Indirect Bulk Flow Heating, Cooling & Conditioning Technology
When energy efficiency, high-quality product output, and a low operational cost is desired, Carrier’s Bulk Flow Heating / Cooling Exchanger, or BMHX, delivers with its efficient indirect heat transfer technology. This equipment utilizes a gravity-fed design to flow material between thermal plates, cooling, heating, or drying the material as it works its way from top to bottom.
Indirect Cooling & Heating
The product is cooled or heated when it moves across plates with water or other heat transfer fluids flowing internally through them. The product touching these plates cools by conduction, and since there is no direct contact between material and thermal fluid, there is no risk of contamination or need for dust collection or scrubbers.
Low Emissions
Since moving air is not used in the cooling or heating process, there is no issue with emissions or dust, making it perfect for locations or materials with strict emission regulations.
High Material Quality
The material moves slowly in a plug flow through the heat exchanger, reducing product degradation and preventing equipment abrasion. The closed environment in the bulk material heat exchanger means it can be operated consistently through different external conditions.
Small Footprint
Designed to move the product vertically, the BMHX has a smaller footprint than other cooling and heating technologies. This allows it to fit into existing plants with minimal retrofitting, making it flexible to current operational requirements.
Low Operating Cost
Operating without moving parts and few ancillary components means the Carrier BMHX is low maintenance and easy to keep operating efficiently. The equipment is designed for easy cleaning and part replacement, reducing downtime and expenses.
Energy Efficient
The Carrier BMHX uses gravity to move the processed material and does not rely on large amounts of process air. Instead, the equipment uses passive temperature change through conduction, resulting in minimal energy use compared to other methods.
Bulk Material Heat Exchanger Features & Benefits
- Indirect heating/cooling design provides intimate contact between solids and plate coils for maximum efficiency. The BMHX uses gravity to move the material being processed and does not rely on large amounts of process air. Instead, the equipment uses passive temperature change through conduction, resulting in minimal energy use compared to other methods.
- Counter-current fluid-to-material flow ensures even heating or cooling of bulk material solids.
- Adjustable feeder on the discharge provides precise control of product flow rate and residence time.
- Material moves slowly in a plug flow through the heat exchanger, reducing product degradation and preventing abrasion of the equipment. The closed environment in the bulk material heat exchanger means it can be operated consistently through different external conditions.
- Little to no air exhaust eliminates the need for ancillary fans and air filtration systems in most cases. Since moving air is not used in the cooling or heating process, there is no issue with emissions or dust, making it perfect for locations or materials with strict emission regulations.
- Designed to move the product vertically, the BMHX has a small footprint compared to other cooling and heating technologies which allows it to fit into existing plants with minimal retrofitting and makes it flexible to current operational requirements.
- No moving parts within product contact and few ancillary components reduces maintenance costs and is easy to keep operating efficiently.
- Designed for easy cleaning and part replacement means reduced downtime and expenses.
Industries & Applications
- Biosolids
- Catalysts
- Chemicals
- Fertilizers
- Food Products
- Foundry Sand
- Lithium-Ion Battery Minerals
- Metal Ore
- Plastic Pellets
- Proppants
- Food Salt
- Sand
Read Our BMHX Case Study
When an innovative manufacturer sought to expand into international markets, new export regulations created a critical processing challenge. Carrier Vibrating Equipment evaluated multiple technologies and engineered a customized thermal processing solution that met stringent heat-treatment requirements while preserving product quality and production efficiency. Download the case study to learn how Carrier helped enable global market access, support business growth, and deliver a reliable long-term processing solution.
Bulk Material Heat Exchanger FAQs
What is indirect bulk solids heat exchange?
Bulk solid material flows downward by gravity through a vertical array of hollow plates. A thermal fluid – water, steam, oil, or gas – circulates inside the plates and transfers heat through conduction directly into or out of the bulk solid. The product and thermal fluid never come into contact, and no process air passes through the material.
What thermal fluids can be used?
The BMHX operates with cooling water, chilled water, hot water, propylene glycol, ethylene glycol, steam, or thermal oil depending on the application and required temperatures. Carrier’s test facility can evaluate performance with water, heating oil, or steam.
Why eliminate process air from the heat transfer step?
Conventional direct-contact systems require large air volumes, high fan horsepower, baghouses, scrubbers, and emission permits. Eliminating air removes particulate and VOC-laden exhaust, reduces energy loss, and simplifies compliance. For reactive, temperature-sensitive, or dust-generating materials, avoiding air contact also prevents oxidation, contamination, and the risk of combustible dust ignition.
Does the BMHX generate process exhaust that requires permitting?
No product-laden exhaust air is generated by the heat exchange step itself. Conventional direct-contact systems generate large volumes of product-laden air requiring baghouses, scrubbers, or thermal oxidizers with associated capital cost, operating cost, and permitting obligations. The BMHX eliminates this exhaust stream from the heat transfer step.
Can it run under an inert atmosphere?
Yes. Because no process air contacts the product in the heat-exchange section, the unit is inherently suited for oxidation-sensitive, hygroscopic, or contamination-sensitive materials. For applications requiring strict atmosphere control, the housing can be configured for inert gas purge.
What if my material isn’t free-flowing?
For materials that don’t flow freely through the plate array, vibration and/or small amounts of gas flow can be added to assist mass flow through the unit. This is evaluated during test runs at Carrier’s Louisville facility.
How does a bulk material heat exchanger improve thermal efficiency?
It transfers heat directly between hot and cold bulk materials without intermediate fluids, improving energy efficiency and reducing fuel use.
What does a test run at Carrier’s facility determine?
A properly conducted test run determines: (1) an energy balance yielding heat duty under test conditions; (2) the effective overall heat transfer coefficient (U) for your specific material – the core parameter driving full-scale surface area calculation; and (3) material handling behavior: flow reliability through the plate array, bridging tendency, segregation, packing, and particle degradation at operating temperatures. These observations inform the selection of plate spacing and the design of the discharge feeder in the full-scale unit.
How do heat exchangers integrate with dryers or coolers?
They can be placed upstream or downstream of thermal systems to preheat feeds or recover heat from processed solids, improving overall plant energy performance.
What maintenance should I expect?
Maintenance focuses on inspecting wear surfaces and airflow paths, which are designed to be accessible for routine checks.