Zenith^® Planetary Gear Pumps - Precise, Pulseless, Repeatable Performance in Hot Melt Spin Pump Applications

[Description]  [Textile Denier Melt Fiber Spinning]  [Specifications]  [Selection]  [Drive Shaft Seal Options]  [Pump Mounting]  [Contract Services]  [Test Stands]  [Pump Models]

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Since 1926, Zenith has provided the man-made fiber industry with precise, pulseless and repeatable gear metering pumps. Form the earliest applications in viscose and hot-melt fiber spinning, through the more recent applications in high performance, specialty fibers, Zenith has met the challenges of the fiber industry with pumps of unmatched performance and quality.

As the largest spin pump supplier to the world's leading fiber producers, Zenith has remained in the forefront of gear pump developments through ongoing programs of research into both pump design and precision part manufacturing. In addition, Zenith Products Division is committed to providing superior quality and customer service with two state-of-the-art, ISO certified production facilities fully integrated to ensure that our fiber producer customers have a reliable source of supply for their critical gear pump needs. Our customer support efforts are further enhanced by a worldwide network of direct offices, service facilities and sales representatives to respond to the demands of the fiber industry.

Planetary Pumps for Textile Denier Melt Fiber Spinning 

The planetary pumps described in this catalog were developed by Zenith to maximize melt fiber production yields and run time. The pumps are available in configurations with 2, 3, 4, 6, or 8 metered outlet streams per pump and in displacements covering the throughput range of 0.1 to 8 liters/hour per stream. When properly installed and operated, the spin pumps provide the fiber producer the following benefits:

• Outstanding stream to stream and pump to pump metering uniformity resulting from superior design, quality and wear resistance.
• Reduced polymer shear and downstream thermal gradients resulting from optimized gear geometry and internal flow paths.
• Superior pump pressure capability resulting from high strength components including a full diameter coupling housing plate.
• Superior pump toughness and durability resulting from through hardened, particle metallurgy components.

In addition to these benefits, the single gear level planetary pump models offer greater stream to stream process temperature uniformity resulting in improved yarn consistency and processability as compared with multi gear level style pumps.

Specifications 

Pump Selection 

The following is a general guide for use with the tables in this catalog in selecting a spin pump for most textile denier, melt polymer applications.  If the pump models described in this catalog are not suitable for your particular needs, Zenith Pumps has more than 1,000 additional spin pump designs as well as extensive custom engineering and manufacturing capability to provide an optimum pump for almost any fiber spinning application.  Beyond the technical data included in this catalog, Zenith Pumps can provide pump performance curves for each pump model describing the volumetric efficiency, operating torque, and temperature rise for any customer specified polymer. Finally, before placing your order, please confirm your pump selection with either the Zenith factory or your Zenith pumps sales representative.

1. Choose a pump model from the table on opposite page based on your requirements for: number of metered output streams, inlet and outlet operating pressures, and maximum polymer viscosity. Additionally, in the case of 6 or 8 stream models, select either the single gear level or the dual gear level model based on your available installation space and/or the anticipated range in throughput.
2. Divide your design pumping rate per outlet stream expressed in cm 3 /minute by each of the displacements available for the selected model to determine the pump speed for each displacement. For the best overall performance, select the pump displacement that results in a pump speed within the following optimum ranges.
   
   • 10-27 rpm for 2, 3, 4, dual level 6, and dual level 8 stream models
   • 8-18 rpm for single level 6 stream models
   • 6-14 rpm for single level 8 stream models

   Steps 3 through 6 are used to verify the mechanical torque adequacy of the pump selected in step 2. If the pump is found to be acceptable, the calculated operating torque from step 5 can be used to size the pump drive.
   

3. Apply the maximum anticipated pump speed in rpm (N), and the pump (K₁ ) factor to the following equation and calculate the average shear rate (SR) in the pump in sec -1.  SR = N * K₁
4. Using this shear rate and a viscosity versus shear rate curve for the spin polymer at the process temperature, determine the apparent viscosity for the polymer (µ) in Poise.  Note: Poise = 10 * Pa-s.
5. Apply the number of metered streams (n), the pump displacement per stream (D), the required pump differential pressure in bar (DP = Discharge - Inlet, note: bar = 14.5 * psi), the maximum anticipated pump speed in rpm (N), the apparent viscosity (µ) in Poise, and the pump (K₂ ) factor to the following equation and calculate the pump operating torque (T) in N-m. Note: in-lbs = 8.85 * N-m. 
   T = ( n * D * DP/62 ) + ( N * µ / K₂ )
   
6. Compare this calculated value with the mechanical torque limit for the pump model  to verify the adequacy of the selected pump.

Drive Shaft Seal Options 

The standard pump models are supplied with universal coupling seals with a tang slot connection. Where improved performance of this type seal is required, an optional outer drive shaft with tang bearing is available. This design will prevent the possibility of drive shaft misalignment or axial loading from causing the coupling to improperly seat and leak. In addition to universal coupling seals, the pumps in this catalog are also available with high temperature packing seals.

Pump Mounting 

To ensure the critical internal pump clearances are maintained and the highest possible metering performance is achieved, the surface to which the pumps are mounted should be flat within 0.0025 mm convex with a surface finish of 4 to 8 rms and the pump mounting bolts should be hot-torqued in three increments to the value specified in the Bolt Torque Tables. If replacement pump wear plates are needed due to damage or to accommodate a new pump design, Zenith Pumps can supply precision engineered and manufactured wear plates to ensure optimum gear pump performance.

Pump Contract Services 

Zenith Pumps offers complete contract repair and service on all types of metering gear pumps used in the fiber industry. With two strategically located service facilities in North America servicing over 40,000 pumps annually, Zenith Pumps has unmatched expertise and resources for the maintenance of precision gear pumps. As a result of our experience and volume efficiencies, our customers save both money and downtime while ensuring the fiber products they produce are of the highest quality.

In support of our maintenance services, Zenith Pumps provides replacement parts for a wide variety of Zenith and non-Zenith precision gear pumps. Please contact your local sales representative or the Zenith Pumps factory direct for further information on this service.

Pump Test Stands 

To support fiber producers that elect to do their own pump repair and testing, Zenith Pumps provides custom engineered pump test stands for volumetric testing of spin pumps and spin finish pumps. Depending on the customer requirements, the test stands can be engineered with different numbers of test positions and different levels of automation. Please contact your local sales representative or the Zenith Pumps factory direct for further information on our pump test stands.

Pump Models 

• Model HSC-6188 Pump 2 Outlet Ports X 1 Level
• Model HSD-6191 Pump 3 Outlet Ports X 1 Level
• Model HSE-6187 Pump 4 Outlet Ports X 1 Level
• Model HSG-6189 Pump 6 Outlet Ports X 1 Level
• Model HSH-6192 Pump 6 Outlet Ports X 2 Levels
• Model HSI-6190 Pump 8 Outlet X 1 Level
• Model HSJ-6182 Pump 8 Outlet Ports X 2 Levels