CHP | Combined Heat and Power

Exhaust Heat Exchangers and Steam Generators

Cogeneration or CHP (combined heat and power) is the process of recovering exhaust heat that is wasted when an engine runs to produce electricity or other process. Cain Industries manufactures exhaust heat exchangers and heat recovery steam generators (HRSG) for natural gas engines, diesel engines, gasoline engines, turbines, microturbine generators and fuel cells. Captured BTUs are transferred back into a desired water, glycol, thermal fluid or steam production heat sink. Suitable fuel types for combustion sources include natural gas, propane, gasoline, biogas, digester gas, landfill gas, diesel fuel and light to heavy fuel oils. Tremendous savings result from overall system efficiency improvements when recovered energy is repurposed within the facility and processes.

CHP Exhaust Heat Exchangers and Steam Generators
Combustion Sources:
  • Reciprocating Engines
  • Turbines
  • Microturbines
  • Fuel Cells
Fuel Types:
  • Natural Gas and Propane
  • Diesel to Heavy Fuel Oils
  • Digester and Landfill Biogas
  • Gasoline
Heat Sinks:
  • Steam Production
  • Thermal Liquids
  • Glycol
  • Water
Cain Industries Is a Proud Partner of:  EPA CHP Partnership Logo

ESG1 | Heat Recovery Steam Generators (HRSG)

Full operating steam pressure from a cold start in less than 10 minutes

ESG1 | Heat Recovery Steam Generators

The fully packaged ESG1 (Exhaust Steam Generator) is selected from 124 pre-engineered standard models with output capabilities of 20 to 350 boiler hp and operating steam pressures from 3 to 400 psig. The ESG1 is shipped complete, ready for operating as either a primary or supplementary steam source.

The ESG1 package is made up of three basic sections:
  • Finned tube heat transfer section
  • Steam flash circulating drum assembly
  • Modulating full port exhaust bypass system

Engine Exhaust Application
Capacity: 600kW to 7MW
Entering Gas Temps: 500°F to 1,400°F
Heat Sink Types: supplemental steam demand and/or primary steam source for steam heating or process steam

Operation and Control
The integral forced circulating water pump continually circulates high temperature water from the steam flash drum assembly to the heat transfer core assembly. BTU is transferred from the exhaust to a high flow superheated water/steam mixture. The superheated water is returned to the steam drum which contains dry pipe, baffles, and lance assemblies, where it flashes into 99% dry stream as its exits out to the system.

As the water is generated into steam and exits the boiler, the modulating boiler feedwater system controls continuous feedwater flow for constant drum water level control. Fail safe controls are built in for full exhaust bypass in the event of electrical or pneumatic loss.

The steam pressure controller maintains the operating steam pressure as it controls the modulating exhaust bypass assembly. This provides solid operating steam pressure under various operating steam load demands.

Quality Control
The ESG1 is manufactured, tested, and stamped in accordance with the requirements of Section I of the ASME Boiler and National Board of Boiler and Pressure Vessel Inspectors code. Boiler trim includes all safety controls and alarms to meet state and federal codes. Final assembly, electrical wiring, and factory adjustments are completed under a strict set of guidelines.

The ESG1 is an easy choice when compared to the “old technology” of a conventional firetube boiler:
  • Completely self-contained package design reduces engineering, installation and maintenance costs
  • Size requires only 1/2 the floor space and 1/2 the weight of conventional boilers, which reduces building size, structural support costs and shipping costs
  • Ease of tube replacement requires no overhead cranes, special rigging, special crews, or extra roof height above the unit, while reducing down time
  • Many shapes and sizes to fit in limited spaces and maintain performance requirements
  • Produces 99% dry steam
  • Provides turndown capability
  • 5-10 minutes from startup to full output
  • Integrated exhaust modulating bypass for safe automatic steam control
  • Explosion-proof heat transfer exchanger
  • Low friction loss for minimum static exhaust back pressure
  • High circulating flow to minimize scale buildup
  • No thermal expansion concerns with cold boiler feedwater
  • Performance aimed at the lowest pinch point in the industry (final leaving exhaust temperature minus operating steam temperature) for maximum thermal efficiency
Minimum Connections
The ESG1 requires only the following connections for a cost effective installation:
  • Steam Outlet
  • Exhaust Flange Inlet and Outlet
  • Single Main Power
  • Single Main Blowdown
  • Feedwater Inlet
  • Pneumatic Control Air (optional)

ESG1 Optional Components

Continuous Blowdown with Intermittent Conductivity Sampling Assembly
Maximize boiler efficiency by periodically sampling surface blowdown water and controlling total dissolved solids. Maintaining optimal levels of concentrations will control the costs of water, energy, and chemicals. Assembly includes: motorized valve, probe, and piping assembly.

Automatic Sootblower
Sootblowers are available either as a manual push button start or fully automatic with timed sequencing. Sootblowers are considered when firing with fuel oil and/or incomplete combustion. Sootblowers are also considered when manual cleanings are not feasible in order to maintain peak performance.

Hinged Access Door for Full Heating Surface Inspection
Hinged access doors are considered when firing with fuel oil and/or incomplete combustion requiring full access on a regular basis for manual cleaning. A hinged access door can be incorporated for 100% finned tube viewing and attention.

ESG1 Standard and Optional Equipment List

Standard Packaged Equipment
  • Modulating Exhaust Bypass Assembly
  • Finned Tube Heat Transfer Assembly
  • Steam Flash Tank Assembly
  • Main Control Panel for Single Voltage Connection
  • VFD Circulating Pump
  • Low and High Water Alarms
  • Modulating Feedwater Valve
  • Surface and Bottom Blowdown
  • Steam Pressure Control
Optional ESG1/ESG Electrical Components
  • Low-Low Water Level Cutout with Manual Reset
  • Secondary High Water Level Cutout with Manual Reset
  • Dry Contacts for Standard Trim Alarm and Boiler Function
  • Modbus Remote Monitoring Controls Communication System
  • Main Control Panel Air Conditioner
  • Control Voltage Battery Backup
  • PLC Indicating Controller Upgrade
Optional ESG1/ESG Mechanical Components
  • Internal Boiler Exhaust Economizer
  • Automatic Timed Sootblower
  • Pneumatic Modulating Exhaust Bypass Actuator
  • Pneumatic Modulating Boiler Feed Assembly
  • Automatic Surface Blowdown Control System
  • Automatic Main Blowdown Control System
  • Surface Blowdown Sampler
  • Steam Flash Drum Vacuum Breaker
  • Exhaust Bypass Spectacle Blind Plate
  • Exhaust Explosion Relief Hatch
  • Chemical Injection Quill
Optional ESG1/ESG Field Installation Equipment
  • Condensate Feedwater Systems and Boiler Feedwater Pumps
  • Water Treatment: Water Softeners, Chemical Feed and Deaerator
  • Steam Stop and Check Valves
  • Exhaust Piping, Elbows and Tees
  • Expansion Joints: Cloth Type and Stainless Bellows
  • Pre-made Snap-on Insulation Wrap for All Water, Steam, Exhaust Piping, Elbows, Tees, Flanges and Components
  • Structural Support Stands
  • Blowdown Separator

HRSR | Exhaust Heat to Liquid Exchangers

Fully Packaged for Small GenSets to Large Turbine Applications

HRSR | Exhaust Heat to Liquid Exchangers

The HRSR waste heat recovery silencer is a modular configuration package with 176 standard models available. It packages standard features such as: full exhaust bypass, full heating surface access, hard shell exterior, stainless interior, 3” thickness factory insulation minimum, and a variety of finned tube types and fin spacings to fit the proper application. The HRSR is designed to receive the total exhaust and liquid flow from a single source and control exit temperatures to the desired performance levels. During full operation, the radial design channels the exhaust flow through an hour glass expansion flow pattern which provides for significant dBA reduction.

The full port exhaust bypass is located at the top for convenient installation. Depending on space considerations, the unit may be installed in the horizontal position as shown below. The unique configuration of the single row design heating surface allows for reduced fouling potential. The full access to the core with optional hinged doors also allows for fast routine inspection and/or manual cleaning. Finned tube replacement requires no overhead cranes, special rigging, special crews, or extra roof height above the unit. Individual finned tube replacement, if required, is fast and easy with minimum downtime.

Engine Exhaust Application
Capacity: 200kW to 7MW
Entering Gas Temps: 300°F to 1,300°F
Heat Sink Types: engine jacket water, process water, boiler water, or ethylene glycol

  • Full exhaust gas bypass assembly
  • Modulating damper actuator (pneumatic or electric)
  • Sound attenuation
  • Stainless steel interior lining
  • Internal heating surface expansion design
  • No joint welds within the heating surface in contact with the exhaust gas stream
  • 10 gauge hard shell seal welded exterior
  • Single row design for complete and full access
  • Compression fitted tube to header attachment requiring no welding for fin tube replacement
  • Ease of tube replacement requiring no overhead cranes or special rigging
  Optional Equipment
  • Liquid temperature indicating control assembly
  • Hinged inspection doors for immediate access
  • Timed automatic sootblowers

Liquid Temperature Control (optional)

Operating Sequence: During a cold startup the exhaust bypass will be powered to the normal operating position. As the liquid temperature rises and approaches a preset point, the exhaust bypass damper will begin to move to the temperature control position. When the desired temperature is completely satisfied the damper actuator will move to the maximum open position, bypassing 99% of the exhaust flow (100% bypass cannot be attained due to some leakage and residual heat in contact with the fin tubing). Included is a 4-20 mA output controller, thermocouple, thermocouple weld and wire, and modulating bypass actuator installed, wired, and tested for a single 120 volt, 1ph, 60hz power connection.


UTR1 | Compact Exhaust Heat Exchangers

Compact Design For Large Engine Heat Recovery

UTR1 | Compact Exhaust Heat Exchangers

The UTR1 (U-Tube Recovery 1) has a compact industrial design that allows for maximum BTU recovery relative to the space allotted for installation. Finned tube spacings range from 3.5 to 6.5 fins per inch, depending on the fouling factor requirements. Standard fin to tube attachment using the nickel braze/weld fin to tube process allows no fin to tube separation to 2,000°F.

The UTR1 can be located above the engine or on the floor for convenient installation. With over 170 standard configurations to choose from, the UTR1 can be designed to meet the closest approach temperature requirements when installation space is not an issue. Easy access allows for quick removal of finned tube rows or core assemblies without disturbing the exhaust gas connections and allows for routine inspections and/or cleaning requirements.

Engine Exhaust Application
Capacity: 200 to 50,000 SCFM
Entering gas temps: up to 1,450°F
Heat Sink Types: process water, boiler feedwater, ethylene glycol or thermal transfer fluids

  • Parallel piping flow arrangement for high liquid flow
  • Series piping flow arrangement
  • Fin tube rack assemblies (spaced for accessible cleaning)
    – Tube materials: carbon steel, TP316 stainless
    – Fin materials: carbon steel, TP304, aluminum
    – Methods of finned tube attachment: nickel brazed, AL-FUSE™ and welded
  • Factory insulation (optional): 2” to 6” thickness available
  • Inspection door for accessing fin tubes
  • Inspection door (optional) for heating surface cleaning
  • 10 gauge carbon steel seal welded exterior
  • 3/4” NPT vent
  • ASME stamp (optional)
  • Lifting lugs
  • Exhaust transition (optional)
  • 3/4” NPT drain
  • I-Beam support
  • 1-1/2” NPT condensate cleanout drain (optional)
Optional Equipment
  • Inspection doors for easy access and cleaning
  • Exterior exhaust gas bypass and actuator assemblies
  • Exhaust piping to UTR1 transitions
  • Rotating sootblowers (automatic or manual)

Automatic or Manual Sootblower

ESG1 and HRSR Optional Equipment

Automatic or Manual Sootblower

The exclusive Cain Industries Timed Automatic Sootblower design is applied to combustion sources where the sulfur content is high and/or combustion efficiency is poor. Heat transfer efficiency is significantly reduced when a soot layer accumulates on the heating surface. The sootblower is also suggested when it is not cost-effective to open inspection doors and clean the exchanger by other means. The sootblower system will continually keep the heating surface at a high performance level and eliminate the day-to-day operator expense and engine downtime.

The blowdown sequence occurs while the engine is in full operation and is fully adjustable. The special flood-jet type nozzles achieve maximum cleaning velocity using steam or air as discharged through an electric control valve (included). Together they form a ”continuous knife edge concentrated spray pattern” surrounding the heating surface. This ”ring nozzle assembly” as attached to a manifolded flexible steel hose assembly, is powered up and down by a pneumatic drive cylinder. Dual timing relays allow complete control for cycle duration and intervals specific to each application.

CHP Case Study

CHP Case Study

A City of Industry, CA dairy depends on a Cain Industries ESG1 Heat Recovery Steam Generator and an HRSR Heat Recovery Silencer Radial working in series to capture the exhaust heat produced from their engine generator. The roof mounted units recover almost 4,000,000 BTUs per hour. The energy is repurposed for steam demand and a water loop used in dairy production. The Cain duo save $244,964 of energy annually ($30.62 per hour) and almost $5,000,000 over the 20-year life expectancy of the equipment. Payback on both units was less than 10 months.

CHP | Combined Heat and Power Exhaust Heat Recovery Video

CHP Exhaust Heat Recovery Video

Cain Industries Releases CHP | Combined Heat and Power Exhaust Heat Recovery Video.

Click to view video!

CHP PDF Summary

CHP Summary Sheet

Cain Industries Releases CHP | Combined Heat and Power Summary Sheet.

Click to download the PDF summary!