The FT94X service unit contains the services, controls and

instrumentationrequiredtooperatethetubularandplateheat exchangersdescribedbelow.TheFT94Xmaybespecifiedwith either or both of the heat exchangers. Switching between the twoheatexchangerstakesamatterofseconds.

Theserviceunitcomprises:aneightinchtouchscreencontrolpanel withtherequiredcontrolsanddisplays;avariablespeedprogressive cavity product feed pump with inlet level sensor and alarm to warn of low product level; a steam-heated hot water system for product preheating; automatic steam control valves for product preheating andfinalheating;acentrifugalCIPpumpandotherfacilitiesrequired forCIPandSIP.

Sensors show product inlet, preheat, final heating and outlet temperatures.Productpreheatandfinalheatingtemperaturesareset bytheoperator.Inletandoutletproductpressureisalsoshown.

Therearevariousservicesensors:pressure,levelandtemperature– seeprocessflowdiagramfordetails.

A sophisticated data logging package enables the measured data to be recorded onto a standard Windows PC (not supplied).

Thesoftwarerecordsalltemperatures,productandsteampressures, feedpumpspeedandmanyothersensorvalues.Datafromoptional accessories (e.g. the flowmeter) is also recorded. Data may be displayed in tables and graphs (both real time and comparisons acrosspreviousruns),andmayalsobeexportedtoMSExcel.

The FT94-20 is a standard tubular heat exchanger design

using a series of concentric 316 stainless steel tubes for product preheating, final heating and cooling. In all cases the product passes down the inner tube and the heating/cooling medium passes through the annulus. Two heating tubes of 1.5 m length are used to preheat the product. Four similar tubes are used for product heating and an additional four tubes are used for product cooling.

Productisgentlypreheatedusingahotwatersystem,whichisitself heatedbysteamviaasecondaryserviceheatexchanger.Inthemain heatingsectiontheproductisindirectlyheatedusingsteamitself.

Productiscoolednormallyusingwaterorchilledwater.Thecooling sectioncanbeconfiguredtoenabletwostageswherethefirststage iswater/chilledwaterandthesecondstageiswater/glycol.

TheFT94-21isasetofstaticmixersfortwotubes.Thesesignificantly improve heat transfer with more viscous products and can be used forimprovingbothheatingandcoolingefficiency.Multiplesetscan beusedtooptimisebothheatingandcoolingperformance.

The FT94-22 product divert option enables product that has not been processed to a sufficiently high temperature to be diverted to drain thus ensuring product quality and heat treatment.

Thediverttemperatureisadjustable.Diversionisachievedusingalow hold-up twin diaphragm valve block operated by compressed air and PLCcontrolled.Divertedproductiscooledinatubularheatexchanger beforebeingledtodrain.

TheFT94-20hasaonesecondholdingtube(at50l/hr)asstandard. ContactArmfieldforlongerholdingtimes.

The FT94-30 uses the sanitary heat exchanger employing the

latest plate design for efficient heat transfer. Performance scale-up is straightforward.Thestandardunitisathreestagesystemwithpreheat (hotwater)finalheating(steam)andcooling(water/chilledwater).

The plates have a complex pressed profile to maximise turbulence

andminimisedeadzones.Thereisarelativelylargegapbetweenplates toenablehandlingofmoreviscousproducts.Theplatesarefittedwith food grade Viton paraclip gaskets for easy replacement as these are simplyclippedinplaceratherthanglued.

Anumberofoptionsareavailabletoenhancetheperformanceofthe standardplateheatexchanger.Theseoptionsinvolveadditionalplate configurations, which can be supplied and fitted or may be easily retro-fitted by theuser.

The FT94-32 homogeniser interconnecting plate enables the homogeniser to be connected downstream of the heating section. The plate is fitted into the cooling section.

The FT94-33 two-stage cooling option provides a complete additional cooling stage, which can be used in conjunction with

a chilled water/glycol supply for the best possible product cooling. Output temperatures below 5°C are possible depending on the product and the flow rate.

An interconnecting link is provided so that the two stages can be operated as a single stage when required.

TheFT94-30hasafivesecondholdingtube(at50l/hr) asstandard.ContactArmfieldforlongerholdingtimes.

Technicalspecifications

FT94X Service Unit Technical specifications		Tubular Heat Exchanger (FT94-20)
Feed pump		Number of tubes	10 (2 preheat, 4 heating, 4 cooling)
Progressive cavity variable speed pump		Tube diameter
Solids handling	Soft 10 mm	(product side)	8.1 mm
	Hard 4 mm	Overall diameter	22.0 mm
Flow rate	30-100 l/hr	Length (heated)	1.46 m
Discharge pressure	24 bar (max)	Product volume	1.0 l
Pre-heat water system		Material	316 stainless steel
Water capacity	~2-3 litres	Assembled test pressure	30 bar
Maximum temp	110°C	Working pressure	24 bar (maximum)
Safety cut-outs	Low level	Plate Heat Exchanger (FT94-30)
	Temperature	Plate overall dimensions	150 x 480mm
	Product pump	Effective area per plate	0.04m2
	Pressure relief valve	Plate thickness	0.6mm
Heating system		Product volume	2.5litres
External steam supply		Materials,Plates	316 stainless steel
Maximum temp	165°C	Gaskets	Food grade Viton
	Relief valve (7 barg)	Max differential test pressure	11.5bar
	Product pump off	Max balanced test pressure	12.5bar
	steam valve closes	Max working pressure	9.6bar
Max product heating duty	17 kW	Working temperature	Max: 170°C
	(preheat + heating)		Min: -4°C
		Number of plates
		FT94-30	Preheating 13, Heating 6, Cooling 13
		FT94-33	Secondary cooling 7