CRI – CSR Test System

According to: ASTM D 5341, ISO 18894
and IS 4023 Meth.B Standards

CRI Dual Oven - System


General description

The CRI CSR Test System is an automatic device for determination of the Coke Reactivity Index (CRI) and Coke Strength after Reaction (CSR). This test device is fully compliant with the specifications in ISO 18894, ASTM D 5341 and IS 4023 Meth. B Standards.

Both indexes C.R.I. and C.S.R. are probably the most important parameters used for assessment of the quality of metallurgical coke. Many coke plants and blast furnaces around the world use CSR as a specification just as important as cold strength, size, and chemistry. From experiences of several laboratories involved in CRI and CSR tests it has been pointed out that the reliability of the results greatly depends on temperature and reaction gas flow rate accuracy in terms of:

  • Accuracy of test temperature (1100 °C) during all reaction time.

  • Isothermal temperature distribution in the coke sample.

  • Accuracy of CO2 reacting gas flow rate (5.0 nl/min).

To obtain best test reproducibility, therefore, the system, includes as standard:

  • High accuracy temperature programmer and controllers.

  • Multizone oven with temperature independent controls for best sample isothermal distribution.

  • High accuracy automatic mass flow meter and control device for CO2.

Test process is carried on by the system with no needs of any action by the operator. Optional continuous weighing system is available to display and to record weight change of the sample during the test. According to Standards, a double drum tumbler device, with automatic counter, is supplied to perform the CSR test (TB 5000). Reaction Tube Cooling System can be optionally supplied to reduce the cooling down time of the Reaction tube at the end of the test (CS 2000).

Available Versions

CRI Test System is available in three versions:

Single Oven System, Double Oven SystemDual Oven System.

Single Oven System

To perform one test at time.

CRI Single Oven

Single Oven CRI Test System

Double Oven System

To improve the number of tests that can be performed.

At the end of the test in the first oven it is possible to start immediately a new test on the second oven. It is not necessary to wait for oven cooling down as in single oven system.

CRI Double Oven System

Double Oven CRI Test System

Dual Oven System

To allow simultaneous operation of two ovens running, fully independently, two tests at a time. The system is provided with independent Carbon Dioxide and Nitrogen lines, together with independent temperature control and programming units.

To perform one test at time

CRI Dual Oven - System

Dual Oven CRI Test System




Heating elements: Silicon carbide elements (20 elements)
Heating Zones: 5 heating zones
Max operating temperature: 1200 °C
Maximum operating Power: 20 kW
External thermocouple: “K” type (inconel shielded)
Inner chamber diameter: 140 mm
Reaction tube type : “Single wall” Type A
 Material:  Inconel 600
 Inner diameter:  78 mm
 Internal thermocouple:  Triple “K” type (inconel shielded)
Flow rate measuring devices  Digital Mass Flow Meters
 Reaction Gas composition  100 % CO2
 Reaction Gas Flow rate:  5 nl/min
 Purge Gas composition:  100% N2
 Purge Gas Flow rate:  3 – 10 nl/min
 Max Weight:  30 kg
 Resolution:  0.1 g
 MAIN POWER:   380 V 3 Ph + Neutral ( 20 kW max)

Vertical electric oven

The electric oven consists of a steel structure placed on a frame and including the silica insulation material. Twenty silicon carbide high temperature heating rod elements are placed horizontally in a stack and are grouped in 5 heating zones to provide separate power control. Replacement of heating elements is fast and easy with no need of refractory maintenance so that oven life is very long.

single oven

Inner high temperature chamber is protected by a quartz tube.

The oven can be equipped, as an option, with a weighing system to provide continuous monitoring of coke sample weight during reduction test.

Control Panel

control panel

Control panel includes complete top quality control and monitoring instrumentation.
Temperature of coke sample is driven by digital programmer and by multiloop digital controller to obtain the best isothermal test condition. A temperature alarm controller assures oven safety cutting off power in case of over temperature.

Automatic inlet of Nitrogen and Carbon dioxide is provided according to temperature program. Gas flow control is obtained by a digital mass flow meter for CO2 and by a rotameter for N2 (as option a mass flow meter also for N2 is included).

Manual gas control is also possible for checking purpose. Optional weighing system allows continuous monitoring of sample weight.
A Touch screen recorder and data logger, and Ethernet connection, provides local and remote recording of test data.

Reaction Tube

reaction tube

Reaction tube is manufactured according to ASTM and ISO Standard dimensions and materials: all parts operating at high temperature are made of INCONEL 600 steel alloy to obtain long tube life.

A copper tube coil assures cooling down of exhaust gases. The reaction tube can be hung to the optional roof electric tackle to provide safe and easy insertion and removing into the furnace.

TB 5000 for CSR determination

Tumbler device for CSR test consists of a wall mounting double drum system. TB 5000 allows to run two sample tests simultaneously.

TB 5000 - aperto - big

The unit is equipped with:

  • Electric motor and gear box
  • Variable frequency drive (TB 5000 –ISO)
  • Digital pre-set counter (to set up total number of revolutions)
  • Positioning feature (for a slow motion for loading/unloading purpose)
  • Safety cage
  • Safety switch on the door
  • Emergency Stop button

In the ISO Version the high accuracy in the revolution speed is assured by the Variable frequency drive that allows a fine adjustment of the speed to 20 ± 0,1 r.p.m.

Auxiliary Equipment



Reaction tube lifting tackle

• For insertion and removing of the reaction tubes
• Vertical electric movement
• Two controlled speeds – low / fast movement
• Manual horizontal movement on rail
• Max. weight 60 kg
• Remote control
• Rail included
• Power 230 V 50 Hz


reaction tube tripods

Reaction tube tripods


• TR 2000 – For CRI-RDI reaction tubes


Cooling System - Complete - small Cooling System - Detail - smallReaction tube cooling devices

• Digital Temperature controller
• Ventilation Fan
• Auto stop at preset temperature
• Power 230 V 50 Hz


  • CS 2000 – For CRI-RDI reaction tubes

Sample preparation devices

Auxiliary equipment for Sample Preparation can be provided together with main instrumentation.

Available devices are:

  • Jaw Crusher for coke
  • Sample Splitter
  • Testing screen machine (with screening trays)
  • Sieving Machine (with sieves)
  • Sieves (for manual sieving)
  • Thermostatic Oven
  • Digital laboratory scale


RB Automazione Catalogue 2017

Download the RB Automazione general Catalogue 2017