Drawing No.
EBAC MF4 TABLE OF CONTENTS Warranty -----------------------------------------------------------------Introduction --------------------------------------------------------------Lumber Drying Principles --------------------------------------------KILN DESIGN & CONSTRUCTION: Stack Size Calculations ------------------------------------------Chamber Size -----------------------------------------------------------Kiln Construction -------------------------------------------------------MF4 Placement & Wiring ----
EBAC MF4 TABLE OF CONTENTS (Continued) APPENDIXES: Oven Dry Method for Determining Average MC -----------Wood Degrade -----------------------------------------------------Troubleshooting ---------------------------------------------------Specifications ------------------------------------------------------Drawings ------------------------------------------------------------- 49 54 56 64 66
LIMITED WARRANTY Ebac Incorporated Lumber Dryers and Controllers carry a one year limited warranty against any defect in workmanship or material. This Warranty will cover all parts and labor required to repair your Ebac Lumber Dryer or Controller. This Warranty is invalid if the unit has been abused, damaged, whether intentional or accidental, or if any modifications have been made to the unit.
Introduction This Manual has been designed to guide you through constructing a suitable kiln chamber, and operating the kiln to obtain maximum output of wood. Also included in this manual are directions and examples for sizing the chamber. We are always pleased to offer advice and assistance when required.
LUMBER DRYING PRINCIPLES When lumber is being dried, the rate of moisture evaporation is dependent on the difference between the vapor pressure of the wet wood and the vapor pressure of the air. When the vapor pressures have equalized, no further drying occurs. This is the point at which the equilibrium moisture content of the wood has been reached.
As damp air is drawn into the machine (see Figure 2) water condenses onto a refrigerated coil. The water is drained off and the dried air is rewarmed with the heat from the condenser coil. The air is re-circulated through the lumber stack, causing more evaporation. Moisture-laden hot air is not simply vented into the atmosphere as in energy wasteful steam kilns; this results in efficient operation.
KILN DESIGN AND CONSTRUCTION Stack Size Calculations: The lumber stack size will depend primarily on the longest length board to be dried. Normally the length of the stack will be equal to the length of the longest board. If your lumber is in short lengths, then the stack length should be a multiple of these shorts. The width and height of the stack can be adjusted to suit your conditions, for instance if you already have a standard package size.
Example 1: we will design the lumber stack for 10,000 BF of 1” lumber, 16’ maximum board length. 10,000 TOTAL KILN BF ÷ 12 = X = X 833.3 1.75 1458 1.
Chamber Size: Having calculated the stack size, it is now possible to calculate the appropriate internal dimensions of the chamber. This is done by adding the required additional space around the stack for the dryer and auxiliary fans, as well as for good air circulation. The recommended additional spaces are as follows: 2 ½ ft behind the stack, 1 ½ ft in front of the stack, 3 ft above the stack, 1 ft on either end of the stack, and 6” in between stacks. These spaces are shown in Figures 4, 5 and 6.
Kiln Construction: The walls and ceiling should be made of 2 x 6 frame construction filled with insulation (Styrofoam, fiberglass, etc. approximately R24). The exterior surface should be ½” CDX plywood or corrugated metal. To provide a good vapor barrier, line the interior with polyethylene film and use tape to close all gaps and cover tack heads. On top of this polyethylene place ¼” gap around each sheet. Caulk these gaps, and then paint the entire kiln with manufactured kiln paint.
MF4 Placement & Wiring The MF machine will be centered on the back wall, opposite the loading doors. This will leave about 1 ft between the machine and the lumber stack. (See Figure 4). The sensing probes should be mounted at least 3 ft from the machine and about 5-ft above the floor. When positioning the Lumber Dryer, care must be taken not to obstruct the air inlet and outlet. The air enters the base of the machine and is discharged from the top.
Maintenance Your Ebac Lumber Dryer requires no routine maintenance but occasional cleaning of certain components will result in a more consistent performance. The evaporator and condenser coils should be cleaned, preferably with compressed air. Care must be taken not to damage the fins. IMPORTANT: NEVER USE STEAM CLEANING ON REFRIGERATION COILS Clean the drain tray, with particular attention to the drain pipe and hose, in order to ensure good drainage.
Ebac Modular Control System Introduction: The main function of a process drying control system is to regulate the conditions inside the drying chamber. However, the needs of individual clients vary, some applications require greater levels of sophistication. The Ebac MCU range therefore includes basic models as well as the ultimate, fully automated, microprocessor drying control system.
MCU1002 Control Unit 14
Overview - MCU1002 The MCU1002 control module is designed to give effective drying, safe drying extended life, simple operation and performance monitoring. Effective drying is achieved by high quality relative humidity and temperature sensors. Safe drying is achieved by including cross-over control. The dehumidifier section, the function of which is to reduce the relative humidity, can under certain climatic and internal conditions cause the temperature to rise to an undesirable level.
7. 24-hour override timer stop “O” and start “I” indicates override not in use and override selected respectively. The above indicators can be used to diagnose fault conditions should they occur. (See the Troubleshooting Guide). 24 Hour Override: This facility is used to increase the rate of initial heating where low relative humidity would otherwise switch off the heater.
Specifications - MCU1002 Control Unit Overall size including handles & Connectors 6 ½” H x 19 ¼” W x 16 1/8” D Case Size 6 ½” H x 19 ¼” W x 11 3/8” D Weight 28 LBS. Operating Voltage 240V / 60Hz / 3pH Operating Voltage Range 240V / 60Hz / 3pH Input Signal (Temperature) 24 VAC (+10% - 15%) Input Signal (RH) 24 VAC (+10% - 15%) Control Action On/Off Control Outputs Heat 220V / 60Hz / 3Ph – 24 Amp Max Cool 220V / 60Hz / 3Ph – 4A Min / 6.
Installation - MCU1002 Unpacking & Pre-Installation Check: Unpack the equipment and check the contents: 1. Control Unit complete with TB Plugs 2. Sensor Unit 3. Interconnecting Cables Check Overload Settings: Remove chassis from case by removing TB plugs from the rear of the unit, remove front fixing screws and withdraw chassis. Overload O/L1 set at -- 3.2A Overload O/L2 set at -- 5.2A Adjust overloads if required and press red reset button to ensure reset.
Connect the process dryer to the control unit via the terminal plug and sockets TB1/TB2. See appropriate interconnecting diagram. Connect the Overheat Vent/Cooling Unit to the Control Unit via the terminal plug and socket TB3. See appropriate interconnecting diagram. Where additional modules are used, interconnect by connecting socket SK3 to socket SK1 and socket SK4 to socket SK2 between each adjacent module using the cables supplied.
Operation - MCU1002 1. Adjust the temperature sensor (thermostat) to the required temperature setting. 2. Adjust the humidity sensor (humidistat) to the required RH setting. 3. Ensure the main power isolator is in the “ON” position. The red stop indicators on the left side of the Facia will be illuminated. 4. Press the green fan start (I) push button, adjacent to the fan symbol, which will illuminate. 5.
Maintenance - MCU1002 Humidistat: If dust or other matter is allowed to accumulate in any sensory element (made of hair, plastic, cotton, wood, or other material) its hygroscopic interchange with the surrounding air is weakened. So remove the dust or other light accumulation at regular intervals by using a soft brush. Reviving (washing of the hair section) should not be done if the humidistat is functioning normally. It should be done only if the regulating precision becomes erratic (e.g.
Spare Parts List -- MCU1002 Description Ebac Part No.
MCU1100 Control Unit 26
Overview -- MCU1100 1. The MCU1100 contains all of the switch gear, overloads, contactors, relays and ancillary equipment necessary to enable one Ebac Lumber Dryer to operate correctly. The above components are not installed inside the drying unit where temperature and humidity conditions could be harsh leading to failure. An MCU100 is required for every drying unit installed within the chamber. 2.
Installation - MCU1100 1. The MCU1100 is available as a freestanding module or may be incorporated inside a rack housing. The unit should be installed by a competent electrical contractor in accordance with local regulations. Wiring sizes quoted are minimum sizes. 2. Connect to an adequate isolated power supply by running three phase and a ground wire to the main terminal block situated on the extreme left of the rear of the unit. Minimum conductor size is #8 AWG cu. 3.
8. Remove free socket located in the terminal TB2. Using conductors with a minimum conductor size of #14 AWG cu, connect each terminal on the free socket to the MF4 lumber dryer terminal block. Ensure terminals are connected in accordance with the following: Free Socket Terminal to 1 12 3 4 5 6 7 8 9 10 Drying Machine Terminal 11 12 Not Used 13 14 15 16 Not Used 9. Remove free socket located in terminal TB3.
Operation -- MCU1100 1. Ensure main power circuit breaker is in the “ON” position. 2. The RED stop switch on the right-hand side of the facia will be illuminated. 3. Press the GREEN start switch on the right-hand side of the facia which will become illuminated. If this does not occur, consult the fault finding section. 4. Repeat steps 2 & 3 with every MCU1100 module incorporated in the system, this will initiate operations of each of the Lumber Drying units installed within the drying chamber.
Drying Lumber Lumber drying, like all drying, is a process of evaporation and occurs at the surface of the wood when the vapor pressure of the air is less than that of the lumber. The greater this difference, the greater the evaporation rate and the greater the rate at which the surface dries. As the surface dries, moisture migrates from the heart of the wood in order to try and equalize the now differing vapor pressures co-existing in the wood.
The oven drying method of moisture content determination should be used for wetter wood, the procedure is given in Appendix I. Drying Rate: It is essential to note that the drying rate varies for different lumbers. Some lumber can be Dried at 10% per day, while others cannot satisfactorily exceed 1% per day.
It can be seen from the graph that to maintain the example-drying rate for lumber twice the thickness, it is necessary to double the load. 2. If the RH setting were left unchanged during the kiln run, the dehumidifier would be on for a shorter period each day as the lumber dried and the vapor pressure difference between the air and the lumber decreased. By the use of the schedules for temperature and humidity this is avoided.
Preparation of the Lumber Stack: The best lumber drying results are obtained when the load of the lumber is of the same species, quality, thickness and initial moisture content. However, this is not always possible. In such situations, the drying procedure should follow the slowest wood in the load -- i.e., the hardest, thickest or wettest boards. The layers of lumber are separated by stickers. The thickness of the stickers is determined by the thickness of lumber most commonly being dried.
5. Set the relative humidity (RH%) to the initial schedule setting. 6. To set the temperature, check the kiln air temperature. Set the thermostat 25°F (14°C) higher than this, but in no case higher than the beginning kiln temperature in the appropriate drying schedule. Increase the kiln temperature by 25°F (14°C) every 24 hours until the beginning kiln temperature from the appropriate drying schedule is achieved.
KILNING PROGRESS SHEET DATE INTO KILN . . . . . . . . . . . . . . . . . . . . . . . . FINAL M.C. REQUIRED . . . . . . . . . . . . . . . . SUPPLIER . . . . . . . . . . . . . . . . . . . . . . . . SPECIES . . . . . . . . . . . . . . . . LOAD NUMBER . . . . . . . . . . . . . . . . . . . . . . . . THICKNESS . . . . . . . . . . . . . . . . TOTAL QUANTITY . . . . . . . . . . . . . . . . DATE TIME SAMPLE NUMBER AVERAGE M.C.% DAYS IN KILN R.H. SETTING % R.H.
Table I Drying Group / Schedule SPECIES Abura Afara Afrormosia Afzelia Agba Alder Apitong Apple Ash Aspen Balsa Basswood Beech Birch, European Birch, American Bitangor Butternut Camphor Cedar, Virginian Cedar, Western Red Chengal Cherry Chestnut Corida Cypress Dahoma Danta Durian Ebony Ekki GROUP SCHEDULE 3 4 5 9 4 4 7 6 6 3 2 3 5 3 5 5 8 8 3 2 8 5 8 4 2 7 8 5 7 9 K J J E J J D A D K H K D F F A D G H J B A D K K A E D C B 38 lbs/cu ft FOR 1% MC 0.31 0.30 0.38 0.50 0.29 0.29 0.39 0.38 0.35 0.09 0.
Table I (Continued) Drying Group / Schedule SPECIES Elm Eucalyptus Fir, Balsam Fir, Douglas Fir, Silver Geronggang Guarea Gum, American Hackberry Hemlock Hickory Hornbeam Idigbo Kroko Jarrah Jelutong Kapur Kauri (Agathis) Kempas Keruing Koa Larch Lauan Lime Mahogany Makore Mango Mansonia Maple, Hard Maple, Soft GROUP SCHEDULE 5 6 1 1 1 4 6 5 5 1 6 5 4 4 9 5 7 6 7 7 5 4 5 3 4 6 5 4 6 4 A D K K K E E C F L E E J E C H E J E D E H E H F H D H E G 39 lbs/cu ft FOR 1% MC 0.30 0.46 0.24 0.46 0.34 0.34 0.
Table I (Continued) Drying Group / Schedule SPECIES Mengkulang Meranti, Dk/Lt Red Meranti, White Meranti, Yellow Merawan Merbau Mersawa Monkey Pod Muhuhu Minunga Miangon Nyatoh Oak, American/English Oak, Japanese Obeche Olive, E.
Table I (Continued) Drying Group / Schedule SPECIES GROUP SCHEDULE Purpleheart Ramin (Melawis) Rhodesian Teak Rosewood, Indian Sapele Sassafras Satinwood Sepetir Seraya, Red Spruce, Quropean Spruce, Sitka Sterculia, Brown Sterculia, Yellow Sycamore Tamarack Teak Utile (Sipo) Walnut Walnut / Claro Whitewood (Yellow Poplar) Willow Yew Yellow Poplar 6 e 4 c 8 d 6 e 5 a 6 d 5 c 7 g 5 f 1 k 1 j 9 b 8 c 6 a 1 k 4 h 5 a 5 e NOT RECOMMENDED 3 k 3 4 3 d g k lbs/cu ft FOR 1% MC 0.48 0.50 0.47 0.34 0.49 0.37 0.
TABLE II Drying Schedules By Lumber Thickness And Moisture Content Average Lumber Moisture Content MC% Maximum Temperature °F °C Minimum RH% 7/4 to 12/4 (1 ¾ - 3°) Maximum Temperature Minimum °F °C RH% Over 12/4 (Over 3°) Maximum Temperature Minimum °F °C RH% SCHEDULE A Green - 60 95 35 70 95 35 75 95 35 80 60 - 40 95 35 60 95 35 65 95 35 70 40 - 30 104 40 50 95 35 55 95 35 60 30 - 20 113 45 40 104 40 45 104 40 50 20 - 15 122 50 35 122 50 40 113 45 45 1
TABLE II (Continued) Drying Schedules By Lumber Thickness And Moisture Content Average Lumber Moisture Content MC% Maximum Temperature °F °C Minimum RH% 7/4 to 12/4 (1 ¾ - 3°) Maximum Temperature Minimum °F °C RH% Over 12/4 (Over 3°) Maximum Temperature Minimum °F °C RH% SCHEDULE D Green - 60 104 40 85 104 40 90 95 35 90 60 - 40 104 40 80 104 40 85 95 35 90 40 - 35 104 40 70 104 40 75 95 35 80 35 - 30 113 45 60 104 40 65 104 40 70 30 - 25 113 45 50 113 45 5
TABLE II (Continued) Drying Schedules By Lumber Thickness And Moisture Content Average Lumber Moisture Content MC% Maximum Temperature °F °C Minimum RH% 7/4 to 12/4 (1 ¾ - 3°) Maximum Temperature Minimum °F °C RH% Over 12/4 (Over 3°) Maximum Temperature Minimum °F °C RH% SCHEDULE G Green - 60 113 45 85 104 40 90 104 40 90 60 - 40 122 50 80 113 45 85 113 45 90 40 - 30 122 55 80 122 50 85 113 45 90 30 - 25 122 55 75 131 55 80 122 50 85 25 - 20 131 60 70 131 55
TABLE II (Continued) Drying Schedules By Lumber Thickness And Moisture Content Average Lumber Moisture Content MC% Maximum Temperature °F °C Minimum RH% 7/4 to 12/4 (1 ¾ - 3°) Maximum Temperature Minimum °F °C RH% Over 12/4 (Over 3°) Maximum Temperature Minimum °F °C RH% SCHEDULE K Green - 50 122 50 80 122 50 85 113 45 90 50 - 30 131 55 70 131 55 75 122 50 80 30 - 20 140 60 60 131 55 65 131 55 70 20 - 15 140 60 40 140 60 45 131 55 50 15 - 10 140 60 30 140 60
Minimum Drying Times For MF Lumber Dryers: Listed below are the estimated times in hours to dry through each lumber moisture content range. The minimum total drying time is found by adding together all the individual times in the column for the species being dried. (Find the drying group and schedule in Table I). Multiply this total by the appropriate thickness and schedule factors given below. Divide the result by 24 to find the total time in days. Allow time for heat up, such as 1 or 2 days.
Average Load Sizes For Each MF4: SOFTWOODS HARDWOODS 1” 4,000 - 7,000 BF 6,000 - 10,000 BF 2” 6,000 - 10,000 BF 12,000 - 16,000 BF 3” 10,000 - 14,000 BF 16,000 - 20,000 BF If quantities needed are larger than those listed above, additional machines can be connected together in the appropriate size kiln. Note: The schedules are purposely conservative. As you become experienced with your kiln, you can increase the load size to be dried.
APPENDIXES 48
APPENDIX I Oven Dry Method For Determining Average Moisture Content: Although moisture meters come in handy, the best method of determining moisture content is the oven dry method which should be done every time you make an adjustment. The oven dry method is actually more accurate than moisture meters, but not very convenient. You do need an accurate scale for weighing the wood samples and an oven (a baking oven will do) to bake the sample.
and the dryer can be turned on. After drying the samples 36 hours in an oven, you weigh them and the weight is 0.94 lb. Starting MC = 1.35 lb - 0.94 lb 0.94 lb X 100 = 44% Now calculate the future dry weight of the plank in the kiln: Plank Dry Weight = 15.4 = 10.7 lb 1 + 44 100 After a few weeks of drying, the plank is removed from the stack and weighs 12.2 lb, Starting MC = 12.2 lb - 10.7 lb 10.
APPENDIX II WOOD DEGRADE Possible Faults During Lumber Drying: Wood shrinkage is responsible for nearly all forms of drying degrade. Correct drying techniques, particularly with regard to drying schedules, minimizes this sort of fault, though it is impossible to eliminate it entirely. The following are some of the commoner forms of degrade.
End cleats, useful in air drying, should be removed from lumber in the kiln since, by restraining proper shrinkage, they may encourage splitting. Splits may already be present in wood, which has been partially dried in the air before transference to the kiln. Furthermore, they may have closed up so as to be invisible. Kiln drying will expose these faults, no matter how carefully it is carried out, and the best that one can hope for is to prevent these faults from extending further.
resulting in appreciable longitudinal distortion. Poor quality woods, and woods in which the grain is seldom straight, such as elm, are extremely prone to distortion, and these must be piled carefully with sticks at short intervals or even weighted down. The overall improvement in shape should compensate for any increase in splitting.
are very prone to collapse, even at moderate temperatures. Collapse manifests itself as local shrinkage which, if great, may in its turn lead to severe honeycombing. Collapse may often be removed by high temperature steam treatment when the wood is nearly dry, but this is beyond the scope of the handbook.
APPENDIX III Troubleshooting: In case of trouble, first check that all instructions in the manual have been carefully followed. Next, go through the following chart. If the problem is still not resolved, call Ebac Incorporated. In most cases, a simple phone call will resolve the question. System Overview: Air is drawn into the dryer where the moisture is extracted from it. Moisture is extracted when the air is passed through the evaporator coil.
MF4 Dryer Symptoms Possible Fault Unit completely Inoperative 1. No power supply. Check the breaker and the power connection. The machine has shut off during mid run. No lights are lit on the control panel. 1. Overheat protector. Allow the machine to cool. When the off light has re-lit, restart the machine. The machine has shut off during mid run. The off light on the control panel is lit. 1. Overheat protector. The protector has already cooled. Restart the machine. 2. Over current protector.
MCU1002 Control Unit Symptoms Possible Fault Green fan start switch does not illuminate when pressed 1. Main power isolator “OFF”. Switch to “ON” 2. Overload adjacent to the contactor C3 tripped. • Ensure fans in the top of the appropriate drying unit will rotate freely and that the motors are in serviceable condition. • Ensure that all three phases are available from the main supply to the control system to the fans inside the appropriate drying system.
MCU1002 Control Unit (Continued) Red stop switch is illuminated (continued) 3. Internal fan overload adjacent to contact C3 has tripped. • Ensure fans in the top of the appropriate drying unit will rotate freely and that the motors are in serviceable condition. Press the square, red reset button on the overload adjacent to contactor C3. Press green restart button. • Ensure the overload setting is correct, i.e., See 3.1. Adjust by sliding indicator pointer to the correct value.
MCU1002 Control Unit (Continued) “Cooling” phase indicator lamps will not illuminate 1. Cooling circuit overload adjacent to contactor C4 has tripped. • Ensure fans and louver motor units in the appropriate cooling units operate freely and are in serviceable condition. Press square, red reset button. • Ensure overload is set to the correct value. See 3.1. If necessary, adjust overload by sliding indicator pointer to the correct value. Press the square, red reset button on the overload.
MCU1100 Control Unit Green start switch does not remain illuminated when pressed. 1. Main power isolator “OFF”. Switch to “ON” 2. Overload adjacent to the contactor C3 tripped. • Ensure fans in the top of the appropriate drying unit will rotate freely, and that the motors are in serviceable condition. • Ensure that all three phases are available from the main supply to the control system to the fans inside the appropriate drying system. (see item 5 in the MCU1100 operation section).
MCU1100 Control Unit (Continued) Red stop switch is illuminated (continued) • Ensure the overload setting is correct, i.e., MF2 Process Dryer. 9A. MF4 Process Dryer 1.9A. Adjust by sliding in indicator pointer to the correct value. After correcting fault press the square RED reset button on the overload. C3 Press GREEN start button. “Drying” indicator lamp will not 1.
MCU1100 Control Unit (Continued) “Heating” phase indicator lamps will not illuminate when drying is called for and the appropriate drying unit’s heater bank fails to operate. 1. Circuit breaker “2” positioned on the rear of the module has tripped indicated by a line of “O” sings on the switch. Check interconnecting wiring between control unit and drying unit for damage or short-circuiting. After correcting fault, select the position that indicates three “I” signs.
APPENDIX IV SPECIFICATIONS - MF4 Height 61” Width 44” Depth 18 ½” Weight 418 Lbs Airflow 3500 CFM Power Rating (Dryer) 7.5 kW (Maximum) Power Rating (Heater 9.0 W (Operates Intermittently) Power Supply 220V / 60 Hz / 3 Phase 42 Amps 440V / 60 Hz / 3 Phase 30 Amps Maximum Operating Temp 140°F (60°C) Finish Epoxy / Vinyl Coated Steel Refrigerant Type: R-22 Refrigerant Charge: 5 KG Special Features: • Stainless Steel Drain Tray for corrosion resistance.
Spare Parts List - MF4: Description Ebac Part No. QTY 1 Drain Tray 2035830 1 2 Evaporator Coil with Cap Tube & Filter 1330902 Dryer 2 3 Condensor Coil 3020725 2 4 Compressor 3820106 1 5 Filter Dryer 3820904 1 6 Fan Blades 3040119 2 7 Fan Motors 3030140 2 8 Heaters 3931607 6 9 Capillary Tubing 3821903 920” 230V / 60Hz / 3 pH 0.
APPENDIX V DRAWINGS & WIRING DIAGRAMS 66
KILNING PROGRESS SHEET DATE INTO KILN . . . . . . . . . . . . . . . . . . . . . . . . FINAL M.C. REQUIRED . . . . . . . . . . . . . . . . SUPPLIER . . . . . . . . . . . . . . . . . . . . . . . . SPECIES . . . . . . . . . . . . . . . . LOAD NUMBER . . . . . . . . . . . . . . . . . . . . . . . . THICKNESS . . . . . . . . . . . . . . . . TOTAL QUANTITY . . . . . . . . . . . . . . . . DATE TIME SAMPLE NUMBER AVERAGE M.C.% DAYS IN KILN R.H. SETTING % R.H.
