Damper & Gates

Damper is basically a mechanical assembly placed into a duct or opening, which may be actuated on command to isolate or regulate gas flow in the system. In a process industry, dampers are designed and engineered depending upon the functional requirements and integration of the damper operation with other part of the system. Moreover, the damper has to withstand high temperature, pressure and corrosive gas environment without failure for its desired lifecycle.

We are manufacturing the world class dampers of various designs depending on the application and operating environment to cater the need of process industry in India and abroad. Our 25 years of experience in thermal power industry along with the modern day’s technology and tools such as computer simulations through Finite Element Analysis and CFD studies for flow and heat transfer analysis gives us the better insight of the problem. With these expertise and experience we provide the optimized material and configuration for damper with maximum life and a better performance at a competitive cost.

Louver damper
Louver damper consists of number of blades mounted on shaft parallel across the duct, wherein the shafts extend out of duct frame and connected together with linkages so as to achieve desired opening/closing relative motion of the blades
Features:
1.    Compact, no bonnet
2.    Lightweight
3.    Good modulation and control characteristics
4.    Fast opening and closing
5.    98 % sealing efficiency for single louver damper with structural seals
6.    99.5 % to 100 % sealing efficiency  for double louver and tandem louver using sealing air

Single Louver Damper
Parallel blades: Adjacent blades rotate in same direction. This type of arrangement is more suitable for flow control in high flow region
Apposed blades: Adjacent blades rotate in opposite direction. This arrangement has a better flow control characteristics (as function of blade position) hence recommended for flow control applications with least disturbances.

Double Louver Damper
    This arrangement is used to combine flow control with 100 % isolation. It consists of two rows of blades mounted in a single frame such that an enclosed passage is formed between these two rows. This passage is the pressurized with ambient air (higher than the system pressure) which creates the barrier consequently, leakage is reduced.

Tandem Louver Damper
    It consists of single row of shafts and blades in which special blades with through passage are used. When closed, it forms an air chamber which can be pressurized above the system pressure resulting in pressurized barrier consequently reducing the leakage.

Guillotine/ Gate damper
It consists of a sliding blade which covers and uncovers the duct opening and seals into its frame in the duct. Various modes of sliding/actuation such as manual, rope & pulley, power screw, pneumatic, hydraulic and integral electric actuator are possible in this configuration.
Features:
1.    Low leakage perimeter
2.    Low pressure drop across the damper
3.    lesser flange to flange space required
4.    lesser sealing air requirement in case of 100% sealing efficiency using externally pressurized air
5.    Better seal design can be incorporated
6.    fewer moving parts and lesser maintenance

Diverter Damper
Tee diverter damper basically extends the capabilities of butterfly damper by combining two butterfly dampers in common T/Y fitting. This combined diverter is used to divert a gas flow into an alternative duct system.

Features:
1.    High sealing efficiency
2.    Low pressure drop across the damper
3.    lower sealing air requirements
4.    flow modulation is also possible
5.    Suitable for high temperature application

Flap damper
This damper is basically designed for effective isolation of coal mill which ensures 100 % isolation for on load maintenance activity.

Features:
1.    High sealing efficiency up to 100% possible in double seal configuration
2.    Lesser probability of gate seizure due to thermal and ash loading.

Butterfly damper
Butterfly damper consists of centrally mounted disc offering reliable on/off and flow modulation operation.

Features:
1.    Lightweight
2.    Simple in design
3.    Quick actuation is possible
4.    Lower cost

 

Mechanical design issues
1.    Considerations for abrasion due to ash particles
2.    Structural design of blade, frame and other members
3.    Flutter considerations
4.    Thermal stresses in the frame
5.    Hinge joint at the corner to avoid excessive stress concentration in rectangular frames operation at elevated temperatures
6.    Bracing, supports and wind loading considerations
7.    Sealing efficiency and blade design to minimize the sealing perimeter
8.    Flexible bearings to accommodate thermal deformations
9.    Proper material selections for bearing material to prevent seizure in operating conditions
10.    Actuator sizing

Research & Development
R & D center at Mechwell Industries ltd. Nasik is having full fleshed capability and infrastructure for Computational mechanics viz. CFD and FEA. At present we are using commercial FEA package ANSYS (workbench and classic environments) along with expert team of post graduate mechanical engineers.
All design configurations are developed as per customer’s specific requirements and subsequently analyzed for structural integrity by means of FE simulations.