HBQ-3000-150-80 Mesh Belt Bright Annealing Furnace

1. Application

The furnace is mainly used for bright annealing treatment of metal parts.

2．Structural Introduction

The furnace is mainly comprised of preheating section,

heating section, cooling section, mesh belt, driving system,

gas pipes, water pipes, and electrical control cabinet.

To reduce gas consumption, the furnace has a bridge structure

for connecting the preheating, heating and cooling section.

There is a tilting angle of ≤8⁰ for connection.

2.1 preheating section

Overall dimension: 2000mm(L)×350mm(W)×200(H)mm

The preheating section is comprised of muffle, furnace door, ignition

device, and fume hood. Since the muffle entrance has 8⁰ tilting angle,

there is one large arc for smooth transition to the level part of the muffle,

which could ensure a stable, vibration-free, and sliding-free movement

of the parts. The outer surface of the preheating section is wrapped

with heat preservation cotton for preheating the parts. The movement

of the rolling wheel of the preheating section could prevent the

deformation of the muffle at the length direction.

Muffle material is SUS-4mm stainless steel plate. Outside material is

Q235-4mm carbon steel.

2.2 heating section

Overall dimension: 3800mm(L)×1700mm(W)×2000mm(H)

Muffle dimension: 3200mm(L)×200mm(W)×100(H)mm

Working size: 150mm(W)×80mm(H)

Heating zone: 2 zones (the temperature of each zone is adjustable,

temperature control accuracy is ±3℃. Each zone has current, voltage,

temperature control meter and over temperature alarm)

The heating section is a rectangular structure. The shell is made from

bent steel plate. The furnace wall is built with molite light refractory bricks

and heat preservation fiber material to ensure a maximum 30℃ temperature

rise of the wall furnace.

The muffle of the furnace is heat resistant stainless steel containing

rare earth elements which is produced by Avesta Sheffield Sweden.

The material can resist a high temperature, and a good anti-oxidation

performance. The muffle is mold formed, and then welded by 402 welding

rods. The muffle is under leak test. The muffle service life reaches 1 year

or more when the furnace has a normal working temperature of 900℃.

3.Main Technical Parameters

4.Gas burning system

The burner system adopts BSREC4C595 gas burner (brand: Xinqida, Beijing),

which includes VML1-2DN15 gas ignition solenoid valve, proportional valve

(Brand: Jingran), air actuators + butterfly valves, filter, reducing valve, high

press igniter (Italy brand) and manual valves.

The burners shall be evenly arranged on the both sides of the furnace bottom,

and the continuous proportion mode is adopted for temperature control.

Controlled burning system:

Each set of self preheating burner is equipped with a burner controller, which

can complete the functions of purging, ignition, large / small switching, flame

detection, flameout protection. The on-site controller has the function of ignition,

flame detection and field debugging. HMI workstation is equipped with working

condition diagram in the furnace, which can directly operate the ignition of burner,

flame size control and observe the working condition. Each burner has a flameout

alarm device. Once the burner goes out or the combustion is not good, the control

system will immediately cut off the natural gas valve in front of the burner and

give an alarm. At the same time, all valves are electrically opened. Once the power

is cut off, the valves will be cut off automatically to prevent safety accidents.

Burning ratio regulation:

The burner is equipped with air-fuel proportional valve and manual flow

regulating valve, which can realize the quantitative air supply of combustion supporting

air and natural gas, and realize the automatic control of high-speed burner and

accurate control of air-fuel ratio (coefficient of excess air a = 1.05 ~ 1.1).

5.Piping system

Combustion air supply system:

The combustion air supply system adopts a high pressure centrifugal fan (power:

7.5KW; air pressure: 8800-7850pa; flow: 1010-1250m³/h). The branch air pipe

of each temperature control area is equipped with electronic electric regulating

valve, which can automatically adjust the air supply with the temperature.

High efficiency convective air preheater uses flue gas heat to preheat

combustion supporting air.

Natural gas pipe

The main natural gas pipeline is equipped with pressure gauge, manual ball

valve, natural gas filter, pressure reducing and stabilizing valve, gas main

solenoid valve, overpressure relief valve, high and low pressure protection

switch of natural gas, etc. When the power failure or the natural gas

pressure is abnormal, the natural gas can be shut down quickly and an

alarm can be given to prevent danger.

6.Fume exhaust system

The exhaust pipe of the front material charging section is incorporated

into the exhaust system of the spray section; the exhaust pipe of the

material discharging section is incorporated into the exhaust system of the

forced cooling section. The two sets of exhaust pipes are respectively

connected to the outdoor.

7. cooling section

Overall dimension: 4500mm (L)×300mm(W)×200mm(H)

The cooling section is 2-layer water jacket structure. The cooling section is

divided into 3 parts for convenience of installation and maintenance. Each

part of the cooling section is set with a water inlet and a water outlet.

To save power, the exit of the cooling section is also set with one 8⁰ tilting

angle. There is also a large arc transition between the level part and the

tilting part. The exit of the cooling section is set with a fume hood and door

curtain to prevent intrusion of air.

The water jacket is under leak test to ensure no water leak. To ensure

safety, the water cooling section is equipped with an anti-explosion device.

If air inside the muffle is not exhausted because of wrong operation and the

furnace explodes due to abnormal inside atmosphere, the anti-explosion

film of the anti-explosion device breaks to release the abnormal pressure

of the furnace inside to ensure safety.

Cooling section muffle material is SUS-6mm stainless steel plate. Outside

material is Q235-4mm carbon steel.

Water inlet and outlet pipe material is stainless steel.

8. driving system

Overall dimension: 1000mm(L)×750mm(W)×800(H)mm

(charging mechanism)

Overall dimension: 1000mm(L)×750mm(W)×800(H)mm

(discharging mechanism)

The driving system is comprised of frequency conversion motor,

reducing gear, driving rollers, support rollers, and mesh belt. The

mesh belt speed is changed by frequency of direct motor of reducing

gear. The mesh belt speed is usually 100-400mm/min (varying with

different products). The inverter used is Delta brand. And for operation

convenience, the control of the inverter is on the control panel.

Mesh belt is the key component of the furnace. And the mesh belt

used is SUS314 heat resistant steel wires supplied by Nippon Steel.

The cross weaved mesh belt has a service life of half a year in normal

working conditions. The mesh belt would expand at high temperature,

but the furnace driving mechanism is set with automatic tension and

correction device to ensure a stable movement of the parts.

9. water cooling system

The parts should be brazed under the protective gas atmosphere. At the

preheating section and cooling section there are both gas inlets. Each

gas inlet is set with a regulation valve and a flow meter. At the cooling

section there are many cooling water loops. To remove the deposit,

there is one deposit cleaning hole near the muffle of the heating section.

The deposit should be cleaned periodically to ensure a smooth flow the

cooling water.

10. electrical control system

The electrical control system adopts Siemens S7-220 PLC control system.

2 temperature control zones are equipped at the furnace side and 2

temperature measurement points. The furnace temperature uniformity

is ≤±10℃.

The temperature controller adopts Japanese conductive meter which

could control the temperature separately. Each heating zone has a

temperature controller.

To ensure safety running of the furnace, the electrical loop is set with a

linkage protection. When the temperature is above the limit value, the

control system would cut off power supply automatically and send out

an alarm signal.

11. Ammonia Decomposition Device

4-1 CXAQ-15 ammonia decomposition device, 1 set;

Rated productivity: 10m³/h (75%H₂ and 25%N₂)

Purity: remaining ammonia: ≤1000ppm; dew point: ≤-10℃

Pressure: 0.1Mpa

Liquid ammonia consumption: 8kg/h

Power: ∽380V,50Hz

Rated power: : 12KW

Water consumption: 4T/h

4-2 CXFC-15 purification device, 1 set;

1)capacity: 15m3/h

2)finished gas purity: dew point≤-70℃; remaining ammonia≤5ppm

3)working pressure: ≤0.1Mpa

4)rated power:3KW; power supply: ∽380V,50Hz;

5)dryer working temperature: room temperature;

6)dryer regeneration temperature: 350℃

7)dryer working cycle: 24 hours;

4.3 Working Principle

4.3.1 general introduction

CXAQ series ammonia decomposition device uses liquid ammonia as

raw material, and decomposes to 75%H₂ and 25%N₂ through the catalyst.

The ammonia decomposition device is comprised of decomposition furnace,

heat exchanger, gasifier, and water cooler. The gas purification device is

comprised of absorption tower, dust filter, valve, and electrical control cabinet.

The liquid ammonia is first gasified, and pressure reduced before entering

the distributor. The ammonia becomes 75%H₂ and 25%N₂ through the catalyst.

The mixed H2 and N2 gas is cooled before the purification device.

4.3.2 catalyst

The catalyst used is usually iron and nickel catalyst. The decomposition

temperature of the iron nickel is 600-650℃, and that of nickel catalyst is

800-850℃. Each kilo of ammonia can produce 2.6M3 H2 and N2 atmosphere.

12. Supply Scope

12.1 bright annealing furnace

A) heating furnace (with muffle tank, 1 piece), 1 set;

B) preheating section (with driving device), 1 set;

C) cooling section, 1 set;

D) burner, 2 sets;

E) accessories for burner, 2 sets;

F) mesh belt, 1 piece;

G) electrical control cabinet, 1 set;

H) ammonia decomposition device, 1 set;

12.2 Spare parts

Accessories for burner, 1 set;

Fuse, 2 sets;

12.3 The wire connecting the online units of the furnace with the control

cabinet should be prepared by the buyer itself. The connection pipes between

the units and other components should be prepared by the buyer itself.