Dairy Creamery Automation

SUMMARY:  

Designed, developed and installed a PLC/MMI system to automate the process of batching/blending milk, pasteurizing and step-heat processing for the making of sheep cheese. The process also included waste handling and CIP.

DESCRIPTION:  

The system employs a PC based MMI for operator control of the process, which allows for the creation of recipes for several of types of cheeses. Some of the parameters include milk (sheep, cow, both, frozen), batch size, and inoculants. 

At process time, the operator selects a recipe, is prompted for and must confirm that the piping is properly connected, and then presses the 'Start' button on the screen. The system then controls the volumetric addition of milk to the processing vat. Once the milk is added, heat is applied according to the recipe profile. If frozen milk was used, there is a 'thaw' cycle that is performed before the heat treatment cycle. 

A separate recorder certifies pasteurization, but the cycle is controlled by the PLC. 

During the process, the operator is prompted to add inoculants. These prompts include the description and weights of the items to add, which can be rennet, mold cultures, acids and other items required to create the curds. 

The PLC controls the valves for heating and cooling of the process vat. Alarms conditions are monitored and displayed to the operator. Temperatures are trended.