Pit-type Resistance Quenching Pit Type Heat Treatment Furnace

1. Overview

RQ₃ series high temperature pit type heating furnace (hereinafter referred to as electric furnace) is a

periodic operation type resistance furnace. The rated temperature is 1200℃, and the furnace is a vertical

shaft type. The furnace cover is hydraulically split, and the furnace is surrounded by resistance belts.

The resistance belts are arranged at the bottom of the furnace, and the furnace bottom plate is laid on top.

There is a stainless steel protection ring in the furnace to prevent the workpiece from colliding with the furnace

wire when entering and leaving the furnace.This industrial electric furnace is suitable for high-temperature

quenching, annealing and other heat treatment processes for various large and medium-sized parts. It has

the advantages of strong sealing inside the furnace, high furnace temperature uniformity, good energy saving

and convenient operation.

2. Main Technical Parameters of pit type furnace

3. Conditions of Use

3.1 Indoor use;

3.2 There is no conductive dust, explosive gas, or corrosive gas that can seriously damage metal and insulation around;

3.2 No obvious vibration or bumps;

3.4 The workshop must have fire-fighting and smoke exhaust facilities.

4. Structural Introduction

The electric quenching furnace is mainly composed of furnace shell, furnace lining, heating elements, protective cover,

furnace bottom plate, furnace cover and lifting mechanism, temperature control system, etc.

4.1 The furnace shell is mainly welded with high-quality 5mm thick steel plates into a solid frame.

The furnace body is divided into four sections and spliced up and down. The entire steel structure has the advantages

of beautiful appearance and high rigidity. The appearance of the furnace body is straight, beautiful, without wrinkles or

unevenness. The exterior of the furnace body is painted with two coats of primer and two coats of topcoat according to

relevant standards. The color code is selected according to the general industry standard or the factory standard of Party A ,

and the key parts are painted with high temperature resistant paint.

4.2 The main body of the lining is constructed with high-quality zirconium-containing refractory fiber folding blocks produced

by Shandong Luyang's vacuum spinning method , using standard fixings and scientific and reasonable mounting methods.

The fiber folding blocks are pre-compressed again before mounting and fixed to the shell with special stainless steel fixings.

The total installation thickness of the furnace lining is 300 mm . The structure has low thermal conductivity, low thermal

dissolution, excellent chemical stability, thermal stability, thermal vibration resistance, excellent tensile strength and corrosion

resistance. The maximum temperature resistance of zirconium-containing aluminum silicate fiber is 1350 ℃, and the material

of the fixings is stainless steel round steel.

4.3 The electric resistance pit type heat treatment furnace bottom is made of a composite lining made of heavy high-aluminum

refractory bricks, lightweight refractory bricks, insulation bricks, etc. The collision-prone parts and load-bearing parts are built

with heavy high-aluminum refractory bricks (high-temperature adhesive is added to the mud during masonry) to enhance the

structural strength of the furnace lining. Expansion joints are left during production to prevent the lining from expanding and

damaging the lining after being heated. The refractory layer is built into a strip groove where the heating element is placed,

and is also used to place the furnace bottom plate.

4.4 The furnace bottom heating element is covered with a furnace bottom plate made of ZG40Cr25Ni20 heat-resistant steel

with a thickness of 30mm. It adopts a new type of buckle to prevent the oxide scale of the workpiece from falling into the

heating element.

4.5 The heating element is made of high-quality high-resistance alloy material HRE resistance belt processed into

a corrugated shape . The resistance belt is fixed with special ceramic screws (see the resistance belt installation

structure diagram for details). Its structure is easy to install and quick to maintain and replace. There will never be

a thermal short circuit with the furnace shell to cause local overheating of the furnace shell. During installation,

a ceramic gasket is placed between the fiber wall and the resistance belt to ensure that the fiber surface is not

in direct contact with the resistance belt, thereby increasing the heating effect of the resistance belt.

The ceramic screws and washers are both sintered and formed at high temperatures using corundum

materials to ensure that they have sufficient strength and service life. The equipment is divided into eight

heating areas. An independent heating group is arranged in each heating section, and there is no cross-zone arrangement.

Resistance band installation diagram Ceramic screw diagram

4.6 The material of the protection ring is stainless steel 310S , with a thickness of 5mm.

Multiple protection rings are installed up and down in the furnace, which effectively restricts the

left and right swing of the workpiece when entering and leaving the furnace, and can prevent the

workpiece from colliding with the furnace wire when entering and leaving the furnace.

4.7 Furnace cover and opening and closing mechanism of the : The furnace cover is made of

3mm thick steel plate in half, and the insulation material is made of zirconium-containing aluminum

silicate fiber folding blocks fixed with anchors, with a thickness of 300mm. The furnace cover is

opened and closed with hydraulic push rods , and pulleys are installed on the left and right furnace covers.

The furnace cover can move 4.8 Electrical control system

4.8.1 The main control components such as power regulator, AC contactor, fast fuse, intermediate relay,

operation switch, button, signal indicator light, etc. adopt reliable products of well-known domestic brands.

The current and voltage indicating instruments are sensitive, accurate, reliable and have a long service life.

4.8.2 Automatic temperature control system

( Control cabinet diagram )

4.8.4 The temperature of each temperature zone is controlled by the Japanese Shimaden SRS13A

series intelligent program temperature controller and regulated by a high-power power regulator.

The main control instrument of each zone communicates with the touch screen, and its output uses

time proportion module technology to directly trigger the power regulator to control the heating process.

4.8.5 The Japanese Shimaden intelligent temperature controller for the pit type electrical oven has

the functions of unified programming of temperature and time, independent setting of temperature and time,

and measurement display. The meter has multiple output modes and multi-channel output control functions,

and can switch between manual and automatic modes online.

(Shimaden SRS13A Temperature Controller)

4.8.6 The smart meter has the function of communicating with the touch screen, so that the process curves

and data of each area can be called up and printed on a USB flash drive at any time, and can also

be randomly stored to automatically store all the actual production heat treatment process data for ≥1 year.

4.8.7 Each zone has three ammeters to indicate the loop current, and each power regulator module is

equipped with fast fuse protection.

4.8.8 MCGS touch screen industrial control machine (10”touch screen) is equipped with a standard USB

interface to facilitate data storage and printing.

4.8.9 The system has high reliability and anti-interference functions.

4.8.10 Collect real-time master control temperature from the lower-level master control instrument.

The state of each zone furnace temperature and its alarm at every moment in the process can be

displayed and recorded in real time until the process is completed.

4.8.11 System Interface

Human-computer dialogue interface: The computer display interface has a colorful system overview,

parameter settings, parameter display, setting curves, process curves, process simulation,

alarm interface, report timing printing and help work interface. All work interfaces are displayed in Chinese.

It has one-button start and stop after the process curve is set.

5. Supply Scope

6. Components Origin