Application Case Study – Using S36 Micro Vacuum Liquid Pump For Circulating Coolant Replenishment

Application Case Study – Using S36 Micro Vacuum Liquid Pump for Circulating Coolant Replenishment

Overview of Circulating Coolant Replenishment Applications

In industrial environments requiring liquid cooling, circulating pumps are typically used to drive the coolant flow within pipelines. However, due to evaporation, leaks, and other factors over time, there is a need to use small-flow micro vacuum liquid pumps to replenish the coolant in the liquid cooling circuit as needed. For example, in the metal heatsink manufacturing industry, testing liquid cooling circuits is essential to evaluate heatsink quality and effectiveness. These test circuits require on-demand replenishment of refrigerant. Utilizing micro-flow control for refrigerant liquid addition enables precise, stable, and reliable coolant replenishment.

In such scenarios, micro vacuum liquid pumps with low flow rates and high head are more suitable as coolant replenishment pumps. Integrated with on-site equipment processes and controlled by level sensors combined with PLCs or microcontrollers, these pumps can promptly activate to draw liquid when the coolant level falls below the normal line, thereby completing the liquid transfer and replenishment task.

The S36 series micro vacuum liquid pump features rapid response, convenient control, and real-time operational status monitoring and feedback. It is particularly well-suited for automated control in application scenarios that require integration with sensors and microcontrollers to achieve precise micro-volume liquid replenishment.

Product Features and Functions

Operational Status Indication
Only the knob speed control type and frequency speed control type are equipped with operational indicator lights, which provide intuitive feedback on the pump’s working status. The top-tier model is equipped with an LCD screen capable of displaying fault codes.
Brushless Motor
Utilizes high-quality brushless motors, offering advantages such as long lifespan, low interference, and high reliability.
Protection Functions
Incorporates overheat protection, overload protection, power under-voltage/over-voltage protection, and reverse connection protection to minimize the risk of accidental pump damage.
Liquid and Gas Dual-Use
Capable of functioning as both a liquid pump and a vacuum pump, and can also handle gas-liquid mixed media. It can run dry and is self-priming.
Modular Connectors
This pump series features an Rc1/8 internal threaded port. It can be fitted with stainless steel quick-connect fittings (for 6mm or 8mm inner diameter tubing), stainless steel barbed air nozzle connectors, or PP plastic barbed air nozzle connectors. The product comes standard with a PP plastic barbed connector.
- The standard PP plastic barbed connector and the optional stainless steel barbed air nozzle are recommended for use with 7*13 silicone tubing. Tube size can be adjusted slightly based on tubing flexibility.
- Two sizes of stainless steel quick-connect fittings are provided for use with 6*8mm or 4*6mm rigid tubing.
  Users can select the appropriate interface during ordering based on their piping requirements.
Speed Control Function
The pump’s flow rate can be adjusted by regulating the motor speed.
- The top-tier model features an LCD touch screen and a speed control signal interface, allowing for start/stop control and speed adjustment either via the touch screen or through frequency signals.
- The knob speed control type includes an external speed control knob for adjusting pump speed and controlling start/stop.
- The frequency speed control type allows for speed adjustment and start/stop control via user-input frequency signals.
Status Memory Function
In the event of a power failure causing the pump to stop, it will resume operation in the same state (including memorized speed and operational status) upon power restoration.
During normal use, when the micro vacuum liquid pump is started via the knob or touch switch, it will operate at the speed set before the previous shutdown.

In factory settings, liquid circulation is primarily achieved using AC circulating pumps as the core pressurizing components, enabling high-pressure, high-flow coolant circulation to drive coolant flow within pipelines. However, such pumps are not suitable for the role of coolant replenishment pumps.

Challenges in Coolant Circulation Replenishment Projects

Most micro vacuum liquid pumps on the market lack speed control functionality. Variations in on-site workload pressure lead to significant discrepancies between actual and expected flow rates, hindering the achievement of automated liquid replenishment control.
On-site applications often require micro vacuum liquid pumps to be self-priming, capable of drawing liquid immediately upon power-on, and able to run dry when no liquid is present.
There is a need to pump liquids with a certain degree of viscosity.
Factory equipment demands that micro vacuum liquid pumps operate continuously 24/7 without power interruption, requiring long lifespan, high stability, and minimal maintenance.

Application Analysis of the S36 Series Micro Vacuum Liquid Pump

The S36 series micro vacuum liquid pump, developed and manufactured by Chengdu Hailin Technology, generally offers a small liquid output flow rate, with an optional flow range of 0.2 L/min to 3 L/min. Its on-site connection to PWM signals enables adjustment of output flow and pressure, and it features pump speed feedback signal functionality, making it more aligned with practical on-site application needs.

The S36 series micro vacuum liquid pump is a dual-use type for both liquids and gases, functioning as either a liquid pump or a vacuum pump. It can run dry and is self-priming. There is no need to prime the pump chamber with liquid before starting; it can directly self-prime to create a vacuum and then draw the liquid.

Being a liquid and gas dual-use type, the S36 series micro vacuum liquid pump can directly run dry to create a vacuum, drawing a container to a certain negative pressure, and then directly pump liquids with some viscosity from the container.

Notes:

Input voltage requirement: 24V ±10%.
Unless otherwise specified, technical parameters are measured under conditions of 20°C and standard atmospheric pressure (101 kPa). Products with other parameter specifications can be customized upon request.
Parameters in the table are measured at the motor’s maximum speed. When speed varies, pressure/vacuum level remains largely unchanged.
The above parameters are measured with the standard PP plastic barbed air nozzle configured. Parameters may change slightly if other types of connectors are used.
The average flow rate in the table is measured using a soap film flowmeter.

Product Types and Specifications

The S36 series products are divided into four types based on functionality: Basic Type, Knob Speed Control Type, Frequency Speed Control Type, and Top-tier Type. Different versions exist within each type based on varying quality control and manufacturing processes. The differences between versions are illustrated in the chart below. For specific distinctions between different types, please visit the Hailin Technology official website at www.mini-pump.com to download the corresponding product manual free of charge.