Vacuum News

SIHI-Ryaland up grade vacuum services at London hospital One of the biggest ever single package medical vacuum plants was produced by SIHI-Ryaland Pumps Limited of Altrincham Cheshire, to provide a vacuum service for all wards and operating theatres. together with the special accident centre, at the 600-bed Brook General Hospital in south east London.

Replacing two small outdated plants, the new centralized vacuum package was specified by Greenwich and Bexley Area Health Authority to meet the latest requirements of DHSS Hospital Technical Memorandum 22 for an expected hospital demand of 2700 I min-’ of atmospheric air.

Designed to meet special operational noise requirements, the SIHI-Ryaland have supplied two units each consisting of an LPH at 1.8 m distance. The quiet running of the unit is facilitated by the absence of internal rubbing parts and is particularly important ar Brook General Hospital as the plant is located beneath an X-ray department.

Comprising two SIHI-Ryaland single stage liquid ring vacuum pumps, each with a capacity of 2350 I min-’ of atmospheric air, the Brook Hospital vacuum plant supplies an operating vacuum of 500 mm Hg.

The air entrained is cleaned by special biological filters before entering the vacuum pumps. Once in the pump the air is scrubbed by the action of the water ring before venting to atmosphere. Also since the pump requires no internal lubrication the air discharged is oil free.

The SIHI-Ryaland vacuum package is a fully contained system having control equipment allowing the selection of manual or full automatic operation of the unit. The facility for a remote alarm indication circuit is standard.

SIHI-Ryaland Pumps Limited, Bridgewater Road, Broadheath, Altrincham. Cheshire WA1 4 1 NB

Vacuum pump goes into service at Bevercotes Colliery Two of the biggest vacuum pumps, supplied by SIHI-Ryaland Pumps Limited, Bridgewater Road, Broadheath, Altrincham, Cheshire are playing an important role in a frothed coal filtering plant, recently updated at the National Coal Board’s Bevercotes Colliery, Nottinghamshire.

SIHI-Ryaland have supplied fwo units each consisting of an LPH 11055 single stage liquid ring vacuum pump, motor and liquid/air separator. The pumps are connected to two 1000 ft’ rotary drum filters which dewater the frothed fines concentrate following the fine coal cleaning process.

The role of the vacuum pump is to create a vacuum lo draw the process liquor through 1000 ft’ of filter, leaving the cleaned coal fines on the filter cloth.

Driven by a 400 hp motor the SIHI-Ryaland liquid ring vacuum pump deals with up to 6000 ft3 of air min-’ at 22 in. Hg Vat. Each pump is vee belt driven running at 475 rpm and absorbing 350 hp. The pumps have been supplied with baseplates, air-water separators and inter-connecting pipework. The total package for the two units weighs 20 tons.

About 800 tons (wet solids) of recovered coal fines are handled by the entire system per day at Bevercotes and the SIHI-Ryaland

vacuum pumps are in continuous operation at the colliery for 20 h out of 24.

Because there is no internal metallic contact, no internal lubrication of the pumps is needed-giving long life with minimum maintenance.

In liquid handling, entrained liquids and condensibles pass through the pump without damage and only momentary reduction in performance.

Absence of reciprocating parts means almost silent and vibration free operation so that there is no need for special foundations.

An added advantage of these SIHI-Ryaland liquid ring vacuum pumps in this application is that they are fitted with special ball valves which automatically govern the effective area of the discharge port to suit the operating pressure. This enables the pumps to operate at pressures as low as 26.5 in. Hg Vat (80 mm Hg abs).

To help maintain the systems and thereby helping to eliminate expensive downtime, pump casings are fitted with inspection ports to allow clear, simple inspection of the pumps interiors.

The pumps are also equipped with a device through which contaminated service liquid can be continuously discharged during operation.

The entire system was installed at Bevercotes Colliery by Don Valley Engineering Co Ltd of Doncaster.

SIHI-Ryaland Pumps Limited, Bridgewater Road, Broadheath, Altrincham, Cheshire WA1 4 1 NB.

Balston reduce hospital filter costs by 80% The Department of Medicine of Charing Cross Hospital Medical School, is an ultra-modern research and teaching establishment. To ensure that practicing staff and medical students are familiar with the very latest techniques and understandings, a number of well equipped laboratories is continuously involved in the preparation and analysis of specimens. Balston Filters recently assisted these laboratories in significantly reducing the cost of routine filter element renewal.

A large number of portable vacuum pumps drawing up to 0.1 torr is used lo degas aqueous solutions, where the presence of gases would interfere with the analysis of specimens. The pumps are also used for freeze-drying and in conjunction with electron-microscopes in connection with the analytical work.

As is normally the case, the gases exhausted by the vacuum pumps carry a heavy oil mist content. The discharge of this oil mist to atmosphere is of course totally unacceptable in any modern working environment. As the vacuum pumps in this instance are portable, the oil mist is captured by a filter installed in the exhaust line from the vacuum pump.

This method of protecting the environment from oil mist contamination was quite satisfactory in principle. However, the type of filter employed, although satisfactory in operation, proved extremely expensive 10 renew. As the department works to a controlled budget, it was therefore decided to investigate rhe possibility of using a different type of filter.

When consulted on the problem, Balston Limited of Maidstone recommended the use of their Type 9955-l 2-CXO unit. Specifically designed for the removal of oil mist from vacuum pump exhaust

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