HYDAC INTERNATIONAL

Contents

• 1. Working Principle
• 2. Application
• 3. Advantage
• 4. Design Condition for Copper Brazed PHE
• 5. Specification & BPHE Dimension
• 6. Standardized Connections
• 7. Installation Guide
• 8. Anti-Freezing Protection Methods for BPHE
• 9. Soldering Instruction
• 10. Cleaning
• 11. Warning
• 12. Warranty Terms
• 13. Label and Marking

? Important Notes

Before proceeding with installation and operation, read this entire manual carefully. Failure to do so can cause injury or property damage.

When receiving heat exchangers, any claims for damage or shortage in shipment must be filed immediately against the transportation company by the consignee. The heat exchangers may have some sharp edges, so exercise caution when handling.

Provided that it is used and maintained in accordance with generally accepted codes of good practice and the recommendations of this User Manual, the product meets the essential safety and health requirements of the Pressure Equipment Directive 97/23/EC.

1. Working Principle

HYDAC Brazed Plate Heat Exchanger (BPHE) consists of chevron plates made of acid-resistant stainless steel. Every other plate is reversed so that the ridges of the herringbone pattern intersect one another on adjacent plates, forming contact points. When these points are vacuum brazed together, two separate systems of channels for two media flow in counter-current are formed. The lattice structure causes vigorous turbulence, thus ensuring maximum heat transfer.

The BPHE is a highly efficient, corrosion-resistant, and pressure-resistant heat exchanger. The standard BPHE is designed to meet 30 bar and 200°C, and the largest size handles a maximum flow capacity of 900 liter/min.

2. Application

HYDAC BPHE can be used for various media:

• All types of refrigerants; ammonia will be used for nickel brazed.
• Organic solvents
• Water
• Oil
• Various brine solutions (glycol mixtures, CaCl₂, alcohols etc.)

HYDAC BPHE can be used in:

• Heat pumps
• Industrial chillers; plastic machines, welding machines, hydraulic presses (oil), and compressor oil cooling
• Air conditioning
• Refrigeration
• Air dryers
• Water coolers; drinking water or process water for various industries
• Temperature holding for storage tanks
• Heat recovery including heat recycling from hot steam
• Indoor heating including floor heating

For refrigerant applications, BPHE functions as:

• Evaporators
• Condensers
• Super-heaters for gas
• Desuper-heaters for gas
• Subcoolers for condensate
• Economizers
• Intercoolers
• Oil coolers

3. Advantage ⭐

HYDAC BPHE provides many great advantages:

• Highly thermal efficiency
• Compact size and less weight
• High working pressure
• High thermal resistances and high operating temperature
• Lower cost for the same performances
• Lower pressure drop and high corrosion resistance
• No gaskets, no leakages
• Easy installation, easy replacement, less maintenance
• Durability

4. Design Condition for Copper Brazed PHE

5. Specification & BPHE Dimension

Diagram showing connection ports labeled A1, B2, D1, C1 at the top, and A2, B1, D2, C2 at the bottom. The diagram illustrates two main flow paths.

6. Standardized Connections

Connections for fluid applications are threaded connectors. Connections for refrigerant units are soldered/sweat connectors.

Threaded Connections

Soldered Connections

7. Installation Guide ⚙️

Illustration 1: General purpose of BPHE.

Illustration 2: Types of fluid applied.

Illustration 3: Arrangements of fluids directions.

Diagram showing fluid flow paths through the BPHE, indicating connections for Fluid 1, Fluid 2, and Fluid 3. The diagram illustrates different arrangements of fluid flow directions (e.g., counter-current) through the BPHE.

Installation Notes

• Always install your BPHE vertically, especially for a refrigerant system, to ensure stability and minimize water volume below the connector.
• To achieve high thermal efficiency and high heat transfer rates, BPHE is best installed in counter-flow direction.
• When BPHE works as an Evaporator: the two-phased (liquid and gas) refrigerant enters the evaporator at the bottom left connector and the single-phased (gas) refrigerant leaves from the top left connector after heat transfer. Water enters at the top right connector and leaves from the bottom right. Heat is transferred from water to refrigerant, and both fluids are in counter-flow direction.
• When BPHE works as a Condenser: the single-phased (gas) refrigerant enters the condenser at the top left connector and the single-phased (liquid) refrigerant leaves from the bottom left connector. Water enters the condenser at the bottom right and leaves from the top right. Heat is transferred from refrigerant to water, and both fluids are in counter-flow direction.

Mounting Suggestions

There are four different ways to mount the BPHE:

• (a) Bottom support: Diagram illustrating bottom support mounting.
• (b) Sheet metal bracket: Diagram illustrating sheet metal bracket mounting.
• (c) Crossbar & bolts: Diagram illustrating crossbar and bolts mounting.
• (d) Stud bolts: Diagram illustrating stud bolts mounting.

• All items should be supported independently.
• Do not apply excessive forces to the fittings.
• Except for small-sized HYDAC HEX S400, brazed PHE cannot fasten directly to the fittings/piping.
• Using flexible hoses or vibration dampers to reduce pulsation, shock, or vibrations caused by the operating system.

8. Anti-Freezing Protection Methods for BPHE ⚠️

Any formation of freezing or icing will damage the BPHE and the refrigeration system. The following methods will prevent BPHE from freezing up:

• Use brine (e.g., glycol) when evaporation temperature is close to the freezing point.
• Low working pressure can cause low evaporation temperature. If the evaporation temperature is below 0°C, it will cause the water to freeze up. As a result, the evaporator may expand and crack open, especially the bottom portion of the PHE, which has the lowest temperature.
• To start the refrigeration system, always start with the water pump for a few minutes, and then start the compressor. To stop the system, always stop the compressor first, and then stop the water pump.
• (1) Low Pressure Cut-off Switch (LP): A low-pressure cut-off switch shall be installed and its value set properly. When the actual evaporation pressure is lower than the setting value, the compressor will be cut off automatically.
• (2) Low Temperature Thermostat (LT): The function of this thermostat is to prevent evaporation temperature from going under 0°C. If evaporation temperature is always above 0°C, then water has no chance to freeze up and expand.
• (3) Water Temperature Sensor: Installation of an anti-freezing temperature sensor near the water outlet is another method to prevent water from freezing up. The setting temperature is suggested at 4°C for buffering purposes.
• (4) Water Flow Switch: Installation of a water flow switch in the water circuit can prevent possible BPHE freeze-up due to low water flow rate. Usually, low water flow rate may be caused by malfunction of the water pump, leaking pipes, pipe blockage due to dirt or large particles, or a dirty filter.

9. Soldering Instruction ?

Cleaning and degreasing the surface of copper pipes and PHE connectors before soldering is important. To avoid oxidation inside the copper pipes and BPHE, protect the inside with N₂-gas. Place the BPHE on a flat surface and wrap a wet rag around the connectors to protect the BPHE from excessive heating. Use a 40~45% silver alloy soldering rod to weld the copper pipe into the connector at a maximum of 800°C. After soldering, clean and dry the connection and BPHE.

10. Cleaning ?

Cleaning of fouled plate heat exchangers is important. Back flushing will remove most of the soft debris that is blocking the inside. The solution used for back flushing shall be a weak acid with a concentration less than 5%, for example, citric acid. If the acidity is too high, the copper and stainless steel inside the PHE might be etched or corroded. Before restarting the system, flush the plate heat exchanger with large amounts of fresh water to purge any remaining acid solution.

Schematic diagram illustrating a cleaning loop with a heat exchanger and a label indicating 'Weak acid' flowing through the system.

11. Warning ⚠️

Fluids that are explosive, extremely flammable, highly toxicant, highly corrosive, or hazardous cannot be applied to BPHE. Examples include ammonia, nitric acid, sulfuric acid, etc.

When unknown quality of water is applied to BPHE, a filter and strainer should be placed at the water inlet of BPHE to filter out dirt or large particles. A mesh size of around 20 is suitable for most cases. Blockage of the evaporator due to dirt or large particles will reduce the flow rate of water, then the water may freeze up, consequently causing the crack of the BPHE.

Chlorinated water, seawater, etc., are not suitable for BPHE because they will corrode and damage the BPHE. For example, swimming pool water.

The solution applied to BPHE shall have a pH value range between 6~8.

Ground water with high sulfuric compound, sulfuric acid, or low pH value, may cause gradual copper corrosion and damage the BPHE within a few years.

A rubber ring always mounts or adheres to the bottom edge of the BPHE to protect the hand and wrist against sharp metal edges. If the rubber ring is not a required part of your order, watch out for the sharp metal edges.

When moving BPHE, always wear gloves and pay attention to the sharp edges around the bottom of BPHE. Some BPHEs come with rubber strips that cover the sharp edges, but some do not. This depends on your request.

12. Warranty Terms ?️

Free of charge if defects are caused by manufacturing material or manufacturing workmanship. Warranty Period is 12 months after exit factory delivery or else, by contract with the purchaser.

Exceptions are:

• (1) The failure or malfunction of BPHE is caused by improper or negligent usage of BPHE.
• (2) Malfunctions from freezing or icing, flood, fire, or any natural disaster, or accident.
• (3) Damages caused by improper or faulty installation, or product exposed to corrosive elements harmful to the structure.

13. Label and Marking

Diagram of the product label showing 'HYDAC brazed plate heat exchanger', Type, Max. working temperature, Max. working pressure, Test pressure, CE marking, and manufacturer information 'Manufactured by KHT Taiwan'.

For tracking purposes, the model name and serial number will be embossed on the plate of the front cover below the two upper connectors of the BPHE.

EC DECLARATION OF CONFORMITY

According to the following EC Directive:

• Pressure Equipment Directive: 97/23/EC

Type: Brazed Plate Heat Exchangers (BPHE)

Pressure Bearing Material:

• Steel 304 (ASTM A240 or JIS G4304/G4305)
• Steel 316 (ASTM A240 or JIS G4304/G4305)

Provided that it is used and maintained in accordance with the generally accepted codes of good practice and the recommendations of the User Manual, this device meets the essential safety and health requirements of the Pressure Equipment Directive.

To prevent the most specific risks of this device, the safety and compliance with the essential requirements of the Directive have been applied. The design, fabrication, inspection, and testing should comply with:

• ASME Boiler and Pressure Vessel Code Section VII, and EN 14276-1 Pressure equipment for refrigerating system and heat pumps, Part 1: Vessels - General requirement.

Brazing Procedure Reference:

• EN 14276-1, Annex B, and ASME Section IX

For the procedure of EC conformity assessment, the manufacturer chooses Module D1 for the complete serials of products, which covers Category I, II at present, and are used for Fluids in Group 2 of pressure vessel equipment. Notified Body is DET NORSKE VERITAS and the Identification number is 0575.

Contact Information

Head Office
HYDAC INTERNATIONAL GMBH
Industriegebiet
66280 Sulzbach/Saar
Germany

Tel.: +49 (0) 6897/509-01
Fax: +49 (0) 6897/509-577
E-Mail: info@hydac.com
Internet: www.hydac.com