Estimating the Size and Cost of Steam Vacuum Refrigeration
When process refrigeration requirements call for utmost reliability in the temperature range of 35 to 80° F or higher, steam vacuum refrigeration deserves first consideration.
Many processes require water at temperatures below those available from the cooling water source. In the range of 55 to 80° F or higher, conventional reciprocating. centrifugal and absorption systems encounter a variety of problems of maintenance and reliability, particularly at the higher temperature levels. Steam vacuum refrigeration systems on the contrary exhibit improved performance, with no change in reliability or maintenance.
Seven Key Considerations. Steam vacuum refrigeration should be considered when:
• Steam is the motive fluid and either high or low pressure steam is readily available.
• Variations in cooling water temperature produce lower condensing temperatures during a large portion of the operating period, resulting in steam economy.
• Reliability is of utmost importance.
• Brackish or scaling water is the only condensing medium (in this case barometric condensers offer a large advantage).
• Outdoor installation is contemplated.
• Chilled water temperature is above 55° F.
• Chilled water temperature range is large.
Basic Types. Three types of steam vacuum refrigeration systems are available today. These are:
• Steam Vacuum Refrigeration With a Barometric Condenser (Fig. 1)
• Steam Vacuum Refrigeration With a Surface Condenser (Fig. 2)
• Steam Vacuum Refrigeration With an Evaporative Condenser (Fig. 3)
