MDDP_BA_66606-4-en_US-1603

6.3.3 Setting grinding gap aspiration 6.3.4 Fig. 6.4 Setting grinding gap aspiration Important ► Product must be able to fall through the set gap without obstruction. Check during production. 1. Set threaded rod (4). → Product throughput 30 mm 2. Tighten counternut (5). 3. Loosen bolts (2), 2 turns. 4. Set fastening angle (3) on both sides with the aspiration sheet (1). → The aspiration sheet lightly touches the rear roller when the rollers are engaged. 5. Tighten the screws (2). Through-spouts (option) ■ No through-spout fastening element inside the machine. ■ Maximum 2 through-spouts through the machine MDDP-800. ■ Maximum 4 through-spouts through the machine MDDP-1000 and MDDP-1250. ■ Maximum 4 through-spouts through the machine MDDQ-1000 and MDDQ-1250. Bühler AG 51 MDDP-MDDQ-66606-4-1603-en-US Chapter 6 Assembly

Fig. 6.5 Through-spouts (4) Through-spout, at the plant (1) Gravity spout, top, at the (5) Sleeve plant (6) Gravity spout, bottom, at the plant (2) Pipe clamp (3) Guard panel Important ► For simple mounting, slide the through-spouts through the machine before the outlet hoppers are mounted. 1. Tighten guard panel (3) to the inlet container. Ensure the correct position of the opening. 2. Remove the bottom bead of the through-spout (4). → The through-spout can only be slid through the machine without the bot- tom bead. 3. Slide the through-spout (4) from the above through the opening of the guard panel and the machine. 4. Connect the top bead of the through-spout (4) and the gravity spout (1) with a pipe clamp (2). 5. Remove top bead of the gravity spout (6). 6. Connect both gravity spouts without bead with the sleeve (5). 6.3.5 Product outlet (option) The outlet hopper can be delivered in various design versions. CAUTION Product backing up Damage to the machine. ► Fit blockage sensor in direct proximity to the outlet hopper. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 52 Chapter 6 Assembly

► Screw outlet hopper (1) from the bottom to the machine. 6.3.6 Direct aspiration (option) ■ Roller length 800: Always fit 2 direct aspiration pipes ■ Roller length 1000/1250: Always fit 4 direct aspiration pipes CAUTION Product backing up Damage to the machine ► Install blockage sensors (1) at the direct aspiration. Bühler AG 53 MDDP-MDDQ-66606-4-1603-en-US Chapter 6 Assembly

► Determine product connections for the ground product at the connecting pieces of the superstructure. 6.4 Connecting supply units 6.4.1 Electrical installation Safety switch Fig. 6.6 Safety switch ► Fit a lockable safety switch near the machine for the drive motor of the grinding rollers. ► Performance Level (PL) “c” in accordance with ISO 13849-1. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 54 Chapter 6 Assembly

► Connect the safety switch (1) for the drive motor of the feed rollers with the output of the frequency converter. Guide the cable through the plastic tube (2). ► Observe local regulations. Grounding A cable (1) is fixed to the machine stand for grounding the machine. Connect this cable with the building grounding (not the motor grounding). Fig. 6.7 Grounding Check: ■ The contact washer must penetrate the paint coat to ensure electrical con- ductivity. ■ Check the bolted joints. ■ The resistance across the butt joints must not exceed 10 ohms. When the resistance exceeds 10 ohms, restore electrical conductivity. Control box For wiring diagram see operating instructions MEAG-MDDx-66690-x-1. Fig. 6.8 Control box ► Carry out electrical connections at the control box (1). ► External supply 24 V ► Control connections to the frequency converter ► Release signal Bühler AG 55 MDDP-MDDQ-66606-4-1603-en-US Chapter 6 Assembly

► Options ► Motor current display ► Serial interface ► Close unused cable glands with blind plugs (2). Sensors The following sensors are connected in the terminal box. ■ Standstill monitoring of the feed rollers ■ Blockage sensors between the top and bottom roller assembly (only MDDQ). ■ Direct aspiration blockage sensors. Machine stop Fig. 6.9 Machine stop Machine stop (1) is internally wired with the machine control system. ► Connect wiring with the plant control system or via profibus. ► Electric terminal DO 0.6 (side 1) or DO 0.10 (side 2). → The drive motor for the grinding rollers is switched off when the signal is not active. See the operating manual MEAG-MDDx-66690-x-1. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 56 Chapter 6 Assembly

6.4.2 Main drive ■ Drive motors are adjusted to the grinding product and product capacity. ■ Drive motors are arranged outside of the machine. ■ Narrow V-belts SPB are suitable as drive units. Pre-stress specified by the belt supplier. CAUTION V-belt pre-stress is too high. Bearing journals and motor bearings could be damaged. ► Correctly tension V-belts. Important ► Drive motors are not part of the delivery. Connecting compressed air Fig. 6.10 Connecting compressed air Connect compressed-air hose (1) of the machine to the compressed-air supply of the plant. ■ Compressed-air hose of the machine □ Dimensions: ø 10/7 × 3000 mm □ Connection thread: G ½\" Bühler AG 57 MDDP-MDDQ-66606-4-1603-en-US Chapter 6 Assembly

6.4.3 Air circuit Schematics Fig. 6.11 Air circuit Schematics (1) Screw compressor “Operation (11) Ball valve with change-over switching” (12) Pressure switch “Engage roller mill (2) Control standby” (3) Pressure switch (13) Compressed-air connection “Change-over switching con- trol” (14) Muffler (15) Fans (4) Pressure tank (16) Motorized flap (5) Automatic drainer (17) Differential pressure gauge (6) Air dryer (18) Differential pressure switch (7) Fiber filter (19) Pocket filter (8) Pressure regulator (20) Solenoid valve with shut-off delay (9) Manometer (10) Pressure switch “Plant stand- by” A Cooling air D Grain silo B Exhaust air E Cleaning/mill C Blower and compressor cham- F Finished product ber Bühler AG MDDP-MDDQ-66606-4-1603-en-US 58 Chapter 6 Assembly

6.4.4 Connecting internal aspiration Connect aspiration pipe (1) and product outlet (3) via the gravity spout at the plant (4, 5). The internal aspiration is closed for the first break passage. See page 68, chapter “Closing internal aspiration”. Fig. 6.12 Connecting internal aspiration (1) Aspiration pipe (4) Gravity spout at plant (side 2) (2) Aspiration cone (5) Gravity spout at plant (side 1) (3) Product outlet (option) (6) Control box (side 1) Bühler AG 59 MDDP-MDDQ-66606-4-1603-en-US Chapter 6 Assembly

7 Commissioning 7.1 Checking the commissioning 7.1.1 Removing the anti-corrosion protection from the rollers 7.1.2 ► Remove the corrosion protection from the rollers with kerosene or white spi- rit. 7.1.3 ► The rollers are treated with PURITY FG2 anti-corrosive medium. Re-lubricating grinding roller bearings ► 5 g grease per rolling bearing. See page 91, chapter “Lubricating the grinding roller bearings”. ► Re-lubricate the grinding roller bearings while the machine is running. Checking the feed gap Feeding segments do not lie on the feed rollers. Minimum feed gap (X) is not fallen short of and set parallel to the feed roller. Feed gap: ■ First break passage: 3 mm ■ Break passages: 0.5 mm ■ Reduction passages: 1 mm Fig. 7.1 Checking the feed gap Bühler AG MDDP-MDDQ-66606-4-1603-en-US 60 Chapter 7 Commissioning

7.1.4 Checking the grinding gap 7.1.5 The grinding rollers do not run on top of each other. Check grinding gap with 7.1.6 feeler gauge when the grinding rollers are engaged. See page 105, chapter “Adjusting the grinding gap”. 7.1.7 ■ Set grinding gap to 0.3 mm for a lever position of 188 mm. 7.1.8 Checking roller drive Timing belt drive: ■ Check and adjust pre-stress when the grinding rollers are engaged. See page 94, chapter “Tensioning roller assembly timing belt”. Gear drive (option): ■ Check oil level, refill if required. Observe oil level marking. Checking scraper Brush scraper bristles ■ Bristles touch the corrugated roller. Knife scraper when the grinding rollers are engaged ■ Checking that they are parallel □ With light gap □ Feeler gauge 0.03 mm □ Two equally thick strips of paper Knife scraper when the grinding rollers are disengaged ■ A gap of at least 2 mm between the knife and the grinding rollers. Checking pneumatic system Central control: Machine in disengaged position ■ For pressure less than 4.5 bar Checking the commissioning No. Check ✓ 1 All transportation aids and assembly fixings have been removed. 2 The electrical installation has been carried out and checked by an authorized, qualified electrician. 3 All electrical terminal boxes and sockets are closed. 4 The machine is grounded. 5 Direction of rotation of the motors is correct. 6 All operating elements, protective devices and warning systems are working properly. Bühler AG 61 MDDP-MDDQ-66606-4-1603-en-US Chapter 7 Commissioning

No. Check ✓ 7 A lockable safety switch is present, and personnel have a match- ing lock. 8 All bolted joints are tightened. 9 There are no foreign objects in the machine. 10 All gearmotors, bearings, etc., have been filled with lubricant. 11 Lubricant filling levels are correct. 12 The V-belt tension is correct. 13 All line connections are tight. 14 Bearings of the rollers are lubricated. 15 Corrosion protection is removed from rollers. 7.1.9 Fire and explosion protection 7.1.10 No. Check ✓ 1 A metal separator is installed upstream from the first break pas- sage. 2 Upon an emergency stop of the plant, the compressed-air supply through an installed valve is interrupted. 3 The belt is tensioned according to the operating instructions. 4 After initially running the machine, recheck the belt tension and adjust tension. Electric safety functions ✓ Check monitoring functions according to the operating manual MEAG-MDDx-66690-x-1: No. Check 1 Blockage sensors for the eight-roller mill MDDQ are calibrated. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 62 Chapter 7 Commissioning

7.2 Setting 7.2.1 Feed roller gap and speed Set the gap and the speed according to the type of product and the product quantity. Fig. 7.2 Adjusting the feed roller ■ Rough adjustment with cap nuts (2). □ Gap runs parallel. ■ Fine adjustment on both sides of the stoppers (1). Ideal feed gap With stationary feed rollers, product is held back in the inlet. Maximum product capacity ■ Feed roller speed reaches 80% of the maximum speed. Minimum speed Operate electric motor no longer than 10 minutes below the minimum speed. Lower speeds heat up the electric motor. ■ Break stock 50 rpm ■ Grinding 30 rpm Maximum speed The speed is dependent on the equipped pneumatic conveying capacity. Product does not block conveying line. Bühler AG 63 MDDP-MDDQ-66606-4-1603-en-US Chapter 7 Commissioning

7.2.2 Ideal speed Speed can be read on the display. ■ Break stock 100 rpm ■ Grinding 60 rpm Manually adjusting the grinding gap 1. Loosen clamping lever (1). 7.2.3 (3) (2) (1) 2. Adjust grinding gap on both sides with the handwheels (2). → One entire revolution of the handwheel is equal to a theoretical roller path of 0.16 mm. 3. Set position indicator (3) to 6 o'clock. Setting position indicator The following settings can be reproduced at any time: ■ Grinding gap adjustment ■ Position indicator adjustment Bühler AG MDDP-MDDQ-66606-4-1603-en-US 64 Chapter 7 Commissioning

1. Loosen screws (4). See page 105, chapter “Adjusting the grinding gap”. 2. Only turn the position indicator (5) manually or with a suction cup handle (6). 3. Tighten the bolts. Bühler AG 65 MDDP-MDDQ-66606-4-1603-en-US Chapter 7 Commissioning

7.3 Blockage sensor MDDQ Blockage sensors are installed for eight-roller mill. The sensors determine backed up product between the top and bottom rollers. If both sensors are com- pletely covered with product, an alarm will trigger. See the operating manual MEAG-MDDx-66690-x-1. (1) Fig. 7.3 Blockage sensor MDDQ 7.3.1 Empty alignment . 7.3.2 1. Clean probe cover. 2. Confirm empty alignment: Press Full alignment 1. Deactivate the blockage sensor during operation: Set up “OFF”. 2. Cover the sensor cover with at least 3 cm of product. 3. Confirm empty alignment: Press and + . 4. Complete adjustment: Set blockage sensor to the desired function (“ON”, “OFF” or “DISP”). Bühler AG MDDP-MDDQ-66606-4-1603-en-US 66 Chapter 7 Commissioning

7.4 Aspiration pipe to product inlet The product inlet (1) is connected with a aspiration connection via an aspiration pipe (2). The aspiration connection is connected with the product outlet. The in- let is aspirated via the conveyor air of the pneumatic lifting. (1) (2) 7.4.1 Fig. 7.4 Aspiration pipe to product inlet Individual internal aspiration ■ Adjust throttle sheet vertically, depending on the desired aspiration effect and the product. 7.4.2 Fig. 7.5 Individual internal aspiration (1) Throttle sheet Internal aspiration half open ■ Standard setting Bühler AG 67 MDDP-MDDQ-66606-4-1603-en-US Chapter 7 Commissioning

7.4.3 Fig. 7.6 Internal aspiration half open (1) Throttle sheet Closing internal aspiration ■ First break stock (whole kernels). ■ External aspiration with an aspiration connection via the product inlet. ■ Close pipe with protective cap (2). Fig. 7.7 Closing internal aspiration (1) Throttle sheet (2) Protective cap Bühler AG MDDP-MDDQ-66606-4-1603-en-US 68 Chapter 7 Commissioning

7.5 Setting direct aspiration 1. Remove grinding chamber doors (1). (2) 2. Set opening. Move lid (2). 3. Loosen bolts (4) and set aspiration pipe (3). (3) (4) 4. Tighten the bolts. Bühler AG 69 MDDP-MDDQ-66606-4-1603-en-US Chapter 7 Commissioning

7.5.1 Setting opening A B CD Fig. 7.8 Setting opening C ½ open D ¾ open A closed B ¼ open ⌀ 70 ½ Opening ⌀ 50 ⌀ 60 ⌀ 80 ⌀ 100 ⌀ 110 ¼ ¼ ½ ½ ¾ 7.5.2 Setting aspiration pipe X 5 Fig. 7.9 Setting aspiration pipe ⌀ 50 ⌀ 60 ⌀ 70 ⌀ 80 ⌀ 100 ⌀ 110 X 18 20 23.5 27 37 44 Bühler AG MDDP-MDDQ-66606-4-1603-en-US 70 Chapter 7 Commissioning

8 Operation 8.1 Preparing for production 8.1.1 Check 8.2 Fig. 8.1 Checking operation ► Lock all cam latches (1). 8.2.1 ► Closed during operation: 8.2.2 ► Cover (2) 8.2.3 ► Side panel (3) Starting and stopping Starting See the operating manual MEAG-MDDx-66690-x-1. Starting after machine stop 1. Eliminate the cause of the fault. 2. Acknowledge on roller mill control unit. 3. Start the machine. Stopping 1. Interrupt the product feed. 2. Switch off the machine. Bühler AG 71 MDDP-MDDQ-66606-4-1603-en-US Chapter 8 Operation

8.3 Checks during operation 8.3.1 Checking and adjustment 8.3.2 Fig. 8.2 Checking and adjustment ► Checking and adjustment during operation is possible with the following devi- ces: ► Front sheet (1) ► Impact plate (2) ► Glazed door (3) ► Grinding chamber door (4) ► Maintenance door (5) Checking knife scraper WARNING Rotating rollers Abrasions or burns to the hands. Cuts to the hands with corrugated rollers. ► Only check the smooth rollers. 1. Open glazed door (1) or grinding chamber door (2). Bühler AG MDDP-MDDQ-66606-4-1603-en-US 72 Chapter 8 Operation

2. Check for visible product winding (1). → Set knife scraper. See page 77, chapter “Setting knife scraper”. 3. Check setting of the knife scraper. 8.4 ► Lightly place a hand or finger on top and check along the entire length of the grinding rollers (smooth rollers). 8.4.1 4. Close glazed door or grinding chamber door. Work during operation Settings Fig. 8.3 Settings (during operation) ► Adjust setting of the machine at the operating interface (1) or at the comput- er in the control room. ► Save all settings through acknowledgement. Bühler AG 73 MDDP-MDDQ-66606-4-1603-en-US Chapter 8 Operation

8.4.2 ► See the operating manual MEAG-MDDx-66690-x-1. Extracting product samples Above the grinding rollers. Fig. 8.4 Extracting product samples WARNING Rotating feed rollers Pulling in and crushing hand. ► Do not touch the feed rollers with hands. ► Wear close-fitting clothing. 1. Open front sheet (1) and impact plate (2). 2. Extract product sample by hand. 3. Close impact plate and front sheet. Below the grinding rollers. WARNING Rotating rollers Pulling in and crushing hand. ► Do not touch rollers with hands. ► Wear close-fitting clothing. 1. Extract product sample by hand. ► Open and unlock grinding chamber door (3). ► Insert stretched out arm with stretched out hand (4) into the grinding chamber. ► Support forearm on the grinding chamber door. ► Extract product sample. ► Close and lock grinding chamber door. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 74 Chapter 8 Operation

2. Extract product sample with a shovel (5). 8.4.3 ► Open and unlock grinding chamber door (3). ► Insert shovel (5) into the grinding chamber. ► Support shovel on the grinding chamber door. ► Extract product sample. ► Close and lock grinding chamber door. Extracting product sample with sampler (option) Fig. 8.5 Grinding chamber doors for sampling (option) (1) Grinding chamber doors for sampling. Bühler AG 75 MDDP-MDDQ-66606-4-1603-en-US Chapter 8 Operation

1. Unlock plug (2) and pull out. 2. Slide sampler (3) with the marking (4) at the top into the opening, up to the stopper. ► Do not open the grinding chamber doors during sampling. 3. Slowly remove sampler (3) with the marking (4) from the top with the product sample. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 76 Chapter 8 Operation

4. Slide plugs (2) into the opening up to the stopper and lock. 8.4.4 5. Repeat the process at the other extraction points. Setting knife scraper Fig. 8.6 Setting knife scraper WARNING Rotating rollers Abrasions or burns to the hands. ► Do not touch grinding rollers when they are running. 1. Open and unlock grinding chamber door. Bühler AG 77 MDDP-MDDQ-66606-4-1603-en-US Chapter 8 Operation

2. Loosen wing nut (2). (1) 3. Set knife scraper (1) with wing screw (3). (2) 4. Tighten wing nut. (3) 5. Close and lock grinding chamber door. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 78 Chapter 8 Operation

9 Fault elimination 9.1 Faults Display does not light up Correction Cause ► Release 24 V. 24 V was not released. Product blockage in inlet Cause Correction Feed rollers are not turning. ► See under “Feed rollers are not turn- ing” fault. Feed rollers are turning too slowly. ► Correctly set frequency converter, set “Max. speed” higher. Feed gap is too small. ► Enlarge gap. Feed rollers are not turning. Cause Correction Local switch on motor set to “OFF”. ► Set to “ON”. Control to “Manual”. ► Set to “Automatic”. Electrical supply to frequency con- ► Check and adjust if necessary. verter or motor is faulty. Motor too hot, poor self-cooling. ► Decrease feed gap so that the motor speed increases. Frequency converter is defective or ► Check, replace if necessary. Provide too hot. better cooling to switch cabinet. Drive belt torn. ► Replace drive belt. Product detection rod “Strain ► Replace product detection rod. gauge” is defective. Foreign objects between the feed ► Remove foreign objects. rollers. Bearings are defective. ► Replace the bearings. Bühler AG 79 MDDP-MDDQ-66606-4-1603-en-US Chapter 9 Fault elimination

Stratification downstream of feed roller. Cause Correction Distribution bridge sticky. ► Clean distribution bridge. Feed roller speed is too low. ► Reduce feed gap. Foreign object(s) in inlet. ► Push feed segment back and remove foreign object. Machine produces dust Cause Correction Product film on roller. ► Clean scraper, then adjust. Product cone set too low. ► Correct on the control. Grinding gap aspiration is blocked. ► Clean aspiration pipe. ► Clean behind the aspiration sheet. Aspiration is inadequate. ► Check airflow, increase if necessary. Too much false air. ► Decrease opening. Knife scraper is not correctly set. ► Set knife scraper. The set gap and grinding gap aspi- ► Decrease gap. ration is too large. Product blockage upstream from the hand guard Cause Correction Product blockage upstream from ► Remove product and adjust distance the hand guard. between the hand guard and the grinding roller. See page 100, chapter “Setting hand guard”. Blockage sensors between the rollers trigger alarm (only MDDQ) Cause Correction Product blockage between upper ► Remove product. and lower grinding rollers. Sensor set too narrow. ► Reset sensor. Product hanging in inlet Correction Cause Aspiration pipe blocked. ► Clean aspiration pipe with soft brush from the inlet. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 80 Chapter 9 Fault elimination

Grinding rollers do not engage Cause Correction Compressed-air supply is not work- ► Check compressor and com- ing or pressure < 4.5 bar. pressed-air network. Stop valve closed. ► Open stop valve. Too little product in inlet. ► Wait until there is sufficient product. Control to “Manual”. ► Set to “Automatic”. Plug at the solenoid valve is loose. ► Insert plug. Pneumatic cylinder is defective. ► Replace the pneumatic cylinder. Grinding rollers do not disengage Cause Correction Compressed-air supply is not work- ► Check compressor and com- ing or pressure < 4.5 bar. pressed-air network. Stop valve closed. ► Open stop valve. “NIVMIN” value is set too low. ► Set “NIVMIN” value higher. Disengagement spring between the ► Fit disengagement spring or replace. bearing housings is missing or de- fective. Pneumatic cylinder is defective. ► Replace the pneumatic cylinder. Grinding gap changes while the machine is running Cause Correction Clamping lever at the handwheel is ► Check grinding gap setting. Tighten loose. clamping lever. Counternut on tension rod loose. ► Check grinding gap setting. Tighten the counternut. Rollers brush the side wall Cause Correction Bearing cover incorrectly mounted. ► Correctly fit bearing cover at the fixed bearing on the drive side. Corrugation nicks Cause Correction Foreign object(s) in the material to ► Fit magnetic separator upstream of be ground. the first break passage. If necessary, install an additional apparatus up- stream of the third break passage re- ception hopper. ► Check pre-cleaning. Bühler AG 81 MDDP-MDDQ-66606-4-1603-en-US Chapter 9 Fault elimination

No ground material at the roller ends Cause Correction Product cone set too low. ► Set “NIVMIN” value higher. Pallets are set too flat. ► Set pallets steeper. Grinding roller bearings become hot Cause Correction Too much grease in housing. ► Remove the excess grease. Too much grease in bearing. ► Remove the excess grease. Incorrect or old grease in bearing. ► Replace grease. Bearing clearance too small. ► Increase bearing clearance. Insufficient grinding operation Correction Cause Timing belt drive too loose. ► Check belt tension, adjust if necessa- ry. Rolling bearings have too much clearance. ► Set clearance or replace rolling bear- ings. Knife scraper quickly worn Correction Cause ► Set weight rod closer to the knife. Contact pressure too high. Product gets caught on the corrugated rollers Cause Correction Brush scraper is worn. ► Readjust brush scraper or replace. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 82 Chapter 9 Fault elimination

10 Maintenance 10.1 Cleaning 10.1.1 Important ► If necessary, have 2 people undertake the work. ► Run the machine empty. See the operating manual MEAG-MDDx-66690-x-1. ► Set all safety switches to “0” and lock them. ► Remove the keys and take them with you. ► Interrupt the supply of compressed air. Interrupting compressed-air supply Interrupt compressed-air supply with stop valve. (1) (2) Fig. 10.1 Interrupting compressed-air supply (1) Position OFF (2) Position ON Bühler AG 83 MDDP-MDDQ-66606-4-1603-en-US Chapter 10 Maintenance

10.1.2 Cleaning schedule 10.1.3 Interval Machine part Dura- Measure tion ► Cleaning 120 h / Feed module once a Roller assembly __:__ week 1500 h / Electric motors __:__ ► Make sure that there is no 3 months __:__ product between the rollers and the roller assembly. ► Clean if necessary. ► Clean cooling fins. Preparing Keep cladding in the external area clean: ■ Painted surfaces with soapy water. ■ INOX surfaces with RF-CLEANER. Fig. 10.2 Preparing 1. Unlock side panel (2) swing out. 2. Fold front sheet (1) up. 3. Unlock cover (3) and fold up. 4. Remove grinding chamber door (4). 5. Unlock maintenance door (5) and fold down. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 84 Chapter 10 Maintenance

6. Unlock clamping bracket (6) on both sides, then lift cover (7, 8) and pull out. 7. Remove guide sheet moving it upwards from the guide plate mounted on both sides (9). ► Guide sheet (10) for the grinding design version. ► Guide sheet (12) only for the first break passage design version. ► No guide sheet for the break passage design version. 8. Loosen nuts (11) and remove guide plates (9) from both sides. ► Loosen 2 nuts per side. Bühler AG 85 MDDP-MDDQ-66606-4-1603-en-US Chapter 10 Maintenance

9. Loosen bolts (13) and remove hand guard (14). 10.1.4 Cleaning feeding chamber 1. Set the safety switch (1) to “0” and lock it. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 86 Chapter 10 Maintenance

2. Lay the collecting trough (3) on the grinding rollers. 10.1.5 3. Unlock latch (4) on both sides. 4. Fold feed module (2) to the front and up. Important Do not touch product detection rod (5) with cleaning tool as it is sen- sitive to impact. WARNING Sharp feed rollers. Serious injuries to hands. Wear protective gloves. 5. Clean interior with a brush. Cleaning the product inlet Fig. 10.3 Safety switch for feeder unit 1. Run the machine empty. See the operating manual MEAG-MDDx-66690-x-1. 2. Set the safety switch (1) to “0” and lock it. Bühler AG 87 MDDP-MDDQ-66606-4-1603-en-US Chapter 10 Maintenance

3. Loosen screws (3). 4. Remove window frame (2) and inspection window (1). Important Do not touch product detection rod (4) with cleaning tool as it is sen- sitive to impact. WARNING Sharp feed rollers. Serious injuries to hands. Wear protective gloves. 5. Clean interior with a brush. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 88 Chapter 10 Maintenance

10.1.6 Cleaning aspiration pipe to product inlet (1) (2) (3) 1. Remove the plug (2). 2. Clean aspiration pipe (3) with a pipe brush (1) from the tool kit. 3. Fit the plug. Bühler AG 89 MDDP-MDDQ-66606-4-1603-en-US Chapter 10 Maintenance

10.1.7 Cleaning grinding gap aspiration 10.2 1. Lift aspiration sheet (1) and remove towards the front. 2. Lift air setting sheet (2) and remove towards the front. 3. Remove product with a brush. Heat treatment Exterminate animal pests using the “heat treatment” method. ■ The temperature in and around the machine may be a maximum of 60 °C. ■ Perform cleaning with a dry cleaning tool. 1. Set the safety switch (1) to “0” and lock it. 2. Clean the machine. See page 84, chapter “Preparing”. 3. Leave cover open. CAUTION Sharp edges in access to feeding chamber. Cutting inju- ries. Wear protective gloves. 4. Fold out feed module. 5. Remove product inlet window. See page 87, chapter “Cleaning the product inlet”. 6. Carry out “heat treatment”. 7. Mount window. 8. Fold in feed module. 9. Close cover. 10. Unlock safety switch (1) and set to “1”. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 90 Chapter 10 Maintenance

10.3 Lubrication Action Re-lubricate with 5 g grease per rolling bearing. 10.3.1 Lubrication schedule 10.3.2 Interval Before commissioning Interval Action 2000 h Re-lubricate with 20 g grease per rolling bearing. Applies to break and reduction passages: ■ Drive power > 18.5 kW ■ Bearing temperature 70 ... 95 °C ■ Front roller speed around 700 rpm Interval Action 4000 h Re-lubricate with 20 g grease per rolling bearing. Applies to break and reduction passages: ■ Drive power up to 11 ... 18.5 kW ■ Bearing temperature 50 ... 70 °C ■ Front roller speed around 700 rpm Interval Action 6000 h Re-lubricate with 20 g grease per rolling bearing. Applies to reduction passages: ■ Drive power up to 11 kW ■ Bearing temperature 50 ... 70 °C ■ Front roller speed around 500 rpm Lubricating the grinding roller bearings Lubricate the grinding roller bearings with greases in accordance with the oper- ating instructions. See page 15, chapter “Roller bearing grease”. ■ Initial filling at factory, 180 g ... 200 g grease per grinding roller bearing. CAUTION Incorrect grease. Compatibility is not guaranteed. ► Miscibility must be ensured with the initially filling at the factory. Bühler AG 91 MDDP-MDDQ-66606-4-1603-en-US Chapter 10 Maintenance

Important ► For hygienic and proper NSF H1 lubrication condition, the bearings must be clean. CAUTION Too much grease in bearing. Damage to bearing from increased bearing temperature. ► At the latest, after re-lubricating 10 times, open bearing housing and re- move grease filling. ► Remove excess grease outside the bearings. 1. Lubricate the the grease nipples (1) on both sides of the machine while the machine is operating. Re-lubricating grinding roller bearings in according with the drive power Re-lubricate grinding roller bearings. See page 91, chapter “Lubricating the grinding roller bearings”. ■ Read operating hours on the roller mill control unit. ■ Measure bearing temperature immediately after machine standstill and the temperature of the bearing housing and add 15 °C. ■ Grease gun hand lever, 1 stroke = 1 g grease. Important ► Proportionally adapt the greasing interval for other speeds. An increase of 100 rpm means a 15 % shorter re-lubrication period. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 92 Chapter 10 Maintenance

10.4 Maintenance 10.4.1 Maintenance schedule Interval Machine part Dura- Measure tion 24 h / once Feeder device, __:__ ► Check product flow. a day grinding and grind- __:__ ► Check pressure in the supply line. ing gap aspiration __:__ ► Check whether product is accumulating between roller and cladding. Remove product build-up 120 h / Compressed-air while the machine is not running. once a supply week ► Visual inspection Rollers and clad- ► Visual inspection ding ► Check for correct operation with engagement and Grinding roller drive __:__ disengagement button. belts ► Visual inspection for leakage. Feed roller drive __:__ belts ► Check temperature, oil level and for noise. Engagement and __:__ ► Check disengagement ► Check knife scraper. Replace if necessary. Gearmotor for feed __:__ ► Check brush scraper. Replace if necessary. rollers ► Remove dust or product deposits. Grinding roller gear __:__ ► Check temperature. Determine bearing tempera- drive (option) ture. 500 h / Plush fabric strips __:__ ► Feed roller bearings, maximum 70 °C once a at the aspiration ► Grinding roller bearings maximum 95 °C month sheet at the reduc- ► Check belt tension: Tension V-belt and set timing tion passages. belt. Knife scraper __:__ ► Drain oil with abrasion and fill with new oil. ► Check oil sight glass and drain plug, tighten if Brush scraper __:__ necessary. Product and ma- __:__ ► Remove dust from cooling fin. chine room (bearing housing, stand) ► Check belts for wear. ► Check belt tension: Tension V-belt and set timing Feed roller and __:__ belt. grinding roller bear- ings 1000 h / Drive belts __:__ 2 months Grinding roller gear __:__ drive (option) 1500 h / Gearmotor for feed __:__ 3 months rollers __:__ Drive belts Bühler AG 93 MDDP-MDDQ-66606-4-1603-en-US Chapter 10 Maintenance

Interval Machine part Dura- Measure Hand guard tion 3000 h / ► Check distance between the hand guard and 6 months __:__ grinding roller. 12,000 h / 2 years Gearmotor for feed __:__ ► Check the oil level. rollers 18,000 h / ► Change the oil. 3 years Gearmotor for feed __:__ rollers ► Check lip shaft seal for oil leakage: Open motor 24,000 h / terminal box lid. Replace if necessary. 4 years Gearmotor for feed __:__ rollers ► Drain oil with abrasion and fill with new oil. Grinding roller gear __:__ ► Lubricate. Same grease as for grinding roller drive (option) bearing. Engagement and __:__ ► Check. Replace if necessary. disengagement ec- centric ► Check. Replace if necessary. Grinding roller drive __:__ ► Replace. belts Gearmotor for feed __:__ rollers Feed roller drive __:__ belts 10.4.2 Tensioning roller assembly timing belt Important Measure the pre-stress with the rollers engaged. 1. Engage grinding rollers. ► Manually engage pneumatic cylinder (1). Press and hold engagement/ disengagement button on the roller mill control unit for at least 10 seconds. 2. Set all safety switches to “0” and lock them. 3. Remove the keys and take them with you. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 94 Chapter 10 Maintenance

4. Release lock screw (2) and bearing bolt (3). 5. Tension belt with a tension bolt (4). 6. Tighten bearing bolt (3). 7. Turn the rear grinding roller (5) 1 revolution counterclockwise. → All teeth are engaged. Bühler AG 95 MDDP-MDDQ-66606-4-1603-en-US Chapter 10 Maintenance

Important It is normal that the measured values on the inside of timing belts are slightly higher than those on the outside. 8. Measure the frequency of the timing belt: ► Switch on measuring instrument (6). ► Position the sensor head outside with a distance (X) of 5 mm from the return belt side. ► Sling timing belt outside with an open-end wrench (7). ► Read the measured value.See page 17, chapter “Measured values for timing belts”. ► Position the sensor head inside with a distance (X) of 5 mm from the re- turn belt side. ► Sling timing belt inside with an open-end wrench (7). ► Repeat both processes 3 to 4 times. ► Adjust the belt tension if necessary. Important V-belt pulley for align in an axial manner for correct belt path. 9. Increase belt tension by 3 Hz. → After initially running, the belt tension decreases. 10. Tighten bearing bolt (3) with a torque of 550 Nm and tighten lock screw (2). 11. Disengage grinding rollers. Bühler AG MDDP-MDDQ-66606-4-1603-en-US 96 Chapter 10 Maintenance

10.4.3 Tensioning the V-belt of the drive Correctly tensioning V-belt is essential for safe operation. Important V-belts too loose ► Grind down and result in inadmissible heating in hazardous areas. Important V-belts too tight ► Put an excessive load on the bearings and result in damage to the bear- ings. Check with spring balance and scale Fig. 10.4 Check with spring balance and scale (1) Test load (2) Deflection ► Apply test load (1) depending on V-belt profile to the V-belts. ► Tension V-belts until deflection (2) is 1/60 of center distance (A).See page 17, chapter “Narrow V-belt SPB measured values”. Bühler AG 97 MDDP-MDDQ-66606-4-1603-en-US Chapter 10 Maintenance

10.4.4 Tensioning the feed roller drive timing belt Fig. 10.5 Tensioning the feed roller drive timing belt (1) Bolts (3) Counternut (2) Tension bolt (4) Drive belt 1. Set the safety switch to “0” and lock it. 2. Remove the keys and take them with you. 3. Loosen three bolts (1) from the motor holder by max. 1 rotation. 4. Loosen the counternut (3). 5. Tension or loosen drive belt with tension bolt (2). 6. Belt tension must be −20 Hz below the set point. See page 99, chapter “Checking feed roller timing belt tension”. 7. Tighten the bolts (1) if the value is correct. → Belt tension increases when the bolts are tightened. 8. Check the belt tension. See page 99, chapter “Checking feed roller timing belt tension”. 9. Tighten counternut (3). Bühler AG MDDP-MDDQ-66606-4-1603-en-US 98 Chapter 10 Maintenance

10.4.5 Checking feed roller timing belt tension Fig. 10.6 Checking feed roller timing belt tension (1) Open-end wrench (2) Timing belt (3) Pre-stress measuring instrument 1. Set the safety switch to “0” and lock it. 2. Remove the keys and take them with you. 3. Check belt tension with a pre-stress measuring instrument (3). ► Position the sensor head 5 mm from and centered on the return belt side. ► Use an open-end wrench (2) to sling drive belt (1) in the center. ► Read the measured value. ► Turn drive belt by hand. ► Repeat this process 3 to 4 times. → Fig. 10.7 Passages (1) Set point of the first break passage: 140 ±10 Hz (double-shaft drive) (2) Set point of break passage: 165 ±10 Hz (triple-shaft drive) (3) Set point of reduction passage: 165 ±10 Hz (triple-shaft drive) 4. If set point is not reached. See page 98, chapter “Tensioning the feed roller drive timing belt”. Bühler AG 99 MDDP-MDDQ-66606-4-1603-en-US Chapter 10 Maintenance

10.4.6 Setting hand guard Fig. 10.8 Setting hand guard (5) Hand guard (only MDDQ) (6) Bolt (only MDDQ) (1) Bolt (7) Spring lock washer (only MDDQ) (2) Spring lock washer (8) Washer (only MDDQ) (3) Washer (4) Hand guard Important ► Between the hand guard (3) and grinding roller, the distance (X) must be between 5 … 8 mm. 1. Loosen bolt (1). 2. Move hand guard (4). ► Make sure that the hand guard runs parallel to the roller. 3. Loosen bolt (6). 4. Move hand guard (5). ► Make sure that the hand guard runs parallel to the roller. 5. Tighten the bolts. 100 Bühler AG MDDP-MDDQ-66606-4-1603-en-US Chapter 10 Maintenance