Q & A

Q:What is a hydrocarbon solvent (also called HC or hydrocarbon)?

A: Simply put, it is a cleaning solvent developed with hydrocarbon molecules as its structure. It is generally refined from petroleum.

Q:What are the characteristics of hydrocarbon solvents??


  • Good cleaning performance: Hydrocarbon solvents are non-polar petroleum fractions like most lubricating oils, anti-rust oils, and machining oils. Therefore, based on the principle of similarity and compatibility, hydrocarbon solvents are better than water-based solvents in cleaning mineral oils.

  • Good permeability: low surface tension, can clean threads or micropores that water-based detergents cannot reach.

  • Low toxicity: According to toxicological tests, the absorption and release toxicity, oral toxicity and skin contact toxicity of hydrocarbon solvents are ultra-low, and they are not carcinogens, making it safer for cleaning operators to use.
  • Good material compatibility: Hydrocarbon solvents do not contain moisture, chlorine, sulfur and other substances, and are pH-free, so they will not react chemically to various metal materials.

  • Can be completely volatilized without any residue: Hydrocarbon solvents are very pure refined solvents that can be completely volatilized at room temperature and under heating without any residue.

  • Environmental protection: Hydrocarbon solvents can be naturally degraded and will decompose quickly when buried in the soil; they do not contain chloride ions and have zero damage coefficient to ozone.




Q:Comparison table between hydrocarbon solvents and general solvents

  • A:

    Cleaning solvent

    Hydrocarbon solvent

    Gasoline, diesel, kerosene

    Water-based degreasing agent


    Generally composed of carbon and hydrogen elements

    It is composed of elements such as carbon, hydrogen and oxygen, but contains a large number of other substances, such as: S.P., aromatic and metal ions, etc.

    Surfactants and additives (alkaline cleaning effect is better, neutrality is worse)


    Extremely low. (The ratio to trichlorethylene is about one thousandth)


    High. Also a carcinogen

    High. Great impact on the environment (environmental hormone substances)

    Controlled substances





    Standard substances specified by laws and regulations


    Extremely low



    Effect on metal surface

    None. Does not participate in metal surface reactions

    The ingredients are unstable and often remain on the surface (sometimes it cannot be determined by visual inspection)

    It is possible to produce unnecessary surface changes, such as hydroxides, etc.

    Oxidation phenomenon



    Prone to oxidation


    Recyclable, recycled by vacuum distillation

    Requires special waste disposal methods

    Wastewater treatment equipment

    PH value


    Should be neutral

    Alkaline, Neutral, Acidic

    Anti-rust properties

    Since the surface will be temporarily polarized after cleaning, it can temporarily prevent rust.

    Maybe, not sure

    none. Rust prevention is required after cleaning (easy to rust)

Q:Why use a vacuum cleaner for hydrocarbon solvents?

  • A

    1. Improve the intensity of ultrasound: Use vacuum degassing technology to expel the air in the hydrocarbon solvent, strengthen the "cavitation effect" of ultrasound and enhance the ultrasound effect.

    2. Cleaning effect without blind spots: The application of vacuum technology can eliminate the air in the blind holes, allowing the lotion to be completely immersed in them, achieving a cleaning effect without blind spots.

    3. Safety/Energy Saving/Emission Reduction: Implementing ultrasonic cleaning, steam bath washing, vacuum drying and decompression recycling and regeneration in a vacuum and decompressed closed environment can achieve safety (blocking oxygen and ignition points) and energy saving ( Lower boiling point), emission reduction (less detergent consumption for recycling and reuse).

    4. Vacuum distillation recovery: The characteristics of hydrocarbon solvents are high boiling point and low flash point. Distillation regeneration under normal pressure is impossible. Using vacuum distillation technology, the boiling point can be greatly lowered and oxygen and ignition points can be blocked from entering the distillation kettle, thereby enhancing the recovery of the solvent and the safety of use.      

    5. Vacuum steam bath + vacuum drying:

      1. Steam bath cleaning: In a closed vacuum environment, the hydrocarbon solvent is heated to produce pure steam for gas phase cleaning of the workpiece, and then the residual oil and particles remaining on the surface of the workpiece are washed away to achieve a very clean effect.

      2. Vacuum drying: After steam cleaning, the temperature of the object being washed increases; then it quickly enters a higher vacuum state. At this time, the remaining detergent on the object will suddenly boil (vacuum bumping effect), achieving 100% drying effect.

      3. Recycling: The vaporized steam is converted into pure liquid through the condenser and then recycled. The loss of detergent is reduced, which leads to considerable emission reduction and energy saving.

Q:Generally, commercially available solvent recovery machines are divided into "batch recovery machines" and "continuous recovery machines". What are the differences?

  • A:



Continuous vacuum distillation recovery machine

Batch distillation recovery machin

Brief description

It can be used in line with the cleaning machine or recycled separately. When the pipeline is configured to start automatically, the dirty liquid in, regeneration liquid out, and waste oil out are all automatic. No liquid or full liquid is automatically monitored and notified by the program. No personnel is required to control the site. The recovery volume is >150L/hr

That is to pour the waste liquid to be recovered into the distillation barrel for recovery. The larger the volume of the distillation barrel, the more amount can be recovered; but the relative recovery time is longer. Generally, a recycling time is about 5 to 6 hours. After each recycling, the personnel need to take out the distillation bag and then add new waste liquid before recycling.

Recycling method

Vacuum distillation (standard configuration)

Normal pressure distillation, vacuum distillation (optional)

Vacuum value

About -700mmHg

About -400mmHg

Vacuum method

Venturi's principle (liquid flowing in a pipe creates a vacuum).

※Liquids (containing dirty liquid/pure liquid/waste liquid) flow in sealed pipes and containers, so there is little volatilization and there is almost no smell on site.

Vacuum generator (the propulsive action of compressed air creates a vacuum)

※At the outlet of compressed air, air and solvent vapor will be ejected at the same time, so the amount of volatilization is high, and the operation site will have a heavy smell.

Recycling amount

>150L/hr. Calculated in "hourly"

Calculated based on the volume of the distillation barrel. For example, the volume is 150L, ​​which is 150L/time. Calculated in "each time", usually about 5 to 6 hours each time


Automatic fluid replenishment/waste discharge, no personnel required, 24-hour operation

After each recycling, the personnel need to take out the distillation bag and then add new waste liquid before recycling.

Cleaning machine connected to use

The dirty, clean and waste liquid pipelines can be used directly after being configured.

It requires independent storage tanks, pumps and control systems to be connected and used.

Q:Vacuum ultrasonic cleaning machines are generally divided into "single chamber type" and "multi-tank type". What are the differences?



Multi-tank automatic vacuum cleaning machine

Single chamber automatic vacuum cleaning machine

Production rhythm



Cleaning process

Vacuum ultrasonic cleaning→normal pressure soaking→vacuum steam cleaning/drying

※The number of slots can be increased or decreased according to needs

Vacuum ultrasonic cleaning→normal pressure soaking/rinsing→vacuum steaming/drying

※The cleaning process can be set as needed


Excellent. The number of slots for different functions can be expanded according to needs. For example, anti-rust, water sink, etc.; functions such as rolling and liquid cutting can also be added

Difference. Single chamber, single solvent cleaning. Do not use multiple detergents at the same time as it will contaminate the chamber.


excellent. Continuous tank changing and rinsing between multiple tanks is less likely to cause accumulated contamination problems.

Poor. Single-chamber cleaning is prone to accumulated contamination problems

Detergent loss

Poor. The movement of baskets between multiple tanks is prone to the problem of solvent evaporation and loss.

Excellent. The basket does not move and evaporates less.

Power consumption

Low. Independent steaming, washing and drying chamber, the temperature can be maintained and less heat source is wasted

High. If the same chamber is used for impregnation of lotion and steaming, washing and drying, the chamber will be cooled down and then heated up again, which wastes a lot of heat energy.

Solvent recovery machine (vacuum recovery machine), degasser - necessary peripheral equipment for hydrocarbon solvents

  1. Solvent recovery machine (vacuum distillation recovery machine): The cleaning of hydrocarbon solvents must be equipped with a solvent recovery machine. As mentioned above, because it has a flash point, it needs to be operated in a reduced pressure environment to ensure its safety. Therefore, it is also called "vacuum distillation recovery machine". During the ongoing cleaning process, a continuous flow of regeneration fluid must be injected into the system to ensure the purity of the cleaning fluid; the larger the amount of regeneration fluid injected, the easier it is to control the cleanliness of the components.

  2. Degasser (vacuum degasser): Hydrocarbon solvents contain a lot of air, so the intensity of ultrasound cannot be used normally. Therefore, a vacuum degasser is needed to extract the air dissolved in the lotion. Enhance the effect of ultrasound. As shown in the picture