The Karad-based manufacturer, Shree Refrigerations (SR) signed an agreement with Swedish Inventor Graphics, to manufacture the Duospray spray dampening system in India. This was during IFRA Hamburg in 2010. And a year later, at PrintPack 2011 in Delhi, the company launched the product for the Indian market.  
 

Since then, SR has supplied more than 1,000 units as a standard option on Manugraph and TPH presses or as a retrofit on old presses with brush dampening systems. 
 

“These installations cover manual, automatic, single- and double-width presses,” says RG Shende, managing director at SR.
 

SR offers two versions of spray dampening system: Duospray and Monospray. Shende explains, “The difference is that Duospray system delivers blanket wash chemical as well as dampening solution through the same nozzle whereas Monospray can spray only the fountain solution.”

Some of the key users of Duospray system include Eenadu, Malyala Manorama, Deccan Chronicles, Tribune, Hindustan Times etc.
 

This product has all the advantages offered by any spray dampening system such as reduction of start-up waste, reduced fountain consumption, improved print quality and reduced operation and maintenance costs.
 

Eliminating the chillers 

“The biggest advantage,” Shende says, “is that this system does not require chillers thereby saving electricity for the user.”
 

This is achieved by using a pneumatically pressurised close tank for fountain solution. When a spray bar is not spraying, there is no delivery from the pressure tank unlike the other systems who use a high pressure pump to continuously circulate fountain solution at high pressure to the spray bars and back to tank. 
 

“This unnecessary circulation heats up the fountain thereby requiring a chiller,” adds Shende. 

The added advantage of the closed tank is that it prevents evaporation of chemicals from the fountain solution. Thus eliminating the requirement of a chiller even in hostile Indian summer. 
 

According to Shende, this fact has been proven at many installations. To prove his point Shende shares a case-study of Malyala Manorama. 
 

“We offered a complimentary chiller along with a Duospray to see how it performs with or without a chiller. Today, Malyala Manorama has returned the chiller as they believe it is not required for doing quality printing. Our contention that Monospray and Duospray do not require chillers in the hot and humid environment of costal areas of Kerala hold true.”
 

This also means that lesser maintenance, lesser moving parts  such as pumps, compressors, fans, etc and also lesser space on shopfloor. Also, when we look at the fountain solution tank, we observe that the capacity is small, just 17 litres. Shende explains that this ensures fountain solution is prepared just few minutes before consumption, and fresh solution is made only after the first mix is consumed. “Thus we can eliminate the need to drain the tank full of fountain solution on a weekly basis due to bacteria growth and loss of mix quality,” says Shende.

 

Valves: heart of the system

When it comes to spray dampening system, valve is the critical component. It is valves’ responsibility to operate at very high on-off frequency (very short cycle time), to give a consistent performance across a wider input water pressure, to deliver a spray with shortest open time, consistent performance over a longer period of time and reliability. Shende says, “These are ensured by a valve with teflon plunger seat, light plunger and strong spring operated by a powerful coil. These valves are rated to perform even when submerged in water.”
 

The plunger seat made of Teflon enables instantaneous open-close action of the valve. “This also means consistent performance over the life as teflon seats do not change their characteristics like rubber seats, hence minimal wear and tear,” says Shende.
 

This system is coupled with robust electronics and communication via computer enables the printer to make small adjustments needed while printing very efficiently thereby ensuring that the plate always get just the right amount of fountain solution. One page of newspaper is serviced by four nozzles, and the printer has independent control over each nozzle, so that he can separately identify and provide a different dampening requirements of four sections of a page.
 

Shende informs that the ROI, depending on print order and number of editions, varies between 1.5-3 years.

 

Alternatives

Speaking about the alternatives available in the market for Duospray, Shende says, “When it comes to spray dampening systems for newspaper presses, Baldwin, Technotrans and Shree Refrigeration are the three names to look out for.”
 

All the systems offer all the advantages associated with spray dampening. 

Shende informs, “The differentiator is that both these alternative systems circulate fountain solution continuously and use only a small part of it. Thus requiring a chiller as the unwanted circulation heats up the water and needs refrigeration.”
 

He further adds, “These chillers have large fountain solution tanks of about 300-400 litres, which means a periodic drain from the tank, which means waste of fountain solution.”

“Besides, three milliseconds spray time is unique to our system. In short, our systems score over the alternatives in power consumption and minimum fountain waste. This makes it a true green system,” says Shende.
 

According to Shende, the power consumption for a typical 6x4-Hi tower press works out as 10 kw when spray dampening is used with chillers, while, it adds up to less than one kw for Monospray or Duospray.

 

Case-study:  Ushodaya Publications (Eenadu)

Shree has installed double width DuoSpray spray bars at Ushodaya Publications (Eenadu) on their Hamada double width-double circumference satellite press on anti set-off spray on the common impression cylinder (CIC). 
 

Shende says, “Four such units were installed at Eenadu, Hyderabad. The application is critical as there is no way any excess water can be delivered on the anti-setoff roller without adversely affecting the print quality causing problems such as ghosting and set-off." 
 

“The fountain requirement is almost a third of the conventional dampening system. This was a challenge and with a thrust on the three milliSecond opening time for getting a spray, we could  accomplish it. The stoppage for cleaning the common impression cylinders was eliminated, and a lot of paper wastage was saved," says Shende.
 

Today, SR has more than 15 installations in Eenadu on Indian as well as imported presses.

SPECIFICATIONS

Operating pressure 3.5 - 4.5 bar

Valve open time 3 millisecond

Contact Shree Refrigerations RG Shande +91 9370745501 rg.shende@shreeref.com www.shreeref.com