The twin shaft concrete mixer of HZS series concrete mixing plant is divided into two series: FJS and JS. The shaft end seal of FJS series mixer is added with pneumatic shaft end protection device on the basis of JS series, and the shaft end protection layer is increased from 3 layers to 4 layers, which makes the operation of the mixer more stable and reliable. The maintenance of the twin shaft concrete mixer is to restore its technical performance improper maintenance will reduce reliability, reduce service life and even cause mechanical accidents

1. Requirements for the use of concrete raw materials

The concrete mixing plant adopts a twin horizontal shaft forced wet concrete mixer, which can mix all kinds of hard, fluidity, plasticity, lightweight aggregate concrete and mortar. The applicable aggregate size shall not be greater than 150 mm, and the aggregate size of 120 ~ 150 mm shall not exceed 10% of the total capacity.

2. Cleaning of wet concrete mixer

The wet concrete mixer shall be cleaned at least once in a working cycle. After daily production, the mixer shall be fully cleaned. The method is: during the cleaning process, put water and a little stone into the mixer for mixing for 5 to 10 minutes, and remove all materials in the machine after cleaning without ponding and accumulation; Wash the pipeline after shutdown to remove dust and adhered concrete inside and outside the mixing tank. Generally, JS1000 mixing machine can add about 150 to 180kg of water, and other types of machines can be increased or decreased accordingly, or they can provide their own high-pressure water gun for cleaning.

When flushing the material door of the mixer, avoid the accumulation of material under the upper flushing to form the phenomenon of foreign matter blocking the material door. During mixing, if the concrete truck is not in place for a long time (more than 20 ~ 30 min, especially in summer), add water to simply clean the mixer.

During normal production, the solidification of concrete in the mixing drum and on the mixing shaft shall be checked regularly. If there is condensation, it shall be removed manually in time as required. Before manually cleaning the mixing drum, the power supply and gas circuit must be cut off, the residual gas must be discharged, and the control room must be locked; When manually cleaning the mixing drum, it is strictly prohibited to knock the mixing shaft, mixing arm and mixing blade violently.

3. Maintenance of reducer

(1) Oil use

Recommended oil for mixer reducer: FJS series adopts gear oil Esso 150 and Mobil 629; JS series adopts gear oil as general gear oil. The oil of the reducer shall be changed after the first operation or replacement of parts for 100-150h. In the future, the oil can be changed every 2000-3000h according to the service conditions and the quality of lubricating oil; Different types of lubricating oils cannot be mixed; The oil level height shall be checked every month. If the oil quantity is insufficient, it shall be supplemented in time.

(2) Precautions

Before startup, check whether the oil level is reasonable and whether the vent is blocked by dirt; If the vent hole is blocked, it is easy to extrude the sealing ring due to the increase of inner cavity pressure during the operation of the reducer, resulting in leakage of the reducer.

After the reducer runs for several hours for the first time, check the shell temperature (no more than 70 ~ 75 ℃) and whether the reducer connecting bolts and coupling connecting bolts are fastened well; The mixer shall be tested every day in the first week of use and every month thereafter.

Replace the oil seal when the reducer is repaired or the oil seal is extruded. Replace the oil seal of the reducer at least once a year. If the reducer is idle for a long time, it shall be filled with lubricating oil first. When it is reused, the excess oil shall be discharged to maintain the correct oil level.

4. Maintenance of unloading mechanism

It is best to use lhm46 anti-wear hydraulic oil, and the oil change cycle shall be determined according to the service conditions. It is generally recommended to replace the hydraulic oil every 6 months, and clean the oil tank, oil suction filter and pipeline. When cleaning the hydraulic system, the environment must be clean and free from dust and other pollution, otherwise it is easy to cause hydraulic system failure, such as damage to solenoid valve and hydraulic cylinder.

The system pressure at startup shall not exceed 12 MPa. If the pressure is too high, adjust the overflow valve. If the wear of the sealing strip of the discharge door exceeds 1 / 2, it needs to be replaced. Do not use too much force when opening the door with the manual pump to avoid damaging the manual pump. After the manual operation, the handle of the manual electromagnetic directional valve must also be turned to the middle position, otherwise the unloading door cannot be opened and closed under the automatic production state.

5. Sealing and lubrication of mixing machine

Generally, 00# lithium grease is used in winter (air temperature ≤ 10 ℃) and 01# lithium grease is used in summer (air temperature ≥ 10 ℃). The oil must be filled into the oil tank through the oil inlet filter. It is strictly prohibited to open the vent cover of the oil tank for refueling. If the oil tank is completely empty, after filling with fresh lubricating grease, it must stand for 10 ~ 15 min before starting the oil pump.

When the mixer works, check whether the grease reaches the shaft end at least twice a day. One spare oil nozzle is installed at the four shaft ends respectively. You can press the ball core of the grease nozzle with your fingernail. If there is no grease, it indicates that the work is abnormal and needs to be checked and cleaned. In case of failure of the automatic lubrication system, it is necessary to supply oil manually, once every 2 hours until there is grease overflow at the four shaft ends inside the cylinder block.

Adjustment steps: open the ball valve, ensure that the air pressure solenoid valve is normally closed, rotate the handle of the pressure regulating valve and adjust the air pressure to 0.1 ~ 0.15 MPa; When the solenoid valve is in working state, it shall be ensured that there is compressed air at each shaft end, and the air pressure is normal when the air pressure is 20 ~ 50 kPa.

When feeding into the mixer, the pneumatic solenoid valve of control system is opened; When the mixer is discharging, the pneumatic solenoid valve is closed. The surface temperature of pneumatic solenoid valve can reach 120 ℃ under continuous working state. Do not touch it to avoid scalding.