The double stage sand making machine, also known as two rotor fine crusher, is a popular sand-making equipment developed on the basis of hammer crusher. Different from VSI sand maker that suits hard stone shaping, this machine is specially designed for medium-hard, wet and sticky raw materials. It integrates two sets of rotors inside one machine body to finish primary crushing and fine crushing in one pass, simplifying the sand production flow for small and medium crushing plants.
Working Principle
Materials enter the crushing cavity from the top feeding port. First, the upper high-speed rotor hammer strikes and breaks the material for preliminary crushing. Then the broken material falls directly into the lower rotor area and gets impacted and crushed again by the second rotor. Inside the sealed chamber, materials collide against each other continuously under high-speed movement, forming hammer-on-rock and rock-on-rock crushing effect.
This machine cancels the screen grate at the bottom. The finished sand discharges directly according to the gap between hammer heads and lining plates. There is no sieve plate to block wet, muddy or sticky materials. Operators can adjust the clearance to control discharge fineness, normally below 3 mm for manufactured sand.
Suitable Materials & Application Scenarios
It handles medium hardness materials and materials with relatively high moisture content well: limestone, bluestone, shale, coal gangue, slag, coal slime, recycled brick and concrete waste.
Common application scenarios:
- Small manufactured sand production line
- Construction waste recycling crushing
- Cement plant, brick factory raw material processing
- Coal and gangue crushing project
- Dry mortar raw material fine crushing
It can work independently or match with vibrating feeder, vibrating screen and belt conveyor to build a compact stationary crushing line. It is widely chosen by customers with limited investment budget and complex raw material moisture conditions.
Core Advantages of Double Stage Sand Maker
- No blocking risk for wet materials: Screen-free bottom structure solves the common trouble of screen sticking and clogging that happens on ordinary hammer crushers when processing damp materials.
- Two-stage crushing in one machine: Dual rotors finish coarse and fine crushing continuously, reduce equipment quantity and lower overall investment cost.
- Uniform finished particle size: Secondary impact crushing helps get well-graded fine sand, less oversize material and low return rate.
- Flexible particle size adjustment: Adjust the gap between hammer and liner plate conveniently to change discharge fineness to meet different project requirements.
- Convenient maintenance: The machine shell can be opened quickly. Workers can inspect and replace wear parts like hammer heads and lining plates easily. Alloy wear-resistant hammers extend service life.
- Compact structure: Small footprint, easy for installation and transportation.
How to Select a Double Stage Sand Making Machine
Before placing an order, confirm these parameters with your supplier:
- Raw material type, hardness and moisture content
- Feeding size
- Required hourly output capacity
- Target finished sand fineness
- Working environment, power supply condition
- Whether you need fixed type or skid-mounted integrated design
Tips: This model is not the best option for extra hard materials such as granite and basalt. For high-hardness rock sand production, VSI sand making machine is more suitable.
Daily Maintenance Guide
Routine inspection reduces unexpected shutdowns and extend service life:
- Check hammer wear condition every shift. Rotate or replace alloy hammer heads in time when they wear seriously.
- Check inner lining plates, fastening bolts and welding points regularly.
- Clean feeding inlet and cavity before startup to avoid hard foreign objects entering.
- Check the tightness of transmission belts and motor running current.
- Lubricate bearing parts on schedule, keep good sealing to prevent dust entering.
- Do not feed oversized hard metal into the crushing chamber.
FAQ
Q: What is the difference between double stage sand maker and VSI sand making machine?
A: Double stage sand maker is two rotor hammer type without screen, good for wet sticky and medium soft rock. VSI crusher is vertical shaft impact type, focused on shaping hard stone to get cubic sand.
Q: Can this machine process construction waste?
A: Yes. It can crush waste bricks and concrete blocks into reusable manufactured sand for backfill and base material.
Q: Does it require a vibrating screen after crushing?
A: It depends on your quality standard. If you need strict sand grading, add vibrating screen to separate coarse and fine fractions.
Closing
For buyers who process wet, sticky and medium-hard raw materials, the double stage sand making machine is a cost-effective fine crushing solution. It reduces line configuration and avoids frequent blockage failures. If you need capacity calculation, layout drawing or parameter quotation, contact our engineering team for customized support.
