F D M Inlet H Discharge I K O E C 6" 6 / 4" / 4" 4 x o 5 / 8 " " 3" L 30 7/ 8" B " 3 / J " G A NC 050 A NC 050 A A B C D E F G H (ANSI) I (NPT) 57 34 43 / 8 3 / 8 40 7 5 / 8 44 / 8 / / 66 34 43 7 / 8 7 5 / 8 40 / 7 44 66 34 44 4 3 / 4 40 / 7 44 J K L M N O 50 / 4 7 4 3 / 4 8 3 / 4 37 7 / 8 59 0 7 / 4 6 0 / 37 7 / 4 59 0 7 / 4 5 / 8 0 / 37 7 / 8 All dimensions in inches unless otherwise noted.
Dry screw vacuum pumps (radiator-cooled) 8 / 4" F D Inlet H Discharge I E C 6" 6 / 4" 4 x o 5 / 8 " " 3" J " 3 / " G K B A NC 050 A A B C D E F G H (ANSI) I (NPT) 57 34 5 3 / 4 8 3 / 8 40 7 5 / 8 44 / 8 / / 66 34 53 7 5 / 8 40 / 7 44 3 / 8 66 34 53 / 8 4 3 / 4 40 / 7 44 J K NC 050 A 30 7 / 8 50 30 7 / 8 59 3 59 All dimensions in inches unless otherwise noted. Busch - all over the world in industry ISO 900 Registered Company Busch LLC 56 Viking Drive Virginia Beach, VA 345 Phone (757) 463-7800 Fax (757) 463-7407 www.buschusa.com -800-USA-PUMP Amsterdam Auckland Bangkok Barcelona Basel Birmingham Brno Brussels Budapest Buenos Aires Copenhagen Dublin Gothenborg Helsinki Istanbul Johannesburg Kuala Lumpur Maulburg Melbourne Milan Monterrey Montreal Moscow New York Oslo Paris Pune Santiago de Chile São Paulo Seoul Shanghai Singapore Taipei Tel Aviv Tokyo Vienna Warsaw Models and specifications are subject to change without notice COBRA NC-07-07/0