Wort Cooler Plate Heat Exchanger, Stainless Steel

Transcription

1 Specifications Number of plates Construction Fully stainless steel AISI Fully stainless steel AISI Fully stainless steel AISI Gaskets Nitrile Nitrile Nitrile Capacity 500 l wort per hour Cooling from 95 C to 20 C with 1 m³ cooling water at 10 C 1,000 l wort per hour Cooling from 95 C to 20 C with 2 m³ cooling water at 10 C 2,000 l wort per hour Cooling from 95 C to 20 C with 4 m³ cooling water at 10 C Cooler surface area (m²) Dimensions (HxWxD) 65 x 18 x 40 cm 65 x 18 x 40 cm 65 x 18 x 40 cm Wort port NW32 tube and DIN32 NW32 tube and DIN32 NW32 tube and DIN32 connector connector connector Water port 1" male gas thread 1" male gas thread 1" male gas thread Construction and Operation Construction The plate heat exchanger consists of a set of profiled flow plates fitted with rubber gaskets. The plates are fitted in the structure and clamped together by a set of tie rods. The capacity of the heat exchanger depends on the number of plates (Figure 1). Plate stack The plates have glued-on gaskets. The gaskets provide sealing between the media and the atmosphere when the plates are clamped together. Double gaskets with intermediate drain areas are fitted at two corners of the plates. The plates are assembled with half of the plates rotated 180 so that the drain areas are located alternately on the left and right sides. In this way the plate stack forms a system with parallel intermediate spaces and media flow in opposite directions in alternating intermediate spaces (Figure 2). Intermediate frames If the plate heat exchanger operates with different media at the same time, it may be necessary to fit intermediate frames. The intermediate frames divide the plate heat exchanger into several sections. The intermediate frames have corner elements that provide the connection between the different sections and/or the pipe ports. Two ports can be present in the same corner element, each connected to its own section of the heat exchanger. See the schematic flow diagram. 1 / 11

2 Support beams Column A Moveable cover B Fixed cover Plate stack Stress beams Tie rod / plug Figure 1 Figure 2 Plate structure Corner punching Holes are punched in the corners of the plates as shown in the drawings (see Figure 4). The media flow in the plate heat exchanger is shown in similar drawings. The punched corner holes are identified by a code. For example, the code "1234" means that all four corners of the plate have punched holes, while the code "0204" means that corners 2 and 4 have punched holes and corners 1 and 3 do not. Identification code The plates are designed to be used facing either left or right by simply rotating the plate by 180. Regardless of the actual orientation of the plates (left or right facing), the hole code (see Figure 3) always starts with hole 1 in the top left corner as seen from the gasket side. Replacing plates Plates can be replaced or new plates fitted after the tie rods have been loosened and removed. Before fitting replacement plates, check that the new plates match the ones to be replaced. The number of plates can be reduced. However, you should bear in mind that plates must be removed in pairs so that the plate stack still consists of an assembly of alternating left- and right-facing plates after the plates have been removed. The plates that are removed must have holes punched in all four corners. If the number of plates is reduced, the clamping hardware must be adjusted to correspond to the remaining number of plates. 2 / 11

3 Caution: Reducing the plate count means that some of the plates are removed, resulting in a smaller heat transfer area. This reduction also causes the pressure drop over the plate heat exchanger to rise. Schematic drawings This guide includes two drawings that depict the supplied plate heat exchanger (a schematic drawing and a diagram). Schematic drawing The schematic drawing shows the dimensions of the plate heat exchanger i.e. the width, length and ports (Figure 5). 3 / 11

4 Diagram (Figure 6) The diagram contains the following information: Plate punching codes Number of plates Port locations Number of intermediate frames and their positions Gasket specifications Schematic flow diagram The diagram shows a side view of the plate heat exchanger, the plate assembly and the media flow through the plate stack. There are four continuous horizontal lines on the diagram that mark the four corner holes of the plates. The left-facing plates are indicated by long vertical lines. The right-facing plates are indicated by short vertical lines. Figure 7 M12V 4 / 11

5 Port locations F = fixed cover B = moveable cover M = intermediate frame H = horizontal V = vertical Example: Vertical support point Corner hole number Intermediate frame of the fixed cover Intermediate frame The paired ports are shown on the symmetrical drawings (Figure 7). The intermediate frames are shown with dashed lines and are applicable to the extent that they are included in the plate heat exchanger. The ports are marked by alphanumeric codes. Gasket structure New gaskets The first plate after the fixed cover and after an intermediate frame must be fitted with a gasket that fills the entire gasket groove. This gasket is trimmed from a standard gasket. Accordingly, you should check how the existing gaskets are trimmed before removing them (see Figure 9). Non-adhesive or adhesive gaskets Some plate heat exchangers are supplied with non-adhesive Sonder Snap gaskets. This allows the gaskets to be replaced without using adhesive. The gasket of the first plate after the fixed cover and the first plate after an intermediate frame must be an adhesive type (see Figure 9). Remove all gasket residues before fitting a new gasket. Please take the following information into account for plate heat exchangers with adhesive gaskets. Adhesive Pliobond 25 / Scotchgrip 847 is a solvent-based nitrile rubber adhesive (25% solids). This adhesive is semi-thermoplastic, which means that old gaskets can be loosened with hot water. Degreaser Use acetone to clean and degrease new gaskets and gasket grooves. Ensure that the degreaser has completely evaporated before applying the adhesive. Caution: Inhaling solvents is harmful to health. 5 / 11

6 Applying adhesive Adhesive can be applied after the gaskets and gasket grooves have been cleaned using a cloth moistened with a cleaning product. The adhesive surfaces must be completely clean, with no fingerprints or the like. Use a brush to apply a thin film of prepared adhesive to the adhesive surfaces of the gaskets. Then set the gaskets aside on a clean, dry surface. Apply a thin film of adhesive to the gasket grooves of the plates and then press the gaskets into the grooves with equal pressure. When applying adhesive to the plates, start with the corners and then do the straight edges. Adhesive application is best performed on a sturdy table. Stack the plates after all the gaskets have been fitted in the gasket grooves. After the gaskets have been glued, re-assemble the plates in the stack and clamp the heat exchanger together again. See the "Dismantling and clamping" section. The plate heat exchanger may be heated with hot water to reduce the adhesive curing time. However, no pressure should be applied to the water. Curing time: approx. 2 hours at C ( F) approx. 24 hours at C (104 F) approx. 48 hours at room temperature If it is not possible to warm the heat exchanger, it should be kept as warm as possible with the connections fitted and started up cautiously. Heat exchanger fitting There are two important aspects that must be kept in mind when fitting a heat exchanger: the required space the piping Required space Provide enough space so that the plate heat exchanger can easily be dismantled for servicing and in the event of any upgrades (Figure 10). It must be possible to remove and replace the plates and tie rods without any problems. It must be possible to pull the moveable cover fully to the rear to provide sufficient space for removing and fitting the plates (Figure 11). 6 / 11

7 Piping The piping must be installed according to the accompanying diagram to allow the plate heat exchanger to achieve its specified capacity. When fitting the piping, bear in mind that it must be possible to remove any rubber sleeves in the fixed cover. The piping must always be fitted on pipe supports so that the plate heat exchanger is not under mechanical stress. The piping must be sufficiently flexible to allow for the thermal expansion of the plate heat exchanger. Initial use and operating instructions The following aspects must be respected when putting a plate heat exchanger into service and using the heat exchanger: Operating pressure Pump starting Pressure surges and vibration Leakage at start-up Air bleeding Pressure rise and temperature changes Leakage during operation Prolonged out-of-service time Operating pressure A nameplate is fitted on the fixed cover of the plate heat exchanger. The maximum operating pressure is shown on the nameplate. This operating pressure may not be exceeded. Air bleeding Air in the plate heat exchanger reduces the heat transfer and increases the pressure drop. For this reason, it must be possible to bleed air from the heat exchanger. Pressure rises and temperature changes The pressure and temperature must be checked regularly during operation. Rising pressure drop and reduced heat transfer are signs of the formation of deposits on the plates. These deposits must be removed. See pages 8 and 9 for information about cleaning the plate heat exchanger. Pump starting The pump should always be started with the valves closed. Then the valves should be opened slowly to avoid pressure surges or liquid surges. Pressure surges and vibration Positive-displacement pumps and similar devices should not be allowed to transmit pressure surges or vibrations to the plate heat exchanger. Otherwise metal fatigue may occur in the plates. 7 / 11

8 Leakage during operation See "Troubleshooting" on page 10. Prolonged out-of-service time A plate heat exchanger that has been out of service for a prolonged period must be drained and cleaned. After draining and cleaning, clamp the plate heat exchanger together with light pressure and cover the plate stack with black plastic to protect the rubber gaskets against exposure to light. Before the plate heat exchanger is put into service again, it must be reclamped to the indicated minimum value. See "Assembly and clamping" on page 8. Leakage at start-up Leaks may occur when the heat exchanger is put into service. They should stop as soon as the gaskets and plates reach the operating temperature and the pressure is evenly distributed over the entire plate heat exchanger. Disassembly and assembly Bear the following points in mind when taking apart or fitting the plate heat exchanger: Relieve pressure and allow unit to cool down Correct assembly and clamping Correct dismantling Relieve pressure and allow unit to cool down Before the plate heat exchanger is dismantled, the pressure must be relieved and the unit must be allowed to cool down to a temperature below 35 C. If the plate heat exchanger is dismantled at a temperature above 35 C, the gaskets may be detached from the plates. Correct assembly and clamping Inspect the plates and gaskets carefully before assembly. The plates must be entirely free from deposits, and the sealing surfaces must be free from grease and other contaminants. A grain of sand on the sealing surface can cause a leak during operation and damage the gaskets. Assemble the plates as shown in the diagram with the gaskets always facing the fixed cover. If the gaskets are new, clamp the plate heat exchanger to the minimum value plus 0.1 mm per plate; otherwise clamp it to the minimum value. The fixed and moveable covers must be parallel to each other. For this reason the clamped assembly must be measured at both the top and the bottom on both sides. 8 / 11

9 Correct dismantling Loosen the tie rods evenly when dismantling the plate heat exchanger. Remove the moveable cover by pulling it straight away from the fixed cover. The maximum permissible difference from one side to the other is just 25 mm. The final part of the dismantling process can be performed on two tie rods fitted in the middle. Cleaning The capacity and the corrosion resistance of the plate heat exchanger depend on the plate stack being in good condition. Manual cleaning Chemical cleaning Solvents Inspection of cleaning Solvents A suitable solvent can be described as "a product that cleans the plate heat exchanger without damaging the plates or the gaskets". Stainless steel has a passivated (protective) film. This film must remain intact, since it is what provides corrosion resistance. Manual cleaning Dismantle the plate heat exchanger and slide the plates apart. Use a soft brush and a suitable solvent to clean the plates. If a thick layer of limescale or a thick deposit of organic material has formed on the plates, place the plates in a tub or basin with a suitable solvent. Never use a steel wire brush, sandpaper or metallic scrapers, as otherwise the plates and the gaskets may be damaged. If necessary, a high-pressure cleaner may be used. If you use a high-pressure cleaner, be extremely careful and do not use any abrasives. Suitable solvents Organic and greasy deposits can be removed by sodium hydroxide (NaOH) with a maximum concentration of approximately 1.5% and a maximum temperature of 85 C. Mixing ratio for a 1.5% solution: 5 parts 30% NaOH to 100 parts of water. Limescale and mineral deposits can be removed by nitric acid (HNO 3 ) with a maximum concentration of 1.5% and a maximum temperature of 65 C. Mixing ratio for a 1.5% solution: 2.4 parts of 62% HNO 3 to 100 parts of water. Chemical cleaning Cleaning with chemical products is only possible if the deposits can be dissolved by chemicals. It goes without saying that only solvents that do not damage any of the materials in the circulation system may be used. Cleaning without circulation is also possible. This is done by filling the plate heat exchanger with a suitable solvent. After the product has been allowed to sit in the plate heat exchanger for a while, it is rinsed out with clean water. An example of chemical cleaning: 9 / 11

10 - Remove product residues and the cooling or heating media - Rinse with cold or lukewarm water - Allow a solution of the solvent to circulate through the system - Rinse with clean hot water - Rinse again with hot water with a decalcifier additive - Rinse again with cold or lukewarm water Inspection of cleaning Cleaning is very important for the effectiveness of the plate heat exchanger. For this reason, the cleaning of the plate heat exchanger must be checked, especially in the initial use period. People often have little experience with the circulation time, temperatures and concentrations of the products that are used. Common causes of inadequate cleaning are: - circulation volume too low - cleaning period too short - insufficient amount of chemicals for the deposits on the plates - operating intervals twice as long Troubleshooting Loss of capacity Internal leaks External leaks Loss of capacity If the heat transfer capacity falls and/or the pressure drop rises, the plate heat exchanger must be dismantled and the plates must be cleaned (see page 8). The plates must be clamped together according to the values stated on the nameplate. External leaks - The plate heat exchanger may be operating at a higher pressure than the specified operating pressure. Check the pressure. If it is too high, it must be reduced immediately to the operating pressure stated on the nameplate. - Adjust the clamping of the plate heat exchanger when it is no longer under pressure. Never exceed the indicated minimum value when adjusting the clamping. The fixed and moveable covers must always be parallel to each other after the plates have been clamped together. - Dismantle the plate heat exchanger for visual inspection. Check whether deposits have formed on the plates, and check the plates for deformation. Check the gaskets. They must be elastic and not deformed, and the sealing surfaces must be clean. Carefully clean all plates and gaskets just one grain of sand on a sealing surface can cause a leak. - A plate stack that has been clamped to the minimum value after cleaning should be free from leaks. If any leaks are present, the gaskets must be replaced. - If there is a leak from the gasket drain holes, the sealing of the drain area is defective or the plate is corroded in the drain area. Internal leaks If the media get mixed together, you should look for the cause in the holes of one or more plates. The only way to eliminate the leak is to replace the plate or plates concerned. 10 / 11

11 User Guide If you suspect a leak, you can use the following procedure to track it down: - Disconnect a pipe from one of the lower pipe ports. Then apply pressure on the opposite side. Media should stop flowing out of the disconnected pipe port after the pressure has stabilised. If media continues to flow out of the pipe port, there is a leak in one or more plates. Dismantle the plate stack and carefully check each plate. Using a special fluid, check the plates for cracks. - Dismantle the plate heat exchanger and allow all the plates to dry. Once the plates are completely dry, fit them in the heat exchanger and clamp them together. Now the media is circulating at full power, but only on one side of the plates (every second intermediate space). The other half of the spaces between the plates is not under pressure and does not receive any fluid. Stop the circulation after several minutes and carefully dismantle the plate heat exchanger, so that the dry sides of the plates are not splashed with water. Now carefully examine the plates and look for any moist spots on the sides of the plates that are otherwise dry. These spots must be carefully checked for cracks using a special fluid. - Take the plate heat exchanger apart and check all plates for cracks with a special fluid. Conversion The plate heat exchanger has a modular structure, so it can easily be made larger or smaller. This means that it is easy to change the capacity of the heat exchanger by adding or removing plates. BROUWLAND BVBA maintains a database of all delivered plate heat exchangers. We would be pleased to advise you on the conversion of existing plate heat exchangers. For this purpose, BROUWLAND BVBA only needs to know the serial number on the nameplate. In response, BROUWLAND BVBA will provide a full description of the conversion procedure and the parts necessary for the conversion. The conversation data will then be added to the database to keep it up to date. Spare parts When ordering spare parts, please provide the type designation and serial number of the plate heat exchanger (shown on the nameplate on the fixed cover). This data is necessary to avoid supplying incorrect parts. - When ordering plates, always state the correct punching code and indicate whether the plate is leftfacing or right-facing (see the section about plates). - When ordering a complete set of gaskets and the accompanying adhesive or when ordering solvents, it is sufficient to state the serial number and the drawing number. If you order individual gaskets, it is important to state the right type. The gasket types and colour codes are shown on the diagram. If you wish to order tie rods, first measure the existing tie rods to ensure that the new tie rods have the right length. When contacting BROUWLAND BVBA with regard to your plate heat exchanger, please state the type designation and serial number shown on the nameplate. 11 / 11