Solenoid valve keeps steam from overheating chocolate
A Midwest chocolate manufacturer roasts cocoa beans and then heats the powderized beans with cocoa butter to make chocolate distributed to well-known food companies that make candy bars, chocolate candy and other related chocolate foods.
The heating of the cocoa butter mixture requires a consistent 130ºF temperature for the water circulating through the jacketed kettle tanks. The manufacturer was experiencing an overheating problem with the tanks resulting in over-cooking of the cocoa butter, causing it to caramelize.
The caramelizing was costing the company $40,000 to $160,000, depending on the size of the batch. Because of this challenge, the business was unable to fulfill orders to customers, which was hurting the bottom line and customer relationships. Forced to stop production altogether to avoid losses, the processor called on CIRCOR Industrial Valves Americas channel partner Somes-Nick & Co. to help fix the problem.
The Challenge: Overheated Steam
The plant was using another vendor’s temperature pilot and pressure regulator to control the steam pressure sent to the plate and frame heat exchanger. The regulator was intended to heat the water and create steam to 130ºF to circulate in the jacket of the tank and cook the product. The challenge was that the other vendor’s regulator was failing to open, causing overheating or stopping the heating process altogether. In addition, the regulators were not sized properly. The isolation valve being used in the old application offered no modulation to maintain the required 130ºF. The company uses three tanks and batches range from 10,000 to 40,000 lbs. They were losing about $4 for every pound of chocolate that caramelized.
The Solution: CIRCOR Valves
The company could not identify the causes of the overheating. CIRCOR channel partner Somes-Nick & Co. held a site visit to do an analysis, and it was discovered that the problem was due to: 1.) no strainer upstream of the valves, 2.) a problem with the interface between the valve and the pilot, and 3.) incorrect valve sizing.
Drawings were done for the company to illustrate how the problem could be solved using CIRCOR equipment. The correct valve size was determined with calculations taking into account the weight of the product being cooked, the required temperature rise and the number of BTUs needed to heat the tank for an hour of cooking. Using that data, an application utilizing a Spence E2, a Spence T14 temperature pilot and a Spence M33 solenoid was recommended. The solenoid valve was placed between the pilot and the main valve. With the new setup, when the water was sent to the heat exchanger, and the resulting heated water reached the desire temperature, the solenoid valve would shut off the steam to the heat exchanger to prevent overheating. As soon as the water temperature dropped 3-5 degrees below 130ºF, the solenoid valve would energize the T14 pilot to heat the water back up to the required temperature.
CIRCOR products were chosen because of the company’s excellent reputation for quality and readily available, easily integrated equipment. The channel partner was able to come up with the ideal solution in a timely manner thanks to having previously worked on about 20 similar systems for other customers requiring steam heat in food and beverage applications.
The process, from the first visit to the installation and solution, took approximately four months. The cocoa processor got product distribution to its customers back on track. The company is also saving the money it was losing on energy to generate unnecessary steam.
For more information, visit www.circor.com