CONTENTS Page 1. THE DRYPAC SYSTEM - CUSTOM MADE 1 2. PRINCIPLE OF OPERATION 2 3. CONTROLS 4 4. FLEXIBILITY 6 5. DRYPAC OPTIONS 7 6. CONSTRUCTION / MATERIALS 8 7. DIMENSIONS 8 8. LAYOUT 12 9. PRINCIPLE AIR FLOW DIAGRAM 13 10. INSTALLATION NOTES 14
1. THE DRYPAC SYSTEM CUSTOM MADE DryPac systems are used to provide cool, dehumidified and decontaminated air for certain processes and/or process rooms. The DryPac principle is simplicity itself. The dehumidifying systems are based on the drying properties of a liquid hygroscopic solution called. A DryPac dehumidifier can supply air with a relative humidity ranging from 20 to 50% RH. Dew points as low as 30 C can easily be achieved. The DryPac system is a flexible (custom-made) system. The air temperature and humidity are controlled simultaneously in the DryPac process. Pre-cooling, after-cooling and after-heating are not usually required. DryPac dehumidification systems are specially designed to use low levels of energy and to minimize total energy consumption. The DryPac system maintains the air at a constant, precise humidity regardless of weather conditions or load variations. Using a DryPac system for air dehumidification usually results in a substantial saving on the running costs of the plant and investment in cooling equipment. Large air volumes 3,400-120,000 m 3 /h Moisture removal 55-2,000 kg/h. The conditioner of the DryPac system Benefits/figures: Cooling and heating takes place outside the unit; can use relatively cheap coolants, such as well water, river and cooling tower water; units made of industrial heavy-duty plastic, very long life span; vertical air flows (VPT), counter current flow (air-) or horizontal air flows (HPT); 1 low running costs; high efficiency; operates as a humidifier too; energy savings; microbiological decontamination; performance reliability; precise humidity and temperature control; flexible system.
2. PRINCIPLE OF OPERATION A DryPac system consists essentially of two components: a conditioner and a regenerator, each with its own pump, see fig. 1. For cooling, dehumidification and decontamination of the air, the system utilizes a hygroscopic liquid called. Besides the temperature, the concentration of determines the absorption capacity. heater Wet air Dry air cooler Spray nozzles Packing (contact surface) Outside air Outside or return air, (hygroscopic liquid) REGENERATOR CONDITIONER Heat exchanger Fig. 1 Working principle of the DryPac Working principle: Conditioner From the conditioner pump unit the is pumped through a cooler to the spray nozzles above the packing (contact surface), see fig. 1, on the right of the drawing. The outside or return air to be conditioned passes through this packing where it comes into close contact with the. Because of this contact with the cold, the air is cooled down and the moisture in the air is absorbed by the. After this process, the dry and cool air passes through a droplet eliminator section which separates droplets from the air stream. Because of the moisture absorption, the level in the pump unit rises and, consequently, the concentration decreases. In order to maintain the same absorption capacity, the solution must be regenerated, in other words the amount of moisture removed from the conditioned air must be evaporated from the again. 2
This is accomplished in the regenerator, the second component of the DryPac system, see figure 1, on the left of the drawing. Regenerator The regenerator also contains a contact surface over which, heated by a heater, is sprayed. The moisture which is picked up in the conditioner will now evaporate from the sprayed in the regenerator. Outside air, waste air from a process or in some cases air from a technical area is blown through the regenerator by a fan. This air picks up the moisture and is discharged into the atmosphere (outside). Extra energy savings is being exchanged between both pump units in order to maintain a constant concentration in the conditioner pump unit. Hot concentrated flows from the regenerator to the conditioner pump unit; cold diluted flows from the conditioner back to the regenerator pump unit. Between these two flows, heat is exchanged in the heat exchanger (optional), so that cooling and heating energy will be saved. 3
3. CONTROLS In order to maintain constant air temperature and humidity, it is necessary to control the concentration and temperature of the. The DryPac system is fitted with 3 electronic control loops: - Temperature control of the dry air - concentration or level control - Maximum temperature control 3.1 TEMPERATURE CONTROL OF THE DRY AIR The temperature of the dry air to the process is controlled by means of an electronic controller. A temperature sensor, mounted in the air duct, is connected to this controller. The dry air temperature set point can be changed by adjusting the set point of the controller. The control valve of the cooler is connected to this controller. This valve controls the flow of cooling medium through the cooler. Outlet air TT TC CONDITIONER Cooler Cooling solution Fig. 2 Temperature control of the dry air. 4
3.2 DRYSOL CONCENTRATION OR LEVEL CONTROL The concentration of the directly corresponds with the level in the pump tank of the conditioner. The conditioner pump tank is therefore equipped with electronic level controller. When the conditioner is absorbing moisture, the level in the pump tank will increase. The level controller is controlled by one electronic controller. The regenerator control valve which controls the amount of heat to the heater, is operated by this controller. More or less heating has a direct effect on the level / concentration in the pump tank of the conditioner. TA xc TC TT LC Heater REGENERATOR solution Pump tank Conditioner Fig. 3 concentration or level control 3.3 MAXIMUM DRYSOL TEMPERATURE CONTROL In order to prevent the Polypropylene construction from excessive thermal tension, the spray temperature is limited to 90 C on the regenerator side. This temperature is controlled by one electronic controller via a temperature sensor, which is mounted in the piping of the regenerator. 5
4. FLEXIBILITY Separate conditioners and regenerators If desired, DryPac regenerators can be located remote from the conditioner. Conditioners are often located in the space adjacent to the conditioned space and the regenerator is located in the building's utility or boiler room. Since one regenerator can handle numerous conditioners, substantial savings can be achieved when one regenerator unit is used with multiple conditioners. As many as 10 conditioners can operate with a single regeneration system. Combination systems Almost endless combinations of conditioners and regenerators, some on available water and others on refrigeration, can be combined to maintain specific air moisture contents in different rooms or areas. C C C C C R R C Building A Building B Building C Fig. 4 Multiple Conditioners on a single Regenerator or one conditioner on one regenerator Advantages of remote regenerators Because the units are separate, the possibility of cross leakage between wet and dry airstreams is eliminated. Performance reliability is consistently high. Several conditioners may be coupled to a single and remote regenerator. This provides greater system design flexibility. Reduces ductwork, utility piping, maintenance and installation costs. Less floor space required for complete system, typically 10% to 40% less. 6
5. DRYPAC OPTIONS The following items are part of the delivery: DryPac conditioner incl. pump and cooler. Axial dry air fan. DryPac regenerator incl. pump and heater. Axial exhaust regenerator fan. / heat exchanger for energy savings. transfer measuring equipment. Level and temperature control panel including transmitters, controllers, cooling and heating control valves. The required charge of The following equipment is optional, but is required for a complete system installation and can be ordered separately: piping. The electrical starter system for fans and pumps with fuses, switches, transformers etc. Equipment to enable use of the system as a humidifier (if applicable). The electrical wiring and connections. Possible pre- or after-conditioning of the air with controls (if applicable). The air ducts, grills, filters, dampers, sound boxes, insulation and the Polypropylene regenerator outlet duct. The cooling and heating plant with piping, insulation and controls. The erection and starting up of the plant. Extra options: a) Standard design: all the components are located on the same floor and in one technical area. As an option the regenerator can be located remote from the conditioner. In general more controls are required, sometimes it is necessary to select other pumps and fans. b) Conditioner and regenerator in modular form for installation/ transport reasons. 7
6. CONSTRUCTION / MATERIALS Generally speaking DryPac dehumidification systems operate 24 hours a day, almost every day of the year, therefore the choice of construction materials is very important. The DryPac conditioners are made of Polypropylene (PP). This industrial plastic makes the DryPac a reliable air dehumidifier with a long life span. The PP's strength has been tested with an under- and overpressure of 2500 Pa and it is resistant to temperatures between 10 and 90 C. For the lower temperature range we can use high density Polyethylene (HDPE). DryPac regenerators are made also of Polypropylene. Some regenerators are reinforced with glassfiber, with PP on the inside and glassfiber reinforced Polyester (GRP) on the outside. Regenerators can operate using hot water or steam. For extra rigidity the conditioners and the regenerators are reinforced with steel bars (wrapped in PP or GRP). All the systems are engineered and manufactured according to the CE regulations. We will prepare an IIB declaration for each system. 7. DIMENSIONS The DryPac conditioners are constructed in two different versions: - a vertical (VPT) and - a horizontal (HPT) unit. Air Outlet Air Inlet Air Inlet Air Outlet VPT - Conditioner HPT - Conditioner The horizontal conditioners are used for technical rooms which are not higher than 3 meters. The DryPac regenerators are available as standard: Air Outlet - as P-regenerator (vertical) - on special request a horizontal regenerator can be selected. Air Inlet P - Regenerator 8
7.1 VPT CONDITIONERS The vertical conditioners have the following dimensions and operating weights, see table 1. On top of these VPT conditioners is the dry air outlet duct placed, meaning the actual height will be slightly higher. Conditioner Type Air flow [m³/h] Min. Air flow [m³/h] Max. Length Width Height Oper. Weight [kg] 2 Nom.Pump Power [kw] 1 Nom. Fan Power [kw] 1 VPT 200 3,400 4,500 1,250 1,465 2,700 750 1.1 3 VPT 400 7,000 9,000 1,825 1,465 2,700 1,000 1.5 5.5 VPT 600 9,000 12,000 2,205 1,465 2,700 1,150 2.2 5.5 VPT 800 12,000 16,250 1,905 2,070 2,750 1,300 2.2 7.5 VPT 1000 14,500 20,000 1,905 2,400 2,800 1,500 2.2 11 VPT 1500 22,000 30,000 2,600 2,400 3,000 2,250 3 18.5 VPT 2000 29,500 40,000 3,200 2,400 3,000 2,750 4 22 VPT 2500 36,750 50,000 3,800 2,400 3,000 3,200 4 37 VPT 3000 44,000 60,000 4,400 2,400 3,000 3,600 5.5 37 VPT 4000 59,000 80,000 5,700 2,400 3,000 4,600 7.5 55 VPT 5000 73,500 100,000 6,950 2,400 3,000 5,500 11 75 VPT 6000 88,000 120,000 8,150 2,400 3,000 6,500 11 75 Table 1. Dimensions/ specifications VPT - Conditioners 1 Nominal Powers listed are for typical installations. Actual pump and fan powers may be higher depending on performance requirements. 2 The operating weights mentioned contain the following components: the unit, frame, pump,, packing and spray nozzles. Excluded are the piping, fan and ductwork. Fig. 5 Sketch of the VPT conditioner 9
7.2 HPT CONDITIONERS The horizontal conditioners have the following dimensions and operating weights, see table 2. Conditioner Type Air flow [m³/h] Min. Air flow [m³/h] Max. Length Width Height Oper. Weight [kg] ] 2 Nom.Pump Power [kw] 1 Nom. Fan Power [kw] 1 HPT 1000 14,500 20,000 1,900 2,400 2,900 1,700 2.2 11 HPT 1500 22,000 30,000 2,600 2,400 2,900 2,600 3 18.5 HPT 2000 29,500 40,000 3,200 2,400 2,900 3,150 4 22 HPT 2500 36,750 50,000 3,800 2,400 2,900 3,650 4 37 HPT 3000 44,000 60,000 4,400 2,400 2,900 4,150 5.5 37 HPT 4000 59,000 80,000 5,700 2,400 2,900 5,500 7.5 55 HPT 5000 73,500 100,000 6,950 2,400 2,900 6,500 11 75 HPT 6000 88,000 120,000 8,150 2,400 2,900 8,000 11 75 Table 2. Dimensions/ specifications HPT -Conditioners 1 Nominal Powers listed are for typical installations. Actual pump and fan powers may be higher depending on performance requirements. 2 The operating weights mentioned contain the following components: the unit, frame, pump,, packing and spray nozzles. Excluded are the piping, fan and ductwork. Fig. 6 Sketch of the HPT conditioner 10
7.3 P REGENERATORS The different types of regenerator are explained in table 3. Regenerator Type Air flow [m³/h] Inlet H 2 O Removal [kg/h] Length Width Height Oper. Weight [kg] 2 Nom.Pump Power [kw] 1 Nom. Fan Power [kw] 1 2,5 P 1,350 70 1,300 1,010 2,550 700 1.5 1.5 5 P 2,700 140 1,170 1,465 2,750 850 1.5 1.5 10 P 4,500 280 1,750 1,465 2,750 1,200 2.2 4 15 P 8,100 380 2,125 1,465 2,750 1,450 3 5.5 20 P 10,700 510 1,950 2,075 2,820 2,000 4 5.5 24 P 12,900 600 1,950 2,400 2,820 2,200 4 7.5 36 P 19,300 900 2,550 2,400 2,820 2,800 5.5 11 48 P 25,800 1,200 3,250 2,385 2,820 3,500 7.5 15 60 P 32,200 1,500 3,850 2,400 2,820 4,100 11 18.5 72 P 38,700 1,800 4,450 2,400 2,820 4,650 11 18.5 Table 3. Dimensions/ specifications P - Regenerator 1 Nominal Powers listed are for typical installations. Actual pump and fan powers may be higher depending on 1 Nominal performance Powers requirements. listed are for typical installations. Actual pump and fan powers may be higher depending on 2 performance The operating requirments. weights mentioned contain the following components: the unit, frame, pump,, packing and spray nozzles. Excluded are the piping, fan and ductwork. Fig. 7 Sketch of the P - Regenerator 11
8. LAY OUT L = length [m] Air inlet Air inlet B = width [m] VPT CONDITIONER HEAT EXCHANGERS P REGENE- RATOR Cooler (optional) Heater transfer measuring equipment DRYPAC CONTROL PANEL ELECTRICAL PANEL (optional) Fig. 8 Standard Layout LxB [m] 2,5 P 5 P 10 P 15 P 20 P 24 P 36 P 48 P 60 P 72 P VPT 200 7x4.5m VPT 400 7.5x4.5m 7.5x4.5m VPT 600 8x4.5m 8x4.5m 8.5x4.5m VPT 800 7.5x4.5m 7.5x4.5m 8x4.5m VPT 1000 7.5x4.5m 7.5x4.5m 8x4.5m VPT 1500 8.5x4.5m 8x4.5m 9x4.5m 9x4.5m VPT 2000 9x4.5m 9.5x4.5m 10x4.5m 9.5x4.5m VPT 2500 9.5x5m 10x4.5m 10.5x4.5m 10x4.5m 10x4.5m 11x4.5m VPT 3000 10x5m 10.5x5m 11x5m 11x5m 11.5x5m 11.5x5m VPT 4000 12x5m 12x5m 12x5m 12.5x5m 12.5x5m 13.5x5m VPT 5000 13x5.5m 13.5x5.5m 13.5x5.5m 13.5x5.5m 14x5.5m 14.5x5.5m 15x5.5m VPT 6000 14.5x5.5m 15x5.5m 14.5x5.5m 14.5x5.5m 15x5.5m 16x5.5m 16.5x5.5m VPT 7000 16x5.5m 16x5.5m 16x5.5m 17x5.5m 17x5.5m 18x5.5m 18x5.5m -Standard selection/ all components are located on same floor within the above mentioned dimensions. Optional: components can be located remote from each other. -Height of room (for VPT) 4 m. HPT height 3m (for information contact DryGenic engineers). -Standard layout, optional: other version 12
9. PRINCIPLE AIR FLOW DIAGRAM CONDITIONER INLET AIR DRY PROCESS AIR COOLER COOLING WATER DRYSOL - DRYSOL HEAT EXCHANGER HOT WATER OR STEAM HEATER REGENERATOR AIR WET AIR TO OUTSIDE REGENERATOR Fig. 9 Principle air flow diagram 13
10. INSTALLATION NOTES Pre-Installation Storage/Transport Equipment should be protected from outside weather conditions prior to installation. Indoor storage is preferred (frost-free). Rigging and Handling DryPac equipment should be lifted only from the base of the unit. Equipment Location The systems are designed for indoor installation. The Engineering Data Tables should be used to determine the operating weight of the conditioner and regenerator units. If the equipment is installed outside, weather protective covering should be provided. The units may be installed outside if air temperature will not be lower than 5 C and the units are protected against ultraviolet light. Conditioner and regenerator units should be set on a level or concrete floor. Adequate space should be provided around the conditioner, regenerator, and heat exchangers for maintenance operations. Filters Both the conditioner and regenerator require frost-free air (min. +5 C). Before entering the dehumidifier the air must be filtered with an F3 (pre-filter) and an F8 or F9 bag filter. The regenerator also needs this filter section at the entrance of the unit. dry air fan and regenerator exhaust fan are selected standard with a total pressure drop of approx. 1100 Pa. The dry air fan should be installed in the outlet duct of the conditioner (underpressure). The regenerator exhaust fan should be installed in the inlet duct (overpressure). Plenums & Ductwork DryPac units are fitted with flanges on the air openings for duct connection. Inlet ductwork must be designed to allow uniform distribution of air across the entire opening. Outlet plenums and ductwork must be designed to allow adequate space for servicing the eliminators and to provide proper airflow through the equipment. Access doors, for servicing the filters, diffusers and droplet eliminators, must be provided in the inlet and outlet plenums. Regenerator Exhaust Ductwork Because the regenerator exhaust air is hot and humid, the regenerator exhaust ductwork should be made of plastic. The material should be rated for continuous duty at 90 C. Other insulated metal ductwork will have a shorter life when exposed to the hot humid regenerator exhaust air. Insulation To prevent surface condensation (sweating) and to minimize coolant use, the piping, ducts, etc. can be insulated. Steam or hot water piping can also be insulated. Fans The total pressure drop of both the conditioner and regenerator is ± 500 Pa. The 14 Piping piping should be PP or in special cases HDPE. Black iron, galvanized and stainless steel pipe is not recommended for piping because these materials will have a short service life.