Oak Street Quarry Bank Brierley Hill West Midlands DY5 2JQ

EXCEL HEAT LTD

Tel:- 01384 560 713 Fax:- 01384 411 742

Oak Street Quarry Bank Brierley Hill West Midlands DY5 2JQ

Operating And Maintenance Manual

For

180C Oven

Order No. 376

Excel Heat Ref. XL1159C

INDEX

Introduction

Safety Precautions

Technical Data

Furnace Description

Operating Procedure

Alarms

Maintenance

Drawings

Data Sheets

Maintenance Schedule Sheet

1.Introduction

Equipment Overview

The installation comprises of an electrically heated vertical lift door oven and lined on the inside with stainless steel, complete with the necessary control equipment.

The door has a lifting shackle to enable the 1000Kg hoist to raise the door to allow access to the oven.

There are two safety pins either side of the door both of which, must be secured in position before any personnel start loading or unloading the oven.

The oven is heated by electrical elements positioned down each side on stainless steel supports. Power to the elements is from a 415 volt, 3 phase, 50 Hz supply. Control is from thyristor units mounted in the panel. The oven is connected to the power and control equipment by a permanent cable connection, which is contained within the trunking and conduit around the oven

The circulation fan is roof mounted and its impellor is just below the roof lining with the shaft and motor assembly outside on the roof.

The exhaust fan is also positioned outside the oven at the back

The low thermal mass insulation is made up of ceramic fibre modules.

The casing is built from steel frames enclosing insulation modules with a stainless steel inner lining.

The control panel is mounted on the ovens right hand side when looking at the oven door.

The control system comprises a two zone programmable temperature controller, paperless chart recorder, a policeman for each zone and necessary ancillary buttons and switches. Thermocouples are mounted in the furnace rear wall to provide information to the controller, over temperature policeman and the paperless chart recorder.

2. Safety Precautions

General

The overall responsibility for operating the plant safely rests with the plant manager.

Personnel must not work alone when maintaining any electrical equipment where a potential difference of 50 volts may be present.

Personnel working on the equipment must be competent and familiar with site safety procedures, permit to work schemes, etc.

ALWAYS isolate the equipment from its electrical power source before removing access covers

Isolate or inhibit all peripheral equipment connected to the system before starting work. When maintaining this type of equipment it may be possible to generate potentially unsafe conditions due to limit switch operation.

Local RF transmissions may cause the equipment to malfunction. Suitable precautions should therefore be taken before using hand held radio transceivers, etc.

The equipment is designed and manufactured to ensure high reliability. It is still possible for component failure to occur, however, and failure to safety cannot always be guaranteed. Failure modes must therefore be taken into account by the customer when designing the overall system to ensure ultimate safety.

Reference should always be made to the Excel Heat Instruction Manual and associated documentation before performing any installation, commissioning or maintenance work on the equipment.

ALWAYS replace guards removed for maintenance purposes before the unit is returned to operation.

ALWAYS tighten loose bolts, nuts and screws and replace split pins, locking washers and other fasteners after maintenance.

ALWAYS renew electrical cables, piping and flexes at the first sign of damage or leakage.

ALWAYS wear approved gloves when handling the treated components. DO NOT assume that because metal is not glowing it is not too hot to handle or touch.

REMEMBER that when noise is excessive, audible warnings may not be heard.

ALWAYS rope off an area from which floor plating has been removed. DO NOT remove the rope barrier until floor plating has been replaced.

ALWAYS replace floor plating over ducts and pits as soon as possible after maintenance has been carried out.

NEVER stand below the furnace unless it is supported to prevent accidental lowing

NEVER move the furnace when personnel are on the roof.

Isolation of Equipment

ALWAYS isolate electrically the circuits associated with equipment undergoing maintenance and any other equipment that presents a hazard.

Ensure that the electrical feed is switched OFF and padlocked in the ‘OFF’ position. If this is not possible, the fuses should be withdrawn and placed in a place of safety from which they cannot be removed without consent. Place a DANGER notice on the control panel to warn would –be operators of danger to personnel.

ALWAYS station a responsible person at the controls of the unit, if it is not possible to isolate the equipment whilst maintenance is being carried out. Place a DANGER notice on the control panel to warn would-be operators of danger to personnel.

DO NOT by-pass safety interlocks without first informing the relevant supervisor and ensuring that no one is in the danger area. Reinstate the interlocks as soon as possible.

Moving Structures

STAND CLEAR of all moving structures.

NEVER operate moving structures without first ensuring that the movement area is clear of personnel and equipment. If lighting or visibility is bad, DO NOT assume that the area is clear until a responsible person has checked that this is so.

NEVER operate any controls when a system is shut down, in such a manner that associated equipment will move when the system is restored.

Lifting Gear

When lifting an item of equipment, ALWAYS ensure that the eyebolts used are designed to carry the weight involved and that additional equipment is not being lifted beyond the design load.

ALWAYS ensure that slings and other lifting gear are in good condition and adequate for the job in hand.

ALWAYS ensure the safe working load of the hoist is greater than the weight of the lift.

Fire Fighting Equipment

ALWAYS ensure that appropriate fire fighting equipment is available and correctly sited at points where the risk of fire exists.

ALWAYS ensure that personnel familiar with such apparatus are immediately available.

When welding or carrying out other operations that present a fire risk, ALWAYS ensure that the appropriate fire fighting equipment is available and ready for instant use.

Carbon Dioxide Fire Extinguishers

The discharge of large amounts of CO to extinguish fire may create hazards to personnel such as oxygen deficiency and reduced visibility.

The dilution of the oxygen in the air by COin a sufficient concentration to extinguish fire, may create an atmosphere that will not sustain life. Such an atmosphere will be produced in spaces subject to total flooding with CO and may be produced by any large volume discharge drifting into adjacent low-lying areas.

Persons rendered unconscious in such atmospheres can usually be revived without any permanent ill effects when promptly removed from the COatmosphere.

Large volume discharge of CO may seriously interfere with visibility during and immediately after the discharge period.

Carbon Dioxide is normally colourless but when discharged from a storage cylinder under pressure it resembles a cloud of steam.

3. Technical Data

Oven Operating Temperature

Maximum operating temperature-180C

Normal operating temperature-180C

Oven Rating

Oven rating-96kW

Recirculating Fan

Number of fans-One

Motor size-1.1kW @ 1450 rpm

Circulation rate-2500Nm3/Hr @ 20C

Pressure-65mm SWG

Maximum Temperature-180C

Electrical Supply-400/3/50

Exhaust Fan

Number of fans-One

Motor size-1.1kW @ 2850 rpm

Volume-2000Nm3/Hr @ 20C

Pressure-80mm SWG

Maximum Temperature-150C

Electrical Supply-400/3/50

Electrical Supply

Supply-400 volts, 3 phase, 50Hz

Control equipment-110 volts, single phase

Oven Internal Dimensions

Width-1500 mm

Length-1500 mm

Height-1500 mm

Overall Plant Dimensions

Width-2800 mm

Length-2700 mm

Height-2800 mm

Casing Height-5300 mm from floor to

Maximum Heighttop of door lifting gear

Weights

Oven Approx-3000 Kg

Process Cycle

Switch On Recirculation fan

Switch On Exhaust fan

Ramp to 150C @ 60C / hour

Hold @ 150C for 1 hours

Switch off Exhaust Fan

Ramp to 560C @ 60C / hour

Hold @ 560C for 4 hours

Naturally Cool to 150C or Below

Switch off Recirculation fan.

4. Oven Description

CAUTION

The Door Gear Needs To Be Bolted Into Position And A Minimum Of Two Straps Fully Weld Between the 50mm x 50mm Box Sections Before Use If In Doubt Please Phone

01384 560 713

Vertical Rising Door

The vertical rising door oven is fabricated from mild steel plate. The casing is stiffened with rolled hollow sections to provide a robust and dimensionally stable construction.

The casing incorporates a lifting shackles designed to accommodate the weight of the oven including the door gear so the oven can be moved into position. We suggest that these lifting points be left in position incase the oven needs moving any time in the future.

WARNING: Never lift the cover when personnel are on the roof of the oven.

Steel panels are located on each side on the back of the oven these have screwed plates which cover the heating element terminals.

The vertical lifted door runs in guides either side of the door, which correctly guide the door during lifting and lowering. These guide also close the door pulling it into the door frame when it reaches the bottom of its travel

The compressing of the two ceramic ropes forms a double seal around the door to the door frame.

The door lifting and lowering is via a propriety 1000Kg hoist, which is controlled by a remote pendant, which is permanently connected to the hoist motor via a 15 metre flexible SY cable so it can be conveniently positioned once on site.

The hoist is equipped with adjustable raise and lower limits switches to prevent over travel.

There is an additional a limit switch, which is activate when the door is fully down which enables power to the heating elements and the fans

When the door is fully lifted there are two safety pegs one either side of the door which must be located, before any personnel should work or load / unload the oven.

The two safety pegs must be located every time the oven door is opened.

Cover Insulation

The cover is lined with ceramic fibre modules to minimise its overall weight and to allow rapid heat up times from cold. The lining thickness is designed to give an economic cold face temperature and to minimise casing losses.

Element

The oven walls accommodate the element and there support brackets. The inner sheeting has been designed to be removable to allow greater access to the elements for maintenance.

The elements are formed into a ‘U’ shape stretching almost the full depth of the oven sidewall for greater uniformity of the heat input.

The elements are a minerally insulated construction with Incoloy sheaths, which work on 230 Volts equally spread over the three phases, give a total installed power of 96 Kw

A competent suitably qualified electrician can replace an element.

ALWAYS isolate electrically the circuits associated with equipment undergoing maintenance and any other equipment that presents a hazard.

DO NOT by-pass safety interlocks without first informing the relevant supervisor and ensuring that no one is in the danger area. Reinstate the interlocks as soon as possible.

The Junction box covers can then be removed, these are located at either side on the back of the oven and can be removed by un-screwing the M6 Button head socket screws.

Once removed inside the junction box are the heating element terminals connect by spade connectors, simple disconnect the failed element un-screw the bulk head brass compression fitting remove the olive (this may require cutting the olive off).

Ensure the oven is at ambient temperature. Lift the vertical rising door using the hoist, ensure the safety pins are correctly located, slide out the inner sheeting, and remove the failed element from inside the oven.

Re-install the new element in the reverse of the above fitting a new compression olive.

Heating Elements

A total of forty-eight elements are included, to give a total connected rating of 96kW. The elements are arranged in two groups of twenty-four along each side wall of the cover. Within each group the separate element legs are connected together in star fashion. All elements phase legs are connected to the electrical phase conductors in parallel within each group, but the star point of each of the groups is separate.

The control is split into two zones, Zone one (bottom), Zone two (top) and

Circulation Fan

One high temperature insulated plug type fan is provided in the oven roof to provide a high volume of atmosphere recirculation over the heating elements and the charge. The fan is mounted close to the underside of the oven roof. With the Stainless steel cowl directing the air flow into the center of the multi vane fan impellor.

The fan is driven by a 1.1kw 4 pole foot mounted, frame size 90S motor running at approximately 1450 RPM giving approximately 2500 NM3/hr at 65mm SWG @ 20C

The fan is started automatically if the oven door is fully down, the down limit switch is activated and via the 1st event relay in the Honeywell UDC 3500 master controller is programmed to switch the fan on.

NOTE:- Never run the oven with the recirculation fan switched off it will seriously damage the fan.

The fans are designed for continuous operation at temperatures up to 560C. The fan is complete with electric motor rated at 1.1kw at 1450 rpm on a 400 volt 3 phase 50 Hz supply

NOTE:-

The Honeywell UDC3500 controller MUST be programmed (event relay 1) to switch the recirculation fan on and off.

The recirculation fan should start at the beginning of the cycle and can be switched off at the end of the cycle providing the oven temperature is Below 150C

If the recirculation fan switched off when the oven is running it will seriously damage the fan and void any warranties.

Exhaust Fan

One direct driven type fan is provided in the oven back wall to provide a high volume of exhaust from the oven. The fan is mounted with a horizontal inlet and a vertical outlet for the exhaust ducting to be connected to (by other) The exhaust inlet to the fan is central about the width of the oven at high level via a stainless steel tube. The purpose of the exhaust fan is to extract possible volatiles at low temperature, 150C maximum, during the initial part of the cycle.

The fan is driven by a 1.1kw 2 pole foot mounted, frame size 80S motor running at approximately 2900 RPM giving approximately 2000 NM3/hr at 80mm SWG @ 20C

The fan is started automatically if the oven door is fully down, the down limit switch is activated and via the 2nd event relay in the Honeywell UDC 3500 master controller is programmed to switch the fan on.

NOTE:- Never run the exhaust fan with the oven temperature over 150C it will seriously damage the fan.

The fans are designed for continuous operation at temperatures up to 150C. The fan is complete with electric motor rated at 1.1kw at 2900 rpm on a 400 volt 3 phase 50 Hz supply

NOTE:-

The Honeywell UDC3500 controller MUST be programmed (event relay 2) to switch the exhaust fan on and off.

If required, the exhaust fan should start at the beginning of the cycle and should be switched off at or below 150C

If the exhaust fan is running when the oven temperature is over 150C it will seriously damage the fan and void any warranties.

On the outlet of the exhaust fan is a mechanical exhaust flap type valve, which opens when the exhaust fan operates.

As requested we have incorporated into the system a auto manual key switch which over rides the controller so the exhaust fan can be operated in the manual mode using the start stop push buttons on the front of the control panel.

Cooling System

There is no direct or indirect cooling on the oven it only cools naturally.

Oven Sealing

The oven door has a double rope seal both of which seal against substantial steelwork.

Electrical Equipment

All the electrical equipment is housed in an oven mounted, front access, sheet steel cubicle located on the right hand side of the oven when looking at the oven door.