The low-temperature wax steam dewaxing machine is a key equipment used for removing wax molds in precision casting, especially in low-temperature wax casting processes. Its core function is to use high-temperature and high-pressure steam to melt and discharge the low-temperature wax molds inside the mold shell, freeing up space for subsequent metal liquid pouring. The following is a detailed introduction about the device:
1、 Working principle
The operation of the low-temperature wax steam dewaxing machine is based on the core logic of "heating and melting the wax mold and discharging it", and the specific process is as follows:
1. Loading and sealing: Place the wax coated shell (usually a hardened shell after multiple layers of coating and sand layers) into the dewaxing bucket to ensure that the shell is placed firmly and avoid tipping over. Close the bucket door and seal it to create a sealed space.
2. Steam introduction and heating: High temperature and high pressure steam is generated by a steam generator (usually at 100-160 ℃, with pressure adjusted according to wax, generally 0.4-0.8MPa), and the steam is introduced into the dewaxing tank. The heat of steam rapidly melts the low-temperature wax mold (with a low melting point, usually between 60-80 ℃) inside the mold shell.
3. Wax liquid discharge: The melted wax liquid flows out through the gate or reserved channel of the mold shell and collects in the wax liquid recovery device at the bottom of the dewaxing bucket.
4. Pressure reduction and cooling: After dewaxing is completed, slowly release the pressure inside the barrel, discharge residual steam, and some equipment will introduce cold air to accelerate the cooling of the shell, avoiding cracking of the shell due to sudden cooling.
5. Wax recovery and treatment: After filtering and settling for impurity removal, the collected wax can be reheated and molded, and recycled for wax mold production to reduce material costs.
2、 Structural composition
The structure of the low-temperature wax steam dewaxing machine is designed around "steam heating, wax liquid recovery, and pressure control", mainly including:
1. Dewaxing drum (main container): Made of high temperature and high pressure resistant steel, it is a closed space for shell dewaxing. The drum door is equipped with a sealing device (such as silicone sealing ring) to ensure that steam does not leak.
2. Steam supply system: including steam generator (electric heating or fuel heating, producing high-pressure steam), steam pipeline, valves (controlling steam flow and pressure), and some equipment will be equipped with steam superheater to increase steam temperature to adapt to different wax types.
3. Pressure and temperature control system: Real time monitoring of parameters inside the barrel is achieved through pressure gauges, thermometers, and pressure sensors. The steam input is adjusted by PLC (programmable logic controller) or manual valves to ensure that the dewaxing process is carried out at the set temperature (100-160 ℃) and pressure (0.4-0.8MPa), avoiding damage to the shell.
4. Wax recovery device: located at the bottom of the dewaxing tank, including a funnel-shaped wax collection tank, a filter screen (filter type shell debris), and a wax output pipeline. Some equipment will be equipped with heating and insulation functions to prevent wax from solidifying and blocking the pipeline during the recovery process.
5. Exhaust and safety system: including exhaust valve (releasing residual steam and pressure), safety valve (automatically releasing pressure when the pressure exceeds the set value to avoid equipment overpressure explosion), emergency stop button, to ensure operational safety.
6. Control system: composed of touch screen PLC、 Composed of relays and other components, it can preset parameters such as dewaxing time, temperature, and pressure to achieve automated operation. Some equipment supports multi-stage program control to meet the dewaxing needs of different types of shells.
3、 Equipment features
1. High dewaxing efficiency: High temperature and high pressure steam can quickly penetrate the shell, causing the wax mold to completely melt and be discharged in a short period of time (usually 10-30 minutes, adjusted according to the size and thickness of the shell), suitable for mass production.
2. Small damage to the shell: The steam heating is uniform, and by accurately controlling the temperature and pressure, the cracking and deformation of the shell caused by local overheating or rapid cooling can be reduced, ensuring the integrity of the shell.
3. High wax recovery rate: The supporting recycling system can effectively collect wax, which can be reused after simple processing, reducing the cost of wax material consumption.
4. Flexible degree of automation: There are both simple equipment with manual control (suitable for small batch production) and supporting equipment for fully automatic production lines (which can be linked with feeding robotic arms and shell conveyor lines to achieve unmanned operation).
5. Strong safety: Equipped with multiple safety protection devices (pressure safety valves, temperature alarms, emergency pressure relief, etc.) to reduce operational risks.