Overview
A major U.S.-based producer of fine salt was experiencing a costly production problem with its table salt cooling process. The facility uses gas-fired evaporators to generate a salt wet cake from a brine solution, followed by rotary filter drum dryers that produce a fine-grain salt at approximately 260 degrees F. The high-temperature salt exiting the dryers was creating significant packaging problems for the table salt product line. The producer contacted Carrier Vibrating Equipment to evaluate cooling options and find a workable solution.
Challenge
The salt produced at this facility serves two distinct end uses: water softener pellet production and table salt. For water softener pellets, the elevated salt temperature was actually beneficial to the pelletizing process. For table salt, however, the high exit temperature damaged packaging labels and made the product difficult to package consistently.
The existing cooling method relied on large storage bins to hold the hot salt until it cooled sufficiently before packaging. This approach required significant labor, consumed substantial floor space in a facility where space was already severely limited, and regularly resulted in label damage from inadequate cooling, all of which added to production costs.
When evaluating alternatives, the producer found that conventional cooling technologies including rotary coolers and standard fluid bed coolers would have compounded the space problem rather than solved it. These technologies also required ancillary equipment including process air fans, dust collectors, exhaust fans, and interconnecting ductwork, making them cost-prohibitive for this application.
The producer’s goals were clear:
Solution
Carrier proposed the VibroCool, an indirect vibrating cooler based on technology developed from Carrier’s foundry industry experience combined with its extensive knowledge of indirect heat transfer via immersed heat exchangers.
The VibroCool is a cylindrical horizontal drum with a horizontal tubular heat exchanger bundle mounted internally, through which cooling tower water or filtered river water is circulated as the heat transfer medium. The drum assembly is supported on steel coil isolation springs and vibrated using a gearbox-driven eccentric weight drive to produce a unique vibratory motion. This motion causes the salt to move slowly through the machine in a gentle, well-mixed, sub-fluidized state. The heat exchanger is positioned so that the circulating bed of salt maintains intimate contact with it throughout, producing high heat transfer rates with the cooling water.
Before committing to a production unit, Carrier shipped a continuous test unit to the plant site to demonstrate the VibroCool’s ability to process the table salt. The unit was trialed by pulling a slipstream of material directly from the production line. Carrier’s engineers worked alongside plant personnel to evaluate product quality and system efficiency. Testing confirmed that VibroCool’s in-bed heat exchangers, combined with the specific vibratory motion, achieved excellent heat transfer coefficients with no degradation to product quality.
The full production unit was then engineered to handle the plant’s complete line capacity, cooling salt from 260 degrees F to less than 140 degrees F. The unit was sized at 3 ft in diameter and 12 ft in length, constructed of 316L stainless steel, with all product-contact surfaces polished to a food-grade finish. All water supply and return lines were close-coupled to a single connection in and out, and a single-point electrical connection served the drive motor.
The VibroCool’s inherently low-headroom design allowed installation in a building with ceiling heights as low as 8 ft, directly addressing the facility’s space constraints. Simple screw conveyors handle feed and takeaway, keeping the full installation straightforward and flexible.
Results
- Salt cooled from 260 degrees F to less than 140 degrees F in a compact single-unit footprint
- Large storage bins and associated labor eliminated entirely
- Label damage from inadequate cooling resolved
- No process air fan, dust collector, exhaust system, or interconnecting ductwork required
- Regulatory permitting burden eliminated due to absence of process air emissions
- Food-grade stainless construction with simple single-point water and electrical connections
- Low-headroom installation compatible with existing facility ceiling height
Contact Carrier Vibrating Equipment
Carrier Vibrating Equipment engineers custom cooling, drying, and handling solutions for food, chemical, and industrial processors. Contact our team to discuss your application and find out which technology is the right fit for your process.