Process Cooling in Food Manufacturing
Process cooling in food production often presents unique challenges—especially when products are viscous, temperature-sensitive, and require strict sanitary controls. This case study highlights how a custom shell-and-tube heat exchanger design helped a salsa manufacturer achieve efficient cooling, reliable clean-in-place (CIP) performance, and long-term operational flexibility.
The Challenge: Cooling a Highly Viscous Product
A California-based engineering firm and representative of Enerquip equipment, HeatX, was asked by an OEM customer to provide a shell-and-tube heat exchanger to cool salsa prior to bottling. The goal was to reduce the product temperature from approximately 200°F to 120°F (93°C to 49°C) before packaging.
While this may seem straightforward, the physical properties of the salsa made the application particularly demanding.
Salsa viscosity varies significantly with temperature. In this case, the product measured roughly 2,000 cP while warm, increasing to more than 9,000 cP once cooled. At these viscosities, achieving turbulent flow inside the tubes of a shell and tube heat exchanger is extremely difficult.
Without turbulent flow, heat transfer efficiency drops sharply. The conventional solution is to compensate by increasing heat transfer surface area and using a high volume of cooling water on the shell side. While this approach can meet thermal requirements, it often results in large, bulky equipment.
HeatX questioned whether a more compact and sanitary-friendly solution was possible and turned to Enerquip for support.
Evaluating Traditional Design Options
Enerquip engineers initially evaluated the feasibility of a single, large shell and tube heat exchanger sized to handle the thermal load. From a heat transfer standpoint, this option could work.
However, sanitation posed a serious concern.
In food manufacturing environments, equipment must be cleaned frequently to prevent cross-contamination and bacterial growth. The salsa producer relied on a clean-in-place (CIP) system, which performs best when cleaning solutions flow through equipment at 5 ft/sec or higher.
In a single, large exchanger, achieving this CIP velocity would not be practical, making thorough cleaning unreliable.
A New Approach: Three Heat Exchangers in Series
To overcome both thermal and sanitary challenges, Enerquip developed an alternative design: three smaller shell and tube heat exchangers stacked in series.
In this configuration:
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The salsa flows sequentially through all three exchangers.
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Sanitary jumpers connect the outlet of one exchanger to the inlet of the next.
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Cooling water flows counter-current, entering the shell of the third exchanger, then moving through the second and first units.
This counter-current flow maximizes temperature differential and improves overall heat transfer efficiency.
Design Features Supporting CIP and Sanitation
Each heat exchanger was designed with sanitation in mind:
- Custom shell designs allowed the shells to be bolted together, simplifying chilled water flow between units.
- Tube-side connections included dedicated CIP inlet and outlet connections on the first and last bonnets.
- The intermediate bonnets relied on the existing sanitary jumpers, reducing piping complexity and overall system cost.
By reducing the size of each exchanger, the system allowed CIP flow rates of 5 ft/sec through the tubes, ensuring effective cleaning between batches and shifts.
Material Selection for Acidic Products
Salsa’s acidic nature required careful material selection. To resist corrosion from both the product and cleaning chemicals, the manufacturer chose super-austenitic stainless steel for all product-contact surfaces.
Although more expensive than standard stainless steel, this alloy provides significantly greater resistance to acid attack and extends equipment service life—an important consideration in continuous food processing operations.
Added Benefit: Redundancy and Risk Reduction
Beyond improved cooling and sanitation, the multi-exchanger design delivered a critical operational advantage: redundancy.
With a single large exchanger, a tube failure could force a complete production shutdown. Repair would require replacing the entire tube bundle, potentially involving months of lead time due to specialty alloy availability.
With three smaller exchangers in series:
- Any single unit can be temporarily bypassed if a tube failure occurs.
- Replacement tube bundles are smaller, less expensive, and faster to source.
- Production downtime and financial risk are significantly reduced.
Results
The final system delivered consistent and efficient process cooling while fully meeting sanitary requirements. The salsa manufacturer gained:
- Reliable cooling performance for a highly viscous product
- Effective CIP cleaning at required flow velocities
- Improved operational flexibility and redundancy
- Reduced risk of extended downtime and costly repairs
This project demonstrates how thoughtful heat exchanger design can solve multiple challenges at once, thermal performance, sanitation, materials compatibility, and operational risk. By rethinking the traditional “single large exchanger” approach, Enerquip helped deliver a solution tailored to the realities of food processing and CIP-driven environments.
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This blog post was last reviewed 2/9/26.