Twin Reversible Screw Conveyor for ATBS

General Description

Acrylamide Tertiary Butyl Sulfonic Acid (ATBS) is a polymer used in many industries such as textile, medical, personal care, water treatment, coatings, chemical, and oil recovery. The market for the granular version of this product is expected to expand at a rapid pace due to the expansion of the water treatment and oil industries where it is used extensively.

SNF Water Science is a specialty chemical company that focuses on treating, recycling, and preserving water. SNF products are specifically used to improve extraction, efficiency, and overall water quality in the oil and mining markets. KWS worked with SNF Water Science on a very unique application for conveying ATBS from a rotary filter press to one of two dryers. For this particular application, ATBS is extremely sticky and must be conveyed under 10-psig pressure.

Design Parameters

1. Product Type: ATBS (Acrylamide Tertiary Butyl Sulfonic Acid)
2. Material Density: 43 Lbs. per Cubic Foot
3. Capacity: 63 Cubic Feet per Hour
4. Duty: 24 Hours per Day, 7 Days per Week

KWS Advantages

SNF and KWS designed a twin ribbon-screw conveyor to mount under a rotary filter press and transfer ATBS to one of two dryer inlets depending on demand. KWS designed the twin screw conveyor using 3D modeling software to ensure proper fit up with upstream and downstream equipment. KWS worked closely with SNF engineers to perfect the design. KWS created a twin screw conveyor with an offset inlet to allow the twin screws to convey material, while increasing trough capacity without increasing screw size. Using ANSI flanges and pressurized seals allowed for the unit to hold the 10-psig for the application. KWS manufactured the twin screw conveyor from 316 stainless steel with an electropolished finish to limit sticking of ATBS to the screw and minimize corrosive interaction.

KWS Special Features

KWS supplied a bulkhead trough end on the drive end for rigidity and ease of maintenance. The bulkhead design moves the drive unit away from the trough end and potential contamination or damage.

The KWS direct-drive shaft mount design offers a compact and cost effective alternative when compared to traditional belt-driven screw conveyor drives. The gear reducer utilizes a hollow bore to accept a drive shaft manufactured by KWS that couples directly to the screw. A variety of gear reducer arrangements are available for direct drives. Right angle helical-bevel right angle gear reducers power each screw. The reducers can be easily accessed for maintenance. Reduction in cost for spare parts and maintenance results in significant cost savings.

Pedestal trough ends are located on the tail end and include an integral platform for mounting pillow block bearings. Inpro Air Mizer shaft seals create a positive purge and eliminate bulk material loss and contamination. Inert gas purges the seal through a precision clearance, pressurizing the seal. The seal is designed to last the lifetime of the equipment, maintenance free with no wearing parts. The Inpro seal accommodates radial run-out, axial movement, and angular misalignment simultaneously.

Internal surfaces of the screw conveyor were electropolished to a mirror finish. The screws and trough interior were fully welded and polished a 150-grit finish on all surfaces. The screws and trough were then electropolished, resulting in a metallically pure surface, an unaffected basic structure, improved corrosion resistance and permanently shiny surface. Electropolishing is required for some sanitary and food grade applications. The smooth and polished surface helps keep material from sticking to the screw. The equipment can be washed down with this smooth and polished finish.