Double Shaft Mixer

Double shaft mixers are core mixing equipment widely used in the production of organic fertilizers and compound fertilizers. Because these machines process powders, granules, and highly moist and viscous materials for extended periods, and involve the coordinated operation of multiple systems including mechanical transmission, sealing systems, and electrical controls, their maintenance is an extremely important and frequent task. The bearings bear the entire load of the machine, and proper lubrication has a significant impact on bearing life, directly affecting the service life and operating rate of the equipment. double shaft mixers are continuous operation equipment and must be operated strictly according to the instruction manual.

Structural Disassembly and Component Description

From an operation and maintenance perspective, a double shaft mixer can be divided into the following modules:

(I) Mixing Module: Includes two mixing shafts and helical blades. The blades are the main working parts and wear components. They are made of wear-resistant materials and have undergone special surface treatment. The blade structure is reasonably simple, easy to replace after wear, and has a long service life.

(II) Power Transmission Module: Includes the motor, reducer, gears, sprockets, and bearings. Gears and sprockets are protected by guards. The bearing housing fixing bolts, reducer bolts, and motor housing bolts need to be tightened regularly.

(III) Sealing Module: Includes shaft end seals and housing seals. The housing seal is tight, preventing fly ash from escaping or leaking.

(IV) Atomizing and Humidifying Module: Includes nozzles and water supply pipelines.

(V) Electrical Control Module: Includes the electrical control system and variable frequency speed control device.

Application scenarios and applicable industries
Double shaft mixers are widely used in mixing workshops of organic fertilizer plants and compound fertilizer plants, powder mixing sections of chemical enterprises, batching and mixing sections of feed processing enterprises, and fly ash humidification treatment sections of thermal power plants and mines.

Common material types

Double shaft mixers can process a wide range of materials, including powders, granules, and highly viscous materials.

Organic materials: Well-rotted livestock and poultry manure (chicken manure, pig manure, cow manure, etc.), straw powder, mushroom residue, and biogas residue.

Fertilizer materials: Nitrogen, phosphorus, and potassium powders, compound fertilizers, and raw materials for blended fertilizers.

Industrial materials: Fly ash, mineral powder, and feed ingredients.

Working mechanism and operating logic
The working mechanism of a double shaft mixer is based on the principle of "twin-shaft counter-rotating spiral convection". The two mixing shafts rotate synchronously in opposite directions, and the blades push the material towards the discharge end while mixing it. The material is repeatedly dispersed and mixed up and down and left and right inside the drum.

Maintenance tips and schedule

The maintenance of a double shaft mixer should be strictly carried out according to the "daily inspection, weekly maintenance, and monthly repair" cycle:

Daily Maintenance: After completing daily operations, the mixer must be cleaned to prevent residue buildup inside the mixer cylinder and on the blades. Lubricate all bearing lubrication points once per shift. Since the twin-shaft mixer operates continuously, the bolts on the equipment and each blade bolt must be tightened regularly every 24 hours. Loose bolts can cause changes in blade angle, leading to slower material movement, reduced output, and increased mixer load.

Regular Lubrication: Change the reducer oil every 6 months. Regularly add lubricating oil to the reducer, bearing housing, and gearbox to prevent wear and damage due to insufficient oil. The added lubricating oil must be clean, and the seals must be in good condition.

Regular Inspection: Regularly check the bending and deformation of the blade shafts. Replace any bent or deformed blades promptly. Replace blades with severe wear at the blade tips. Regularly clean any clumps of material from the bottom of the tank to prevent increased load, blade wear, damage, or jamming upon restarting. Regularly inspect the nozzles of the atomizing device for blockages, and promptly unclog or replace the nozzles.