Temperature Resistant & Heated Head Pumps


KNF heated head and heat-resistant process diaphragm gas pumps are specially designed to transfer hot gases in analytical, chemical, industrial, and process engineering applications. Temperature-resistant pumps can transfer air as well as neutral or aggressive gases at temperatures up to 460 °F (240 °C). In order to prevent condensation of the measuring gas, KNF's heated head pump types utilize temperature-resistant pump head components with optional thermostatic or electronic temperature control.

View temperature-resistant & heated head pumps & specs

Diaphragm Pump Design

The design principles of KNF diaphragm gas pumps contain two important characteristics for process engineering:

  1. The pumped media is not subjected to contamination.
  2. Diaphragm pumps exhibit a high level of gas tightness.


Gas Pump Applications  

Diaphragm gas pumps have become standard for many analytical applications. Based on their design, they operate without lubrication and, therefore, cannot contaminate the medium. For analysis of hot gases, it is also critical that the gas sample temperature remain constant. Otherwise, the constituent parts could condense out, leading to inaccurate results.

    Finite element calculations were employed in the design of the pump head insulation ensuring the best possible thermal insulation & thermal distribution.

    Avoiding condensation of gases

    Process engineering and chemical analysis both depend on the ability to transfer hot gases and vapors. KNF diaphragm pumps with temperature-resistant components -- able to withstand up to 460 °F (240 °C) -- are ready to handle these challenges. However, temperature resistance alone is not enough in many applications. In these cases, it is equally important for the temperature of the medium to remain constant during the transfer process. KNF diaphragm gas pumps with insulated temperature-resistant, and heated heads provide the solution to this problem.


    Insulation of the Pump Head - an Ingenious Solution

    There are two important requirements for the temperature-resistant pump:

    1. homogenous temperature distribution throughout the entire pump head in order to prevent cold spots and condensation.
    2. minimal heat emissions into the ambient air to avoid significantly elevated temperature in the analysis cabinet.

    For these purposes, patented insulation fully encapsulates the pump head in the form of a removable cover. The insulation has four layers: First, air provides insulation directly at the pump head. This enables contact-free assembly, and convenient cover removal. Next, comes an inner hood made of stainless steel whose surface reflects heat radiation, thereby ensuring homogenous distribution of temperature in the pump head. The third layer is a fiberglass fleece, protected by a plastic hood, which is the fourth and final layer.


    PC software interface for programming heating cycles

    Electronic Temperature Control

    KNF heated diaphragm pumps with electronic temperature control (.26 version) allows the user to conveniently set the desired head temperature as well as the hysteresis (how many degrees the temperature may fall before heating begins again). These heated pumps are equipped with a PT 100 thermal sensor, which enables regulation to be performed electronically. A display indicates the current or desired temperature, and the operator can select units of Fahrenheit or Celsius.

    Additionally, KNF heated pumps equipped with electronic controls have a function for increased reliability in analyzing results and lowering energy consumption - a preheating mode. When activated, the preheating mode ensures that the pump starts only after it has reached the required operating temperature. This feature provides a safeguard against the analysis medium being pumped at a stage when constituent elements could condense out of the pump head.

    Finally, KNF offers a number of alternative materials, motor types, and accessories including an RS 232 interface for applications where the electronics need to be controlled externally. Click here to learn more about custom pump configurations.


    Contact a KNF Application Engineer to discuss your specific requirements

    View Video: KNF Process Media Pumps for Industrial Applications