One ice and ice-cream maker eliminated service problems and minimized noise and vibration concerns with a compressor retrofit.

Extreme vibration in existing compressors at Brookshire Grocery Co.'s ice and ice cream plant caused chronic maintenance problems. So when the Tyler, Texas, company expanded its facility, quiet compressors became a priority. Brookshire, which also operates 152 grocery stores in five states, had been using compressors for several functions throughout its facility. The excessive vibrations resulted in more than just costly maintenance headaches.

"The vibration problems also lead to extreme noise in the engine room," said Richard Cogburn, Brookshire's ice plant refrigeration supervisor.

Seeking Answers

The goal to reduce vibration to solve both the maintenance and noise issues directed Brookshire to Vilter Manufacturing Co., Cudahy, Wis., a 135-year-old maker of compressors and condensers for refrigeration systems. Vilter installed six single-screw compressors in the 491,000 ft2 plant expansion. The units primarily are used for two purposes: ice production and warehouse refrigeration of perishable products.

During ice production, the compressors freeze the ice, then use hot gas from the compressors to release the ice from the ice tube machines made by Vogt Ice, Denton, Texas. After the ice tubes are harvested, the compressors then cool the refrigerant to start the freezing process again. The ice-bin room maintains a steady range of 12oF (-11oC) to 14oF (-10oC), while the ice-bagging area is controlled at 52oF (11oC).

In the banana ripening area of the plant, the compressors are used to maintain room temperature of 55oF (12.8oC) to 58oF (14oC). The same cooling process is required in the stone-fruit room, where fruits such as peaches and apricots ripen.

Since the installation of the six Vilter compressors, vibration problems and the associated maintenance issues have been eliminated, due in part to the compressors' single-screw design. The units have one main rotor and either one or two gate-rotors, which result in quieter operation compared to the previously used twin-screw compressors.

In addition, Cogburn noted that the single-screw compressors are more energy efficient than their earlier models.

"Two outside energy consultant companies each reached the same conclusion," he said. "The Vilter units save energy." The savings is because the dual-slide design of the single-screw compressors provides up to 20 percent better efficiency at part-load conditions.

Microcontrollers also contribute to Brookside's improved efficiency. According to Coburn, the Vilter controller settings allow for individual control, user-friendly operation and ease of custom programming. The units can operate individually or allow multiple compressor sequencing through a single controller. Or, in the case at Brookshire, the compressors interface with the industrial control equipment used throughout the plant.

Customer service also was a plus for Brookside. Vilter's district manager, Bill Goggins, "calls to make sure that everything is going okay, which is great, but we really have no service concerns," Cogburn said.

Vilter Manufacturing LLC