The ENCON MVC Evaporator product line has standard offerings that range in capacity from 40-4,000 gallons/hour. These systems operate on steam or electricity and compressed air at a typical operating cost of $0.01-$0.02* per gallon of distilled water. Materials of construction include 316 Stainless Steel and Super Stainless alloys for more corrosive waste streams.
The ENCON MVC Evaporator is highly automated with minimal need for manpower intervention. Automation includes: wastewater feed, automatic discharge of concentrated residue from the Separation Tank, automatic transfer of distillate from the distillate sump, and automatic cleaning (Clean-in-Place) of heat exchangers. Numerous variables such as temperature, pressure, and water level are monitored continuously, and will trigger various alarm conditions that notify the operator of deviation from normal operating mode.
The ENCON MVC product line is defined by capacity and alloy based nomenclature as referenced in the tables below.
For example, the ENCON model MVC300-33333-33331B-A1-10-5 is a 300 gallon/hour system heated with electricity and with separation tank, piping, and heat exchangers constructed with 316 stainless steel.
Installation for the ENCON MVC Evaporator is very straight forward and is generally handled by facilities, maintenance, or plant engineering personnel. ENCON Service Technicians are readily available to assist during the installation process based on the needs and capabilities of the customer.
After fabrication and quality control testing, the system is disassembled into five skidded sections that fit in standard truck trailers (for domestic shipments) or high cube 40 containers (for international shipments). These sections are labeled for easy mechanical and electrical reassembly after arrival at customer’s site.
Primary connections include plumbing from the holding tank, sump, or pit to the wastewater feed connection, plumbing from the residue pump connection, to the residue tank, plumbing from the distillate pump connection to the distillate holding tank, and plumbing from the cleaning solution holding tank to the cleaning solution feed line.
Finally, power is run to the main power disconnect switch located behind the operator interface panel. All primary components including feedstock pump, recirculation pump, vapor compressor, concentrate discharge pump, level probes, pressure transducers, etc. are pre-wired and pre-plumbed within the boundaries of the MVC.
What is Mechanical Vapor Compression?
Mechanical Vapor Compression (MVC) is the evaporation method by which a compressor is used to compress and thus increase the pressure of the steam produced. Since the pressure increase of the steam also generates an increase in the steam temperature, the same steam can serve as the heating medium for the liquid being concentrated from which the vapor was generated to begin with. This makes this evaporation method very energy efficient. When this compression is performed by a mechanically driven compressor, the evaporation process is referred to as MVC (Mechanical Vapor Compression) or MVR (Mechanical Vapor Recompression).
ENCON MVC Evaporator Process Description (Refer to diagram below)
- Unheated wastewater is fed to the liquid vapor separation tank (1) and is heated to a boil by steam or an electric heating element (6).
- Recirculation pump begins circulating heated water through the main heat exchanger (2) and back into the separation tank (1).
- Steam flows up through the mist pad (8) to inlet side of vapor compressor (4).
- Compressed steam from vapor compressor (4) is forced through the steam side of main heat exchanger (3) giving up latent heat to the counter flowing water from the separation tank (1).
- High temperature distillate flows out of the main heat exchanger (3) to feedstock heat exchanger (7) giving up sensible heat to feedstock wastewater.
- Upon reaching steady state, cold feedstock wastewater is fed at a constant rate through the feedstock heat exchanger (7) to raise temperature before feeding to recirculation loop.
- Concentrate is periodically discharged based on temperature, conductivity or time from separation tank (1) to concentrate tank (9) through residue pump (10).
Automated and Easy to Use Control System
The ENCON MVC Industrial Evaporators are controlled with Programmable Logic Controllers in NEMA 4 enclosures and are designed to UL508 and NEC standards. The MVC control logic allows for highly automated operation to minimize the requirement for operator intervention. The graphical user interface allows for an easy to interpret “snapshot” of the system status at any moment.
Durable Vapor Compressor
Innovative positive displacement rotary blower with patented special three lobe profile rotors with LOW-pulse system to reduce the pressure pulsation. Reinforced roller bearings provide a calculated operating life of 100,000 hours at the maximum design speed and pressure conditions. Wear free labyrinth and oil seals on each shaft. Design provides for simple maintenance.
Plate and Frame Heat Exchanger:
Large surface area and compact design for energy efficient operation in a small footprint. Corrosion resistant stainless and super stainless plates for long term operation. High temperature and chemically resistant gasket material for longevity and durability.
ASME Separation Tank
Stainless and Super Stainless tanks built to ASME standards for corrosion resistance and longevity. Large access door for ease of cleaning. Easy to access mist eliminator pad to ensure high quality distillate.
Reliable Measurement Devices
High quality control devices to ensure reliable system operation.
All MVC Control panels are equipped to allow for connectivity and remote monitoring and support by ENCON Evaporators Service Technicians.