10 May 2002

INCINERATIONFIRESUPENTHUSIASMNOW

Concerns over burial and the

loss of fallen stock

collection make incineration

an increasingly popular

choice. Mervyn Bailey

checks out whats available

CARCASS disposal is part and parcel of pig breeding and fattening operations. But on-farm burial is likely to become more restricted, if allowed at all, composting is currently illegal, and opportunities to have fallen stock collected at little or no cost are diminishing.

All of which leaves controlled incineration as the most likely option for many pig units.

While both efficient and effective, incineration carries costs. Equipment and installation will typically run to £3500-£8000, depending on size/capacity. Running costs for fuel and maintenance will amount to £2-£5/sow, according to ADAS calculations.

Further costs are incurred with high throughput incinerators – anything with a burn capacity of more than 50kg/hour – because they fall more fully under the scope of environment protection regulations.

Happily, there is a reasonable choice of incinerators with a burn rate less than the 50kg/hour limit, to which environment protection smoke limits still apply, but not the full gamut of pollution regulations.

Fuelled by diesel, kerosene or gas, most are fully insulated for burn efficiency and protection of the outer structure. Many have a high temperature secondary chamber to burn off any products otherwise likely to escape up the flue. Most are also front loading.

Turkington Engineerings Turco incinerators, distributed by G E Baker, are an exception. They have two large doors set into the angled roof of the structure, allowing carcasses to be dropped in from a loader bucket. A sliding end door is provided for removing ash.

The larger 380kg/0.85cu m capacity Turco T3 is the more popular model with pig producers, according to G E Baker. This is capable of cremating a fully-grown sow in an eight-hour cycle at a burn rate of 47kg/hour.

The T3 is constructed from thicker steel than the 130kg/0.32cu m capacity T1. But on both models the top, bottom and sides are lined with replaceable firebrick and refractory panels, with air vents for secondary air control.

Automatic timer

A high-pressure oil burner is set with an automatic timer providing 28 or 35 second bursts of fuel, with temperatures reaching 1000C. Fuel consumption is said to be 20 litres/3.5 hour burn for the T1 and 80 litres/six hour burn for the T3.

The square-section Derwent incinerator from Waste Spectrum has a load capacity of 300kg/1.33cu m and is front loading with the aid of an optional trolley and hand winch. The main combustion chamber has a solid hearth, allowing wet material, such as offal, to be burned.

Consumption of LPG, liquid or natural gas is put at 10 litres/hour for a burn rate of 50kg/hour. An after burner or secondary chamber is fitted as standard.

The Hot Hearth incinerator from Bodo Fabrications is an oil-fuelled unit, front loading and big enough to take a 300kg sow. Burners are located in the top of the unit, but a circulation fan sucks air beneath the brick-lined hearth floor to help dry out carcasses and improve combustion efficiency.

Howdens Model PD 35B is gas or diesel-fuelled and features electronic control of burner ignition, high/low burner setting and temperature monitoring. It also has an air fan to achieve even temperature distribution, a photocell flame failure sensor, and a door microswitch to prevent the burners firing while the incinerator is being loaded.

Furnace volume is 350kg/3cu m within a unit which comprises a furnace chamber constructed of 110mm (4.3in) thick aluminous refractory, backed by 100mm (4in) of insulation. A secondary chamber is part of the design.

Filling is through a 1.2m x 1.2m (4ft x 4ft) front door opening, while ash removal is through a separate door at the far end of the rearward-inclined solid hearth floor.

Techtrols cylindrical Pyrotec A50 incinerators come in a range of sizes to suit requirements, but all are rated to come within the 50kg/hour burn rate limit to be exempted from most environment protection regulations.

All are accessed through a full size front door and can be fuelled by oil, gas or LPG.

Basic design

The most basic design comes with various options for emission and odour control, including an afterburner and secondary combustion chamber to ensure that any volatile waste gases are destroyed before emission to the atmosphere.

The Plus version is more sophisticated as it comes complete with an enlarged secondary chamber as standard, temperature control for better fuel economy and burn efficiency, and a more elaborate electronic control system.

For operator safety, there are door-burner interlocks to prevent firing while the incinerator is being loaded. The big capacity L versions of the Pyrotec A50 incinerator can have a winch access point within the rear wall of the main chamber for easier loading.n

Left: Techtrol makes its Pyrotec cylindrical incinerators in a range of sizes – this big capacity L version can be fitted

with a winch access point

to assist loading.

&#8226 Wide range of capacities.

&#8226 Can be costly to use.

&#8226 Diesel, kerosene or gas-fuelled.

&#8226 G E Baker – 01359-240529.

&#8226 Bodo Fabrications – 01953-456528.

&#8226 Howden – 01291-630370.

&#8226 Techtrol – 01614-766955.

&#8226 Waste Spectrum – 01905-362100.

The 380kg Turco T3 incinerator from GE Baker is top-loading through two large doors with hydraulic cylinder assistance.